ESE's works engine tuner

[Frits Overmars]

Regarding the 100cc pipe; can we say that a properly controlled sliding exhaust could mimic the wider powerband and maybe even give a little more peak power than the 100cc pipe?A properly controlled sliding exhaust will give a lot more power than the 100 cc kart pipe, and provided it has enough movement, it will also give a powerband that is at least as wide. But sliding pipes won't be allowed in karting.


I believe Frits once said that Jan Thiel modified a reed intake engine to give 48hp.That was 49 hp, measured at the gearbox exit shaft. The engine was the reed-valve Derbi 125 cc GP-engine of 2004.


not sure what to do with the large boyesen intake ports on the aprilia.That sufficiently identifies which Aprilia cylinder you are talking about. And I cannot repeat it often enough: check the coolant passages each side of the exhaust duct on that cylinder; they may be partly of even completely blocked.

[bjorn.clauw.1]

A properly controlled sliding exhaust will give a lot more power than the 100 cc kart pipe, and provided it has enough movement, it will also give a powerband that is at least as wide. But sliding pipes won't be allowed in karting.


Would be used on a rs125. I allready turned the cilinder around so I can make a straight (150mm sliding) pipe. Only downside is intake is against crankshaft rotation. Cilinder will use a cast iron sleeve with the top part exposed to the coolant (following Makr's design)



That sufficiently identifies which Aprilia cylinder you are talking about. And I cannot repeat it often enough: check the coolant passages each side of the exhaust duct on that cylinder; they may be partly of even completely blocked.

Yes, the passages are really tiny, will open them up (a lot) to improve the coolant flow. Following your advice I modified a vw waterpump which is now belt driven from the ignition rotor and flows 45l/min at 10000rpm. Exhaust duct will be modified to follow wobbly's design. Port geometry will be rsa125 style. Only unknown is the intake geometry with the boyesen ports. No idea if this will flow enough to match the rest/if there is any room for improvement here.

320047320048

[Juho_]

I always thought that big boyesens delivering the fresh charge directly into the transfers could be an advantage, but finding any information on this is proving to be hard.
I have believed, that the boyesen ports are supposed to be directed to the case.

http://i300.photobucket.com/albums/nn8/enskapate/Tekniikka/YZ250/th_c01e8b91-4937-4ef3-898e-f15555138647_zps7phbbytu.jpg (http://s300.photobucket.com/user/enskapate/media/Tekniikka/YZ250/c01e8b91-4937-4ef3-898e-f15555138647_zps7phbbytu.jpg.html)

Like in the YZ 250 '96-> cylinders. Older YZ 250 cylinders have kind of same design as Rotax 122/123's.

Rotax 122/123 cylinder's boyesen ports are aimed nearly straight to the A/B transfers divider (or atleast it looks like that, when watching pictures I found).


Correct me if I'm wrong!

[bjorn.clauw.1]

Rotax 122/123 cylinder's boyesen ports are aimed nearly straight to the A/B transfers divider (or atleast it looks like that, when watching pictures I found).


Correct me if I'm wrong!

That is correct, they are aimed straight ahead. My line of thinking was this could help the inflow in the cylinder when piston is at bdc and the engine is on the pipe. Making the transferduct volume larger because the volume behind the reeds can be added to the transfer duct volume. (Straight in means no bends need to be negotiated to suck mixture in). Just a thought as the common belief on this is that the mixture going in the cylinder is that amount that resides in the transfer ducts.

[AndreasL]

Sorry to interrupt the interesting ongoing discussions with some old hat and basic questions...

We have all learnt that putting a "to good" pipe (i.e. FOS Concept, Wobbly etc) at a "crap transfer old school cylinder" is a bad thing.

But how good or bad a pipe is possible for the crap setup?

Any rules of thumb, ideas and guides besides/in addition to "run a 1000 random sims in EngMod" how to find the limit would be very helpful.

The FOS Concept have got me started but its obvious that I need to reread everything about pipes posted here.
This is not easy! (Remember wobs posted a "guidelines" to what was effecting what part of the pressure trace curves, but that was some 900 pages ago!!! Need to see if I can find it again.)

Anything specific to look for in EngMod to see when the pipe is sucking to hard at the transfers, letting the fresh gases take a short cut out the exhaust?

Thanks in advance!

[wobbly]

As I have shown before there is no intake flow when the piston is at BDC, the reeds are closed.
But there can still be significant flow as the transfers are closing edit due to inertia effects in the intake length.
This stream that is perpendicular to the B duct entry can badly affect the flow regime at the entry to the B duct, and no matter what is
done to enhance B port flow ( ie higher, wider, hooks in the port etc,) no more power eventuates.

Thus it would seem that directing the flow downward into the floor of the cavity under the transfer duct entry area is better than a straight shot
that ends up crashing into the B duct front wall.

Re the " overscavenging effect " of super efficient pipes on crap transfers, I have emailed Neels to see if he can detail the best way to identify the effect actually occurring in EngMod.
All the engines that have this possible issue I have dealt with, also have the problem that a fat pipe simply wont fit on the bike ie TZ350.

[AndreasL]

Thanks wobs for running my errands! :2thumbsup

On a side note, yesterday I was informed of some dyno results from 2 other cylinders like the one I try to sim in EngMod.
Not having any real dyno numbers up until now for what is possible with this engine have made me VERY doubtful to my skills using EngMod and if the program is realistic to use "as is", without the so hated fudging of numbers, to have believable results for my type of engine.

The conclusion seems to be that I have to apologies to Neels ;) and I hope that I have some comparisons between sim and dyno to show in a couple of month. (Yes, this is sloooow.) Hopefully it shows that even a 50cc old moped engine, "tuned to death" at 6-8 bar BMEP :rolleyes:, is handled well by EngMod even when run by a n00b at 2t tuning. Hopefully...

[bjorn.clauw.1]

As I have shown before there is no intake flow when the piston is at BDC, the reeds are closed.
But there can still be significant flow as the transfers are closing edit due to inertia effects in the intake length.
This stream that is perpendicular to the B duct entry can badly affect the flow regime at the entry to the B duct, and no matter what is
done to enhance B port flow ( ie higher, wider, hooks in the port etc,) no more power eventuates.

Thus it would seem that directing the flow downward into the floor of the cavity under the transfer duct entry area is better than a straight shot
that ends up crashing into the B duct front wall.


Thanks for the explanation Wobbly, will add redirecting boyesen ports to my (lengthy) to do list.
(This would also explain why rotax opend up the boyesen ports towards the bottom of the transfer duct entry on the new rotax dd2 and made a guide for them in the crankcase halves - compared to the older 122 cylinder)
320050320049

Still interfering with b duct flow but a lot better then the older 122 style. I will cut them out even deeper to mimic the YZ250 Juho posted.

[AndreasL]

(remember to choose "flat view")

Do you have to be a member to have this option?
If not, I have to be blind or something...

Tried to register but had the same "password missing problem" TZ reported.

[bjorn.clauw.1]

Do you have to be a member to have this option?
If not, I have to be blind or something...

Tried to register but had the same "password missing problem" TZ reported.

Jep, when registered "flat view" appears. (Registered without problems)

[AndreasL]

Tried again but no go for me Bjorn.
Strange...

[bjorn.clauw.1]

Tried again but no go for me Bjorn.
Strange...
check your pm

[Flettner]

SOOO, now the dust has settled, what of the Ryger? Were we all duped? Or was it a case of something not transfering across to production from prototype very well? Was it 70HP simulated but not in real life? But Frits drove the Kart and gave glowing reports so there must have been some real power at some stage in development.
But Luc F keeps saying "wait another week" "information released shortly" , I think we are past "peak" Luc :laugh:
There must be something to all this Ryger Hype but its hard to decipher, something must have gone wrong with their test programme, I believe about five or six months ago.
Harry should have spilled the beans here on KB and we would have sorted the problems out for him:msn-wink:
Perhaps we are without knowing?
O well, on with our own "rygers" I guess. I'm over it.

[wobbly]

Yea you are right Flett,we were so enamored by Frits rhetoric that just maybe we got blindsided.
As I said the person or people that are running the Ryger PR bullshit spin doctor machine should be shot, or at the very least
have their private parts chewed off slowly by army ants.
The absolute incompetence that we see in the CIK application with drawings that dont match the reality of the attached pictures etc etc makes me spew,
and this usually only happens when I down the wrong cocktail of serious chemicals, whilst listening to a torture tape loop at 112dB of Donny or slut features Ga Ga.

[F5 Dave]

You'd think that sort of activity would be easy enough to avoid

[adegnes]

I double checked my engine model in engmod yesterday, and as I couldn't find anything wrong I went on to experimenting with fuel.

How bad would it be to run 10% oil mix?
Meth/nitro mix containing >10% oil and < 30% nitro is outside the restrictions and readily available in Norway.
Common RC fuel; methanol with 30% Nitro. Only thing changed was compression to 22:1 from 14.5:1, and afr adjusted to 3:1(picked a number I thought would be in the ballpark).
The results speak for themselves...
320065

[AndreasL]

As mentioned before, by Frits, nitro don't add power, it multiplies it. You get what I mean.
Nice result Alex!

What version of the 2tPost do you run?
I believe I have the latest version but can't get the cursor to show up. :scratch:

[adegnes]

As mentioned before, by Frits, nitro don't add power, it multiplies it. You get what I mean.
Nice result Alex!

What version of the 2tPost do you run?
I believe I have the latest version but can't get the cursor to show up. :scratch:

My version is 2.2.6a

[AndreasL]

Thanks adegenes.

Not sure about the "a" but 2.2.6 it is...
I will see what Neels says.

[adegnes]

Something weird/interesting:

I had another go with my bike on the roller yesterday. Now with the gas/xylene mix. It started and seemed to run fine, but didn't want to rev much higher than 12k under load. Max temps where low, CHT 280°F, EGT 1035°F. It did not sound/act rich.
Could this be the fuel once more? Maybe most of the xylene is just passing through without contributing much to the combustion? I'm basically running lean, but not hot cause the unburnt fuel cools the chamber/piston?

I'm ditching the homebrew fuel.




....Unleaded likes to be alot richer and makes more power with more advance so that setup makes best power at around 1050.


Ok, so 1035F EGT is pretty much what to expect from unleaded, CHT is still far too low at 280F.
Conclusion; Most of the xylene in my mix was burning late in the combustion process, not contributing much to pressure rise in the chamber, but heating up the pipe. Makes sense?

[AndreasL]

Gents, Kelvins or Celsius please! 😉😂

[peewee]

any word if them thermos are done yet

[FastFred]

SOOO, now the dust has settled, what of the Ryger? Were we all duped? Or was it a case of something not transfering across to production from prototype very well? Was it 70HP simulated but not in real life? But Frits drove the Kart and gave glowing reports so there must have been some real power at some stage in development. But Luc F keeps saying "wait another week" "information released shortly" , I think we are past "peak" Luc :laugh: There must be something to all this Ryger Hype but its hard to decipher, something must have gone wrong with their test programme, I believe about five or six months ago. Harry should have spilled the beans here on KB and we would have sorted the problems out for him:msn-wink: Perhaps we are without knowing? O well, on with our own "rygers" I guess. I'm over it.

Not duped, excitement and marketing hope dashed by reality, I expect they absorbed a few ideas from the input on this thread, and something may still come of it.

The local ideas look pretty promising, plenty of talented people here.

[TZ350]

Ok, so 1035F EGT is pretty much what to expect from unleaded, CHT is still far too low at 280F. Gents, Kelvins or Celsius please! ����

F = Fahrenheit converting F to C .... 1035F = 557C and 280F = 138C , plenty of converters on Google.

Kelvin and Celsius both have the same size steps, the difference is:-

Celsius starts at the freezing point of water and is 100 equal steps to the boiling point of water.

Kelvin starts at absolute zero and is 273K at the freezing point of water (yes, ice is hot compared to some things in the universe) and Kelvin is 373K at the boiling point of water.

So:- 1035F = 830K and 280F = 411K

You could have found out for your self, a quick Google would have given you the answer....... ​:spanking:

[Flettner]

any word if them thermos are done yet

No, and no word either.

Reality, always spoils the fun.

[AndreasL]

"same size steps"

"starts at the freezing point of water and is 100 equal steps to the boiling point"


Yes, isn't it wonderful?! :rolleyes:
Steps of tenth and hundreds. Art to the engineers brain. ;)

And I did convert it before I posted. And yes, I use horsepower in favor of kW. :laugh:

[adegnes]

I use Celsius most of the time myself. I like Fahrenheit's higher resolution on temp gauges, and most people I discuss engine stuff with use it.

[TZ350]

Yes, isn't it wonderful?! :rolleyes: Steps of tenth and hundreds. Art to the engineers brain. ;) And I did convert it before I posted. And yes, I use horsepower in favor of kW. :laugh:

Agreed, I prefer horsepower too. Science and the natural world, it is all very interesting, just wish I had more time to explore it all ..... :niceone:

[peewee]

No, and no word either.

Reality, always spoils the fun.

i thought you were the guy was wipping them up ? :laugh:

[TZ350]

I use Celsius most of the time myself. I like Fahrenheit's higher resolution on temp gauges, and most people I discuss engine stuff with use it.

I am currently installing a four channel data logger on my new bike, an aircooled 125cc 2T. It will be the first time I have collected any real temperature data, I hope I can get it to work properly because it will be very interesting to see what happens with the air cooled motor and how much we can improve the cooling with ducting.

[wobbly]

Dont mention wipping near Flett, he is one of those leather people,and as a secondary fetish has a CNC in his bedroom.
With no TV one has to keep amused at night.

[AndreasL]

Agreed, I prefer horsepower too. Science and the natural world, it is all very interesting, just wish I had more time to explore it all ..... :niceone:

Me to!


I am currently installing a four channel data logger on my new bike, an aircooled 125cc 2T. It will be the first time I have collected any real temperature data, I hope I can get it to work properly because it will be very interesting to see what happens with the air cooled motor and how much we can improve the cooling with ducting.

Very interesting! You can never have to much data.
I have the data logger used in one of the race cars I ran some years ago.
Some day I hope to fit it to the old moped to get a better picture of what's happening and to get better input data for EngMod. I'm looking forward to see the results.

What logger is it you have?

[wobbly]

Neels replied to my question ( along with the latest updates ) about what to look for to detect " overscavenging " as it relates to a too efficient pipe
mated to badly designed transfer ducts.
The problem is that the scavenging regime is pre defined, not simulated,thus does not change with a change in pipe design.
So we are stuck with having to build experience on this by testing in reality.
As an example I know that Erv Kanemoto tried 110mm pipes on a test TZ750 cylinder and lost power, no matter what configuration he tried.
And this was confirmed a few years later by Mike Sinclair, so in the case of a huge overbore with dead straight transfer ducts that have very little
directional control,that experience sheds some light on the physical limits.
Then there is the case of the CPI cylinders I have tested with 72mm bore on 58 stroke for the RZ/Banshee cases.
These have transfer ducts good as can be physically fitted into the cylinder confines of the studs, plus an extra set of ports ( making 8 including the 2 boost ports ).
But the teacup duct shape is absolutely minimal.
The pipes I could fit on the bike were 125 diameter, and the sim was absolutely accurate - predicting an almost perfect curve shape at 12% higher power than seen at the
rear wheel on a DynoJet.
In the sim, going fatter made very little difference to the power,why I dont know,maybe a combination of the Yam 6 poor scavenging and the STA limitations having a
greater effect than the pipes efficiency.

[ief]

Must be a way to fudge this Wob, lol :devil2:

[AndreasL]

Thanks wobs.

Neels informed me about it to.

Guess I can play around with the belly diameter to see what happens.
At least I can learn something from it.

[1948rod]

hi i have a slight interest in the old yam. kt100s. would it be too imposing to ask wobbly if you would post the dimensions of the pipe you designed for the kts. so i could have a play for speedway racing. cheers.

[wobbly]

The KT100 pipe was designed to be used with a nozzle at the flange with a tapered header.
And the end cap was spun on a die that I made, but I havnt had any of these parts for several years now.
I havnt got a drawing as such but you can have the .dxf to have all the parts laser cut in 0.8mm CDS.
Now I find I cant upload a .dxf, so send me a PM with your email and I will forward the file.
Here is a pic of the finished pipe, the real trick is the backwards angles of the 3 cone diffuser and the progressive stagger
of the bleed holes in the internal rear cone.
This thing took months of dyno work to perfect, and I made over 2000 of them all exactly the same by hand - no other pipe ever came close to matching
the peak power or power band width so it won hundreds of titles here,in USA and England where open pipes were/are allowed.

[Yow Ling]

F = Fahrenheit converting F to C .... 1035F = 557C and 280F = 138C , plenty of converters on Google.

Kelvin and Celsius both have the same size steps, the difference is:-

Celsius starts at the freezing point of water and is 100 equal steps to the boiling point of water.

Kelvin starts at absolute zero and is 273K at the freezing point of water (yes, ice is hot compared to some things in the universe) and Kelvin is 373K at the boiling point of water.

So:- 1035F = 830K and 280F = 411K

You could have found out for your self, a quick Google would have given you the answer....... ​:spanking:

So just what is wrong with the Farenheit scale 100*F = the temperature of deers blood and 0*F = the temperature of a slurry of ice and salt, makes perfect sense to me, then the French came along and appleid a complex algorithim to it to make this great 0 to 100 scale into a different 0 to 100 scale

[TZ350]

So just what is wrong with the Farenheit scale 100*F = the temperature of deers blood and 0*F = the temperature of a slurry of ice and salt, makes perfect sense to me.

320082

The golden age of science and discovery ...... love it. :woohoo:

320083

Demonstrating that living creatures need air by suffocating the pet budgie was a hoot too.

Then those boring ethics committees stepped in.

[TZ350]

Me to! Very interesting! You can never have to much data. I have the data logger used in one of the race cars I ran some years ago.

What logger is it you have?

320085

Four channel K type thermocouple temperature probe amplifier and SD card data logger.

320086

The amplifier with the green terminal strip is on the left and the data logger itself is on the right hand side. The det sensor box is just above it.

The tank is quite narrow so I can see and adjust them quite easily. They are glued to the frame with building adhesive. In wet weather I will tape a plastic box over them.

Keeping the wiring neat is becoming a challenge.

[41juergen]

Wob, you mentioned longer time ago that the Aux Exports shall be lower as the main port to ensure a better / stronger flow pulse starting from the main port. How much should the Aux port be lower, about 1mm or even more (which would of course reduce a bit more the blow down)?

[Frits Overmars]

Wob, you mentioned longer time ago that the Aux Exports shall be lower as the main port to ensure a better / stronger flow pulse starting from the main port. How much should the Aux port be lower, about 1mm or even more (which would of course reduce a bit more the blow down)?Jürgen, an answer in millimeters would be useless unless you also specify the engine's stroke; 1 mm would be not nearly enough for a 250 cc engine and far too much for a 6,5 cc model engine. You may have mentioned your engine's stroke here before, but not all of us will recall it.
I'd say that the aux ports are usually about 3° lower than the main exhaust port. And even this could lead to misunderstandings: if the main exhaust timing were 194°, then the aux ports would have a timing of about 188°. Geddit?
Now let's hear Wobbly's preference.

[wobbly]

C'mon Frits we all know the Aprilia had 2mm of stagger so that surely must be the magic number.
But in reality ( and Neels sim is firmly in that realm ) the amount of stagger is end use and setup specific.
As you lift the Aux, you of course increase the Blowdown STA, and the natural effects of this are to pump up the area around peak power and into overev,
and to loose mid power.
This approach though then starts to reach the diminishing returns quandry - more Blowdown helps power, less stagger starts to reduce peak power, catch 22 again.
Sadly you loose more mid than you gain top ( I ruined a KZ10 doing exactly that ) but if the cylinder has a PV that closes off the Aux then this system
greatly ameliorates that problem.

A CVT needs a ton of front side and peak power, so the Aux can be higher,as mid is unimportant ,especially with a good PV servo system.
Then we have the variable of how wide the Aux are,and the shape.
A really wide Aux around to bore center,can be much lower and still maintain the STA, a pure triangle shape can also be higher as this reduces the port linking
( helped by small end plugs as well ) but high square Aux have very good STA numbers that sadly also increase the A port short circuiting, so cant be as wide or you loose
power everywhere.
In short, the only way to get this nailed down is to take all this info into account and optimize the STA needed for your end use in EngMod.
Remembering at the same time, a single dimensional sim cant detect the bad effects of A port short circuiting, so your own intuition is just as important as the computer result,before hitting the dyno.
As always - no free lunch, and no simple answer.

[ief]

Hence why Jan made changes 0.25mm at a time, didn't get it right first time neither.

[adegnes]

The latest software has a new pipe heat release model incorporated, and for a racebike like the NSR you should use rpm driven pipe temp.
325*C at the start of the powerband and 425*C at peak power, say 8000 and 12,000.
If using a solenoid powerjet then this is modeled best by going to 450* in the overev.


Are these numbers for avgas, unleaded, or it doesn't matter?

[wobbly]

The numbers I gave I have used for nearly every engine on AvGas, as we are not allowed 110 etc here,and very few race engines use unleaded.
But as a general rule unleaded makes better power when slightly richer than AvGas, so the egt is a little lower, thus so will the pipe wall heat release model.
Against dyno testing charts on AvGas the model is all but perfect, we need some confirming dyno info from a really good sim to predict unleaded accurately.

[JdG]

Came across this video and had to share this with you guys. I think it's just enough Bucket related... http://www.flabber.nl/artikel/gast-op-een-vespaatje-vernietigt-een-motorrijder-op-een-600-cc-yamaha-xj6-47490

Here's the link to the guys webpage: http://niculin93.jimdo.com/motori/zirri-m1l-2014/

Greetz,

Jacob

[41juergen]

@Frits: of course you are right, I'm too much focused with working on my engine... :facepalm: So it's a 56mm bore and 50,7mm stroke (TZR250 3XV) 125cc cylinder. To get better blow down I went up to 200° CA main ex port and will go round to the center line of the bore with the aux ports (with plugged piston pins).
@Wob: got it, will change the parameters in EngMod and will see were to go. The cylinder has the Yamaha drum PV with servo motor, so I can play with that a bit.

I'm still struggling with the changes in the turbulent model to get the sim back close to what I saw with the 2015 version. It looks like that the TUbMax numbers jump much more between the iterations than before, not sure how to improve that...

[FastFred]

http://www.flabber.nl/artikel/gast-op-een-vespaatje-vernietigt-een-motorrijder-op-een-600-cc-yamaha-xj6-47490 Here's the link to the guys webpage: http://niculin93.jimdo.com/motori/zirri-m1l-2014/ Jacob

super fun .................... :clap:

[wobbly]

You will get much different results with the correct Turbulent numbers entered in the combustion inputs.
The initial Burnrate prescribed averages, are just that, very average, and as soon as you start to get high turbulence in the chamber from
an MSV number that is working correctly the TuB will rise due to the increase in flame speed ( and thats just one parameter ).

[adegnes]

I just run turbulent all the time. Youtube keeps me busy while waiting for sims to finish(and usually my sims are within a small rpm range, say 12-16k). It's not that slow anymore, noticed a huge difference moving to a faster computer. When doing full rpm range runs on my old 1ghz beater I used to leave it overnight...

[wobbly]

Running Turbulent is still way slower than entering the correct Burnrate numbers.
I have a 4.2GHz overclocked twin core rocket computer, and no way could I sit there watching the traces slowly walk across the screen.
when in Burnrate you cant keep up with the trace speed.
Its so easy to write a file and enter it, that seems a real waste of time not to do it.

