ESE's works engine tuner

[husaberg]

Tempting. But part of the reason I like these bikes is that fact they are 250cc. If I wanted to go big I would just build 690 single 4 stroke. Still will one day.

Sorry now i am confused........Presumably the only class it will be eligible for is F3......
F3 goes up to 400cc 2 strokes........
Are you really really wanting to be the underdog that much?

[speedpro]

If I wanted to go big I would just build 690 single 4 stroke. Still will one day.

You don't have far to go.

[richban]

Are you really really wanting to be the underdog that much?

....Yep....

[husaberg]

http://www.youtube.com/watch?v=X0kVLtxvKwU&feature=player_detailpage

yeah yeah i know;)

[wobbly]

Peak power of the 250 kart engines was around 10600 and reved to 11600 if needed.
Big ends didnt last long but who cares, plenty of National titles.

[dmcca]

Peak power of the 250 kart engines was around 10600 and reved to 11600 if needed.
Big ends didnt last long but who cares, plenty of National titles.

What engine were you using as a base for this? Assuming 66.4 x 72 or did the mods include squaring things up?

[wobbly]

Early 2000 CR250s were the most used - before Avgas and Methanol were stopped by the wise men..
Stroke is way too long, but as I said we reved the tits off the things and replaced the cages regularly.
The early KTM had a shorter stroke and went very well, but needed a huge amount of porting and welding to make it work.

[2T Institute]

What a funking lemon. Just started to strip the top ends. Only got as far as removing the barrel on the bottom cyclinder to find 3/4 of a piston and a completely shaged bore. At that point I gave up and am now having a beer thinking of how I should proceed with what is now turning into a complete engine rebuild.

Did you remember me saying this a few pages back?


You can get 65hp with just bolt on bits and an ignition. However, you will run into the problem of the shit RGV piston which at 65hp is at their limit. The pin boss will disintergrate and take out the cylinder on the right that or the tang between the arch will break off.

Another reason not to flirt with the old kit set up, (unless you have a VJ21) a programmable allows you to split the timing between cylinders. ALWAYS happens on the bottom cylinder :msn-wink:

[richban]

Did you remember me saying this a few pages back?



Another reason not to flirt with the old kit set up, (unless you have a VJ21) a programmable allows you to split the timing between cylinders. ALWAYS happens on the bottom cylinder :msn-wink:

I think this was more a case of 40000k's and no love.

I have finished the head drawing and dropped them of to be machined. New cylinders on the way and pistons after that. Frame mods should be done next week. So end of the month bike will be ready for the track. We will see how that goes but thats the plan. Oh and ignitech also on the way.

[dmcca]

Just thinking aloud here (which i usually end up regretting)... been pondering variations on the exhaust dam idea and whether or not theyd be of any benefit, initially considered a horizontal divider across the exhaust port positioned at the height of TPO and what effect that would have on pulse strength and short circuiting... but what about the concept of a powervalve flap on the floor of the exhaust port that raises the floor up to the level of the transfers as revs increase... could this widen the power spread? If i was really clever id think of a way to incorporate a 6th transfer port in this floor flap that opened to give more transfer area at high rpms.

[Frits Overmars]

Just thinking aloud here (which i usually end up regretting)... been pondering variations on the exhaust dam idea and whether or not theyd be of any benefit, initially considered a horizontal divider across the exhaust port positioned at the height of TPO and what effect that would have on pulse strength and short circuiting... but what about the concept of a powervalve flap on the floor of the exhaust port that raises the floor up to the level of the transfers as revs increase... could this widen the power spread? If i was really clever id think of a way to incorporate a 6th transfer port in this floor flap that opened to give more transfer area at high rpms.I am all for raising the exhaust duct floor, but why do it only as revs increase?

[kel]

If i was really clever id think of a way to incorporate a 6th transfer port in this floor flap that opened to give more transfer area at high rpms.



re the port under the exhaust port, how would this port be orientated?
My crude flow testing of the auxiliary transfers shows the hook at the rear of the port drives a stream underneath the main flow and towards the exhaust port. This would seem (on the surface) to drive the residual burnt gases towards the exhaust port aiding in cylinder purging. If a port was added under the exhaust port floor would this not work against this perceived effect?

[Yow Ling]

http://www.youtube.com/watch?v=3F_0PvbKo44

might help with the imaginary 2 stroke in our heads

[TZ350]

284436

I have been playing with EngMod simulating the Ball Valve and trying different scenarios.

284438

I have been looking at how the 24mm throttle body will go with the Ball Valve.

284440

And found that the Ball Valve on its own was likely to be better than with the plenum.


284439

Then I had the bright idea to simulate the Ball Valve 24mm throttle body combo with a Boost Bottle.

284437

Red Line is the Ball Valve and 24mm throttle body, Blue line is with a Boost Bottle. It looks like something worth checking out in real life on the dyno.


284449

I wouldn't get to hung up on the hp numbers, the real thing to take notice of, is that EngMod2T is pointing out that a Boost Bottle with the Ball Valve is a worthwhile direction to explore.


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

284965

The original idea was to run the 32mm Ball Valve inside a plenum feed by a 24mm carb equivalent, but things change and now I am going to try it with a 24mm insert first.

284966284967284969

The 24mm venture insert is going hard up behind the Ball Valve. I am not sure exactly where reversion will accour but it looks like it will be a reasonably short inlet tract.

The insert has an aerofoil shaped leading edge and the trailing edge is a 14 degree (included angle) divergent cone, in fact it diverges at 14 deg more or less all the way out to the rotary valve face.

284968

32mm Ball Valve with 24mm carburetor equivalent throttle body venture behind it.


285027T

Took a sneaky peak at TeeZee's special inlet, just to see if it was actually 24mm.

It will be interesting to see how he fits a boost bottle in there, looks a bit tight.

Making a bit of progress.

285964285965285966

My mission at the moment is a boost bottle, it took me two - three weeks just looking at the problem to even see how I could fit one in, and have the bottle and piping all pointing down hill and get the gear box and clutch cover to seal around the pipe.

Normally I would not bother with such things as boost bottles, they traditionally being a carb tuning aid but Engmod said it might be a good idea and it should boost torque everywhere.

When you look at the restricted inlet I have to work with, there maybe something in it.

In my new engine the 24mm restriction in the inlet is only 25mm away from the rotary valve face and I have been able to fit the 12mm id boost bottle tube between the restriction and valve.

When you look at it, its easy to imagine the motor drawing air from the boost bottle and the 24mm inlet at the same time, then the boost bottle being re charged when the rotary valve closes.

The class rules restrict me to a 24mm carb equivalent. The area of the 24mm inlet is 4.5cm2 and boost bottle tube 1.1cm2. So the boost bottle represents a 25% increase in area or equivalent to having a 26mm carb. Not much maybe or even a perfect comparison but it looks like something to try.

I am anxious to get this BB thing sorted and the engine re assembled so I can get on with the much more interesting job of getting it to run with fuel injection.

[Flettner]

Thank you for the update, we all eagerly await progress reports.

[cotswold]

Check this lads race bike, It's built for 50cc racing in the uk...

details:

Wheelbase 43.5", Head angle 26 degees, trail 3.75". Weight (wet) 47kg. Undamped forks. 90mm drum brakes. Constructed from 1.5 mm, ERW steel tubing and mild steel sheet.


He has used a ty50 motor and the wheels are from a Tomos moped, he is off racing for less than $800

[F5 Dave]

I was reading Practical Sportsbikes magazine, specifically the AR50 100MPH project and noticed that the ESE thread was mentioned! I hope that they don't mind me posting this, it's advertising on their behalf so I doubt they will, but see the attachments for some sneak peaks.

It's a good build and I hope they achieve their goal, actually, it's a great magazine with lots of stink wheel articles and builds. We've just subscribed to the magazine too.
. . .

281658281659281660


Well I'd been looking out for the latest issue to see how they are doing (mag takes months to get to NZ so we're out of date - yeah yeah;))

Ran to 106mph on the dyno at 12,000 which I think was well past their peak power. Net result so far; 87mph but unable to hold 6th gear. They had jetted down a step to try improve (where they got 87) & it nipped up. Apparently was just getting too hot between runs & not jetting fault.

I'd argue that aircooled bike is petrol cooled & it has to run that bigger than optimum jet.

Either way they are cleaning it up & rechecking on the dyno so we have to wait another month (unless we get a spoiler from overseas guys). They will try gear it down if they can't pull 6th this time. Frankly I think it was crazy they didn't have a range of gearing for a top speed attempt on a Tiddler.

I still predict 92mph. I am not trying to knock them, it is a good effort & the bike looks great for what it is, true to the original idea rather than a liner attempt (they drafted a kid to ride it). I just think a bigger carb & some more revs would have helped their cause somewhat.



[edit] July issue, just looked on site & Aug issue advertised so we're not that far behind, but no mention of it in blurb.

[TZ350]

I'd argue that aircooled bike is petrol cooled & it has to run that bigger than optimum jet.

Yep ... totaly agree, found many times that what was best hp on the dyno was to lean on the track. Wob made some good points about finding the optimum exhaust temp on the dyno then replicating that on the track. Interesting stuff.