[41juergen]

I run the turbulent model when defining the chamber with squish and comp and than put the data into the pre described table. Neels told me he modified the combustion part which changed the TUbMax and of course power. But as I have dyno curves of some of my projects which correlated very good I'm now getting definitively to low with the power estimate. Don't know how to fix that, went down with comp and combustion efficiency, but as said now being to low in the power estimate. Does anybody have a good idea for me what parameter to change?

[adegnes]

Running Turbulent is still way slower than entering the correct Burnrate numbers.
I have a 4.2GHz overclocked twin core rocket computer, and no way could I sit there watching the traces slowly walk across the screen.
when in Burnrate you cant keep up with the trace speed.
Its so easy to write a file and enter it, that seems a real waste of time not to do it.

You are absolutely right...but there's alot of interesting stuff on youtube!

[adegnes]

I run the turbulent model when defining the chamber with squish and comp and than put the data into the pre described table. Neels told me he modified the combustion part which changed the TUbMax and of course power. But as I have dyno curves of some of my projects which correlated very good I'm now getting definitively to low with the power estimate. Don't know how to fix that, went down with comp and combustion efficiency, but as said now being to low in the power estimate. Does anybody have a good idea for me what parameter to change?

Are your sims showing too low numbers?

[polinizei]

I run the turbulent model when defining the chamber with squish and comp and than put the data into the pre described table. Neels told me he modified the combustion part which changed the TUbMax and of course power. But as I have dyno curves of some of my projects which correlated very good I'm now getting definitively to low with the power estimate. Don't know how to fix that, went down with comp and combustion efficiency, but as said now being to low in the power estimate. Does anybody have a good idea for me what parameter to change?



try "combustion efficiency"

1 = 100%
0,94 = 94%
....

[41juergen]

I'm to high in TUbMax and corresponding to that too low in power estimate. I already went down from 0,87 to 0,85 for the stock 3XV engine (which has only 50 HP for a 250cc... :facepalm:). I also had in an other project the comp from 15,5 down to 14,5. With the old version I didn't had the high TUbMax and the power showed the same data I got from dyno pulls...
Am I right that when using the pre-described model filled with the vibe parameters from the turbulent model the TUbMax result will be the same as when using the turbulent model (all other parameters still the same)?

[teriks]

The latest software has a new pipe heat release model incorporated, and for a racebike like the NSR you should use rpm driven pipe temp.
325*C at the start of the powerband and 425*C at peak power, say 8000 and 12,000.
If using a solenoid powerjet then this is modeled best by going to 450* in the overev.

Would this pipe temperature setup be correct for a more or less static rpm application?
Methink it is (partly at least) needed because of shifting and accelerating thru the rpm range, and that for static rpm the variation would be at least smaller?

[wobbly]

If TuB is too high and you get screen deto, then the only parameters to kill this are - Timing, Compression and Stinger Size.
High MSV, over 40M/s will affect the combustion parameters and crank up TuB,but if you adjust this down,you have to then rerun Turbulent.
Yes, the imported numbers from a Turbulent run copied into a Burnrate file, will operate identically.

The pipe wall temp numbers give me the best correlation to many many AvGas dyno runs, and the % temp change from the bottom of the power band
into the overev is the same change as is seen in the EGT when doing a single gear heavily loaded DynoJet pull.
I really dont see any point in constant rpm power readings,I try my best to load the engine on the dyno to replicate the acceleration rate as seen on track.
This is easy with a DynoJet 160 that has a programmed in variable load control, that increase with wheel speed,as does aero on track.

[teriks]

The pipe wall temp numbers give me the best correlation to many many AvGas dyno runs, and the % temp change from the bottom of the power band
into the overev is the same change as is seen in the EGT when doing a single gear heavily loaded DynoJet pull. Well a really heavy load would be quite close to static RPM id guess.

I really dont see any point in constant rpm power readings,I try my best to load the engine on the dyno to replicate the acceleration rate as seen on track.
Me neither, for engines intended for road use that is. Though my application is "Survive 5-10 seconds heavy load before ~10-15 seconds of acceleration and a rise in rpm of some 3-4kRPM, followed by 45-55 seconds of more or less constant rpm, maybe some 1krpm variation around 33krpm". Add to that that the first few seconds is at zero airspeed, and the last ~50s is at some 350km/h witch should have some unwanted effect on pipe cooling.

Guess this parameter too applies for another of those (not so)educated guesses, or better yet, an egt logger. The power curve looks much more appealing when I apply the rpm dependent wall temp though. ;)

[emess]

the imported numbers from a Turbulent run copied into a Burnrate file, will operate identically.


That was always true for me with previous versions of Engmod, but not with the latest version, 5.2.5

Comparing a Turbulent run to Prescribed using imported values from the Turbulent run, I get significantly different results with v5.2.5.

Turbulent runs show Max power down 2hp in 36 over the prescribed run and TUbMax differs by 35° or more. (This sounds similar to 41juergens post 22303 on the previous page.)

In older versions the delay times in exported cmb files were suspiciously similar at different rpm, almost always ending in .99 and mostly changing by whole units. In the new version, delay values from a turbulent run differ at each rpm and vary smoothly which seems more realistic so the new version looks better (for me at least) as long as I always run the Turbulent model.

Mick

[marsheng]

I am currently installing a four channel data logger on my new bike, an aircooled 125cc 2T. It will be the first time I have collected any real temperature data, I hope I can get it to work properly because it will be very interesting to see what happens with the air cooled motor and how much we can improve the cooling with ducting.

I have a 4 channel gpxpro. It is fantastic. It just works. Recently I seized my maico and looking at the cht I can see it increasing on the last lap before the sudden stop.


This one is for the engineers.

How do you frustrate an engineer beyond all reason? Tie him to a pole and then fold up a road map the wrong way!

[AndreasL]

Trying some new turbulent runs after the update.

DETO as hell!

Does any one have a clue about what TuBmax is safe for unleaded 95 from the pump?
Or any other unleaded that might give me a clue.
Now it seems lika >860°C and we have deto.

May be a stupid question, but is a run full of "deto" as good to use when generating the turbulent file or is it essential that the sim is detofree?

EDIT: Upps, the stinger was still down at 8mm... New run it is.

[41juergen]

Some should better listen to the hints of the wise ones... :scratch:
So after running the turbulent model (also with deto's as hell) and putting the data into the pre-described table everything is good again. For any reasons the TUbMax goes back down to the numbers seen before, also power goes up again similar to what I had before. There is a difference between the two models running the same Vibe input data. Running all sims with the turbulent model is not the right way to do.

So follow the advise of Wob and Neels how to proceed and everything is good again....
Thank's Wob!

Regarding the pipe wall temps: if going with 100 octane pump gas with slightly richer in AFR shall the wall temps also be reduced a bit, let's say to 315°C for the start, 415°C for peak and 440°C for the overrev area?

[ief]

How many percent of Neels his userbase is actualy knowing what they are doing? Guess that won't be to much (?) Meaning my guess would be 'fudging' is more common then not whitch is a shame of the program but allmost unavoidable. How to tackle that? Would there be way's for Neels to make it more foolproof and if so, how?

Opted for a userforum a long time ago but that won't happen I guess...

Just thinking out loud.

[adegnes]

Some should better listen to the hints of the wise ones... :scratch:
So after running the turbulent model (also with deto's as hell) and putting the data into the pre-described table everything is good again. For any reasons the TUbMax goes back down to the numbers seen before, also power goes up again similar to what I had before. There is a difference between the two models running the same Vibe input data. Running all sims with the turbulent model is not the right way to do.

So follow the advise of Wob and Neels how to proceed and everything is good again....
Thank's Wob!

Regarding the pipe wall temps: if going with 100 octane pump gas with slightly richer in AFR shall the wall temps also be reduced a bit, let's say to 315°C for the start, 415°C for peak and 440°C for the overrev area?

I see no problem with running turbulent all the time, if you don't mind the relative slowness.
Edit: wait what? You saw massive detonation when running turbulent, but none when running the generated combustion file in prescribed mode?

Re temps; here's what I did:
1050f egt unleaded is 16% < 1250f egt avgas
325 - 16% = 273
425 - 16% = 357

Might be totally wrong, but makes sense to me.

[AndreasL]

Edit: wait what? You saw massive detonation when running turbulent, but none when running the generated combustion file in prescribed mode?


Me to.
Don't really now what to trust or what TuBmax to consider safe for my unleaded pumpgas.

[ief]

Isn't it so that turbulent uses none (or only ignition curve????) of the input from the combustion file, thus giving deto way easier? Then it calculates the vibes and stuff and you use those figures the next run, no more deto.

That make sense?

[adegnes]

This is the exact same model run in turbulent vs prescribed with a combustion file I got from another turbulent run.
Weird.


320133320134

[adegnes]

Isn't it so that turbulent uses none (or only ignition curve????) of the input from the combustion file, thus giving deto way easier? Then it calculates the vibes and stuff and you use those figures the next run, no more deto.

That make sense?

Turbulent uses entered ignition timing and afr.

[emess]

Turbulent uses entered ignition timing and afr.

Turbulent uses ALL the data in the cmb file as well as compression ratio, squish clearance, charge temperature, fuel, purity and more as a starting point to calculate the combustion delay, duration, vibe a & vibe m values . It does this on each iteration refining and homing in on what it calculates to be good solutions to the equations.

Detonation can occur any time during the refinement or on every iteration if TUbMax is too high for the fuel used and Wobbly has explained how to sort this with ignition timing, compression ratio, stinger diameter and squish clearance or a combination of those factors.

With the new version there are significant differences in power & TUbMax between a Turbulent run and a Prescribed run that uses the exported combustion data from an otherwise identical turbulent run so I'm now using Turbulent all the time.

[adegnes]

Turbulent uses ALL the data in the cmb file as well as compression ratio, squish clearance, charge temperature, fuel, purity and more as a starting point to calculate the combustion delay, duration, vibe a & vibe m values . It does this on each iteration refining and homing in on what it calculates to be good solutions to the equations.

Detonation can occur any time during the refinement or on every iteration if TUbMax is too high for the fuel used and Wobbly has explained how to sort this with ignition timing, compression ratio, stinger diameter and squish clearance or a combination of those factors.

With the new version there are significant differences in power & TUbMax between a Turbulent run and a Prescribed run that uses the exported combustion data from an otherwise identical turbulent run so I'm now using Turbulent all the time.

What I ment was it doesn't use the numbers entered for "delay", "duration" etc.

[emess]

What I ment was it doesn't use the numbers entered for "delay", "duration" etc.

It has to have reasonable starting values for delay, duration etc to allow solutions to be calculated in a reasonable time and to ensure the iterations converge instead of 'blowing up' and becoming unstable.

[ief]

And in that light I also assumed (thought I understood) that it did just that, take some default values and work from there...

Gotta revisit it again (gave up for the time being) but I'm pretty sure it freaked out (flamefront error) on deafault vibe and delay as well, ignition nothing strange and in normal run no deto at all...

Tuff stuff again this... we'll get there, some day :)

this:

"With the new version there are significant differences in power & TUbMax between a Turbulent run and a Prescribed run that uses the exported combustion data from an otherwise identical turbulent run so I'm now using Turbulent all the time."

Is totaly over my head.

[adegnes]

It has to have reasonable starting values for delay, duration etc to allow solutions to be calculated in a reasonable time and to ensure the iterations converge instead of 'blowing up' and becoming unstable.

Ok, I see.

[polinizei]

I got a message from Neels.


The turbulent model requires refinement as it takes too long to burn the last 5% under some conditions so on some engines it is fine while on others it is not. To stop this I had added a small check but the solution added mass and a quicker burn. In normal testing it added about 0.1% which was ok but in some cases it added as much as 5% which is why I removed it. I am continuing the development.

[peewee]

My pick is the top where the water is hottest as more thermal energy is lost the greater the thermal difference is, ie bulk energy is lost more rapidly from a hotter surface than a cooler one.

would you happen to know if I need a rectifier and regulator ? I know nothing of this electric stuff

heres what I know of the fan: Power Requirements 10.5V to 14.5V DC Only
Amp Draw 3 Amps
Watt Draw 30 Watts

heres what I know of the engine magneto: 11.5v min 16.3v max ( this must be taking into account a 16v regulator already installed) according to the owners manual

[bucketracer]

would you happen to know if I need a rectifier and regulator ? heres what I know of the fan: Power requirements 10.5V to 14.5V DC Only Amp Draw 3 Amps Watt Draw 30 Watts

heres what I know of the engine magneto: 11.5v min 16.3v max ( this must be taking into account a 16v regulator already installed) according to the owners manual

You will need a Rectifier/Regulator and a smoothing Capacitor too, or a battery. A battery acts like a really big smoothing capacitor.

320144

The rectified voltage is all ripply, the smoothing capacitor makes the rectified voltage from the bikes magneto/generator more like the sort of smooth DC voltage you would get from a battery. The regulator regulates the voltage to something like a maximum of 14V. 14V because you need something a little higher than 12V to re charge a 12V battery.

320149

[marsheng]

A magneto is used to charge the battery. Most magnetos start to charge just above idle. As the voltage is proportional to the rate of change of flux the faster you rev the motor the higher the voltage. At max rpm this can be a 100 volts. A regulator keeps the output at 14 or so volts to charge the battery. The next thing to consider is how much power the magnto can deliver. Most magnetos are designed to supply the minimum for the bike. Eg if you have a 50watt headlamp the the magneto will be around this figure. What tends to happen is that as the rpm rises so does the voltage. As the voltage rises the headlamp takes more power. P=v2/r. This then stops the magneto producing high voltages.

Bottom line is a small bike will have a small magneto and a cap plus cdi load will work. Big bike probably not.

PS multmeters do not accurately measure magneto voltages.

[peewee]

I don't want the extra weight of a battery so that's out of the question. originally it had lights powered by the stator magneto but the lights are no longer used. rather I wanted to power a fan instead. owners manual doesn't tell me what the amps or watts are but only the volts. 11.5v/2500rpm. 16.3v/8000rpm.

originally there was a regulator and maybe a rectifier but ill have to check my other manual about that. maybe I can just get a oem regulator/rectifier and plug it back into the wiring system ? would a smoothing capacitor keep the volts steady so they wont fluctuate up/down with rpm like marsheng mentioned ? I remember the lights got brighter as the engine revved up. I guess the fan would be affected the same way

ill see if I can draw a diagram of the wiring system as of now and maybe someone can give me advice where to hook in with the regulator/rectifier

[F5 Dave]

Reg/rec is one device. Should hold things below 14.5V. You will need a decent size smoothing capacitor.

[TZ350]

320149

There are three wire (three phase) and two wire (single phase) stators. Bucket has posted a picture of a three phase unit. A single phase unit would only have one generator coil with two wires coming off of the stator.

320163 use these with a 50Volt 4,700 uF capacitor instead of a battery, good for about 25Watts max.

Single phase Rectifier/Regulator cheap as chips of Trademe. We use these ourselves.

320164 320162

Another single phase unit, the two yellow wires go to the stator, and a three phase unit, the three black wires go to the stator.

320166320167

My single phase voltage rectifier/regulator, yellow wires to the stator and red and green to the battery. I use a bigger voltage rectifier regulator on the Beast because the total current draw could be 10Amps (120 Watts) and we use the smaller voltage rectifier regulators with the CDI only bikes because they have only about 1.5Amps (18 Watts) power demand.

320165

I use a battery on my Beast because I have EFI fuel injection and the fuel pump has to take power from the battery to build up some fuel pressure before the engine will start.

Otherwise I would replace the battery with one of these 50Volt 4,700 uF capacitors. We use these capacitors (from Jacar) with the smaller rectifier regulator (Trademe $9.50) on our bikes that have Ignetec CDI digital ignitions. No battery required, just push and go.

[TZ350]

320174

A single coil can actually be wound around several stator elements. This monkey bike stator has a high voltage winding wound on two stator elements and a single 12Volt coil wound around three stator elements.

We use these Monkey bike generators and strip the high voltage windings off and if we want more power then we wind a second lot of 12Volt windings and parallel them up for more current carrying capacity. So even though all six bobbins have windings on them and there are two distinct 12Volt sides they are all joined together into one logical single phase coil with only two power (yellow) wires coming from the stator.

320175

Loncin Monkey bike generator unit with a Suzuki RG50 flywheel center bolted (and glued) into it.

[marsheng]

would a smoothing capacitor keep the volts steady so they wont fluctuate up/down with rpm like marsheng mentioned ?

The power from the magneto is a pulsing signal, the cap averages the voltage per rev. It does not keep it from rising as the rpm rises.

For me a battery is a must as I can then power my instruments. Instruments are a must for race bike development.

[mr bucketracer]

320174

A single coil can actually be wound around several stator elements. This monkey bike stator has a high voltage winding wound on two stator elements and a single 12Volt coil wound around three stator elements.

We use these Monkey bike generators and strip the high voltage windings off and if we want more power then we wind a second lot of 12Volt windings and parallel them up for more current carrying capacity. So even though all six bobbins have windings on them and there are two distinct 12Volt sides they are all joined together into one logical single phase coil with only two power (yellow) wires coming from the stator.

320175

Loncin Monkey bike generator unit with a Suzuki RG50 flywheel center bolted (and glued) into it.thats realy what carb i should put on my 50, is that one 28mm?

[TZ350]

what carb i should put on my 50, is that one 28mm?

320179

It is a 24mm OKO, nearly everything we have is 24mm equivalent one way or another.

[TZ350]

Page 1490 ........


I have used the Lambda in the front muffler mount for ages on the dyno and at the track in karts ( its allowed during practice ).
The end of the rear cone is a very hot spot and the sensor seems to like this ( its heated as well of course ).
The readings are very stable and I have only had to replace a sensor once in hundreds of dyno runs.
But generally i am only doing full throttle pulls on the dyno so cant use the sensor for part throttle adjustment.
For that you would need load control, or have full data logging at the track, which we have.


I am puzzled that this actually works. As a good 30% of the delivered air to the engine goes straight out the exhaust port never to return to the cylinder, this must result in 30% of delivered oxygen going down the exhaust pipe. This is equivalent to a four-stroke running 30% lean of stoichiometric afr. Now a wideband sensor will indicate the correct lean afr for the four-stroke so how does the sensor give useful information for the case of the two-stroke?


I must admit I was very skeptical about using a lambda on a 2T, especially as several dyno operators told me they wouldnt use
the sniffer on a Dynojet ( even with its inline filters etc ) as it continually shit the probes.
But in 07 when we first went to USA racing the SKUSA CR125 box stock class,I saw a probe mounted thru an alloy bung welded
right at the front of a muffler.
The Lambda read the A/F going past inside the perf tube.
I asked to look at the data on the PI system, and there it was, a perfect readout varying with throttle and track position, between 12:1 and 15:1.
The fact it was 12.8:1 at full noise down the shute,told me it was saying the right things, as the egt was 1280*F, just as we were running - right on the edge.
The Yanks were obsessed with trying to get the fueling number correct the whole lap, and this made the corner exit ratio " correct " but slower.
And that jetting was too lean down low to get the kart launched at the starts as well.
So I ignore the numbers in this area and do all the bottom end response against the rear brake, on the stand.
If it will snap off the bottom when given instant full throttle from idle, then the pilot/needle/tube/slide are correct.
If it snaps from 1/2 throttle,without hesitation, or blowing a heap of rich smoke,then the mid jetting is correct.
We shot for a specific egt number in accordance with the weather, and this always corresponds with a A/F around 12.6 to 12.8.
So as we can use the egt ( but not Lambda ) in races I can then track the weather and jet change on egt alone.


This fits exactly with what ive found... I use a wideband o2 on the dyno and it is extremely reliable... made up a simple vacuum setup using a funnel held up against the main extraction fan for the room and it pulls exhaust gasses up through a 1/4 inch diameter copper tube thats pushed up the silencer. Reading are basically taken from the beginning of the silencer and drawn up past the sensor via rubber hose. The numbers are highly repeatable and after doing enough bikes you get to know exactly what AFR each bike likes at each rpm/throttle position. My dyno is an eddy current so i hold it at 4 or 5 rpm points and then test each point at 1/4, 1/2, 3/4 and full throttle... end up with a matrix of AFR's and its then very easy to make adjustments to pilot, needle or main to alter the AFRs at each point. Before using this setup i went through about 3 sensors a month ($$$ :o), now i use 1 or 2 a year and the dyno is used 3-4 days per week. I also find 12.6-12.8 to be a good range to aim for up top, then slightly leaner around 13.5 at mid throttle and mid rpm, and leaner again around 14 at low throttle and low rpm.... this is for offroad and MX bikes though. Im about to setup a KTM330 with an Ignijet so we'll see how this method goes with EFi....




My guess is the CHT follows the actual temperature in the cylinder by a few seconds. Obviously the heat generated has to heat the head which heats the probe and this takes time.

I presume that once I tap off coming to a corner that the cylinder heat will go down straight away.

From the graph it looks like the delay is around 7-8 seconds. Does this sound correct?

The highest temp (190 Deg C) is midway round the hairpin at Ruapuna. (See the dot)

320232


Here is another plot.

See how the temperature drops with the 'high' speed down the straight. The max is still behind the corner.

So I suppose a question is, does the bike seize from overheating or over cooling? Would be quite a different story with a water cooled motor.

320233


This is very interesting. I would have thought the cart guys would have looked into this. I hope someone can shed some experienced light on it.

Maybe this is the first time we have any real publicly available aircooled cylinder head data. I would love to know the interpretation and what the data means.

If this is truly the way it is in realty with a good motor then there is nothing much to fear from running a well tuned big hp aircooled motor hard down the straights its just what happens in the corners that matter.

PS, please tell us more about the data logger you are using, I would like to use one too. I have a 4 channel unit but it does not record temperature relative to the position on the track.


If you are getting lower temps at high rpm,then high temp at lower rpm ( throttle opening ) then I would say the main jet is rich and the overun jetting ( that is the pilot/needle/tube combo is lean ).

You need alot of fuel ( rich ) in the bottom end jetting to stop a lean condition on the overun, when road racing - even more so with an aircooled engine.

It needs to be actually rich ( smoking ) off the bottom when free running - and having a case full of rich mixture as you open the throttle on corner exit is always faster.

The high corner temps would also be an artifact of the over advanced midrange we talked about previously.

I discovered this years ago when initially using a straight line motoplat ignition on an air cooled YZ125 kart - on Methanol back then.

When we changed to a later model retarding unit, it was way hotter mid corner, and lean on corner exit.

It needed way more fuel to keep the CHT/EGT under control at lower rpm with a ton of mid advance.

I missed this, Wob must have posted as I was writing mine.


Two strokes like an ignition curve approximating to an inverse of the power curve.
With around 28* in the mid range, that ramps up from an easy kick starting 10* at idle to about 1500,2000 rpm.
Then as the bmep rises and the pipe gets in sync with the port we pull out timing in relation to the dynamic compression created by the wave action, to prevent detonation in the end gasses.
Most engines like around 15* of timing at peak torque, we then drop this away after peak to increase the heat released into the pipe.
We have a finite amount of heat energy to use to heat trapped combustion gas,heat the water, heat the piston/head, or release it into the pipe.
The ignition delay sets the amount dispersed into each element and how much this creates power at the crank is set by the interaction of each component part.


249567

In working out a curve to programe into the Ignitec we did various dyno runs with a straight line setting but different base advances. The runs were cut short as we were only looking at the lower part of the curve.

249566

Same runs compaired to my previous KX80 fixed ignition 16* BTDC (Red Line).


WTF ….. The Beast screams around the track on full song for a whole lot of laps then quits when taken out for an easy trot around in the two warm up laps for the next race, what is that all about?????

261714

Damage is in the exhaust port area, and thats a steel ring thats cleanly snapped in two.

I will dig out the dyno graph and ignition curve.


Rob,re the Ignitech curve "issue". I have found that the engine will not make much if any more power, as shown by the dyno load it will pull, but by adding a heap more timing, it will for sure
operate much , much better on part throttle response, on track. Here is a 125 kart engine curve that made 50RWHp,and won 3 back to back 125 National titles easily. This thing would deto like mad on part throttle at 6000 if held there, but on track it would pull out of 1st gear hairpins hard enough to spin the tyres on full throttle from the same rpm, then rev out to 14200. A TPS and a 3D map would achieve a better result, but I didnt have a RS125 Honda carb at the time.


.........

261718

To be on the safe side we had richened the mixture up (Blue line)

261717

And in case the piston might be to close to the head we tried an extra 0.5mm base gasket (Red Line) but we didn't like that and took it out again.

But it is interesting to see what lifting the barrel only 0.5mm does.

261716

There is no evidence the piston was hitting the head, just a lot of derbis crushed into it. I regret we didn't lift the head for a look after the first race, then we would know for sure, but it was going so well I didn't want to disturbe it.

261719 261720

The original dyno graph and ignition curve.

With a straight line ignition curve the engine made max power around 16 degrees, the advanced portion improved the lower power curve. The ignition curve is 16 degrees at 12,750rpm and retads 10 degrees by 13,500 rpm for max over rev. This curve was carefully developed on the dyno using full throtle runs and took a lot of work and time.

10 degrees retard, on full throttle is that excessive? is it OK to hold it on full throtle in the max retard area at 13-14,000 rpm for longish periods? like holding out to the end of a short straight.

Any way the problems happened at lower rpm and lesser throttle openings when the motor wasn't being driven at race pace.


I am wondering if this could be the problem? and I might need to use a TPS and go the 3D map way, or at least switch between 2 maps depending on rpm and throttle position.


The one and only reason you get a destroyed piston like that is DETONATION.
And looking at the Ignition curve you have posted it is immediately obvious why the thing keeps on blowing up.
NO 2T race engine making any sort of power can take anything like the advance numbers you have except in very fast, short burst, transient testing.
If at any time you had held the engine on part throttle at 10,000 rpm in 6th gear on the dyno, then done a roll on test it would have seized instantly.

I have never seen in 30 years of dyno testing any engine making reasonable Hp that would take 22 degrees of advance at peak torque, 12200 , then 20 * at peak Hp, 12400 in this case.
You have the wrong end of the stick completely with the comment about holding the engine in the overev region.
Its safe as houses up there as its BMEP is low ( little dynamic com ) plus there is not much advance, alot of the heat energy is going into the pipe - not the piston and head .

The real issue is exactly as per the comment of mine you posted re that 125 kart engine - the edvance curve it liked when used at full throttle in the mid range,would deto its tits off when held
for any time at those low rpms, be that on part throttle for a fast corner, or slow acceleration due to corner loading.
In a kart, part throttle is very rarely seen in a corner, as they have tons of grip.In a bike you run part throttle in corners most of the time, especially in the area just under the peak torque point
and having 27* of timing at 11,000 is going to kill the thing every time unless jetted well rich.

Using fuel to cool an over advanced engine looses power big time and it is impossible to set up an ideal ignition curve on a rolling road with no instrumentation at all.
With no deto sensing or being able to track EGT plus CHT you have no idea about what is happening with a particular ignition setup at all.

You used the port timing map off the sim I did as well as the head geometry, that put the overall engine efficiency quite a bit higher, but then ignored the combustion file that had an ignition curve tailored to suit the bmep
plus the overriding fact that it is an air-cooled engine.
If you take the sim as I last ran it then do a Turbulent Model with your ignition curve,the TuMax will be thru the roof,and the program will probably scream DETO WARNING at you in the mis range.

The way to go is pointed to by the fact that the RACE box has two curves that can be used in all sorts of ways - one of which is as per Honda RS125 setup, using a shift rum sensor that has allows alot of advance
in gears 1 thru 3, then uses a retarded map in gears 4 thru 6th when the acceleration rate is alot lower.
But really you first need to get a handle on a single map, that can be used in any gear at any TPS without it destroying itself.

These issues have nothing to do with an inherent problem with the 2T engine as some are joking about - I went to the kart nationals over Easter, with over 300 entries, only one siezure of a 2T all weekend that I heard about,
and that was caused by some idiot running so low on fuel it sucked air.

[speedpro]

I'm thinking of proposing a rule. We have to consider handlebar width, I see no reason not to have to consider how far out the carb sticks.

[TZ350]

I'm thinking of proposing a rule. We have to consider handlebar width, I see no reason not to have to consider how far out the carb sticks.

I am already on to it, I have proposed a bike can be no wider than its length or the number of dollars it took to build it, whichever is greater ..... :rolleyes:

320202320203320204

Anyway my carb sticks out the front .... :bleh:

[ken seeber]

https://www.youtube.com/watch?v=Bp4tGTNNi1I

Any Rygers in this lot? :wacko:

Fletto, get a move on !!!! Before it's too late.

[JanBros]

I am already on to it, I have proposed a bike can be no wider than its length or the number of dollars it took to build it, whichever is greater ..... :rolleyes:

320202320203320204

Anyway my carb sticks out the front .... :bleh:

what are the plates with springs for (on the side of the cylinder above carb entrance ?
and there are 2 versions ?

[ief]

I am already on to it, I have proposed a bike can be no wider than its length or the number of dollars it took to build it, whichever is greater ..... :rolleyes:

320202320203320204

Anyway my carb sticks out the front .... :bleh:

If it works to it's full potential or not (yet) I so do like the way you came to this construction :clap:

[Frits Overmars]

https://www.youtube.com/watch?v=Bp4tGTNNi1IDid I mention KISS before?:D


I'm thinking of proposing a rule. We have to consider handlebar width, I see no reason not to have to consider how far out the carb sticks.Talking about KISS: if you think you need a maximum width rule, stipulate a maximum width; no need to mention the handlebar or any other part of the bike.
As for that width being asymmetric (two feet of carb sticking out on one side): don't bother; things will sort themselves out or prove to be unpractical.
The best rule is an absent rule; the second-best one is a short and simple rule. So let's try to Keep It that way: Short and Simple.

[TZ350]

what are the plates with springs for (on the side of the cylinder above carb entrance ? and there are 2 versions ?

It is the blow off valve. There was combustible mixture in the plenum chamber. The first version blew the plate so hard against the studs that the plate bent. The second version used the Scotch Bright as a cushion, works very well.

The plenum bike has actually been test ridden in the drive and for several practice outings at the track. Testing was stopped when we realised there was considerable fuel dropout in the plenum and we became concerned about how much oil (how little) was actually getting to the engine.

EFI is an attempt to overcome the lack of mixture control through fuel drop out and the doubtful oiling problem.

Couple of video clips, first ever startup and driveway test. The clips are quite old, when we first tested the plenum idea it was to overcome the perceived restriction of a 24mm carb but it became quite clear that at 20hp the 24mm carb was not the problem.

Now we are regularly knocking on the door of 30hp the idea was worth re visiting, but it is doubtful that even at 30+hp the plenum is really necessary. Fun idea though.

Starts Easy.

<iframe width="420" height="315" src="https://www.youtube.com/embed/YxiEo8cgopg" frameborder="0" allowfullscreen=""></iframe>

Crisp as under power, throttle response was Ok on the track too. Motor 125cc plenum 1,200cc but should possibly be 3,000 according to EngMod2T.

<iframe width="420" height="315" src="https://www.youtube.com/embed/p4ef-WUO1Qs" frameborder="0" allowfullscreen=""></iframe>

We found some interesting results on the dyno. It may be possible to make the plenum with two chambers the smaller one to resonate for a low end off power torque boost then open the plenum up to its full size for full on power.

[ief]

Allways thinking it must be me or something I misunderstood but... latest test update and turbulent runs great, Neels the man. :first:

[adegnes]

Allways thinking it must be me or something I misunderstood but... latest test update and turbulent runs great, Neels the man. :first:

Nice!
Go Neels!

[marsheng]

My guess is the CHT follows the actual temperature in the cylinder by a few seconds. Obviously the heat generated has to heat the head which heats the probe and this takes time.

I presume that once I tap off coming to a corner that the cylinder heat will go down straight away.

From the graph it looks like the delay is around 7-8 seconds. Does this sound correct?

The highest temp (190 Deg C) is midway round the hairpin at Ruapuna. (See the dot)

[TZ350]

The highest temp (190 Deg C) is midway round the hairpin at Ruapuna. (See the dot)

That is very interesting, not what I would have guessed.

Hairpin least amount of cooling air flow and greatest amount of engine heat soak, or maybe part throttle detonation heating the head. It will be very interesting to know what is happening there.

Is it similar for the other corner apex's coolest on the straight hotter at the apex?

[AndreasL]

Allways thinking it must be me or something I misunderstood but... latest test update and turbulent runs great, Neels the man. :first:

Is this with the version released some days ago?
Anything special/different how you ran your sims compared to before?

I'm still not getting what is supposed to be the most accurate way to do the sims or how to interpret the results when comparing older and newer runs.

One turbulent run to generate a turb file.
Very much deto.
Run the newly generated file in prescribed.
No deto.
Different results then from before the latest update.

I think it's the same as others have reported.
But is the way described above still "the one to be trusted for now"?

[adegnes]

Is this with the version released some days ago?
Anything special/different how you ran your sims compared to before?

I'm still not getting what is supposed to be the most accurate way to do the sims or how to interpret the results when comparing older and newer runs.

One turbulent run to generate a turb file.
Very much deto.
Run the newly generated file in prescribed.
No deto.
Different results then from before the latest update.

I think it's the same as others have reported.
But is the way described above still "the one to be trusted for now"?

I asked Neels the same question, and what you describe(run turbulent, create combustion file, use file in prescribed mode from then on) is the best way to go about things for now(and the best way anyways, if you want to save time).
He is of course on the case!

[ief]

It is not the latest release from a couple of days ago but a later (today), I think I should call it beta or something? :)

I didn't use it much before since it wouldn't work for me so nothing to add in that regard, only thing now is that I'm not asked to save the new file but Neels is on that for sure...

[AndreasL]

I asked Neels the same question, and what you describe(run turbulent, create combustion file, use file in prescribed mode from then on) is the best way to go about things for now(and the best way anyways, if you want to save time).
He is of course on the case!

Tack Alex!

Asked the same but guess Neels is hard at work not satisfied with this set back in his software.

Thats the way I have always run it, just wanted to be sure that it was nothing special to consider for the moment.

But I'm still a bit lost in the "turb - deto, prescribed - no deto" and what to trust.

[AndreasL]

It is not the latest release from a couple of days ago but a later (today), I think I should call it beta or something? :)

I didn't use it much before since it wouldn't work for me so nothing to add in that regard, only thing now is that I'm not asked to save the new file but Neels is on that for sure...

Good to know ief.

Thanks.

[ief]

I might be totaly wrong but... My feeling is there are way more important things then turbulent model to get a proper sim result. To me it only seems to add some power in the powerband. Offcoarse, if you are on the threshold of deto it might be very important but how to cover all the other basis (first) into getting a proper result?

Curious to see how you all think about that?

[wobbly]

Yes you are right,in that if you get the TuB curve shape the same as your torque curve, with a peak at say 900" then that means your ignition
curve, com, stinger etc are in the ball park.
But 900 is too low,in that cranking up the TuB just short of deto will always generate more power.
Having the correct numbers in the Comb file will then allow you to confidently vary each element in turn, to see if say more com increases the TuB to 950 ( without deto )
but changing the stinger does the same thing but makes more power etc.

[wobbly]

I have just run the update,and reran a Burnrate Comb with its original written Turbulent numbers, then rearan a new Turbulent, then saved that new Turbulent numbers file
and reran that as Burnrate.
The power numbers are with a 1/2 a Hp in 35 for a full out KTM85 and the TuB numbers are within 10* at 980" peak.
So small variations due to the new code, but nothing that tiny changes in ignition timing or even Combustion Efficiency would not enable me to get equality - as it stands I
wont even bother.
And this sim is right on the edge in every respect, so i would fully expect that if Neels has made an improvement to the way Combustion is handled then such small changes
are just fine with me.
In fact thinking about legacy files, if you now rerun the last Dat2T sim setup, the new result simply becomes a better baseline to rework from if needed.

[TZ350]

I'm thinking of proposing a rule. I see no reason not to have to consider how far out the carb sticks.

320221

You must be thinking of the Keihin 38 - 24mm equivalent carb..... :laugh:

320220320219

This carb is perfectly legal by the recent MNZ clarification of how a carb should be measured for size.

After some adjustment the 38 was officially the same equivalent size as the original GP125 24mm carb.

320222

Woops look 31 hp 2012.

Now I know I have a 32 hp graph some place ... :scratch:post it when I find it. Is there any point to this 24mm carb restriction rule.

[TZ350]

We have stopped going backwards with Chambers RG50 and started making some positive progress.

320226

Lower blue - 21:1 compression ratio.
Green - 15:1 compression ratio.
Red - Inlet 160 deg duration was 120. This is one of those Suzuki piston port/case reed engines.
Blue - 100 main jet, was 110.

Tokoroa here we come.

[mr bucketracer]

We have stopped going backwards with Chambers RG50 and started making some positive progress.

320226

Lower blue - 21:1 compression ratio.
Green - 15:1 compression ratio.
Red - Inlet 160 deg duration was 120. This is on of those Suzuki piston port/case reed engines.
Blue - 100 main jet, was 110.

Tokoroa here we come.whats your pipe of ? home built or a copy of something?

[41juergen]

I have just run the update,and reran a Burnrate Comb with its original written Turbulent numbers, then rearan a new Turbulent, then saved that new Turbulent numbers file
and reran that as Burnrate.
The power numbers are with a 1/2 a Hp in 35 for a full out KTM85 and the TuB numbers are within 10* at 980" peak.
So small variations due to the new code, but nothing that tiny changes in ignition timing or even Combustion Efficiency would not enable me to get equality - as it stands I
wont even bother.
And this sim is right on the edge in every respect, so i would fully expect that if Neels has made an improvement to the way Combustion is handled then such small changes
are just fine with me.
In fact thinking about legacy files, if you now rerun the last Dat2T sim setup, the new result simply becomes a better baseline to rework from if needed.

I can confirm what you found. With the latest update the numbers are very close... Neels is just working to finalize a new version I think.

[F5 Dave]

My guess is the CHT follows the actual temperature in the cylinder by a few seconds. Obviously the heat generated has to heat the head which heats the probe and this takes time.

I presume that once I tap off coming to a corner that the cylinder heat will go down straight away.

From the graph it looks like the delay is around 7-8 seconds. Does this sound correct?

The highest temp (190 Deg C) is midway round the hairpin at Ruapuna. (See the dot)
Try it again with a bigger pilot jet.

[speedpro]

We have stopped going backwards with Chambers RG50 and started making some positive progress.

320226

Lower blue - 21:1 compression ratio.
Green - 15:1 compression ratio.
Red - Inlet 160 deg duration was 120. This is one of those Suzuki piston port/case reed engines.
Blue - 100 main jet, was 110.

Tokoroa here we come.

That says to me you should add inlet timing and possibly drop another jet. Certainly drop a jet at Tokoroa if it's on the money in the workshop.

[AndreasL]

Note to self: Check your spam box in the mail program you use! Grr

Thanks all for the insight how you do your sims.
Noting different than I do mine so then I'm good.

It was just the timing of this little glitch that was "perfect" as I'm just tweaking for more TuBmax and no deto as wobs described above.

[adegnes]

Note to self: Check your spam box in the mail program you use! Grr

Yep, mine showed up in the trash too. Haven't had the time to try it out yet.

[marsheng]

Here is another plot.

See how the temperature drops with the 'high' speed down the straight. The max is still behind the corner.

So I suppose a question is, does the bike seize from overheating or over cooling? Would be quite a different story with a water cooled motor.

[wobbly]

If you are getting lower temps at high rpm,then high temp at lower rpm ( throttle opening ) then I would say the main jet is rich
and the overun jetting ( that is the pilot/needle/tube combo is lean ).
You need alot of fuel ( rich ) in the bottom end jetting to stop a lean condition on the overun, when road racing - even more so with an aircooled engine.
It needs to be actually rich ( smoking ) off the bottom when free running - and having a case full of rich mixture as you open the throttle on corner exit is always faster.
The high corner temps would also be an artifact of the over advanced midrange we talked about previously.
I discovered this years ago when initially using a straight line motoplat ignition on an air cooled YZ125 kart - on Methanol back then.
When we changed to a later model retarding unit, it was way hotter mid corner, and lean on corner exit.
It needed way more fuel to keep the CHT/EGT under control at lower rpm with a ton of mid advance.
Many years later we had the same issues with a water cooled engine, running hot CHT on the overun into corners, again it needed a very rich pilot and a big tube
to keep the temps down,and as a result it also ran way harder off the turns as well due to the cooler pipe wall temp.

[TZ350]

My guess is the CHT follows the actual temperature in the cylinder by a few seconds. Obviously the heat generated has to heat the head which heats the probe and this takes time.

I presume that once I tap off coming to a corner that the cylinder heat will go down straight away.

From the graph it looks like the delay is around 7-8 seconds. Does this sound correct?

The highest temp (190 Deg C) is midway round the hairpin at Ruapuna. (See the dot)

320232


Here is another plot.

See how the temperature drops with the 'high' speed down the straight. The max is still behind the corner.

So I suppose a question is, does the bike seize from overheating or over cooling? Would be quite a different story with a water cooled motor.

320233


This is very interesting. I would have thought the cart guys would have looked into this. I hope someone can shed some experienced light on it.

Maybe this is the first time we have any real publicly available aircooled cylinder head data. I would love to know the interpretation and what the data means.

If this is truly the way it is in realty with a good motor then there is nothing much to fear from running a well tuned big hp aircooled motor hard down the straights its just what happens in the corners that matter.

PS, please tell us more about the data logger you are using, I would like to use one too. I have a 4 channel unit but it does not record temperature relative to the position on the track.


If you are getting lower temps at high rpm,then high temp at lower rpm ( throttle opening ) then I would say the main jet is rich and the overun jetting ( that is the pilot/needle/tube combo is lean ).

You need alot of fuel ( rich ) in the bottom end jetting to stop a lean condition on the overun, when road racing - even more so with an aircooled engine.

It needs to be actually rich ( smoking ) off the bottom when free running - and having a case full of rich mixture as you open the throttle on corner exit is always faster.

The high corner temps would also be an artifact of the over advanced midrange we talked about previously.

I discovered this years ago when initially using a straight line motoplat ignition on an air cooled YZ125 kart - on Methanol back then.

When we changed to a later model retarding unit, it was way hotter mid corner, and lean on corner exit.

It needed way more fuel to keep the CHT/EGT under control at lower rpm with a ton of mid advance.

I missed this, Wob must have posted as I was writing mine.


Two strokes like an ignition curve approximating to an inverse of the power curve.
With around 28* in the mid range, that ramps up from an easy kick starting 10* at idle to about 1500,2000 rpm.
Then as the bmep rises and the pipe gets in sync with the port we pull out timing in relation to the dynamic compression created by the wave action, to prevent detonation in the end gasses.
Most engines like around 15* of timing at peak torque, we then drop this away after peak to increase the heat released into the pipe.
We have a finite amount of heat energy to use to heat trapped combustion gas,heat the water, heat the piston/head, or release it into the pipe.
The ignition delay sets the amount dispersed into each element and how much this creates power at the crank is set by the interaction of each component part.


249567

In working out a curve to programe into the Ignitec we did various dyno runs with a straight line setting but different base advances. The runs were cut short as we were only looking at the lower part of the curve.

249566

Same runs compaired to my previous KX80 fixed ignition 16* BTDC (Red Line).


WTF ….. The Beast screams around the track on full song for a whole lot of laps then quits when taken out for an easy trot around in the two warm up laps for the next race, what is that all about?????

261714

Damage is in the exhaust port area, and thats a steel ring thats cleanly snapped in two.

I will dig out the dyno graph and ignition curve.


Rob,re the Ignitech curve "issue". I have found that the engine will not make much if any more power, as shown by the dyno load it will pull, but by adding a heap more timing, it will for sure
operate much , much better on part throttle response, on track. Here is a 125 kart engine curve that made 50RWHp,and won 3 back to back 125 National titles easily. This thing would deto like mad on part throttle at 6000 if held there, but on track it would pull out of 1st gear hairpins hard enough to spin the tyres on full throttle from the same rpm, then rev out to 14200. A TPS and a 3D map would achieve a better result, but I didnt have a RS125 Honda carb at the time.


.........

261718

To be on the safe side we had richened the mixture up (Blue line)

261717

And in case the piston might be to close to the head we tried an extra 0.5mm base gasket (Red Line) but we didn't like that and took it out again.

But it is interesting to see what lifting the barrel only 0.5mm does.

261716

There is no evidence the piston was hitting the head, just a lot of derbis crushed into it. I regret we didn't lift the head for a look after the first race, then we would know for sure, but it was going so well I didn't want to disturbe it.

261719 261720

The original dyno graph and ignition curve.

With a straight line ignition curve the engine made max power around 16 degrees, the advanced portion improved the lower power curve. The ignition curve is 16 degrees at 12,750rpm and retads 10 degrees by 13,500 rpm for max over rev. This curve was carefully developed on the dyno using full throtle runs and took a lot of work and time.

10 degrees retard, on full throttle is that excessive? is it OK to hold it on full throtle in the max retard area at 13-14,000 rpm for longish periods? like holding out to the end of a short straight.

Any way the problems happened at lower rpm and lesser throttle openings when the motor wasn't being driven at race pace.


I am wondering if this could be the problem? and I might need to use a TPS and go the 3D map way, or at least switch between 2 maps depending on rpm and throttle position.


The one and only reason you get a destroyed piston like that is DETONATION.
And looking at the Ignition curve you have posted it is immediately obvious why the thing keeps on blowing up.
NO 2T race engine making any sort of power can take anything like the advance numbers you have except in very fast, short burst, transient testing.
If at any time you had held the engine on part throttle at 10,000 rpm in 6th gear on the dyno, then done a roll on test it would have seized instantly.

I have never seen in 30 years of dyno testing any engine making reasonable Hp that would take 22 degrees of advance at peak torque, 12200 , then 20 * at peak Hp, 12400 in this case.
You have the wrong end of the stick completely with the comment about holding the engine in the overev region.
Its safe as houses up there as its BMEP is low ( little dynamic com ) plus there is not much advance, alot of the heat energy is going into the pipe - not the piston and head .

The real issue is exactly as per the comment of mine you posted re that 125 kart engine - the edvance curve it liked when used at full throttle in the mid range,would deto its tits off when held
for any time at those low rpms, be that on part throttle for a fast corner, or slow acceleration due to corner loading.
In a kart, part throttle is very rarely seen in a corner, as they have tons of grip.In a bike you run part throttle in corners most of the time, especially in the area just under the peak torque point
and having 27* of timing at 11,000 is going to kill the thing every time unless jetted well rich.

Using fuel to cool an over advanced engine looses power big time and it is impossible to set up an ideal ignition curve on a rolling road with no instrumentation at all.
With no deto sensing or being able to track EGT plus CHT you have no idea about what is happening with a particular ignition setup at all.