[F5 Dave]

Even then you might want to throw in some fudge factor for aircooled bike, unless you purposely went out of your way to get the plot particularly hot on the dyno (he says from a position of ignorance of not trying it). Guess he would have tried that on a KT.


Is it time for a beer yet?

[TZ350]

Even then you might want to throw in some fudge factor for aircooled bike.

Yes I think your right, probably adapt Wobs idea. So after getting close on the dyno, note what exhaust temp works well on the track and then jet for that on any given day.

Wobs exhaust temp idea is all about being able to reliably jet for different days and changing conditions to get the best out of the bike.

But how to measure and record exhaust temperature ....:scratch:

[Drew]

Can get exhaust temp sensors for diesel motors. Do petrol engines not have them?

[TZ350]

I am sure they do but I don't know what to buy or where to get it or how to log the data.

[Drew]

I am sure they do but I don't know what to buy or where to get it or how to log the data.

Ah, yes I see the problem.



Sinks away to continue trying to learn something from all the clever cunt.

[Farmaken]

How about this : Check out

http://thesensorconnection.com/category/egt-probes/all-egt-probes

They list a two stroke specific sensor and also do data loggers

[Yow Ling]

these guys make nice egt stuff
http://www.exhaustgas.com/ProductDetail.asp?ProductID=814&DepartmentID=10&CategoryID=54&RepID=&BasketID=

[kel]

re the port under the exhaust port, how would this port be orientated?

No takers?
I dont think the transfer port under the exhaust would work (in a conventional setup). Maybe splitting into two ports and aiming low and wide i.e away from the bore centre line might work?
If they were angled straight down the middle then they'd surely work against the action of aux transfer purging effect
If they were angled steeply up then too easy to short circuit straight out the exhaust port
Plus opening so late in the cycle I'm guessing they would rely heavily on the expansion chamber drawing the charge through, which just makes the above worse?

[TZ350]

Rob Metkemeijer's MB40 prototype engines are cast using the lost-wax method. Below you see a mold with exhaust and transfer cores, a wax cylinder and the end product.

Hopefully Frits or someone who has one of these can tell use more about the transfer angles.

286038286040286042

It has been done, Ok so its a model aero engine, but the idea must work.

And it looks like the exhaust is so wide (no piston ring) it covers three transfer ports. The middle one under the exhaust port looks relatively flat, the side ones look steeper.

Frits Fos cylinder.

286041

[diesel pig]

these guys make nice egt stuff
http://www.exhaustgas.com/ProductDetail.asp?ProductID=814&DepartmentID=10&CategoryID=54&RepID=&BasketID=

I have one of these they are very good. I have not melted a piston since I have had it. I have had DNF's since but the EGT help there too because I knew it was not a melted piston before I stop rolling since the gas temp's were not high enough.

[bucketracer]

What about one of these.

Lap times with splits and all sorts of data acquisition like CHT, EGT etc.

286046

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

286047

For each session recorded in Circuit Racing mode, the GPX has the ability to graph a map of the track on screen, without even uploading to your PC. In addition, you have the ability to play the lap in real time with your RPM, speed and split times all displayed on screen at the same time.

The GPX universal-input channels offer flexible digital/analog recording capabilities, record any and everything you are interested in seeing on your race vehicle.

With GPX, out of the box you have the ability to record gear, throttle position, wheel speed, RPM, temperature, pressure and suspension data... all with configurable alarms.

286045

The Data Acquisition menu allows you to define, calibrate and set the sampling rate for all of the data you're wired to collect. With a range of 5-250Hz, the GPX gives you the freedom to decide how much data you want to collect. Also available are temperature and switch alarms which you can customize to alert you of dangerous vehicle conditions.

Pricing, USD

286048

[teriks]

Hopefully Frits or someone who has one of these can tell use more about the transfer angles.

286038286040286042

It has been done, Ok so its a model aero engine, but the idea must work.

I never saw it in person, only exchanged a few words with Rob about it when it was in testing. If I remember correctly, it made good power on the dyno, although it didn't live up to the dyno results in flight testing at the time.

I guess Frits will correct me if I'm wrong ;)

[Moooools]

What about one of these.

Lap times with splits and all sorts of data acquisition like CHT, EGT etc.

286046

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

286047

For each session recorded in Circuit Racing mode, the GPX has the ability to graph a map of the track on screen, without even uploading to your PC. In addition, you have the ability to play the lap in real time with your RPM, speed and split times all displayed on screen at the same time.