You used the port timing map off the sim I did as well as the head geometry, that put the overall engine efficiency quite a bit higher, but then ignored the combustion file that had an ignition curve tailored to suit the bmep
plus the overriding fact that it is an air-cooled engine.
If you take the sim as I last ran it then do a Turbulent Model with your ignition curve,the TuMax will be thru the roof,and the program will probably scream DETO WARNING at you in the mis range.

The way to go is pointed to by the fact that the RACE box has two curves that can be used in all sorts of ways - one of which is as per Honda RS125 setup, using a shift rum sensor that has allows alot of advance
in gears 1 thru 3, then uses a retarded map in gears 4 thru 6th when the acceleration rate is alot lower.
But really you first need to get a handle on a single map, that can be used in any gear at any TPS without it destroying itself.

These issues have nothing to do with an inherent problem with the 2T engine as some are joking about - I went to the kart nationals over Easter, with over 300 entries, only one siezure of a 2T all weekend that I heard about,
and that was caused by some idiot running so low on fuel it sucked air.

[adegnes]

TZ, you don't happen to have the gp engines stock crankcase volume recorded somewhere do you? Other measurements are greatly appreciated too!

I'm designing a pipe for my neighbor's bike in engmod.

[TZ350]

TZ, you don't happen to have the gp engines stock crankcase volume recorded somewhere do you?

Bucket did some measurements, I think the number less transfers is 470cc but best follow the link and check.


Crankcase Compression Ratios Revisited

He also posted on page 500 a lot of info or links to info on the Team ESE GP125 engines. From memory we got good results with the Ex at 80atdc 72% bore width, Trans 114atdc and In 145/85 to get any power we found that the rear transfers had to be opened up. Anyway take a look at what Bucket posted on page 500.

[adegnes]

Bucket did some measurements, I think the number less transfers is 470cc but best follow the link and check.



He also posted on page 500 a lot of info or links to info on the Team ESE GP125 engines.

Thank you great sir!
Man I suck at searching...

[marsheng]

PS, please tell us more about the data logger you are using, I would like to use one too. I have a 4 channel unit but it does not record temperature relative to the position on the track.



It is a GPX Pro 4. This is one of the best instruments I have ever bought. As an Electronic Engineer I have designed, built, bought many instruments over the past 50 years. This one it up there with the best.

Switch it on, go ride and it picks up the track and then feeds you info. By the second lap, it starts giving me faster of slower LED flashes each time it crosses the finish line and all I do is switch it on. If the start finish line is not correct, you just edit it on the screen.

You can program the unit for different bikes so I use it for the SR500 and Maico.

http://www.xtracing.com/en/gpxpro/index.php

http://www.racesupplies.co.nz/products/xt-racing-gpx-pro-4-and-pro-8/

[marsheng]

More info.

http://www.racesupplies.co.nz/assets/Uploads/XT-Racings-GPX-Pro.pdf

[TZ350]

Great thanks for that.

I added some of Wobs ignition curve comments to my previous post.

[adegnes]

Any ideas for balance factor on a 45ish deegre upside down engine supposed to have peak power at about 15krpm? 50%?
It's vibrating badly and spewing fuel out the carb vent and overflow, event hough the carb is rubber mounted.


http://youtu.be/CpZVKVwfG0Y

[marsheng]

Any ideas for balance factor on a 45ish deegre upside down engine supposed to have peak power at about 15krpm? 50%?
It's vibrating badly and spewing fuel out the carb vent and overflow, event hough the carb is rubber mounted.

I've been playing with balance factors and have had little success.

What I have found is that sometimes adding a head brace reduced the vibrations, other time, removing the front engine mount !! Both made quite a big improvement.

I do know that the Aermacchi 350 which had a horizontal mount had a 20% BF

My guess is some where in between. Say around 35-40%.

It also depends on the frame design as well, not just the motor.

Cheers Wallace

[wobbly]

Yes, the further forward the cylinder is tilted from vertical the balance factor should be reduced.
Engines that are around 30* tilted drop to 35 to 40 %, so my guess for a 45* tilt would be 30 to 35%.
What you are trying to achieve is the minimum vertical shake component that is felt the worst by your hands
on the bars - horizontal shake is no where near as annoying to the riders parts that contact the chassis.

[adegnes]

Thanks guys!

[F5 Dave]

Well I'd dismissed the Sutter project as a bit of folly, interesting toy for the wealthy perhaps. But in a fit of work time blues I bought a PB and an unhealthy lunch to take my mind off. Not usually a tomb of decent technical writing since JR departed this mortal coil. But the fuel injection points were interesting and next progression is direct injection and then traction control.
The chassis evolutionary path that also took place at the time the 500s phased out was interesting too.

What has this got to do with buckets? Well nothing really but it made for a decent lunch read. I'll cough my way through the rest of the mag but it will probably be a skim read at best.

[husaberg]

I've been playing with balance factors and have had little success.

What I have found is that sometimes adding a head brace reduced the vibrations, other time, removing the front engine mount !! Both made quite a big improvement.

I do know that the Aermacchi 350 which had a horizontal mount had a 20% BF

My guess is some where in between. Say around 35-40%.

It also depends on the frame design as well, not just the motor.

Cheers Wallace


I have found the same thing with Head steadies, also the frame material as well as the design makes a difference, For instance CR500's vibrations are felt much more with the Alloy frame than they do in the original steel chassis. whether its is stiffness or resonance or design (or both) I am not sure. But a lot of old British twins had different balance factors depending on the frame they were mounted in.
Also some older bikes also have oversize engine mounts that make maters worse.

[adegnes]

Are there any supplementary "tricks" for minimizing carb vibration and fuel frothing?
Are horizontal shakes better than vertical for the carb too?

Hmm... The vibrations may have gotten worse after I restricted the sideways movement in the engine mounts to eliminate flying belts.

[husaberg]

Are there any supplementary "tricks" for minimizing carb vibration and fuel frothing?
Are horizontal shakes better than vertical for the carb too?

Hmm... The vibrations may have gotten worse after I restricted the sideways movement in the engine mounts to eliminate flying belts.

Kevin Cameron discussed (An itailian ducati tuner I can't think of his name edit later it was Actually Gordon Jennings own Aermacchi 250 :laugh:) in TDC 1. He was using lead weights on remote float bowls on Ducatis etc. The fuel was vibrated away and formed foam with air at certain frequencies. The theory was to tune to a complimentary frequency or harmony by trail and error much it like a guitar or piano.
I have seen it done with British bikes with TT and GP carbs as well. These generally have a separate mount to isolate them further. from memory the square matchblock float chambers are worse but they may have a pivoting float rather than a pole slider float valve.
(Note the pommy bikes had solid mounted carbs as did the Jenning Macchi.)
Maybe you inlet rubber is just too hard.

[adegnes]

Kevin Cameron discussed (An itailian ducati tuner I can't think of his name edit later it was Actually Gordon Jennings own Aermacchi 250 :laugh:) in TDC 1. He was using lead weights on remote float bowls on Ducatis etc. The fuel was vibrated away and formed foam with air at certain frequencies. The theory was to tune to a complimentary frequency or harmony by trail and error much it like a guitar or piano.
I have seen it done with British bikes with TT and GP carbs as well. These generally have a separate mount to isolate them further. from memory the square matchblock float chambers are worse but they may have a pivoting float rather than a pole slider float valve.
(Note the pommy bikes had solid mounted carbs as did the Jenning Macchi.)
Maybe you inlet rubber is just too hard.

Tuning carb weight to a different resonant frequency sounds interesting.

My Inlet rubber is pretty soft, at least when warm.

I suppose it doesn't help that my crank is kinda light, and without a flywheel there's not much Inertia to dampen the vibrations. Then there's the steel rotary valve too.

[husaberg]

Tuning carb weight to a different resonant frequency sounds interesting.

My Inlet rubber is pretty soft, at least when warm.

I suppose it doesn't help that my crank is kinda light, and without a flywheel there's not much Inertia to dampen the vibrations. Then there's the steel rotary valve too.

Maybe its too soft?
You could perhaps stick some hose clips on the float bowl, or try sticking on some wheel weights, It can't hurt (unless get hungry and nibble on the lead :msn-wink:)
Do you have a pole slider carb float or a flap valve one?
I am pretty sure almost all the GP bikes that were rotary valve (I think) had poles floats. I muse they were less affected by tilting the carbs)
Wob has also previously mentioned they had problems with he front facing carbs on the BSL500 until they were converted the floats to pole sliders due to the front driving under brakes (and viva versa)

[SwePatrick]

Are there any supplementary "tricks" for minimizing carb vibration and fuel frothing?
Are horizontal shakes better than vertical for the carb too?

Hmm... The vibrations may have gotten worse after I restricted the sideways movement in the engine mounts to eliminate flying belts.

Mount car-tire balanceweight´s on carb.
and have the carb isolated from engine with rubber.

Good luck! :)

[adegnes]

Maybe its too soft?
You could perhaps stick some hose clips on the float bowl, or try sticking on some wheel weights, It can't hurt (unless get hungry and nibble on the lead :msn-wink:)
Do you have a pole slider carb float or a flap valve one?
I am pretty sure almost all the GP bikes that were rotary valve (I think) had poles floats. I muse they were less affected by tilting the carbs)
Wob has also previously mentioned they had problems with he front facing carbs on the BSL500 until they were converted the floats to pole sliders due to the front driving under brakes (and viva versa)



Mount car-tire balanceweight´s on carb.
and have the carb isolated from engine with rubber.

Good luck! :)

It's an Oko pwk, so flap valve, isolated with rubber mount already.
Good idea with the tire weights, I'll try that or something similar and see if it helps. How about less weight, I could try removing the "velocity stack" first to see if that has any effect, maybe stick on a pod filter too.

Does changing the balance factor matter much for the engine, or is it mostly to minimize the "electric" sensation of riding a vibrator?:clap:
What I mean is does my carb/engine care if the vibrations are horizontal, vertical or anything in between?

[adegnes]

Maybe I could attach a rubber piece with some mass to it onto the carb, should act like a damper soaking up the vibrations?
Just like how you dampen drum skins with tape and other stuff to remove unwanted frequencies.

Frits, do you remember what balance factor was used in the Rumi?

[Frits Overmars]

Maybe I could attach a rubber piece with some mass to it onto the carb, should act like a damper soaking up the vibrations? Just like how you dampen drum skins with tape and other stuff to remove unwanted frequencies.
Frits, do you remember what balance factor was used in the Rumi?No I don't. But for the balance factor it doesn't matter if the cylinder is pointing up or down. All that counts is the deviation from horizontal (and the way it is mounted in the frame, and the frame's stiffness and inertia in horizontal and vertical directions).

About the various float guidance systems: In the Aprilia disk-valve racers the floats were pole dancers. Mikuni also employed pole dancers, though their carbs did not appear on disk-valvers. Keihin used hinged floats on their Honda works carbs.

[adegnes]

No I don't. But I think for the balance factor it doesn't matter if the cylinder is pointing up or down. All that counts is the deviation from horizontal (and the way it is mounted in the frame, and the frame's stiffness and inertia in horizontal and vertical directions).

About the various float guidance systems: In the Aprilia disk-valve racers the floats were pole dancers. Mikuni also employed pole dancers, though their carbs did not appear on disk-valvers. Keihin used hinged floats on their Honda works carbs.

Ok, thanks anyway!

I'll tear down the engine and check what the factor is now, then go from there. (read: balance it to what wobbly suggests)

[AndreasL]

Ok, thanks anyway!

I'll tear down the engine and check what the factor is now, then go from there. (read: balance it to what wobbly suggests)

Note to self 2: Check balance factor of the new Rito crank.

Thanks for the reminder adegnes.

[karter444]

Wobbly
kartsport NZ have just made the latest CIK muffler compulsory for anyone running a KZ2 regardless of the year the pipe and engine were homoligated . The importer of the mufflers is giving 2 options for sale a mid range and a top end muffler . I would have thought that if a pipe is designed correctly with the correct stinger dimensions then the muffler should not have any impact on engine performance .Am I correct in thinking this ??
cheers

[wobbly]

Ha ha, an assumption is usually an error waiting to be revealed.
On a KZ2 the muffler core/stinger makes a huge difference.
There are ( or was ) 2 types, those with the perf slightly larger than the stinger OD ( what I would call a normal type )
and another that had a perf around 40mm ID.
The big core muffler is identical up to peak power, but past 13,000 the power curve simply flattens out, without diving off into a vertical line
at say 14000.
By using thin inserts in the front of the stinger, and varying the length of stinger inside the muffler core I gained nearly 25 Hp at 14,000
ie it was 15 Hp that became 40, rolling down from a 47.8 Hp peak.
Its legal also to machine back the spigot face of the cylinder to shorten the pipe, if you happen to want it to spin the 15,000 - who wouldnt.

[MotleyCrue]

By using thin inserts in the front of the stinger

Cool, can you describe what you are referring to.

[wobbly]

OK, so here is a sketch in the style of DaVinci.
I varied the insert ID in 0.2mm increments,balancing the power output with deto level and jetting on the dyno.
There are 2 stinger sizes available, I started with the larger size, and this tube with the step formed by the insert makes more power than does
the smaller tube stinger on its own.

[husaberg]

No I don't. But for the balance factor it doesn't matter if the cylinder is pointing up or down. All that counts is the deviation from horizontal (and the way it is mounted in the frame, and the frame's stiffness and inertia in horizontal and vertical directions).

About the various float guidance systems: In the Aprilia disk-valve racers the floats were pole dancers. Mikuni also employed pole dancers, though their carbs did not appear on disk-valvers. Keihin used hinged floats on their Honda works carbs.

Right you are with the Keihins, some further pics of the NSR500's.
I do wonder though if the float pivots were mounted the other way around to close off on hard braking.
I can't remember if they were $25,000 or $100,000 US

I will post Wobs Quote (when I find it)
320274320275320276320277320278320279

I found it

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130134206#post1130134206

The air solenoids on the RGV/RS250 type Keihin carbs are there for emmission and air fuel correction at part throttle settings.
One feeds air into the primary circuit to lean off the mixture at just off idle conditions and the second one feeds air into the emulsion tube to lean off the mixture at higher rpm/part throttle.
The switching points are set by the ECU depending upon rpm and TPS position.
The F3 race kits blocked these off, and used a different jet setup for high perf usage.

The KR3 had special carbs on a few bikes, as they had nightmares trying to get the Keihins off RS125 Honda to work running around the wrong way.They used a pump around system to keep the fuel level at a constant height.
I finally figured out what was happening when building the BSL.
The floats were being pulled down under hard braking - flooding the bowls.So I had CNC bowls made up with floats from TMX carbs running on rods, instead of pivoting.

This was posted on another thread Turbo CR500
Looks neat
http://sandiego.craigslist.org/csd/mcy/5481564457.html
http://images.craigslist.org/00J0J_dTomNxMsP33_600x450.jpg

[JustHarry]

at a bit of a loss at the moment. :brick:
wallace and i are putting a new ignition onto my kr150 using an ignitech dc-cdi-p2. its only in the testing phases at the moment. idles beautifully, it has a nice clean signal on idle. but when the revs get up a bit the signal is getting a lot of noise and around 6000 the ignition starts jumping between 6000-17000rpm so going on the rev limiter. the way the pick up is at the moment is that its getting a signal off a small hole in the flywheel, probably a balancing hole. so rather than having no signal then a pulse, im getting a signal then a pulse of no signal, is this still good enough way to have it set up?
any reason why the ignition would be jumping up and down the revs so much?
i may not have explained this quite right but its best as i understand it
https://scontent-syd1-1.xx.fbcdn.net/hphotos-xpl1/v/t1.0-9/12801674_934133496694207_8411631668697721271_n.jpg ?oh=51cf9f80f391230049d5018105e81295&oe=575961E6https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-xpl1/v/t1.0-9/12791013_934133540027536_565195957940296706_n.jpg? oh=181dabcad78ab6e6fca589b0a8a95301&oe=5796A50F&__gda__=1464532682_19c350a2dcaf869700c6220659bad50 1
soz for crap pictures it was dark and my phone is shit

[bjorn.clauw.1]

at a bit of a loss at the moment. :brick:
wallace and i are putting a new ignition onto my kr150 using an ignitech dc-cdi-p2. its only in the testing phases at the moment. idles beautifully, it has a nice clean signal on idle. but when the revs get up a bit the signal is getting a lot of noise and around 6000 the ignition starts jumping between 6000-17000rpm so going on the rev limiter. the way the pick up is at the moment is that its getting a signal off a small hole in the flywheel, probably a balancing hole. so rather than having no signal then a pulse, im getting a signal then a pulse of no signal, is this still good enough way to have it set up?
any reason why the ignition would be jumping up and down the revs so much?
i may not have explained this quite right but its best as i understand it
https://scontent-syd1-1.xx.fbcdn.net/hphotos-xpl1/v/t1.0-9/12801674_934133496694207_8411631668697721271_n.jpg ?oh=51cf9f80f391230049d5018105e81295&oe=575961E6https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-xpl1/v/t1.0-9/12791013_934133540027536_565195957940296706_n.jpg? oh=181dabcad78ab6e6fca589b0a8a95301&oe=5796A50F&__gda__=1464532682_19c350a2dcaf869700c6220659bad50 1
soz for crap pictures it was dark and my phone is shit

Hello, never worked with ignitech so I don't know if you can specify the pickup signal composition/puls duration/number of pulses, but I use (as do most I believe) a positive puls trigger like below. Could be quickly verified if you drill the hole through, thread it and use the head of a small bolt for your pickup. (And offsetting the pickup) if there is no embossed surface provided on the original flywheel.
320284


Also, the exposed copper between red wire from your pickup twisted with the yellow one makes for a nice short antenna to pick up HF interference.

[sonic_v]

at a bit of a loss at the moment. :brick:
wallace and i are putting a new ignition onto my kr150 using an ignitech dc-cdi-p2. its only in the testing phases at the moment. idles beautifully, it has a nice clean signal on idle. but when the revs get up a bit the signal is getting a lot of noise and around 6000 the ignition starts jumping between 6000-17000rpm so going on the rev limiter. the way the pick up is at the moment is that its getting a signal off a small hole in the flywheel, probably a balancing hole. so rather than having no signal then a pulse, im getting a signal then a pulse of no signal, is this still good enough way to have it set up?
any reason why the ignition would be jumping up and down the revs so much?
i may not have explained this quite right but its best as i understand it
https://scontent-syd1-1.xx.fbcdn.net/hphotos-xpl1/v/t1.0-9/12801674_934133496694207_8411631668697721271_n.jpg ?oh=51cf9f80f391230049d5018105e81295&oe=575961E6https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-xpl1/v/t1.0-9/12791013_934133540027536_565195957940296706_n.jpg? oh=181dabcad78ab6e6fca589b0a8a95301&oe=5796A50F&__gda__=1464532682_19c350a2dcaf869700c6220659bad50 1
soz for crap pictures it was dark and my phone is shit

That hole needs elongated. At the moment it only represents 5 degree crankangle. Try it at 20 degrees.
Ignitech's pulse rotors have quite a long dwell angle. Have a look on their site.
Actually, 3/4 down this pdf there is a good diagram. http://www.ignitech.cz/en/vyrobky/dccdip2/manual_dccdip2_en.pdf

[sonic_v]

That's a nice compact scope.

What make and model is it?

[Tim Ey]

@Justharry:
Did I get you correct and you run the Ignitech "reversed" with the hole beeing the lobe? Then I would tend to agree - you may need to get it a bit longer and probably deeper, too. Wobbly once wrote the perfect lobe lenght for the ignitech - If I am not mistaken it was 15°? 20°? dont know exactly.

[F5 Dave]

Annnd to save Wob the effort, what plugs are you running? Resistor type?

[Grumph]

I'm reading this as the flywheel having a lobe as usual but it's getting a second unwanted signal from the balancing hole...

Can the pickup be moved further away from the wheel ? Don't know about ignitechs but some of those pickups will work at up to 1mm gap. Might get it out of the interference from the hole.

And Harry - that isn't a very flattering pic of Wallace......

Edit - some clarification needed please wallace. Does the rotor have a lobe ?

[adegnes]

Hefty dyno roller you got there!

[FastFred]

I'm reading this as the flywheel having a lobe as usual but it's getting a second unwanted signal from the balancing hole...

Early on Team ESE had a lot of trouble with ghost triggering from the balance holes and the trigger seeing the rotor magnets. The trigger could see the magnets through the rotors steel shell. Try more gap between the trigger and rotor and run it in an area away from balance holes. If you can, remove the magnets.

[wobbly]

I have found that the input circuit will work fine if the lobe length is at least as long as the magnetized poles diameter.
What you have with a hole is the signal polarity is reversed, this is OK on a late model firmware where it has auto sense, but can be a nightmare to figure
out on older units.
And as ESE found, the trigger can easily sense the magnetic field entering the hole thru the now very thin steel rotor wall from behind,especially as
the pole is directly over the hole.
I have had problems when the balance holes are nowhere near the pole, but still under the trigger body that contains the coil windings.
You can try reversing the trigger leads,but of course you have programmed in a straight line and strobed the firing point on lines marked
on the rotor/stator set to that advance angle - yes ?.
The ECU should trigger off a dropping signal, usually created by the second edge of a lobe.
Having a hole will generate a rising signal off the second edge, so the programming should be changed to suit.
90% of the time erratic timing is caused by RF - and the first question as above, are you are using a 5K plug cap, and a resistor plug as well - yes ?.
You will notice that the trigger wires are at opposite ends of the ECU plug to the coil wires,thus having a nice tidy loom with them all bunched together is asking for trouble,they
should be separated physically as much as possible, as soon as they exit the loom plug.
I cant see in the pic, but I bet the coil power wire is sitting on, or is close to the trigger signal or earth wire running up to the bike off the bench - and of course having
long leads like that are all great parallel aerials for RF injection to the ECU.

[JustHarry]

I'm reading this as the flywheel having a lobe as usual but it's getting a second unwanted signal from the balancing hole...

Can the pickup be moved further away from the wheel ? Don't know about ignitechs but some of those pickups will work at up to 1mm gap. Might get it out of the interference from the hole.

And Harry - that isn't a very flattering pic of Wallace......

Edit - some clarification needed please wallace. Does the rotor have a lobe ?

the pick up is as far away as the mount we have will allow. its about 1-1.5 mm i guess. wallace will proably reply soon enough and clarify what i cant.


I have found that the input circuit will work fine if the lobe length is at least as long as the magnetized poles diameter.
What you have with a hole is the signal polarity is reversed, this is OK on a late model firmware where it has auto sense, but can be a nightmare to figure
out on older units.
And as ESE found, the trigger can easily sense the magnetic field entering the hole thru the now very thin steel rotor wall from behind,especially as
the pole is directly over the hole.
I have had problems when the balance holes are nowhere near the pole, but still under the trigger body that contains the coil windings.
You can try reversing the trigger leads,but of course you have programmed in a straight line and strobed the firing point on lines marked
on the rotor/stator set to that advance angle - yes ?.
The ECU should trigger off a dropping signal, usually created by the second edge of a lobe.
Having a hole will generate a rising signal off the second edge, so the programming should be changed to suit.
90% of the time erratic timing is caused by RF - and the first question as above, are you are using a 5K plug cap, and a resistor plug as well - yes ?.
You will notice that the trigger wires are at opposite ends of the ECU plug to the coil wires,thus having a nice tidy loom with them all bunched together is asking for trouble,they
should be separated physically as much as possible, as soon as they exit the loom plug.
I cant see in the pic, but I bet the coil power wire is sitting on, or is close to the trigger signal or earth wire running up to the bike off the bench - and of course having
long leads like that are all great parallel aerials for RF injection to the ECU.

i will probably see Wallace this evening. we will look into elongating the hole. or maybe putting a different flywheel on as would taking more meta out make the flywheel unbalanced?
yes i have a resistor plug. but whats a 5k plug cap?

cheers Harry

[AndreasL]

Wobbly, or any other with knowledge.

The benefit of a programmable ignition have been proven time and again in this thread.
All being more or less racing engines though.

Is it possible to quantify, roughly, what the benefits of i.e. a Ignitec on a lower reving engine?
Lets say a low tech 50cc peeking at sub 10000.

And as a second thought, how will a relatively low rpm 500 MX bike be effected by the possibilities a adjustable ignition gives? Just set it up with a scaled curve from any other "good" bike and the benefits will be the same?

[wobbly]

A 5K plug cap is a resistor type.
The best is the blue or black soft rubber type by NGK as is used on Jetski's
Any digital ECU must have resistor plugs and cap, as this forms a low pass filter to kill RF from the HT lead to the plug.
An Ignitech will always give unending problems without both - and it will be impossible to use a usb adapter on the RS232 input
whilst the engine is running, the laptop will crash constantly due to the RF hash all over the loom wires.

[marsheng]

Having had a sleep, I have a few options. The pulse really nice and has a sharp rise time of around 80 volts. The false triggering may be the magnets in the flywheel. Funny, it will not trigger on a -ve pulse or if I reverse the pick-up coil. As the pulse is really good, a bit of electronic trickery should tidy it up the noise and make a nice clean signal. I'll post the results.

The drum is very nice, around 700kg and was used to make cardboard. It is that heavy that going through the gears is very similar to riding on the road.

Scope is a Rigol. I was told that it is made in the same factory as HP and this is their own brand name.

http://www.rigolna.com/products/digital-oscilloscopes/ds1000e/ds1052e/

or free shipping

http://www.dx.com/p/rigol-ds1052e-5-6-tft-lcd-50mhz-2-channel-digital-color-storage-oscilloscope-30573#.VuHPUiJP_-s

PS a good video for 125 in Thailand - 402m and 185kph.

https://www.youtube.com/watch?v=THoECJhMSl8

Cheers Wallace

[Yow Ling]

Having had a sleep, I have a few options. The pulse really nice and has a sharp rise time of around 80 volts. The false triggering may be the magnets in the flywheel. Funny, it will not trigger on a -ve pulse or if I reverse the pick-up coil. As the pulse is really good, a bit of electronic trickery should tidy it up the noise and make a nice clean signal. I'll post the results.

The drum is very nice, around 700kg and was used to make cardboard. It is that heavy that going through the gears is very similar to riding on the road.

Scope is a Rigol. I was told that it is made in the same factory as HP and this is their own brand name.

http://www.rigolna.com/products/digital-oscilloscopes/ds1000e/ds1052e/

or free shipping

http://www.dx.com/p/rigol-ds1052e-5-6-tft-lcd-50mhz-2-channel-digital-color-storage-oscilloscope-30573#.VuHPUiJP_-s

PS a good video for 125 in Thailand - 402m and 185kph.

https://www.youtube.com/watch?v=THoECJhMSl8


Cheers Wallace


I have a P2 on a kr150 with no problems, used the stock pick up

[marsheng]

I have a P2 on a kr150 with no problems, used the stock pick up

This is an older bike that has one high voltage coil in the magneto that charges the "CDI" and provides the trigger. Some clever Jap must have designed this system. The while system comprises one wire from the magneto and a 'coil' and a spark plug lead. Nothing else.

[JustHarry]

@Justharry:
Did I get you correct and you run the Ignitech "reversed" with the hole beeing the lobe? Then I would tend to agree - you may need to get it a bit longer and probably deeper, too. Wobbly once wrote the perfect lobe lenght for the ignitech - If I am not mistaken it was 15°? 20°? dont know exactly.
You would be correct we are using the hole as the point for the pick up

[ief]

Any ideas on adding a floor-port with a cylinder fed cylinder to extra feed the boost port I presume?

See it on honda mb's for instance?

[wobbly]

The floor port on an MB has nothing to do with feeding the boost port.
It is just adding intake area not masked by the piston moving up and down in the intake port.
It works the same as Boyesens,but doesn't badly affect the B port duct flow like they often do.
An MB has a good cylinder boost port in that it has proper front and back walls to direct flow, not just a roof and the piston face
like many simpler designs.

[d2t]

So I was bored at lunch today and decided to make a mock-up Ryger-style stepped piston for my dead RM60 cylinder (43mm bore). Of course, it's just a display piece as all of the drawings posted so far have been garbage. It makes me curious if homemade pistons are a viable option for race engines. I normally buy forged pistons but I have a lot of this 6061 aluminum laying around. Could I possibly make my own in the lathe to try different crown shapes or will anything I make just destroy cylinders?
320309

PS - Yes, I know the picture is blurry. My phone doesn't have adjustable focus. And yes, I know the lathe work is bad. I made it by hand. Normally I'd CNC this sort of thing.

[ief]

The floor port on an MB has nothing to do with feeding the boost port.
It is just adding intake area not masked by the piston moving up and down in the intake port.
It works the same as Boyesens,but doesn't badly affect the B port duct flow like they often do.
An MB has a good cylinder boost port in that it has proper front and back walls to direct flow, not just a roof and the piston face
like many simpler designs.

Makes sence, tnx.

Don't have the mb cyl at hand but saw pictures. Anyway, 2 points why they wouldn't work for the litlle tomos then, lol. Making an utterly detuned engine behave like something you want without changing revs seems not as easy as one might think... getting engmod to show it maybe even harder.

Fun none the less :)

[bucketracer]

It makes me curious if homemade pistons are a viable option for race engines. I normally buy forged pistons but I have a lot of this 6061 aluminum laying around. Could I possibly make my own in the lathe to try different crown shapes or will anything I make just destroy cylinders?

320309

Plenty of people have made their own, if you have the alloy and some machining equipment, then its worth a try.... :2thumbsup

[tjbw]

So I was bored at lunch today and decided to make a mock-up Ryger-style stepped piston for my dead RM60 cylinder (43mm bore). Of course, it's just a display piece as all of the drawings posted so far have been garbage. It makes me curious if homemade pistons are a viable option for race engines. I normally buy forged pistons but I have a lot of this 6061 aluminum laying around. Could I possibly make my own in the lathe to try different crown shapes or will anything I make just destroy cylinders?
320309

PS - Yes, I know the picture is blurry. My phone doesn't have adjustable focus. And yes, I know the lathe work is bad. I made it by hand. Normally I'd CNC this sort of thing.

These was some discussion about two-part pistons made by makr that you may find interesting:

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page1433 #21486

He used 6061 and 2024 but suggested that 4032 may be better, this has higher silicon content and lower thermal expansion than 6061.

[JanBros]

Makes sence, tnx.

Making an utterly detuned engine behave like something you want without changing revs seems not as easy as one might think... getting engmod to show it maybe even harder.

Fun none the less :)

if you find any tricks, please share. I'm trying the same thing with a Honda Sky moped for motorcross and I to can hardly increase the rev's (max about 8.500-9.000 rpm).
curently using 180/130° timings, squish area of 50%, compression of 11.7 and managed to keep the same bottom end, and better from 30km/h (haven't got a dyno, use a GPS tracker for comparisons) and gain 12km/h on top speed.

fun indeed, and very cheap :D

[d2t]

These was some discussion about two-part pistons made by makr that you may find interesting:

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page1433 #21486


Thanks. I read that post some time ago and completely forgot. There's so much info on this thread that it's hard to keep track. Somebody really should organize this into a book or at least make a contents page (with links).

Also, in regards to all this ignition wiring talk... I should mention that there might be some benefit in wrapping your own coils. I have friends who race electric RC cars and many of them will vary the amount of windings or the gage of the wire to perfectly fit the power output desired (while trying to prevent those little DC motors from overheating). The same goes for converting your crank rotations into electrical current. If the coils are wound more than what you require for power generation, I'd imagine you are sacrificing some hp into wasted magnetic resistance. Some time ago I added an extra pickup coil to my KX85 to power a headlight. I never had it dyno'ed but I'm pretty sure it cost my engine a fraction of hp. Probably pretty small but everything counts at the track.

[ief]

Gaining top speed wasn't to hard (with upping the revs ofcoarse but managable) and I think a better exhaust wil make a huge difference as wel but it's the low end I'm strugling with. There is a huge difference in running cold and warm/ hot (AC) and I'm trying to figure out how to minimize that without different cooling but by changing port timing, crancase volume, com etc. Driving away seems to be influenced the most and I can only wonder how things will be in hotter wether. It does do this stock as well but to a lesser degree.

Since my timings are pretty low, even 'tuned' 157 109 I was thinkng maybe higher timings would work giving the piston less exposure time to the heat and longer cooling from incomming mixture and perhaps upping the crankcase volume and softening the reed but engmod doesn't seem to agree, that could be my model tho. How much influence the a/f mixture has in this case I'm not sure, kind of hard carb to deal with aswell since it is the simpelesed of simpelesed dellorto sha but tunable none the less, only have to figure out how it reacts to what (airbox mostly). And only having a but dyno doesn't help things but ah well, fun and games.

I'm not sure how well these bikes would translate to oneanother btw.

[adegnes]

Here you go!


Page 1000

On Page 500, Bucket has links to how Team ESE built their 26, 28 and 31 hp engines:- http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page600)500

And Micks post below is your most useful tool for finding all the other good stuff on the Team ESE (or any) thread, try it.



What F4 or Bucket racing is all about:-





Here are some other very interesting threads:-
Foundry:- http://www.kiwibiker.co.nz/forums/showthread.php/162399-The-Bucket-Foundry/page29
Team GPR:- http://www.kiwibiker.co.nz/forums/showthread.php/150352-Team-GPR?p=1130775246#post1130775246
Frame and Chassis:- http://www.kiwibiker.co.nz/forums/showthread.php/145224-Race-chassis/page38
Chris C's photos:- http://www.kiwibiker.co.nz/forums/showthread.php/153656-Chris-Bucket-photo-thread-Bandwidth-warning/page5
Old #6:- http://www.kiwibiker.co.nz/forums/showthread.php/68694-6/page49
Bucket Lap Records:- http://www.kiwibiker.co.nz/forums/showthread.php/117354-Bucket-lap-records/page8
Photographic History of Bucket Racing:- http://www.kiwibiker.co.nz/forums/showthread.php/167592-A-photographic-history-of-Bucket-racing/page3
Ecotrons engine management:- http://www.kiwibiker.co.nz/forums/showthread.php/159112-Ecotrons-Engine-Management/page5


2T Engine development software:-

Porting Program http://www.porting-programs.com/

EngMod2T http://www.vannik.co.za/EngMod2T.htm

There is an option in "Thread Tools" to download the complete text off this thread.

There are also over 7000 images on this thread, use "Thread Tools" to view them and then click through to the original post about them.

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Page 600 is worth a look at:- http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page600

A Link through to Husaburgs vast library of pictures.





Its worth the visit ......

And there are also over 7,000 images on this thread. Follow the link below and you will find screen shots of the process.



Blowdown STA (Specific Time Area) is everything and determines the RPM ceiling and power output of your motor.

Optimum Exhaust Port Duration is 190 deg but blowdown STA requirements may force you to use a longer exhaust duration.



Wob often refers to the vital dimensions and Frits posted a diagram of them. Stick to these %%% to get good results.

301223
Frits suggested design criteria for a good pipe.

301224

Click on Husabergs link to read about transfer port angles.



Transfer Ports. Low and Wide is the go….



The 135mm inlet tract length from tip of reed to carb bellmouth rule of thumb.



302659 Frits's version of a short carb setup.



A lot of the decade pages have collections of quotes and links to other interesting things.

Page 990 Blowdown STA, Ex porting plated cylinders, port layout and port angles.
Page 980 No links list but there is talk about spark energy and EGT
Page 970 Fuel - Oil and EGT talk
Page 960 Wob - Fuel and Oil Talk and Crank inertia.
Page 950 Its all about exhaust blow down …..
Page 940 Fixers 50cc adventures – ports & heads – Wob talks about Bad Gas.
Page 930 Frits 50cc pipe – Husburgs large links list, parts books, steering head brgs
Page 920 Big links list, allsorts. Tokoroa GP videos.
Page 910 No links list but the page is about fitting a 12V generator stator.
Page 900 Frits thoughts on O2 sensors – EFI Fueling theory – Wob on EGT
Page 890 DIY Foundry tips – EFI data – Detonation Management (tec paper) – more EFI
Page 880 Big list of Flettners Foundry posts and pictures.
Page 870 YZ & Bighorn Dyno results – Dyno Vids and EFI talk
Page 860 Air cooling and ducting and Carb air inlets, next page Greymouth Race
Page 850 1st run of the EFI Beast
Page 840 Husaburgs big links list on Power Jets – High temp epoxy and Ex port dam.
Page 830 Plugging piston pins – Cyl Heads (no radius) and Plug to Piston distance.
Page 820 Det sensor & Ignitec setup – Exhaust port dam – Boost Bottle – Insulating Paint
Page 810 Links – about Razing the Exhaust port floor
Page 800 Link to dyno graphs for the YZ & BigHorn EFI Bikes & a lot of EFI stuff
Page 790 Car & bike museum pics _ Wobs pipe.
Page 780 Setting up an IgniTec DC-CDI-Race-2 ignition – Big list of links.
Page 770 Wobs views on triple ex ports – first run of the EFI YZ250
Page 760 Port Angles – lots of Pipe design info – Fast model aero engine.
Page 750 Case Com – Basic 2T tuning – BigHorn EFI
Page 740 Case Vol – Deto – Inlet Length – Over rev deto.
Page 730 Pipes – Deto – Lambda – Temp probes – CrankCase CR – Variable headers.
Page 720 Inlet tract length – GP125 service manual – Picture of how to read a plug + Wobs comments
Page 710 Fuel and Power Jets - EGT and CHT - Crank build
Page 700 Talk about wide and low transfers – Case volume and dyno graph – det and Lambda sensors.
Page 690 Pipe talk and ideas about making mufflers.
Page 680 Talk about the Trombone pipe and more of Frits and Wobs views on pipes.
Page 670 Pipes – blowdown STA numbers – Trombone pipe.
Page 660 Lots of links on pipes – Ariel Arrow – and CVT
Page 650 Links – Frits and Wobs views on pipes – CVT transmissions – 30 vis 24 carb dyno graph
Page 640 Links to Wobs views on pipes – crank balance factor – connecting a laptop to the Ignitec
Page 630 More of Wobs views on pipes – Frame & wheel weights – correct O ring grove sizes
Page 620 Links to Cooling Water Flow – Case Comp and Pipes – Setting up 2T carburation.
Page 610 Simulation packages – combustion efficiency – transfer ducts – chamfered exhaust top edge.
Page 600 Books that can be down loaded and Frits talks about why 190 Ex duration is so good.
Page 580 No links but page is about mounting carbs and the 24mm pumper carb & 28hp dyno graph.
Page 570 No links but the page talks about carburation – emulsion tubes and pilot jets.
Page 560 No links, the page is mostly about 96 vis Av gas with dyno test.
Page 550 No links list but the page is mostly about TZ400 build and cranks and rods.
Page 540 No links, the page is mostly about Wobs success with the 400 project.
Page 530 Ignition – setting up det sensors without a dyno – wings inside reed valves – poly quad head
Page 520 Mostly about what some wheels weigh, ATAC valves and crank stuffers.
Page 510 Bucketracers general Links List
Page 500 Bucketracers links list of how to make a mid 20’s hp Suzuki GP125



pit-lane.biz is another really good thread:-

http://www.pit-lane.biz/f34-gp125-et-250-snif (http://www.pit-lane.biz/f34-gp125-et-250-snif)

http://www.pit-lane.biz/t5121-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-4

http://www.pit-lane.biz/t4072-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-3-locked

http://www.pit-lane.biz/t3173-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-2-locked

http://www.pit-lane.biz/t117-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-1-locked



NSR250 suspension tuning:- http://nsr-world.com/tuning/250-tuning/suspension/

NSR250 Engine Tuning:- http://nsr-world.com/tuning/250-tuning/engine/

Ed Tuck racing (NSR250):- http://edetuckracing.blogspot.co.nz/...5-pistons.html (http://edetuckracing.blogspot.co.nz/p/fitting-rm125-pistons.html)

http://www.twostrokeracelab.com/

http://www.2strokers.com/index.php?topic=184.0

[seattle smitty]

An MB has a good cylinder boost port in that it has proper front and back walls to direct flow, not just a roof and the piston face
like many simpler designs.

For possibly the ultimate in IM-proper ports, you should get to see a late-Sixties/early-Seventies Johnson/Evinrude outboard triple of 55-60hp, maybe that company's first loop-scavenged engine: very big bore and short stroke (and short rods) with the two big transfers (the 55hp) and the equally-large boost port (the 60hp) looking like they were just scooped out of the cylinder walls; could make you barf!! But OMC sold them in huge numbers for years, even with a factory racing version.

[adegnes]

Here's a different approach to getting the crank's balance factor right:

http://www.accessnorton.com/balance-factor-test-t16773.html

[Frits Overmars]

Here's a different approach to getting the crank's balance factor right:
http://www.accessnorton.com/balance-factor-test-t16773.html
Made a jig with a tiny brass tube superglued & taped to a heavy block, set it on a jack stand next to the Norton 750 motor. Inserted a 1/32 wire sharpened to a needle point.
Taped a piece of sheetmetal to the timing cover. My motor is now balanced at 65% wet (72% dry) in solid featherbed frame.
Sat on the bike with brakes on & revved it to 6000 while my wife Beth pushed the sharp wire against the sheet metal.I used to fit a piece of wire somewhere to the bike and watch in which plane it vibrates as the engine slowly climbs through the revs, but your scratch method is nice.
I may have to borrow your wife though.
My motor is now balanced at 65% wet (72% dry)What do you mean by wet and dry?

Your scratch circles may be a good indication that the vibrations are equally strong in vertical and horizontal directions. But is that what we want? Horizontal vibrations are less disturbing to the rider, so you would have to go for horizontally-elongated ellipses. And then the question remains: how severely elongated?

[adegnes]

I used to fit a piece of wire somewhere to the engine and watch in which plane it vibrates as the engine slowly climbs through the revs, but your scratch method is nice as well. I may have to borrow your wife though.What do you mean by wet and dry?

Your scratch circles may be a good indication that the vibrations are equally strong in vertical and horizontal directions. But is that what we want? Horizontal vibrations are less disturbing to the rider, so you would have to go for horizontally-elongated ellipses. And then the question remains: how severely elongated?

I should probably have said; Here's one approach to visualizing the balance factors effect on directional vibration.

I just provided the link, not my work and not my wife.

I think these cranks are oil filled in some way.

[Grumph]

I think these cranks are oil filled in some way.

The pin has quite a large reservoir which on a std Norton crank may hold about 30ml of oil.
Some aftermarket ones may hold more.

[jfn2]

Wobbly:
What is the best way to contact you? I would like to send some pictures for you to look at. I have tried to pm you but for some reason I can't get it to work. Thank you very much.

[husaberg]

Wobbly:
What is the best way to contact you? I would like to send some pictures for you to look at. I have tried to pm you but for some reason I can't get it to work. Thank you very much.

You need to post a few more posts to receive further site privileges
You can respond to his pm if he was pm's you though.
Also you can't attach images to a Pm unless they are hosted elsewhere.

[AndreasL]

Upps... I believe I just bought me self a KTM 200 SX.
A real bastard with mixed parts from all over the place.

Or if you're kind, a -06 125 with a 200 kit and upgraded suspension.
More then I can handle any way.

I have som vague memories about someone having run one in EngMod.
Not that I have any plans to modify it, but some sims could be fun.

[F5 Dave]

They wheelie nice and are quite fun. Keep the tyres sharp and don't forget to put oil in the gas. Thats it. Step away from the porting tools.

[ac3_snow]

Want to say thanks very much to Chambers and TZ from ESE who between the two of them brought 5 50's down for the F5 GP over the weekend. Wicked effort and fantastic to have so many angry little engines screaming around the track! We had 12 entries only one of which was a 4 stroke.
Cheers again for the ride :niceone:
<a data-flickr-embed="true" href="https://www.flickr.com/photos/sonscc/25684989021/in/album-72157665931978555/" title="_MG_5296"><img src="https://farm2.staticflickr.com/1644/25684989021_1689de4701.jpg" width="500" height="333" alt="_MG_5296"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
<a data-flickr-embed="true" href="https://www.flickr.com/photos/sonscc/25685558961/in/album-72157665931978555/" title="_MG_5038"><img src="https://farm2.staticflickr.com/1718/25685558961_8028ff2fea.jpg" width="500" height="333" alt="_MG_5038"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>

[Frits Overmars]

Looking at the above pictures I noticed that in all cases the transponder is fitted at the front fork as unsprung mass.
That is not very good for roadholding and very bad for the transponders themselves. They really don't like the shaking.

[Sketchy_Racer]

Looking at the above pictures I noticed that in all cases the transponder is fitted at the front fork as unsprung mass.
That is not very good for roadholding and very bad for the transponders themselves. They really don't like the shaking.

Have to run them low to trigger the timing loop on the kart tracks. We run them on the upper fork leg in the "big bike" classes.

[ac3_snow]

Have to run them low to trigger the timing loop on the kart tracks. We run them on the upper fork leg in the "big bike" classes.

Normally we would have them on the upper fork leg as well. For some reason that track has terrible interference, only thing we can put it down to is the airport?
Much better this time around with our own loop, but the GP wasn't the right time to start experimenting with different transponder locations.

[MotleyCrue]

Any more news on Ryger engines ? Have they shown up at any events recently ? I heard LucF was going to have update info but I skimmed through several pages in this thread and dont see anything.

[Muciek]

Nope, nothing new.

[adegnes]

Tried weighting the carb down with an old bicycle inner tube, thinking that it would provide some dampening too. Didn't help much.
Raised the bowl fuel level, no better.
Suddenly it quit firing. Pulled the plug, here's what I found:

320456320457

Looks like aluminum to me.
Thought; ah crap, holed piston....but there's still compression and it fired right up again with a new plug and fuel in the tank.
Yep, stupid.

I'll pull the head to take a look at the piston, hope it hasn't shared to much of itself...

Could detonation be why it doesn't want to rev past 12-13k? It just starts sputtering with occasional pops out the carb.

[Frits Overmars]

Tried weighting the carb down with an old bicycle inner tube, thinking that it would provide some dampening too. Didn't help much.Maybe because that old inner tube doesn't weigh much. Rubber can be used to attach two masses to each other without transmitting too much vibration, but it won't absorb vibration in itself.
Try increasing the mass of the carb by sticking on some rim balance weights. That will lower the vibration frequency.
Maybe that is what your setup needs, maybe it will worsen the problem, in which case you'll have a good clue where to look.


Could detonation be why it doesn't want to rev past 12-13k? It just starts sputtering with occasional pops out the carb.I doubt it. Did you try the old trick of establishing whether the problem is ignition-related by narrowing the plug gap?

[wobbly]

Frits is on to it, drop the gap to 0.4mm say and try it.
What ignition is it running - and why are you running a lawnmower plug in a race engine.
Get a R7376 in there, this will be of great assistance if the CDI is marginal at high rpm/power.