The GPX universal-input channels offer flexible digital/analog recording capabilities, record any and everything you are interested in seeing on your race vehicle.

With GPX, out of the box you have the ability to record gear, throttle position, wheel speed, RPM, temperature, pressure and suspension data... all with configurable alarms.

286045

The Data Acquisition menu allows you to define, calibrate and set the sampling rate for all of the data you're wired to collect. With a range of 5-250Hz, the GPX gives you the freedom to decide how much data you want to collect. Also available are temperature and switch alarms which you can customize to alert you of dangerous vehicle conditions.

Pricing, USD

286048

Go hard or go home.

http://www.msel.co.nz/epages/motorsportelectronics.sf/en_NZ/?ObjectPath=/Shops/motorsportelectronics/Products/MOT18016

[wax]

Why not just use a mychron 4

[Flettner]

The LINK will data log as well.
Frits, what is the out come of this FOS? cylinder?
Considering this type of cylinder is keeping me awake at night, I need some sleep.

[F5 Dave]

A snip at eight grand, good one Max.

[wobbly]

Re egt and data logging.
The ONLY egt probes to use are the ones from Ex Gas Technologies, their Stingers are guaranteed for 2 years and I havnt managed to kill one in 5 years.
The twin screen 52 series Digatron kits they sell on EBAY are about 1/2 the price of the GPX and are easily the best bang for the buck.
The Sensorconnection guys sell LCD kits that do temps etc but dont have anything like the power for the money.

Air cooled race engines are thermally limited to the extent we HAVE to use fuel to cool, rather than make serious power.
On the dyno and on the track the KT will fade badly as soon as the pipe forces it to make any more than around 16Hp on direct drive.
Adding more fuel cools it down enough to get it to finish a race, but then its slow.
Dropping the peak power in favour of a wider average ,lower, powerband will allow the cooling system to cope better and the power stays consistent for longer.

Just an observation re the latest tangent some of you guys are lurching off on.
It amazes me that before most have a really good understanding and working knowledge of what amounts to pretty simple normal two stroke port technology, we now
want to launch of into the detail of seriously off the wall geometry's, that are so esoteric you cant even get an SAE paper that researches the detail.
I know a transfer under the EX is damn interesting, but I cant help but think that if all the effort was spent discussing and then doing the simple stuff better, we would already have reliable 35 Hp buckets.

[G Jones]

I cant help but think that if all the effort was spent discussing and then doing the simple stuff betterOr as I tried to tell one customer - "there ain't no shortcuts"....
Thanks for your PM - I've not forgotten to answer - just working through a few ideas before I reply...

Another subject - any of you guys found a way to machine a combustion chamber "nicely" ?
I have knocked up a couple of tools to machine squish & chamber - if anyone's interested - I've taken a couple of photos - I know it looks crap - but it was reasonably cheap to make - and it does the job reasonably accurately - I've posted them on my website if you want to take a look...

http://www.maplesigns.co.uk/photogallery/thumbnails.php?album=29&page=1

Any suggestions for improvements gratefully received - or if you've found a better way...(at minimal cost)
Cheers - Gordon.

[Moooools]

The LINK will data log as well.
Frits, what is the out come of this FOS? cylinder?
Considering this type of cylinder is keeping me awake at night, I need some sleep.

Yeah the LINKs datalogging really does suck. It barely has any capacity so you run out of storage while trying to start the thing. You can set a parameter to only record during some event (Wheel Speed > X or whatever) but it still doesnt last long and you inevitably end up missing some data that you want.

But if you have a CAN bus capable data logger or have an rs232 input then you can log most of your vitals on that. Although LINK is a pain in that it will out put some stuff on CAN and not rs232 and some stuff on rs232 and not CAN.

There is a reason people the Missing LINK. However from a price perspective it is plenty decent for most things that bucket racers would be doing.

[Moooools]

A snip at eight grand, good one Max.

Clearly so much overkill and completely pointless for buckets but the Motec i2 software for post analysis is truly fantastic. It is just so well sorted and very capable. It used to be that you could import data from other data loggers onto i2 but in more recent versions that has stopped.

Unfortunately even if you don't need 50 odd channels and want to go to the cheaper end of MOTEC it still costs you your first born child.

http://www.msel.co.nz/epages/motorsportelectronics.sf/en_NZ/?ObjectPath=/Shops/motorsportelectronics/Products/MOT18022

[TZ350]

Page 820 ...

286699


Yea you need the output to ground option, this earth's the Ignitech input to retard mode.

286698

http://www.ebay.com/itm/Knock-gauge-for-detonation-sensor-klopfsensor-NEW-/181138934401

Rich these are the det sensor posts that I could find.


258175 258176

So that is Aprilia RS250 and RGV250 that have cable operated TPS's, now that is very handy ......



Thanks for the layout, TZ suggested I should stand them all on end and number them according to their length but having a proper layout plan is much better.


Forget the homemade bullshit, get one of these with the extra wire to ground.
When it sees deto it can ground an Ignitech input and retard the timing automatically.
You get flashing lights and engine protection all in one shot, and cheap as chips - made in Czech so it likes being connected to an Ignitech - same lingo..
Works perfectly - when you get it trimmed correctly it will tell you where to manually pull out timing, then it just operates as a failsafe.

http://www.ebay.com/itm/Knock-gauge-for-detonation-sensor-klopfsensor-NEW-/110818862446?pt=Race_Car_Parts&hash=item19cd51a56e&vxp=mtr#ht_1582wt_1297


263028

Ok mine turned up today.

263027

And a couple of two wire sensors I picked up cheap from the local garage.


263081

BOSCH p/n 0 261 231 046

263082

Other sensors can be found here too. http://www.bosch.com.au/content/language1/html/4563.htm


Good luck with the Deto sensing TZ. I like the little warning instrument!

Here's how I mounted my sensor. I drilled-tapped an old head bolt and screwed a stud.

263051263052

My sensor has a PN 0-261-231-001, what's yours?
According to this http://www.phormula.co.uk/KnockCalculator.aspx , deto freq for 56mm bore should be 10.2kHz.
According to Bosch datasheets for PN -047 (http://www.bosch-motorsport.de/en-US/literature/en-US/Knock_Sensor_KS-R_Datasheet_51_en_2779074187.pdf) & -120 (http://www.bosch-motorsport.de/pdf/sensors/knock/KS-P.pdf), sensors are able to catch frequencies from 1 to 20 kHz.
I assume all Bosch sensors can sense knock within this range (?)

edit: As for the pick-up voltage, I think it won't be more than +-10V. I had a voltage test yesterday with a data acquisition device in real time! I spinned the crank by hand and recorder the voltage waveform from the pick-up in the PC. As RPM increase, amplitude (and freq of course) of the pulses increase - by hand-spinning it didn't exceed 3~3.5 VAC. Sure it was a lot of fun to watch! http://www.kiwibiker.co.nz/forums/images/smilies/biggrin.gif


The shock waves from deto will be transmitted right thru the cylinder and the case.
I have seen many times where for no apparent reason the head or barrel studs loosen off - not because they weren't torqued correctly, but due to the
gasket being crushed momentarily from deto.
Many cars have the det sensors on the side of the block,some with multiple sensors for cylinder pairs.
All that happens when the sensor is further away from the chamber is that the shock intensity is reduced, so the sensitivity of the amp must be wound up - not an issue.


Relocated the knock sensor. I found some steel head bolts and faced one off, then drilled and tapped it. And made a standoff that was carefully faced off as the knock sensor likes to be securely mounted on a very flat surface. The black goop (silicon glue) on the blue wire is there as a strain relief and hopefully it will stop the vibration breaking the wire where it is attached to the copper head fin.


The Trumeter 7111 is no longer stocked by RS but they do have something similar.

269009

703TR002N-512D RS part number 183-5952 $63.50 ... 5-12V and less than 10mA so easily self powered and at 500Hz fast enough to count all deto events as seen by the Knock Gauge or similar, as 200Hz in a 2-Stroke equals 12,000 rpm.

269008

And here is something if you want to try your hand at making a complete det counter for your self.

269011

RS part number 185-6090 $45.30

You could box this along with an amp or frequency filter from Jaycar and make you own little compact det counter.

269012

Electrical specs.

269014

Two different ways to go, with an amp you would count the high amplitude deto peaks or you could use a band or high pass frequency filter and count whatever passes through it.


More on the TPS thing.

This is an email I sent to Ignitec.

Hi
We have several bikes with Ignitec Sparker DC-CDI-P2 tunable two channel ignitions.
We want to use the TPS function.
We found that a 5K Ohm TPS unit worked OK but a 25K one gave us trouble.
Is a 25K resistance wrong?
What resistance TPS do you recommend?
Thanks

This is their reply.

Hello,
Standard automotive TPS has resistance about 5 kOhm.
25 kOhm is strange. Is it regular automotive TPS ?
276981
We recommended to use automotive TPS.
Jiri Krejzl
IGNITECH

It Looks like a (nominal) 5k Ohm TPS is the unit of choice for the Ignitec.