[adegnes]

Maybe because that old inner tube doesn't weigh much. Rubber can be used to attach two masses to each other without transmitting too much vibration, but it won't absorb vibration in itself.
Try increasing the mass of the carb by sticking on some rim balance weights. That will lower the vibration frequency.
Maybe that is what your setup needs, maybe it will worsen the problem, in which case you'll have a good clue where to look.

I doubt it. Did you try the old trick of establishing whether the problem is ignition-related by narrowing the plug gap?


Frits is on to it, drop the gap to 0.4mm say and try it.
What ignition is it running - and why are you running a lawnmower plug in a race engine.
Get a R7376 in there, this will be of great assistance if the CDI is marginal at high rpm/power.

Ok, more weight it is!

My plug was gapped to 0.4mm...
Ignition problems seems likely, with a standard br10es it wont go past 8k.
I'm running a PowerSpark ignitionhttp://www.power-spark.de/index_en.html. They claim 30000rpm and constant ignition energy etc. but yeah, starting to doubt it.

Could be time to order an ignitech, as I probably should have in the first place, I'll see what the r7376's can do for me first.

I just aquired this ignition tester "IgnitionMate", reading through the manual atm, maybe it can shed some light on whats going on.

320458

Thanks!

[adegnes]

Hooked in the ignimate and fired up the bike.
The "spark" scale(amperage maybe?) had consistent high values all the time, not so with voltage.
At idle close to 10kv, falling to around 4kv at 7k. Could only do a short test cause it's late and I don't want to piss off the neighbors.
I think we've got our problem...

[TZ350]

2016 Tokoroa GP ..... page 1


GP Boneshaker...


https://youtu.be/8EwKlNBTgsc

Tokoroa GP


The results of the 2016 Grand Prix from Tokoroa are now up on mylaps. You can see them here:-

http://www.mylaps.com/en/events/1241354

Between myself, my Australian mate Ian who flew over from Sydney for the meeting and my mate Jason who was also riding in FT, we took about a million photos. I was up late processing and uploading them for your viewing pleasure. You can check them out here:-

https://www.flickr.com/photos/sonscc/albums/72157665931978555

A massive congratulations to Nathanael Diprose who once again took out the double winning both the F4 and F5 Grand Prixs. Nathaniel also posted two new lap records: F4 41.530s and F5 43.827s which are both far quicker than previous records. The pace was hot in the top 10 with a stacked field of very well prepared bikes turning up from around the country. Caleb Adlam was impressively riding out of his skin, however Nathaniel's consistent fast laps were unmatched. Solid riding mate, having been on a very well sorted bike myself and to still be blown out of the water impressed the hell out of me, the bar is set very high.

F5 was very tight for most of the race with Glen Skachill hot on Nathanael's tail, dipping into the 43s bracket in pursuit. Glen "gave it everything he had" out there but couldn't break Nathanael's momentum. Rick Ford rode the 'Factory' ESE 50 to third place having only been on the bike a handful of times. Congratulations Rick in being the only person to podium in all bucket classes over the years - F4, F5 and Sidecar.

Congratulations Chris Lawrence and Scrivy for claiming the NZ Sidecar title from Rick and Henk this year in a very close and entertaining battle to the end closely followed by Mel and Brian.

And finally congratulation to all 29 riders who turned up to contest the Formula Tokoroa race! Kyle Hammond showed his experience to come through from 12th on the grid and win (burgle) by a massive 28 second lead. Steven Lee and Blair Lambarth took out second and third place with solid and consistent riding. New comer and promising talent Jason Haselden qualified on pole but crashed after 4 laps (his first bin) showing the level of enthusiasm in the field. There were a number of riders who definitely picked up enough pace to make their way into the GP, I believe Mel came around to let you know, we look forward to seeing you there next year! Cheers Chris


Video of the start of Formula Tokoroa from the weekend. 28ish bikes plunging into turn one. What a beautiful sight it is to see so many bikes turn up. The future is strong.

https://www.facebook.com/groups/1623256484603284/permalink/1656612371267695/


The youtube channel xjet has a quadcopter-view video of the 2016 Formula Tokoroa meet!

https://www.youtube.com/watch?v=zpUHZiPk_8M

I've noticed that this guy flies his RC planes at the airfield next to the track, was only a matter of time before he recorded a bucket meet.


Tricycles.;)


https://youtu.be/OSahIJXsuGQ

and some random Team GPR pictures.

320465320466

320468

The mighty Team GPR 125cc air cooled two stroke with a hidden secret.

320467

Inside the air scoop is two high powered fans, these worked well and if the bike had a generator it looks like the fans would have been able to keep the engine temperature more reasonable for the whole race, clever idea.

320470

Another interesting bike in the Team GPR pits was this FXR, interesting because the young fella that built it was able to make a very competitive bike for $1500 and that included buying the original road bike. He did very well, and was more than a match for most when he was out racing on this bike.

320469

And elsewhere in the pits I found a fuel injected Yamaha R15. The 150cc R15 engine slotted very neatly into the SDR rolling chassis.

[TZ350]

2016 Tokoroa GP ..... page 2

320503320504

Tims very neat looking 50 with a second radiator hidden in the tail.

320501

Nicks 50.

320502320499

Rogers and Andrews 50's

320500

The mighty Team GPR 50.

[TZ350]

2016 Tokoroa GP ..... page 3

320507

The only 4 stroke in the F5 GP, it went pretty well and is an easyish conversion. Take a FXR150 rolling chassis and fit a Honda 100 engine. Easy to ride and goes pretty well.

320505

Richbans 50. MC21 rolling chassis and Derbie engine. I thought a 50cc engine would be lost in the NSR250 chassis but it does not look out of place.

320506

This one was put together by Chambers and peddled to third place by Rick. Second place was taken by Glen riding F5Daves 50 and first of course was Nathaniel on his dad's 50.

320509320508

A couple of 50's that have oversize cylinders so they can run in F4. Rods very fast Aprilia and Rogers very neatly prepared bike, I am not so hot on makes and models, but I think it was originally a NSR50

320510

This F4 2T really interests me because it has the stinger for the muffler coming from the center of the dwell section of the expansion chamber instead of the end of the reverse cone as is traditional done, works well.

[TZ350]

2016 Tokoroa GP ..... page 4

320514

After a bad start in the GP the rider of this bike was cutting his way through the field in commanding style. Untill he was unseated coming over the brow of the hill. Somehow the bike righted itself and continued on riderless for some distance down hill.

320513320511320515320512

Some of the other F4 2T's

The GP was won by a very smooth and consistently good rider on a 2T. Second and third were 4T's with 2T's scattered through a very strong field of 4T's.

On board video from the four stroke 4T that eventually finished on the podium. The bike was built by Scott and ridden by Chris for the race.

320516


Some on board from the racing. The good bits start at about 6:45 and I finally get past Regan and into 3rd place at 9:20. I had a bit of a crap start really, running the wrong gear and stuffing up lines until I set into a rhythm. Still fun and quick enough to claw back Regan. The race was 40 laps long so I cut out a bunch of sections where I'm riding by myself to fit within Youtube's 15 minute video limit.

After looking at my GPS timer, i got just over 100km at the end of the straight and was way way way to slow through the final corner at about 38km/hr mid corner, sigh. Probably after crashing there last year riding my FXR on the bumps. Theoretical fastest time was a 42.2 compared to my actual 42.599 which shows my consistency was off. I'd love to have another crack at getting into the 41s with more practice time but I'm sure there's a line from here to the GPR door with people looking for a factory ride! hahaha


https://www.youtube.com/watch?v=lpxXgx2Tf7Y

[Yow Ling]

2016 Tokoroa GP ..... page 4

Can only get six photos a page that is why there will be four posts when I have finished tonight.

Ok so you only had a roll of 24 in your camera, pick the prints up from chemist on your way home

[peewee]

Frits is on to it, drop the gap to 0.4mm say and try it.
What ignition is it running - and why are you running a lawnmower plug in a race engine.
Get a R7376 in there, this will be of great assistance if the CDI is marginal at high rpm/power.

wob them r7376 are expensive buggers at $35 or so. what advantage will they have over a br8eg ? also the ground strap looks real thin. does it easily melt off ?

[wobbly]

The R7376 has a fine wire Iridium center electrode, same as cheap EIX plugs.
But the similarity ends there.
It has a special ceramic composition that wont crack and drop lumps into the cylinder at the first sign of deto shock like an EIX.
The ground strap is also a fine wire ,made of platinum - and it wont melt in a nuclear explosion, let alone your seizing cylinder.
This is then expensively laser welded onto the shell, so that wont fall off like those of an EIX or EGV do all the time.

The fine wire combination needs way less voltage to ionize the spark gap, and the resultant flame kernel is way bigger than a normal fat wire plug.

You will soon learn to read the ignition advances effects/tuning by the color change position of this ground strap.
An lastly the resistor element is of a high quality - unlike the other plugs that go open circuit regularly using high power DC DC ignitions.

They are the exact same nose configuration as the shorty race plugs for a HRC RS125/250, but are 1/4 the price, and use a normal plug cap
not the special NGK ones that cost more than the race plugs do.
But the absolute best part - they are worth up to 2 Hp over a BR10EGV in a race 125 engine, seen it dozens of times in all manner of engines.

I posted a dyno sheet on here of a 50 Hp 125 example, ages ago.
Would have to be one of the best detail tuning finds I have seen,ever.
Dont fuck about, there are no excuses,they are bulletproof,just use them.

Looking at a good race CDI on a scope they usually have around 30KV as the gap is being ionized, this then drops to around 12-15KV during the "burn " period.
The rpm should not matter at all.

[JanBros]

The R7376 ...

there are many different R7376's, like ***-10, ***-8, ...

do the 8/10/... correspond to the normal grade of plugs, meaning is the R7376-10 the correct replacement for a BR10ES ?

[peewee]

i think the 7,8,9,10 etc just indicates the heat range just as it does for other ngk plugs

[sispeed]

Thanks to all for the thread an all the information in it. I enjoyed reading for days.
Nearly 1500 pages is great.
10 or what ever number on a NGK plug means the heat range. Whatever type it is.
Ok and I break English, so sorry for the spelling
Siggi

[wobbly]

Yep, the number is the normal heat range as for other plugs.
I might add that I doubt a power increase would be seen in a scenario where the power level is low, a huge spark from a good DC ignition or a better spark from a good plug may make no
difference at all.
But in a marginal situation the fact that the plug makes an easyer time for the ignition - it may get rid of a misfire,and thats a big power increase.
When enough is enough is enough.

[TZ350]

there are many different R7376's, like ***-10, ***-8, ... does the 8/10/... correspond to the normal grade of plugs, meaning is the R7376-10 the correct replacement for a BR10ES ?

320471320492

There can be a number like "10" at the end of the NGK plug code and this denotes the pre-set plug gap.

For a NGK BR9HS-10 the "10" here means a pr-set gap of 1mm and the plug is a "9" heat range and for a R7376-10, maybe the "10" also means the R7376 also has a pre-set gap of 1mm???


The number for the R7376-8 or R7376-10 does not mean the gap. This number means the heat range.
TZ is right there might be a number at the end that specifies the gap but this is the heat range
http://www.ngk.com/product.aspx?zpid=26333

Thanks Sispeed, so NGK racing plugs have a different numbering system....

320493

Apparently there are also fake NGK plugs, here is a link to distinguishing between real and fake NGK plugs:- http://www.slideshare.net/athangal/distinguishing-fake-ngk-spark-plug

[cotswold]

Yep, the number is the normal heat range as for other plugs.
I might add that I doubt a power increase would be seen in a scenario where the power level is low, a huge spark from a good DC ignition or a better spark from a good plug may make no
difference at all.
But in a marginal situation the fact that the plug makes an easyer time for the ignition - it may get rid of a misfire,and thats a big power increase.
When enough is enough is enough.

I am just converting my NSR50 to a 10mm plug, the bike with the crappy Honda head made 13.9hp on TZ's dyno, I am struggling to find a good plug in 10mm for less than $80 which is divorce material.
Wob which plug should I be looking at for this scenario ?? I have bought a couple of Iridium plugs but after reading what you said about them dont fancy using them.
Using a PVL ignition

[ken seeber]

Frits, Wobbly and any other clever dudes,
Is anyone aware of using a significant cylinder offset relative to the crank centreline, sometimes called deSaxe(?).
I know that this is used in some current 4 strokes, but I am thinking obviously of modern high performance 2 strokes. I do remember that someone (Jan Thiel I think) said that they tried pistons and found that any offset, either way, was better than no offset. But this is just piddly stuff, say +/- 0.5 mm, I am thinking of a lot more, say 5 to 10 mm.
The potential advantage being a shorter duration compression stroke and a longer power stroke with more crank leverage.

[wobbly]

Significant DeSaxe gives exaggerated piston port asymmetry, problem is ALL the ports become asymmetric in open/close timing.
Mock it up in SolidWorks or write a spreadsheet exported to a graph to see if its what ( you ) is really needed.

Re the 10mm plug issue, I have done,solved this once before.
Bore thru the plug hole and then press in a tophat insert with some small fins around the OD to suit a "normal " 19mm plug length with 14mm thread.
Then weld the insert in around the bottom and the top.
No plug issues and no heat transfer issues.

[lodgernz]

Re the 10mm plug issue, I have done,solved this once before.
Bore thru the plug hole and then press in a tophat insert with some small fins around the OD to suit a "normal " 19mm plug length with 14mm thread.
Then weld the insert in around the bottom and the top.
No plug issues and no heat transfer issues.


Tim (Cotswold) and I have deliberately made our head inserts with 10mm thread (x 19mm length) for our 50s for reasons of combustion chamber space, but it sounds like you're saying dump them and go back to 14mm.

[cotswold]

Tim (Cotswold) and I have deliberately made our head inserts with 10mm thread (x 19mm length) for our 50s for reasons of combustion chamber space, but it sounds like you're saying dump them and go back to 14mm.

No Roger certainly not, I'm after a plug that wont fall to bits and wreck my nice new head with it's 10mm thread, the last thing I want to do is go back to a 14mm plug. I bought a couple of Iridium plugs (NGK) but Wobbly reckons they will fall to bits, so I am after a suitable race plug in 10mm that costs less than $80 each as I have a wife that will make her feelings very plain if I go buy a box of them. :(

[ken seeber]

Significant DeSaxe gives exaggerated piston port asymmetry, problem is ALL the ports become asymmetric in open/close timing.
Mock it up in SolidWorks or write a spreadsheet exported to a graph to see if its what ( you ) is really needed.

Thanks Wob, yeah I did have a spreadsheet coming on feeling, but I just wondered if anyone had actually given it a go, despite the potential benefits/disbenefits of the resultant asymmetric timing.

[lodgernz]

No Roger certainly not, I'm after a plug that wont fall to bits and wreck my nice new head with it's 10mm thread, the last thing I want to do is go back to a 14mm plug. I bought a couple of Iridium plugs (NGK) but Wobbly reckons they will fall to bits, so I am after a suitable race plug in 10mm that costs less than $80 each as I have a wife that will make her feelings very plain if I go buy a box of them. :(

My response was to Wobbly, not you Tim.
I totally share your feelings. I used a CR9EIX at Tokoroa, and previously at Taumarunui and Kaitoke, with no problems, but I don't trust those plugs.

[cotswold]

My response was to Wobbly, not you Tim.
I totally share your feelings. I used a CR9EIX at Tokoroa, and previously at Taumarunui and Kaitoke, with no problems, but I don't trust those plugs.sorry Roger I read that without my brain in gear

[sispeed]

The number for the R7376-8 or R7376-10 does not mean the gap. This number means the heat range.
TZ is right there might be a number at the end that specifies the gap but this is the heat range
http://www.ngk.com/product.aspx?zpid=26333

[Frits Overmars]

Is anyone aware of using a significant cylinder offset relative to the crank centreline, sometimes called deSaxe(?). I know that this is used in some current 4 strokes, but I am thinking obviously of modern high performance 2 strokes. I do remember that someone (Jan Thiel I think) said that they tried pistons and found that any offset, either way, was better than no offset. But this is just piddly stuff, say +/- 0.5 mm, I am thinking of a lot more, say 5 to 10 mm.
The potential advantage being a shorter duration compression stroke and a longer power stroke with more crank leverage.Jan tried it a long time ago, at Bultaco I think it was, so it must have been around 1976, and he did find what you remembered.
Aprilia RSA pistons have 1 mm offset in the direction of the exhaust port, which is in the direction of rotation for the RSA and against the direction of rotation for the RSW: as far as I know, the same type piston was used in the RSA with rear rotary inlet and forward-facing exhaust, and in the RSW with side rotary inlet and rearward-facing exhaust.
Advantages? I am not aware of any.


Thanks Wob, yeah I did have a spreadsheet coming on feeling, but I just wondered if anyone had actually given it a go, despite the potential benefits/disbenefits of the resultant asymmetric timing.I gave it a go before there were spreadsheets, so it's a real program (the things they call apps nowadays). Hope you can get it to run. It should work in Win-98, maybe Win-XP as well.
320484

If you play with the program, you will notice that enlarging the offset also enlarges the stroke of the piston. So don't overdo it, or you may find yourself with an illegal cylinder capacity :p.

[peewee]

What are you going to use that tank for, Peewee? A motor home ?


frits I never knew there was a motorhome with just 2cylinders running on methanol :killingme. the fuel tank wasn't as easy as I figured it would be and probly the last one I ever do

[Flettner]

frits I never knew there was a motorhome with just 2cylinders running on methanol :killingme. the fuel tank wasn't as easy as I figured it would be and probly the last one I ever do

Peewee, how hard is it to get those tyres? I have a plan for one.

Don't ask about the thermostat housings, I'll get on to them this week. Ish.

[Frits Overmars]

Peewee, how hard is it to get those tyres? I have a plan for one.I can't imagine it flying, so maybe it will have to float. Are you planning a paddle steamer Neil?

[peewee]

there not hard to get but what are you using it for? theres alot of different sizes and scoop configurations and carcass thickness

[Flettner]

I can't imagine it flying, so maybe it will have to float. Are you planning a paddle steamer Neil?

Every year we go to the Aria two day trail ride, and every year they hold what's called the mud run, mostly standard fourstrokes enter. Ususally funny but no one has a real go at it. I was thinking a light twostroke with lots of power and a paddle wheel one for the driven front wheel as well:first:
And a decient belly pan.
Look it up on youtube, Aria mud run.

[TZ350]

Aria mud run .....

<iframe width="560" height="315" src="https://www.youtube.com/embed/YLByut17Vjw" frameborder="0" allowfullscreen></iframe>

[peewee]

skatrak is what I always use but theres a few other brands. chengshin has some motorcycle sized paddle tires that are fairly inexpensive. ebay might have some used ones, otherwise this is probly the cheapest http://www.chaparral-racing.com/product/cheng-shin-p-c7220-surge-paddle-rear-tire/368-1360.aspx

[ken seeber]

. I was thinking a light twostroke with lots of power and a paddle wheel one for the driven front wheel as well:first:
.

Turns out the F1 was all 4 strokes, so had some time to help Neil with the design. No charge. :niceone:

320564

[TZ350]

Now that my new bike is nearly ready I need to develop a new Alpha-N fuel injection map. The axis's of an Alpha-N map is throttle position TPS and RPM. The steps between cells need to be in even steps. That is not even RPM or TPS steps but even changes in engine load.

"Torque" is largely related to the motors Trapping Efficiency of the air passing through it.

"Delivery Ratio" is everything when it comes to quantifying airflow through a two stroke motor and it is the air flow that needs fuel added to it in the correct proportions. Trapping Efficiency is the measure of how much of this air/fuel is trapped to be com-busted.

Initially I thought changes in Torque could be used to represent changes in engine load and could be used for developing a fuel injection map. Well that might be Ok for a four stroke but now that I have tried that approach I now think that Delivery Ratio is the more suitable measure for developing a two stroke map.

Air flow (Delivery Ratio) through a throttle is not linear. The greatest changes happen between 20 - 40% throttle opening.

320573

The first requirement is to find the throttle openings that corresponds to even Delivery Ratio (air flow) steps.

320572

Then I modeled these throttle openings in EngMod2T and got a reasonable correlation and reasonably even layer of Transfer Efficiency steps in the power region of the simulation.

This information at each TPS position and RPM point should make a handy start for developing the new map.

The rest of the simulation data (all 12 of them) are posted on the Ecotrons thread. Because the Transfer Efficiency graphs are probably similar to any performance 2T with a few adjustments to the rpm points the numbers may make a useful start to any 2T Alpha-N map project.


Once I started to understand how EFI worked it was relatively easy to get full power runs but it was quite hard to develop a map that is good for part throttle and transition from full throttle to closed and back to open again. This has been the biggest issue holding me back from having a track ready EFI bike.

Now to map it all out.


Simple in XL

320596

320597

Job done, now to see if it actually works.

[Muciek]

Wobbly (or anyone with experience on oils) any thoughts on Penrite oils for 2T compared with other stuff for racing purposes?

[JanBros]

Look it up on youtube, Aria mud run.

great fun :clap:

the things men invent to do with motorcycles :lol:

[1948rod]

re the offsetting the cylinder. does this give a straighter push on the crank as in a tangent if done to excess. if this is so the effective stroke [crank pin to crank center line] during the power stroke which is where the power comes from. the piston to rod angle would be reduced giving less friction. no idea if this is true just a thought from a humble follower of this great forum.

[wobbly]

Quote " if this is so the effective stroke [crank pin to crank center line] during the power stroke which is where the power comes from ".
What power - as far as we know to date,there is no proven power to be had with DeSaxe cylinder or piston offset.
Anything gained from a more linear push on the rod/or less friction is seriously affected by non optimal port timing asymmetry.

[adegnes]

Now that my new bike is nearly ready I need to develop a new Alpha-N fuel injection map. The axis's of an Alpha-N map is throttle position TPS and RPM. The steps between cells need to be in even steps. That is not even RPM or TPS steps but even changes in engine load.

"Torque" is largely related to the motors Trapping Efficiency of the air passing through it.

"Delivery Ratio" is everything when it comes to quantifying airflow through a two stroke motor and it is the air flow that needs fuel added to it in the correct proportions. Trapping Efficiency is the measure of how much of this air/fuel is trapped to be com-busted.

Initially I thought changes in Torque could be used to represent changes in engine load and could be used for developing a fuel injection map. Well that might be Ok for a four stroke but now that I have tried that approach I now think that Delivery Ratio is the more suitable measure for developing a two stroke map.

Air flow (Delivery Ratio) through a throttle is not linear. The greatest changes happen between 20 - 40% throttle opening.

320573

The first requirement is to find the throttle openings that corresponds to even Delivery Ratio (air flow) steps.

320572

Then I modeled these throttle openings in EngMod2T and got a reasonable correlation and reasonably even layer of Transfer Efficiency steps in the power region of the simulation.

This information at each TPS position and RPM point should make a handy start for developing the new map.

The rest of the simulation data (all 12 of them) are posted on the Ecotrons thread. Because the Transfer Efficiency graphs are probably similar to any performance 2T with a few adjustments to the rpm points the numbers may make a useful start to any 2T Alpha-N map project.

Great work!

[marsheng]

re the offsetting the cylinder. does this give a straighter push on the crank as in a tangent if done to excess. if this is so the effective stroke [crank pin to crank center line] during the power stroke which is where the power comes from. the piston to rod angle would be reduced giving less friction.

Here is quite a good explanation. More offset more vibration.

https://rideapart.com/articles/free-power-offset-cylinders-explained

[TZ350]

320598

This is what my new Alpha-N map looks like. Pretty pleasing to see the map is mostly even steps in the 7,000rpm and above area.