[TZ350]

Re egt and data logging.
The ONLY egt probes to use are the ones from Ex Gas Technologies, their Stingers are guaranteed for 2 years and I havnt managed to kill one in 5 years.

The twin screen 52 series Digatron kits they sell on EBAY are about 1/2 the price of the GPX and are easily the best bang for the buck.
The Sensorconnection guys sell LCD kits that do temps etc but dont have anything like the power for the money.

Air cooled race engines are thermally limited to the extent we HAVE to use fuel to cool, rather than make serious power.
On the dyno and on the track the KT will fade badly as soon as the pipe forces it to make any more than around 16Hp on direct drive.

Adding more fuel cools it down enough to get it to finish a race, but then its slow.
Dropping the peak power in favour of a wider average ,lower, powerband will allow the cooling system to cope better and the power stays consistent for longer.



Rob, Running egt and cht you can watch both rise in unison as the rpm and power rise.
As soon as deto starts the cht will shoot up, the egt will flat line or drop as radicals are formed in combustion.
The best data logging gauge ( and the ONLY reliable egt probes ) are here.

http://www.exhaustgas.com/ProductDetail.asp?ProductID=805&DepartmentID=12&CategoryID=54&MenuID=sub4&BasketID=&RepID=

Thanks Wob ...


Air cooled race engines are thermally limited to the extent we HAVE to use fuel to cool, rather than make serious power.

My copper finning is all about lifting the thermal limit.

286086

And clarification from the MNZ RR Commissioner re using a petrol powered leaf blower for forced air cooling, yes I asked.

286087286088

Next move in the cooling stakes is to use ducting to force the cooling medium to scavenge more completely between the fins.

286089286090

The exhaust port dam is so easy to impliment it certainly would be worth while looking at it again some more in the near future.

[quallman1234]

Clearly so much overkill and completely pointless for buckets but the Motec i2 software for post analysis is truly fantastic. It is just so well sorted and very capable. It used to be that you could import data from other data loggers onto i2 but in more recent versions that has stopped.

Unfortunately even if you don't need 50 odd channels and want to go to the cheaper end of MOTEC it still costs you your first born child.

http://www.msel.co.nz/epages/motorsportelectronics.sf/en_NZ/?ObjectPath=/Shops/motorsportelectronics/Products/MOT18022

If you wish to stay on the cheap size of shit and wanna datalog.
Just buy a Ardunio board with SD card onboard and just use that, might need to watch how much current/voltage (easily fixed) you put into it but its a 30$ solution. I've used it as a Suspension Datalogger, with a linear pot.
You could output to a homemade dash for it also. Might be on the slow side however.

[tdc211]

I tried those sensorconnection 2stroke egts thermos last year and they are very slow on response time.
I called and complained. They sent me some faster probes for free, which work better.

[TZ350]

285964285965285966

My mission at the moment is a boost bottle, it took me two - three weeks just looking at the problem to even see how I could fit one in, and have the bottle and piping all pointing down hill and get the gear box and clutch cover to seal around the pipe.

Another step forward with the boost bottle.

286105

The alloy block is for sealing the clutch cover to the crank case.

286107286106

Cut the clutch cover away around the BB pipe and sealing block.

286108

Bit of Devcon putty mixed in the correct ratio by weight.

286104

With a bit of luck and plenty of sealant, we should be able to keep the gear box oil inside the case.

[senso]

If you wish to stay on the cheap size of shit and wanna datalog.
Just buy a Ardunio board with SD card onboard and just use that, might need to watch how much current/voltage (easily fixed) you put into it but its a 30$ solution. I've used it as a Suspension Datalogger, with a linear pot.
You could output to a homemade dash for it also. Might be on the slow side however.

Not Arduino(crappy libs), but I'm developing a custom dash board, and data-logger, and if it ends costing 100€, I'm doing it wrong, and at least I can pack it with Gb's of space from either a "slow" sd-card, or 8-16MB of fast flash, with gps speedo, 4 thermo-couples, a couple analog spare inputs, tacho, deto, PTC/NTC temp sensors, hall effect speedo, almost everything those multi thousand dollar, for much, much less(yes I'm working for free, but spare time I can afford).

[Frits Overmars]

And clarification from the MNZ RR Commissioner re using a petrol powered leaf blower for forced air cooling, yes I asked.What kind of clarification, Yea or Nea? I would argue that any petrol powered device, meant to keep you going, should add to the bike's cubic capacity, number of cylinders and total carburetter area.


The exhaust port dam is so easy to impliment it certainly would be worth while looking at it again some more in the near future.Amen to that.

[husaberg]

A bit of luck and plenty of sealant, we should be able to keep the gear box oil inside the case.


Order some of EMOT's Special ex USSR designed insulating paint (http://www.emot.nl/specials.php) and give it a lick Rob.:msn-wink:

Although It's been brought up before a few times, i don't think any of the buckets have tested it out yet.....
http://www.emot.nl/specials/thumbs/picture_809.jpghttp://www.emot.nl/specials/thumbs/radarsat2_preparatifs_02.jpg

That plus slapping on a massive ducted heat sink to the bottom of the crankcase if you have room.
<img src="http://www.walmate-cn.com/asp_bin/Webeditor/UploadFile/200912712511738.jpg" width="265px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282172&d=1367302087" width="230px"/>

Lastly slap one of these on the EX pipe. As they seemed to know what they were doing.
<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=249819&d=1320056953" width="140px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282328&d=1367567731" width="210px"/>

[Yow Ling]

And clarification from the MNZ RR Commissioner re using a petrol powered leaf blower for forced air cooling, yes I asked.



Would you mind posting your question to Billy and his reply ?

[jasonu]

What kind of clarification, Yea or Nea? I would argue that any petrol powered device, meant to keep you going, should add to the bike's cubic capacity, number of cylinders and total carburetter area.

Yes to that


Would you mind posting your question to Billy and his reply ?

Yes to that too.

[TZ350]

Order some of EMOT's Special ex USSR designed insulating paint (http://www.emot.nl/specials.php) and give it a lick Rob.:msn-wink:
Although It's been brought up before a few times, i don't think any of the buckets have tested it out yet.....
That plus slapping on a massive ducted heat sink to the bottom of the crankcase if you have room. Lastly slap one of these on the EX pipe. As they seemed to know what they were doing.

Hi Husa, I like your paint and heat sink idea and have just won this on Trademe. 80x70x80mm and 12V 0.25A fan.

286130

And yes I agree, if the heat sink is on the underside then a heat shield on the exhaust pipe will be necessary.

[husaberg]

Hi Husa, I like your paint and heat sink idea and have just won this on Trademe. 80x70x80mm and 12V 0.25A fan.



And yes I agree, if the heat sink is on the underside then a heat shield on the exhaust pipe will be necessary.

def not my idea's just regurgitated them.:yes:
I was thinking more ducted fresh air for the heatsink like the JPS Norton (ie Peter williams cut up oil can) duct to cool the troublesome fuel pump overheating (suffered because of the heat soak from the aircooled engine apparently) The mechanical Fuel pump worked of the swingarm pivot (very clever) They also tried it running of the engine vibration and it worked well other than when the vibes smoothed out a peak revs due to the balance factor and it stopped pumping enough fuel.;)

[Sketchy_Racer]

Or as I tried to tell one customer - "there ain't no shortcuts"....
Thanks for your PM - I've not forgotten to answer - just working through a few ideas before I reply...

Another subject - any of you guys found a way to machine a combustion chamber "nicely" ?
I have knocked up a couple of tools to machine squish & chamber - if anyone's interested - I've taken a couple of photos - I know it looks crap - but it was reasonably cheap to make - and it does the job reasonably accurately - I've posted them on my website if you want to take a look...

http://www.maplesigns.co.uk/photogallery/thumbnails.php?album=29&page=1

Any suggestions for improvements gratefully received - or if you've found a better way...(at minimal cost)
Cheers - Gordon.

The way you have set it up is the best solution for making accurate curves on a manual lathe. You might see some improvements from increasing tool rigidity but apart from going to CNC control there is no other suitable methods I can think of.

Nice work!

Cheers,

-Sketchy

[dmcca]

I am all for raising the exhaust duct floor, but why do it only as revs increase?

After a couple of scotch's the other night my thought was that at lower rpm (below the tuned range of the pipe) the higher floor and therefore smaller volume duct might further increase the negative impacts of the pipe... so i pondered whether there would be any benefit in altering the floor height to influence this... but now that the scotch has worn off and ive thought more about it ive realised that a very clever person has already invented the ATAC system to achieve the same result with less complexity.

[Frits Overmars]

After a couple of scotch's the other night my thought was that at lower rpm (below the tuned range of the pipe) the higher floor and therefore smaller volume duct might further increase the negative impacts of the pipe...Now I can understand your line of thought. Must be good stuff you're drinkin.

[TZ350]

Would you mind posting your question to Billy and his reply ?

Here is the MNZ RR Commissioners reply to my two questions.


Hi Rob,

Answer number 1 is,Yes it would be classed as a watercooled engine so therefore could be no bigger than 100cc.

Answer number 2, I see no reason why an auxillary engine could not be petrol powered provided it is at the front of the engine,Therefore not forcing induction in any way and it is in no way powering the machine.