320599

And the spread sheet with the original EngMod simulated transfer ratio data and the calculations for developing the new Alpha-N map.

Hopefully get to try it on the dyno soon.

[bucketracer]

Interesting to see what can be done with EngMod. Looking forward to seeing how it turns out, should be good .... :corn:

[sispeed]

Found this due to a search for other stuff.
http://www.evanscoolant.com/faq/general-questions/
If you use this would it isn't a watercooled engine :rolleyes:

[Frits Overmars]

Found this due to a search for other stuff.
http://www.evanscoolant.com/faq/general-questions/
If you use this would it isn't a watercooled engine :rolleyes:It would also be illegal in most forms of circuit racing, the reason being that spilled water will only temporarily wet the track but spilled non-water coolants will make the track unusable for days.

[sispeed]

Makes sense not to use it on a track.
Was more of a joke for the Bucket aircooled rule

[Flettner]

Turns out the F1 was all 4 strokes, so had some time to help Neil with the design. No charge. :niceone:

320564

Yes that's it right there.

Somone has to have a serious go at the mud run don't they? AND it has to be a loud high powered twostroke.
Rurual NZ, you should see the kids afterwards all playing in the mud, the fun we had:laugh:

[TZ350]

Mud fun ... yum ...:woohoo:

[TZ350]

.

Page ..... 1500 .... How to search within the ESE mega-thread?



(Insert long sigh here) I hate, I hate to ask this, because I know I've seen the answer somewhere, the answer to various members' questions about how to narrow down a KB search. But as always, I'm unable to find this info (using Advance Search with every word combination I can think of). Generally my subject searches will refer me to the ESE thread. All ten thousand pages.
When you use advanced search make sure you are searching with single content option tab at the top. It also helps to add in the user name. If you know who posted it.


Rather than use the site search which usually fails, use Google so to search this site use an ordinary search phrase and after it add
site:www.kiwibiker.co.nz (http://www.kiwibiker.co.nz)
for example
Frits pisa site:www.kiwibiker.co.nz (http://www.kiwibiker.co.nz)
the same will work for other sites with the appropriate site address
Mick


There's an even better way if you're wanting to search within a particular thread.

For example if you wanted to search for “disc valve” in just the ESE thread, first you need to find the thread URL ID. Go into the ESE thread and grab the following info from the URL bar:

kiwibiker.co.nz/forums/showthread.php/86554

Now in google, search for: disc valve inurl:kiwibiker.co.nz/forums/showthread.php/86554

Using inurl: will only return results that have the appended string in the URL, so this search will target only that thread.

You might get just one result followed by text saying irrelevant results were omitted – just click “search with the omitted results included” to get a complete search.

You’re going to want to make your search as specific as possible, and let Google do the ranking.

edit: And just a quick follow up - don't even bother with the site's search. vBulletin search is notoriously useless, let Google do the leg work.


Also page 500, 1000 and 1250 have a basic directory and a lot off the decade (10th) pages have their own small collections of quotes of interesting technical posts from the last few pages.

There are over 7000 images on this thread, use "Thread Tools" to view them and then click through to the original post about them.


How to view all the images.

293109

Go to Thread Tools at the top of the page and View Thread Images.

293112

Now roll to the bottom of the page.

293110

Here you can sort them from the beginning.

293111

70 to a page, there are 6,000+ images

293113

If you find something interesting just click on the images title and it will take you to the original post.


http://www.kiwibiker.co.nz/forums/showthread.php/145224-Race-chassis?p=1130221509#post1130221509
http://www.kiwibiker.co.nz/forums/showthread.php/145224-Race-chassis?p=1130224186#post1130224186

Well over 200 people viewed the pics which by KB standards is a lot, as they had no cleavage.
(I am not sure if this will work) but I have posted over 10,167 pics in KB

http://www.kiwibiker.co.nz/forums/imgbrowser.php? Sorry you need to click on Husaberg view images set to begining set the image finder to 70 per page and by number of views.

If you are looking for 2T tuning technical information. Because this is a show and tell thread, this thread is best read backwards, ie start at the last page and read back towards the beginning that way you get to read the answer without having to wade through the confused questions.

A lot of the decade pages have collections of quotes and links to interesting things.

Page 1500 Links List.
Page 1490 Wiseco vis other pistons discussion.
Page 1480 Discussion with data maps about why Marshengs bike runs hotter in the corners.
Page 1470 Wiseco vis other pistons and their short comings.
Page 1460 Page talks about HCCI. Bike catches fire at Wanganui Cemetery RR.
Page 1450 Working with pumper carbs.
Page 1440 The insides of the Ryger is revealed on this page.
Page 1430 Pumper carb tuning talk.
Page 1420 The Frepan TZ400 built by Wobbly. Lots of links and pictures.
Page 1410 Air/Fuel ratio meter and how to use a Lambda sensor with a two stroke.
Page 1400 2:1 Pipes, and the power advantages of cutting the Ex side of the piston short.
Page 1390 EngMod2T, simulating and testing pipe designs.
Page 1380 Dyno results, testing different sized air correction jets.
Page 1370 Links to Rod/Piston kits and parts suppliers.
Page 1360 Dyno results for some F5 Bucket 50cc bikes.
Page 1350 To much talk about the Ryger so celebrating the work other people are doing in their sheds.
Page 1340 Frits on why the ring peg should be at the 6 o’clock position.
Page 1330 Peoples interesting projects.
Page 1320 Links to Rods and Pistons technical data.
Page 1310 Celebrating Kels very neat and rather quick KR125/RS project.
Page 1300 Celebrating peoples home built racing projects.
Page 1290 People doing real Bucket building stuff. Ryger uses up a lot of space from here on.
Page 1280 Links to Peewee’s, Lightbulbs, Adegnes’s and Ken Seebers racing projects.
Page 1270 Transfer Port Theory.
Page 1260 Ex and Transfer port design with pictures.
Page 1250 Links List
Page 1240 2T development Software, Port Theory, Interesting Sites
Page 1230 Compression Ratio, Ex duct shape and length, Fancy spark plugs.
Page 1220 Reed Valve Petals, Oxygen Sensors, Exhaust duct step at the pipe flange.
Page 1210 Ignition Trigger Woes, EngMod 2T and Blow-Down, Fuelling Curve.
Page 1200 Frits on power spread and the ratio of the maximum and minimum points in the power band.
Page 1190 No data, but a lot of talk about what the Ryger engine might look like.
Page 1180 Frits on 2T fuel consumption. M50 cylinder portmap and EngMod2T analysis.
Page 1170 Engine/Gearbox oils and bearings. Transfer duct shape and optimal Ex port timing.
Page 1160 Frits - Engines need large crankcase volumes, Power vis Handling.
Page 1150 Serious talk about crankcase volume.
Page 1140 Measuring the transfer duct length, Ignitec, Expansion chamber design, Trombone pipe.
Page 1130 Team GPR Edgecumbe Videos …. Cooling 2T’s …. 3xEx vis T port,
Page 1120 Crank Balancing, Ceramic Coating, Plugs, Piston Edge chamfers, RS125 pipe dimensions.
Page 1110 TeeZees progress on the EFI thing with the Beast.
Page 1100 No Data but some talk about pickups and EngMod 2T transducer position in the pipe.
Page 1090 Links about the Detonation Sensor and Temperature Data Logger.
Page 1080 No Data, the plenum is protested, Frits on Blowdown and Transfer window height.
Page 1070 Exhaust Duct shape, Kawasaki and BRC EFI dyno videos.
Page 1060 No Data but talk about Port shape and Flow in a duct on this page.
Page 1050 EngMod2T setup talk about pipes, transfer ports and the TubMax graph.
Page 1040 Basics of pipe design and how to influence where the point of maximum depression occurs.
Page 1030 Racing at Greymouth, its well worth a look to see Team GPR in action.
Page 1020 Pipe dimensions, Seattle Smittys hydroplanes. Husaburgs piston link.
Page 1010 Suspension Tuning.


Page 1000 has a lot of useful information and links. http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page1000?p=1130773139#post1130773139




Page 990 Blowdown STA, Ex porting plated cylinders, port layout and port angles.
Page 980 No links list but there is talk about spark energy and EGT
Page 970 Fuel - Oil and EGT talk
Page 960 Wob - Fuel and Oil Talk and Crank inertia.
Page 950 Its all about exhaust blow down …..
Page 940 Fixers 50cc adventures – ports & heads – Wob talks about Bad Gas.
Page 930 Frits 50cc pipe – Husburgs large links list, parts books, steering head brgs
Page 920 Big links list, allsorts. Tokoroa GP videos.
Page 910 No links list but the page is about fitting a 12V generator stator.
Page 900 Frits thoughts on O2 sensors – EFI Fueling theory – Wob on EGT
Page 890 DIY Foundry tips – EFI data – Detonation Management (tec paper) – more EFI
Page 880 Big list of Flettners Foundry posts and pictures.
Page 870 YZ & Bighorn Dyno results – Dyno Vids and EFI talk
Page 860 Air cooling and ducting and Carb air inlets, next page Greymouth Race
Page 850 1st run of the EFI Beast
Page 840 Husaburgs big links list on Power Jets – High temp epoxy and Ex port dam.
Page 830 Plugging piston pins – Cyl Heads (no radius) and Plug to Piston distance.
Page 820 Det sensor & Ignitec setup – Exhaust port dam – Boost Bottle – Insulating Paint
Page 810 Links – about Razing the Exhaust port floor
Page 800 Link to dyno graphs for the YZ & BigHorn EFI Bikes & a lot of EFI stuff
Page 790 Car & bike museum pics _ Wobs pipe.
Page 780 Setting up an IgniTec DC-CDI-Race-2 ignition – Big list of links.
Page 770 Wobs views on triple ex ports – first run of the EFI YZ250
Page 760 Port Angles – lots of Pipe design info – Fast model aero engine.
Page 750 Case Com – Basic 2T tuning – BigHorn EFI
Page 740 Case Vol – Deto – Inlet Length – Over rev deto.
Page 730 Pipes – Deto – Lambda – Temp probes – CrankCase CR – Variable headers.
Page 720 Inlet tract length – GP125 service manual – Picture of how to read a plug + Wobs comments
Page 710 Fuel and Power Jets - EGT and CHT - Crank build
Page 700 Talk about wide and low transfers – Case volume and dyno graph – det and Lambda sensors.
Page 690 Pipe talk and ideas about making mufflers.
Page 680 Talk about the Trombone pipe and more of Frits and Wobs views on pipes.
Page 670 Pipes – blowdown STA numbers – Trombone pipe.
Page 660 Lots of links on pipes – Ariel Arrow – and CVT
Page 650 Links – Frits and Wobs views on pipes – CVT transmissions – 30 vis 24 carb dyno graph
Page 640 Links to Wobs views on pipes – crank balance factor – connecting a laptop to the Ignitec
Page 630 More of Wobs views on pipes – Frame & wheel weights – correct O ring grove sizes
Page 620 Links to Cooling Water Flow – Case Comp and Pipes – Setting up 2T carburation.
Page 610 Simulation packages – combustion efficiency – transfer ducts – chamfered exhaust top edge.
Page 600 Books that can be down loaded and Frits talks about why 190 Ex duration is so good.
Page 580 No links but page is about mounting carbs and the 24mm pumper carb & 28hp dyno graph.
Page 570 No links but the page talks about carburation – emulsion tubes and pilot jets.
Page 560 No links, the page is mostly about 96 vis Av gas with dyno test.
Page 550 No links list but the page is mostly about TZ400 build and cranks and rods.
Page 540 No links, the page is mostly about Wobs success with the 400 project.
Page 530 Ignition – setting up det sensors without a dyno – wings inside reed valves – poly quad head
Page 520 Mostly about what some wheels weigh, ATAC valves and crank stuffers.
Page 510 Bucketracers general Links List
Page 500 Bucketracers links list of how to make a mid 20’s hp Suzuki GP125





Page 490 The Trombone, Ex port resonance and Transfer port stagger.
Page 480 A vid of the Trombone, transfer timing and hot gases entering the transfers because of insufficient blow-down for the rpm.
Page 470 Blow-down STA ... Specific Time Area.
Page 460 No list but the page talks about Boost Bottles.
Page 450 Links to the basic info for building a 30+ hp Bucket.
Page 440 No list, page talks about power and air correction jets.
Page 430 Carb inlet lengths and crankcase volumes.
Page 420 Transfer ports and the importance of the up swept angles, the Leaning Tower of Pisa principle explained.
Page 410 Rolling road dynos, main and power jet ratio.
Page 400 Links to the basic info for building a 30hp Suzuki GP125 Bucket engine.
Page 390 Links to Frits collection of Aprilia stuff.
Page 380 Transfer duct shape and STA's.
Page 370 No list but the page talks about Jan Thiel and racing 50's.
Page 360 Frits chamber calculations formula.
Page 350 PJ switching, Wob and crank shaft balance.
Page 340 Muriatic Acid, main brg float, Husburgs con rod dimensions.
Page 330 No list, page talks about expansion chambers, race gas.
Page 320 High temp silicon, Yama Bond, crankcase sealing, air solenoids Vid clips of Mamola.
Page 310 Copper for cooling, sprockets for cooling, steering head brgs.
Page 300 How to determine STA numbers.
Page 290 B/E dimensions, delivery ratio, Honda Ex Step, stinger nozzel
Page 280 Aprilia RSA port layout explained, pumper carb, links to gluing up the GP cases.
Page 270 Link list on how to make a decent high 20's hp Suzuki GP125 Bucket engine.
Page 260 Over rev cough and what it means, Mallory metal for crank balancing.
Page 250 27hp from a 1978 Suzuki GP125
Page 240 Aprilia RSA cylinder stuff.
Page 230 Porting Calculator and a lot of other useful tech links.
Page 220 RG50 part numbers, 2-stroke carb atomisers explained
Page 210 Page is mostly about the results from the TRRS
Page 200 Simple 18 hp Suzuki GP Bucket engine using a RG250 pipe.


Etc ...


On Page 500, Bucket has links to how Team ESE built their Suzuki GP125 26, 28 and 31 hp engines:- http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page500


Transfer Port theory


Yes, pipes, a bit to take in
http://www.dragonfly75.com/motorbike/ECtheory.html

Starting from the beginning I have been trying to find the posts that talk about pipes and collate and edit them. There is heaps of it, mostly from Wobbly and pages 620 630 640 650 660 670 680 690 700 710 720 730 740 750 760 770 780 1040 and 1050 have un edited collections of raw material.

[TZ350]

Page 2 .... 1500

New Zealand F4 Bucket racing.


I want to see race 2 of this ....

https://www.youtube.com/watch?v=HcK1As59jkI

The great sound of a two stroke Bucket, real music.


GP Boneshaker...


https://youtu.be/8EwKlNBTgsc

2016 Tokoroa GP


Fritz sent these through.
http://kiwibiker.co.nz/images/DKW-Jawa-KTM-Ossa-Rumi-Fath-Stredor-Seel-Hessels-carbs-CRP.zip
http://kiwibiker.co.nz/images/Honda-Suzuki-Yamahai.zip
http://kiwibiker.co.nz/images/Jamathi-Piovaticci-Bultaco-Garelli-Kreidler.zip


Here are some pictures to help you on your way Peewee.
313049 313050 313051 313052313053


having a header say 28% or 36% of the tuned length will invariably produce huge holes in the torque curve - due to the incorrect positioning of the diffuser.



Cutting or sleeving headers to do a dyno test, is that simply doing that and trying to analyze the results is completely pointless if you have not measured the pipes beforehand to see what the original design intent was.


If the header is short to start with, and you then shorten it more, the tuned length may be perfect, but the negative effect from the now silly short header length will overpower any of the good effects of the overall length.


Conversely if the header was short and you lengthened it, the power increase may be mainly due to now having a " correct " % of header - though the pipe length may be completely wrong for the port timing.



The squish following the piston shape by using CNC is even more important if you are pushing the limits with around 50% SAR and very tight clearance. This also works together with the sharp edge into the bowl.



As we were on the subject of scavenging angles, now would be a good time to write something about the radial angles of the A-transfers.


Surely a duct with a radial angle of over 20° offers a smaller cross-section to the flow than a duct that enters the cylinder perpendicularly?


Yes it does. But there are two good reasons to angle it upward anyway.


First, perpendicular mixture streams coming from the A-ports would collide and slow one another right down. The upward angles provide for less velocity losses and less pressure losses, so despite their smaller cross-section, upward ports may flow as much, if not more, than perpendicular ports.


(Now you may well ask why the B-ports do not get the same treatment; that is because the central scavenging column, resulting from all incoming scavenging streams together, must not have too much radial velocity, or the loop scavenging will result in a loop-loss into the exhaust).


Second, there is a thing called scavenging balance (I invented the word for my personal use, so this may well be the first time you ever saw it).


If you looked closely at the scavenging picture of the MB-cylinder I posted earlier today, you may have noticed that the 'radial scavenging directional resultant'
had a value of 101,045°. 90° would have meant 'straight up'; more than 90° indicates that the central scavenging column is leaning towards the exhaust side of the cylinder.


But we don't want that; it is bad for the scavenging of the rear part of the cylinder, and it is risky because it may provoke scavenging losses straight into the exhaust.


But how can we prevent a scavenging column from toppling over to the exhaust side like the leaning tower of Pisa? Not by pushing against its basis, but by pushing higher up. Hence the radial angle of the A-ports.


The pictures will tell the story. (If only the Pisa architect had known a bit more about two-stroke tuning....)


The picture of the girl, its important transfer theory. You will have to go to page 1000 to read about it.

[TZ350]

Page 3 .... 1500

The EFI story with pictures if you follow the links back to the original posts.


Posted because someone asked where to find it all, so a recap on the basics of the Beasts Engine.


TeeZee tested his 24 against a 30 in a back to back test. The 30 didn't make anymore power than the 24.


Ok, making a bit of progress with setting up the EFI systems throttle body.


Det Sensor. Next week I hope to get all the chopping and changing of the wiring done then I can start playing with setting up the Ecotrons EFI program for a trial run...


The mid chamber bleed re visited as it might be useful for some low end boost......


One of the most useful things I have added to the fuel injection system is a switch that turns the fuel pump off.


Tim gave me a hand tonight, we started to make progress when we moved the injection end point. I think we originally had the injector squirting into closed ports.


Flettner makes the point that it is important, in fact the whole key to successfully fuel injecting a two stroke, is to have the injection period timed to end at the transfer port closing.


First cut at verifying the timing of the injection end point.
Lashed a regular trigger coil to a 12V solenoid with a bolt through it. Set the Ignitec map to zero, now it will fire immediately it sees a trigger pulse.


Spent sometime tonight trying to figure out why there was no signal at the injector. Then realized that at TPS = zero the injection map is = to zero. So bumped the first line up to 100 and bingo the injectors were firing.


The next move is to try the lash up Flettner suggested, and yes I still had sparks and by switching the leads plugged into the injector socket I could easily figure out which was the injector energizing and shut off points. And now I can setup the injector close point and with the timing light I can clearly see where the injection events are happening on the flywheel.


Ok ..... I dusted off my old valve powered signal generator and oscilloscope. And brought some science to the problem, and it looks like it is not me.

Later realised it was me, I did not have the steps in the map as even as they needed to be in real life and when the ECU tried changing between injectors with the engine under load it was tripping over a step and becoming confused.


Connected up a signal generator and oscilloscope to the Beast and had a look at how the EFI injector pulses behaved at a simulated 2,000 to 12,500+ rpm. And then with the motor running. Five things I learned about my EFI setup today.


Ok finally got the O2 and exhaust temperature sensors installed. No idea if they are in the optimum place but they will do for a start. Now that it all seems to be working I am really looking forward to getting a bit of time on the dyno to play with this thing.


I am now starting to make some headway with tuning the Beast and I am beginning to enjoy using the Ecotrons small engine EFI kit for two strokes and its 2T tuning software. Recorded some RPM and TPS data along with the Lambda O2 sensor.


Ok, making progress, that's if you can call getting it wrong progress. Ecotrons has a very clever self tuning feature where you tell the map what Lambda you want at what RPM and the ECU will read the ALM O2 sensor and adjust the mixture for you. Being able to make planned mistakes is a step better than just making ignorant mistakes and not knowing why. So .... its progress.


Posted because I was recently asked about the det sensor I used. I earthed one of the two wires. Probably does not matter which.


The detector/amplifier I got of Ebay comes with lights and I currently use an optional extra output to signal the ignition to retard when there is detonation.


Started making a new injector manifold that points the small Ecotrons injectors across the transfer port windows, previously the outside pair had just fired straight into the B transfer ports and impinged on the back of the cylinder liner.


Making some progress with the new fuel injection manifold. The injectors are angled so they squirt more horizontally across the transfer port. The small (bottom left) injector from the Ecotrons Small Engine EFI kit for two strokes has had the clips on its top cut back so the fuel barb can be swiveled in different directions.


Unlike finicky carburetors, with fuel injection there is not the over enriching problems you get when the inlet stream bounces back and forth several times in the inlet tract. Passing the carbs needle jet several times and picking up fuel on each pass. With EFI I don't have to be so conservative with the rotary valve timing and can experiment a little.


New injector manifold to direct the fuel streams across the transfer ducts. There will be three 126 g/min injectors, with the middle one firing first then the outer ones come in when the engine gets up on the pipe. The center injector is angled up so as to cool the underside of the piston crown by squirting through a slot in the piston skirt.


The plenum re visited ... The problem was, with the carb on the outside we got excessive fuel dropout in the plenum, EFI should cure that.


Started work on the fueling map, things are starting to come together, but probably making adjustments in to big a steps. More patience is required. When I shut the throttle after a 12k pull the motor sounded like a hive of angry hornets, to lean on over run.

The big learn of the night was the truth of the quote below.

"" One thing you have to always remember with alpha-N is that you don't actually know where the effective WOT is any more (i.e., when you have enough throttle that opening it further doesn't affect the amount of air being ingested). At low RPM WOT could be only 20% throttle. ""


Ok this is where my thinking is at tonight, possibly wrong but there you are. So I am none to sure about how useful the BSFC would be as it looks more rpm and engine efficiency than load dependent.

But what interests me is the Delivery Ratio as I think this is the total volume of air that is passing through the motor and as we all know fuel and air needs to be mixed at a set ratio, even if some of it gets wasted out the exhaust.


I knew the VE table was all about cylinder filling and I thought the cell values on an Alpha-N table were all about the volume of fuel to squirt but I have had to re-think that. From the Ecotrons manual. LOAD based Alpha-N system. For two-stroke engines, the default fuel mapping is Alpha-N method.


For my bike, at 12k ish the delivery ratio is about 120% of the cylinder volume and the amount of air (charging ratio) in the cylinder at BDC is only about 80% of the delivered air and less than that actually gets trapped (trapping efficiency) at exhaust port closing, so you can see that a fair swag of air is lost out the exhaust port. And my guess is that the bulk of the air that is lost is the first air entering the cylinder as the transfers start to open and if there was extra fuel already in the transfers that would be lost with it.


Now the opening time can start before the transfer opens and the close time after so that leaves me a clear 1.5 to 1.7ms of full on injection time. The start point can be early but it looks as if the timing of the injection end point is going to become critical if we are going to get the bulk of the injection happening towards the end of the transfer event.


That is pretty much what I have been trying to achieve with the upwards directed injection stream from the central injector.


If a carburettor has one advantage over fuel injection, this is it. When the quantity of fuel is controlled via the open/shut time of an injector, it is practically impossible to create a homogeneous mixture at the injector. And I'm not even talking about vaporized fuel here; I'm just talking about every part of air getting the same number of fuel droplets. Fortunately for us much of the necessary homogenisation takes place in a two-stroke's crankcase, with the con rod stirring things up and transferring its heat to the yet-unvaporized fuel droplets. But with direct fuel injection you lose this advantage, and the con rod bearing looses most of its cooling.


Hi Speedpro, I agree with everything you say but "weak mixture - no", well not in this case because this engine runs well with a carb but not with transfer port injection EFI so the problem must be with the EFI or at least with the way I am trying to use it.

Remember with a carb all inducted air has fuel mixed with it but with EFI this is not necessarily true. The problem with EFI and transfer port injection is that as the rpm gets up, a lot of air can get through the port but there is not necessarily enough time to inject sufficient fuel into the air stream.


Making progress, touching 12,000 rpm and nearly 25hp 3 to go.


26 hp and repeatable, but so fiddly to get and still detos like mad, however much fuel I throw at it. All the extra fuel does is make more exhaust smoke.
I think there really is just not enough time, 1.8ms for the injection cycle through the transfers at 12krpm. Ok time to change over to injecting down the inlet tract.


Ok, rearranged the injectors, injector one is still in the rear of the cylinder and injector two is firing down the carb. With the injection cycle timed to end at inlet closing. Red line is both injectors in the rear of the cylinder. Blue line is with the second injector in the inlet tract. The lines diverge at the point the inlet injector takes over. Its interesting because it goes to show that carbs can be pretty good.


The Blue line is my best with transfer port injection the Green line is where I have got to today with the twin injectors aimed down the inlet throat. It was the same map as the transfer port injection, and better than yesterday's single injector effort.


Well tonight's effort was a total bust, the two injectors send out such a cloud that it wets out on the bellmouth and dribbles down into the plenum which totally negates the reason for having injectors in the first place. Ie to stop fuel pooling in the plenum.

I can see the advantage of having the injectors behind the throttle slide like they have on the BRC engine. Gave up for the night after the EFI filled the crankcase with raw fuel.


Alpha-N maps need to be smooth without any peaks or severe troughs between cell steps. Ecotrons has a function where you can export a map to an Excel spread sheet and use the charting function to help smooth the map data. Raw data and the chart showing how rough the data is and the engine ran just as roughly. Smoothed data and chart.


Making progress towards the magic 28, at least now I know this EFI thing is going to work. Just a lot of careful step by step adjustment of the maps is required. I expect time and patience will see it running very nicely. I also thought it had a terminal deto problem. Deto turned out to be the piston hitting the head.


27.6hp - getting close with EFI to the best ever achieved with a carb on this cylinder. Blue line is where we started, Red line is where we are now. The big issue is getting back on the gas and running to rich below 8,000 rpm. Anyway it is coming right bit by bit.


The EFI is touching 28, but its still very reluctant to come back on the throttle after rolling off.

It will be a pig to ride so I guess I will take my laptop to Tammers and the weekend for me will be all about starting off the back of the grid and adjusting the EFI map to try and get the Beast track ride-able.

I am looking forward to it as I might have more luck getting it right by riding it than trying to tune its low to mid range on the dyno. Anyway the weekend away camping with every one else will be fun and the local RSA does a real great Saturday night dinner ..... Yum ... :p

Tammers was a bust, Bike was a real pig to ride.


Ok after months in the wilderness I finally figured it out. I was right about needing smaller injectors. So it looks like, to maximize tune-ability you need to minimize the injector size......... in hindsight its so obvious really .... :facepalm: Not perfect yet but very very promising.

With a smaller primary injector things start to come right.


Injectors turned up from Ecotrons today, four days from date of order and two of them were weekend days, pretty good service in my books. I fitted a smaller injector and did a bunch of runs at different throttle settings. Interesting that the 60, 50 and 40% runs carry on out to close to 13,000 rpm. Blue line is the TPS. 100-90-80-70-60-50-40% throttle settings. It is certainly throttling and coming back onto the power much better. I will have to analyse the data to see if I can use an even smaller injector.


The EFI lesson I learnt last month was, that to get the greatest range of tune ability I needed to use the smallest injectors possible that will still do the job. I know, pretty obvious, but there you go.

I read the Ecotrons EFI manual and saw that the map must have as many even steps as possible and I thought that meant dividing the rpm range up as evenly as possible, seemed logical, but wrong again.

The bike bucked around swapping between the staged injectors as the EFI struggled to jump from one cell to another on the steeper parts of the fueling curve.

I guess what they really meant was that the changes between cells need to be as even as possible.

So I don't need even spacing between the rpm break points and can have big or small gaps between them so long as there are no big steps between the values of adjacent cells.

I can now throttle on/off pretty well and do a series of part throttle runs, the last one is at 30% TPS, it looks a bit lean.

Its not perfect but is running a lot better, so for what its worth here is the current Alpha-N map.


Carburetors are great because of their analog ability to change the fuel delivery with changes in air flow at the same throttle setting. EFI, well EFI is not forgiving at all.

The Ecotrons Alpha-N map has 16 rows to work with and I had concentrated them in the area where the power is, as you do. Well that turns out to be a mistake because there is not much difference in fuel demand per cycle between 100% throttle and 90 or 80 or even 70 at max power and virtual no difference at all above 40% in the 3 to 6000 rpm range.

The big jumps were between the lower throttle settings where there was not much excitement happening, well the mistake is that the CPU has a hard time bridging the big gaps below 40% especially when it is also trying to swap between low and high injectors at the same time.

As it turns out, it was a mistake to concentrate my map in the power area, but I guess I will forgive myself..... :laugh:

29hp


Different problem, but I feel your pain Dave. Been working my arse off on this EFI thing. 90% throttle consistently makes more power than a 100%, 80's pretty close to and 70 is not far behind.

309768

I keep making more power but can't get it to come back onto the throttle properly.

I just want it to throttle properly so I can ride it , Bah humbug, and stamp my feet.


Finally getting some place with the EFI after strapping a small laptop onto the tank and riding the bike around looking for the bad spots in the map. I can now wind it out, throttle off and have it come back onto the throttle again. Its now ride-able enough to make it worth taking to a practice day for further refinement. Dyno runs recorded at 100-90-80-70-60-50-40 and 30% throttle.

I have made more power in the past but the point of these dyno runs is that it is running reasonably well at different throttle openings and it is also something of a guide for refining the Alpha-N map some more.

Its a two stage injector system with three injectors, the middle 60 g/min unit is for starting, slow running and over run after shutting off. A pair of 80 g/min units provide fuel as the engine comes on the pipe then the middle injector chimes in again so all three are firing as the rev's get around 10,000 rpm.

I checked the data logger and the middle injector is chiming back in at 9,500 rpm on WOT so I have achieved one of may aims, squirting raw fuel at the underside of the piston crown to cool it when the engine is making real power, I am very happy with that.

The biggest issue was selecting the right sized injectors, I had chosen ones that were to big, to big and there is not enough range of tuning adjustment and it took a while to work my way down to quite small injectors.

The quest for even steps on the Alpha-N map.


Now that my new bike is nearly ready I need to develop a new Alpha-N fuel injection map. The axis's of an Alpha-N map is throttle position TPS and RPM. The steps between cells need to be in even steps. That is not even RPM or TPS steps but even changes in engine load.

"Torque" is largely related to the motors Trapping Efficiency of the air passing through it.

"Delivery Ratio" is everything when it comes to quantifying airflow through a two stroke motor and it is the air flow that needs fuel added to it in the correct proportions. Trapping Efficiency is the measure of how much of this air/fuel is trapped to be com-busted.

Initially I thought changes in Torque could be used to represent changes in engine load and could be used for developing a fuel injection map. Well that might be Ok for a four stroke but now that I have tried that approach I now think that Delivery Ratio is the more suitable measure for developing a two stroke map.

Air flow (Delivery Ratio) through a throttle is not linear. The greatest changes happen between 20 - 40% throttle opening.

320573

The first requirement is to find the throttle openings that corresponds to even Delivery Ratio (air flow) steps.

320572

Then I modeled these throttle openings in EngMod2T and got a reasonable correlation and reasonably even layer of Transfer Efficiency steps in the power region of the simulation.

This information at each TPS position and RPM point should make a handy start for developing the new map.

The rest of the simulation data (all 12 of them) are posted on the Ecotrons thread. Because the Transfer Efficiency graphs are probably similar to any performance 2T with a few adjustments to the rpm points the numbers may make a useful start to any 2T Alpha-N map project.



Now to map it all out.



320596

320597

Job done, now to see if it actually works.


320844

Well.

The good news is that after months of work I have finally given Mr.Bigglesworth a thrashing on the dyno.

The bad news is that there is still a reluctance to come back on the throttle.

320845

Fortunately the Ecotrons EFI software has a data capture function. Max power was at 12250 rpm and max over rev rpm was 12888.

320846

Looking at the left hand courser the yellow line is Inj0 (the small injector) and the blue line Inj1 (the big injector) and the brown line is maximum injection time available. It can be seen that both injectors are topped out at 10,325 rpm. This suggests that Inj1 (the big injector) is to small.

320847

With high rpm and the TPS at 0% Inj0's pulse width is 1.140ms (right hand courser) which is less than the allowable minimum opening time of 1.8ms so on over run Inj0 is still to big.

So the big injector is a touch to small and the small injector is still to big for good tun-ability when throttling off and opening the throttle again like you would negotiating a corner at speed.

Ok, so off to Ecotrons to buy some more injectors.


320857

A fuel injector has a tuning range just like this jet kit has. And just like when you get down to the smallest jet in the kit and still need to go leaner you need a smaller jet kit or injector to move to the next lower tuning range.

That is my problem with the small injector, it is just not small enough to give me the tuning range required to handle the minimum fueling requirements on high rpm over run on a closed throttle. I need the next smaller injector.

Well it is not the end of the story but at least it is progress.


The Ecotrons EFI has barometric and air temperature sensors for automatic fueling compensation so hopefully once I am on the money with the dyno the ECU's auto compensation will give pretty much the same results as changing the jets 3 times a day.

I feel very comfortable with tuning the EFI system for maximum power, above 50% throttle position that is relatively easy.

The problem I am struggling with is at the low end, if this was a carb then the EFI bit that is challenging me now is the area covered by a carb's pilot jet and transition to the slide cutaway.


May I ask why you're not using a wideband O2 to tune this area? It would be relatively straightforward with a wideband and a brake dyno.

I started out trying to get a 12.5:1 A/F everywhere on the map, as you do if you don't know any better. Things weren't going well and I gave it away when it was pointed out to me that it was the short circuiting fooling the O2 sensor into thinking the system was running lean when it was not.

It really confused things and it looked like the O2 sensor was not going to be very useful so I discarded it. But your experience encourages me and it looks like that with a bit more experience myself I might be able to get somewhere with it now I have a better idea of what is going on and can see that 12.5 in the peak torque area is good and something like 14 in other areas might be a good number.


Why a brake dyno? Then you would be developing an engine for a set of circumstances that it will never see on a race track. Going through the revs on an inertia dyno and registering revs, torque and lambda simultaneously is an excellent way of establishing an injection map. Besides, running constant revs on a brake dyno with too little fuel or too much ignition advance may kill your engine, whereas it might survive on an inertia dyno.


When i say brake dyno i mean an eddy current or similar that allows both constant rpm tests and normal 'runs'... Im sure that doing only constant rpm tests is not ideal.

Personally I do a combination of both to tune an engine and so far it has worked well for me, especially when tuning the low throttle area that TZ was talking about... in saying that ive only ever had an eddy current dyno, never an inertia-only dyno. And have developed my own methods of tuning without ever seeing first-hand anyone else's process for tuning a two stroke... maybe its a case of ignorance is bliss, however I find my process to be very quick and very reliable for a wide range of engines.

I find that the lambda sensor is a little slow to react at low revs and part throttle. Its fine at higher revs and higher throttle. By holding the engine at a certain rpm point for 3-5sec at each throttle position it gives the readings time to stabilise and gives much better, more repeatable data.

I start by doing a range of fixed rpm tests at different throttle openings, with the revs building higher each test... eg 4000, 6000, 8000, etc at 1/8, 1/4, 1/2, 3/4, full throttle. By doing this you can easily see the areas that need changing (pilot, slide, needle diameter, clip position, needle taper, main jet, etc).

If there is a serious problem with the tune you will always catch it before doing damage as you’ll see AFR's begin to lean out or detonation begin to show before you get too high in rpm. Once I’ve done basic tuning like this then i do full runs and constant load testing and fine tune if necessary, but these are normally only very minor changes.

Whether the AFR reading is showing true AFR or not doesn’t really matter, the numbers can still be used to tune an engine... around full throttle and peak torque it is fairly reliable to use ~12.5:1 and leaner readings below that, down to around 13.5-14:1 at part throttle/low rpm.

Of course you still need to use experience and 'feel' to do the fine tuning but the AFR numbers will get you close. Even if the engine is not actually seeing 14:1 at part throttle/low revs, its still a repeatable data point that can be used to tune an engine. Its certainly a lot better than guessing, especially when tuning the part throttle areas.


+1 the above.Adding that putting the Lambda in the stinger, seems to be way more stable and repeatable when logging the A/F data.

Using data this way is something that you really don’t appreciate how good it is until actually doing it.
Hence TeeZees surprise when I related that every time you change a small item in the engines tune - the dyno result for sure is not telling you really what you want to know, unless you reject every time to hit a predetermined baseline.

As Jan Thiel said, most all of the pipe testing at Aprilia was a complete waste of time, when he finally realised allot of the power differences were down to how the egt reacted to that pipe.

Not that the pipe was "better " for some aspect of scavenging, or trapping efficiency in making more or less power.

[SwePatrick]

Now that my new bike is nearly ready I need to develop a new Alpha-N fuel injection map. The axis's of an Alpha-N map is throttle position TPS and RPM. The steps between cells need to be in even steps. That is not even RPM or TPS steps but even changes in engine load.

"Torque" is largely related to the motors Trapping Efficiency of the air passing through it.

"Delivery Ratio" is everything when it comes to quantifying airflow through a two stroke motor and it is the air flow that needs fuel added to it in the correct proportions. Trapping Efficiency is the measure of how much of this air/fuel is trapped to be com-busted.

Initially I thought changes in Torque could be used to represent changes in engine load and could be used for developing a fuel injection map. Well that might be Ok for a four stroke but now that I have tried that approach I now think that Delivery Ratio is the more suitable measure for developing a two stroke map.

Air flow (Delivery Ratio) through a throttle is not linear. The greatest changes happen between 20 - 40% throttle opening.

320573

The first requirement is to find the throttle openings that corresponds to even Delivery Ratio (air flow) steps.

320572

Then I modeled these throttle openings in EngMod2T and got a reasonable correlation and reasonably even layer of Transfer Efficiency steps in the power region of the simulation.

This information at each TPS position and RPM point should make a handy start for developing the new map.

The rest of the simulation data (all 12 of them) are posted on the Ecotrons thread. Because the Transfer Efficiency graphs are probably similar to any performance 2T with a few adjustments to the rpm points the numbers may make a useful start to any 2T Alpha-N map project.



Now to map it all out.



320596

320597

Job done, now to see if it actually works.

I think you are complicating it to much.
Just add fuel in 'map' to get it running.
Adjust up and down to get it running nice.
Put it on dyno, adjust for best performance.

No calculations at all..

quickest and easiest way to get it out on the track ;)

[Sketchy_Racer]

I think you are complicating it to much.
Just add fuel in 'map' to get it running.
Adjust up and down to get it running nice.
Put it on dyno, adjust for best performance.

No calculations at all..

quickest and easiest way to get it out on the track ;)

That works when you have a base map to begin with (thinking power commanders etc) However when setting up a fuel system from scratch what Rob is doing is exactly the level of detail that will be required to get the bike to even be in the window of take it to the track where you can start adding compensation fueling.

TZ - I've recently had the delight of going through the pains that you are now with a Igni-jet system on a F3 bike. It's no easier on that than what you are doing, luckily though being a foul-stroke I could run a lambda sensor to get the partial throttle tuning dialed in quickly once the base map was built up.

-Sketchy

[TZ350]

TZ - I've recently had the delight of going through the pains that you are now with a Igni-jet system on a F3 bike. It's no easier on that than what you are doing, luckily though being a foul-stroke I could run a lambda sensor to get the partial throttle tuning dialed in quickly once the base map was built up. -Sketchy

Good to hear you are having success with your EFI system.

Yes, I found it relatively easy to get to full power runs but it is that part throttle, especially the full to closed then open again like you would throttling off for a corner that I am struggling with.

I found a lambda sensor did not help me much as the fuel lost with the inevitable short circuiting always made things look to rich when in fact they were not.

I think Wob has talked about putting the sensor at the stinger, I would like to know more about that.


I think you are complicating it too much. Just add fuel in 'map' to get it running. Adjust up and down to get it running nice. Put it on dyno, adjust for best performance. No calculations at all. quickest and easiest way to get it out on the track ;)

True, sounds simple, well maybe, anyway it is pretty much what I have tried. I have had some success, but it is funny that the smallest part of the map. The area below 25% TP that I am having the most trouble with and it is this area that affects the rideability of the bike the most.

320621

I had to do a little learning to get here but these are dyno runs from a map developed the way you suggested. With the various dyno runs in 10% steps from 100 down to 20%TP below that fueling was so bad the engine would not run well enough for any data to be recorded.

Now that I understand it a bit more I will follow your advice and take it to the track for practice on a Saturday. That way, if I stay out of everyone else's way I can play with the map and different sized primary injectors.

Another reason for calculating it all out carefully is that with staged injection you need predictable even steps between cells in every direction otherwise the ECU becomes confused when trying to swap between injectors.

320622

The cross over in the 4,000 rpm area in the EngMod simulation is interesting too, I saw hints of this on the dyno but did not understand the reason for it until I saw the simulation.

If it was a dragster non of this low speed stuff would matter but a road race bike needs to be rideable under every condition. Including just trickling around the track to line up for the start.

[AndreasL]

Love your approach to this TZ!

Very scientific, a good view of what's happening (great for trouble shooting/future adjustments) and even if it's not a 100% "correct way" (I have no clue but think it makes sense the way you approach this.) you are in control and can take it from there.

One more thing, simulation programs and calculations are not magic wands that will spit out the optimum answer I was tools by the guy that sold me my chassis simulations program (car racing). It's a tool and have to be used as one.

TZ's case above is a great way of showing just that I think.
Time consuming for the time being, but fun, and most likely rewarding in the end.

Love it!

[jonny quest]

TZ, do you have an "accelerator pump" function turned on and working?

[TZ350]

Love your approach to this TZ! Very scientific, a good view of what's happening (great for troubleshooting/future adjustments) and even if it's not a 100% "correct way" you are in control and can take it from there.

Simulation programs and calculations are not magic wands that will spit out the optimum answer.It's a tool and have to be used as one.

Time consuming for the time being, but fun, and most likely rewarding in the end.

Love it!

Totally agree, it is just a tool and like you say, hopefully rewarding in the end..... :D

I came to this EFI project as a total novice and pretty much gone about the EFI map thing in every wrong way that is possible. Learnt a few things, like use the smallest injector possible, not the largest. I think my latest mapping effort will be a move in the right direction.


TZ, do you have an "accelerator pump" function turned on and working?

Yes, but not sure if I am doing the right things with it.

Pretty sure it is plain over fueling on closed throttle and when the throttle is opened again it takes a bit of time to clear. The hunting when it tries to swap injectors does not happen everywhere on the old map so it suggests there is a problem with the size of the steps between some cells.

The only advice I got from Ecotrons was to make the steps between the cells even. When you think about it, what does that mean? Anyway I could not get any better clarification, cultural differences in the use of the English language I guess.

Smooth even steps, I tried smooth RPM steps, smooth TPS steps, smooth numerical steps, smooth torque curve and fuel delivery steps.

The whole Ecotrons mapping system runs on changes in engine load so now I am going to try smooth changes in "Transfer Ratio". The numbers on the map look disjointed but the Xl spread sheet graphic shows a relativly smooth transition between cells.

So hopefully this is another step forward.

[Flettner]

TZ, do you have an "accelerator pump" function turned on and working?

That was one of the biggest problems with my F9 injection, the fuel accelerator pump was turned on (and I didn't know), it took a long time to figure out it was causing problems. Finaly found it, turned it off, problems solved. It's not only not needed but is also a big problem.4T only. Using a Link Atom ECU.

[FastFred]

Learning to use the Ecotrons electronic fuel injection ProCal tuning software based on the experiences of a complete newbee with no previous EFI experience.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/Bubbles-2_zpsb58f2623.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/Bubbles-2_zpsb58f2623.jpg.html)

The Ecotrons fuel injection system is my first experience with EFI. Sure, I had seen fuel injectors and mass air flow meters before and had some idea of how they worked but I am a total newbee to EFI when it comes to installing one and setting it up.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/EFIKitandWiringHarnes_zps9419d2bd.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/EFIKitandWiringHarnes_zps9419d2bd.jpg.html)

I brought the Ecotrons single cylinder two stroke Small Engine Kit with two fuel injectors, the kit is easy to put together as it comes with its own wiring loom and everything is labeled.

TZ for 2T's and Speedpro 4T's have posted virtually everything as they have gone along, very useful if you are going to try experimenting with EFI and a Ecotrons fuel injection kit.

[wobbly]

I have used the Lambda in the front muffler mount for ages on the dyno and at the track in karts ( its allowed during practice ).
The end of the rear cone is a very hot spot and the sensor seems to like this ( its heated as well of course ).
The readings are very stable and I have only had to replace a sensor once in hundreds of dyno runs.
But generally i am only doing full throttle pulls on the dyno so cant use the sensor for part throttle adjustment.
For that you would need load control, or have full data logging at the track, which we have.

Dont despair TeeZee, the factories had exactly the same issues with part throttle response of FI,in 2T racebike use.
For example when Foggy went to a test with a FI bike to see if he wanted to have a go at GP racing - he said it was a piece of shit and it was completely unrideable.
End of test, end of career.

[TZ350]

Thanks Wob for the heads up about the sensor position. Yes, sometimes I do despair about doing better than the factory's with EFI, well I am making progress and today feel more optimistic and give it about a 40/60 chance of success.

[FastFred]

Dont despair TeeZee, the factories had exactly the same issues with part throttle response of FI,in 2T racebike use.
For example when Foggy went to a test with a FI bike to see if he wanted to have a go at GP racing - he said it was a piece of shit and it was completely unrideable.
End of test, end of career.

I think TZ has said his own EFI efforts so far have been a piece of shit and totally unrideable or something like that, so I guess TZ is right up there with the Factories.

But I think he will get it right though ..... :Punk:

[sonic_v]

I have used the Lambda in the front muffler mount for ages on the dyno and at the track in karts ( its allowed during practice ).
The end of the rear cone is a very hot spot and the sensor seems to like this ( its heated as well of course ).
The readings are very stable and I have only had to replace a sensor once in hundreds of dyno runs.
But generally i am only doing full throttle pulls on the dyno so cant use the sensor for part throttle adjustment.
For that you would need load control, or have full data logging at the track, which we have.



I am puzzled that this actually works. As a good 30% of the delivered air to the engine goes straight out the exhaust port never to return to the cylinder, this must result in 30% of delivered oxygen going down the exhaust pipe. This is equivalent to a four-stroke running 30% lean of stoichiometric afr.

Now a wideband sensor will indicate the correct lean afr for the four-stroke so how does the sensor give useful information for the case of the two-stroke?