Hope this clarifies these issues for you.
Cheers Billy



On Tue, Jul 30, 2013 at 4:25 PM, .... wrote:


Hi Billy
I need your help with this.
A while back I asked for clarification on two points for F4/F5 (Buckets) I know your busy but this is a very competitive class where people at the pointy end invest a lot of thinking outside the box and development effort into their bikes and these points are important to me.

(Q1) Is an air cooled still an air cooled when you use water injection into the inlet manifold as a detonation supresent?

Solo motorcycles shall have two engine capacity classes:
F4 2 stroke 55-100cc
2 stroke 55-125cc air cooled
4 stroke 55-150cc

(Q2) Independently (battery) powered accessories like water pumps have been accepted on Buckets for a long time. I would like to use an independently powered accessory (fan) driven by a small petrol motor for air cooling . The question is if battery powered accessories are OK because they cant move the bike on their own then is a petrol powered accessory (leaf blower) that can't move the bike on its own equally OK.

Many Thanks
Rob
MNZ Race Licence Number 2188

[Flettner]

Wow, so, on a wet day with water induction ( raining ) you are in fact illegal. ??
Billy, are these your ideas or are you looking at the FIM rule book?

[kel]

re the port under the exhaust port, how would this port be orientated?


I was having a look at the pit-lane thread the other day as I was looking for the RSA head details as posted by Frits, and I stumbled on discussion re raising exhaust port floor and adding an extra transfer duct. As always its been done before -

Jan Thiel
"Yes, I did that in 1974, without success!
At Aprilia I had a cylinder cast, in 2007, with the underside of the exhaust raised to the level of the upper
transfer port height.
It was my intention to lower this until the power became good.
But when I realized that I would be retired when the cylinder would be plated I abandoned it, and had it
CNC machined to 'normal'
A pity!"
For more click here http://www.pit-lane.biz/t117p900-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-1-locked

Thank goodness the best arent constrained by others.
Innovators, inspirers, leaders :rockon:


But wait theres more - also from Pit-Lane
SAE paper 2006-32-0061

[husaberg]

Here is the MNZ RR Commissioners reply to my two questions.







(Q2) Independently (battery) powered accessories like water pumps have been accepted on Buckets for a long time. I would like to use an independently powered accessory (fan) driven by a small petrol motor for air cooling . The question is if battery powered accessories are OK because they cant move the bike on their own then is a petrol powered accessory (leaf blower) that can't move the bike on its own equally OK.
Hi Rob,


Answer number 1 is,Yes it would be classed as a watercooled engine so therefore could be no bigger than 100cc.

Answer number 2, I see no reason why an auxillary engine could not be petrol powered provided it is at the front of the engine,Therefore not forcing induction in any way and it is in no way powering the machine.

Hope this clarifies these issues for you.
Cheers Billy


Wow:scratch: i find that response illogical, as the petrol powered device is powering a fan which is in turn powering the engines cooling system. and is petrol powered therefor is adding to the engines total cylinder capacity.
On the other side of the coin it will also free up all the rules like why use precious engine or battery power or engine power to charge to run an alternator to power ancillaries such as water pumps and electrical generators, oil pumps,fuel pumps, crankshafts etc. Valves can be converted to pneumatic etc and powered by an ancillary engine as well then. I wonder how long it is before the other classes catch on...........

Actually why does it need to be petrol powered? those scale aircraft glow engines would be lighter..........

[wobbly]

You can do all of that now - here is the electric water pump on the Pre 82 Junior - Frepin400.

[husaberg]

You can do all of that now - here is the electric water pump on the Pre 82 Junior - Frepin400.

http://www.bdkraceeng.co.uk/Electric%20Water%20Pump%201.html


Compare two cooling systems, A and B. In system B the water flows three times as fast and picks up only half the amount of heat per liter, compared to system A.
Then system B removes 50% more heat than system A! And provided your piston clearance is OK, you just cannot have too much cooling. In the Aprilia RSA125 the water pump circulates 160 liter per minute. That is 3 liter per HP per minute!

Nowadays we have a fine solution for avoiding corrosion; it's called plastic. Saves weight too.

I don't know exactly how the NZ dollar is doing, but that sum will probably buy you two of these:
http://www.hvg-engineering.com/index.php?action=article&group_id=10000015&aid=127&lang=NL

what actually is the actual total draw in watts to run the ignition and charge the battery on your slave ignition dyno system Wob?

[Ocean1]

Another subject - any of you guys found a way to machine a combustion chamber "nicely" ?

Any suggestions for improvements gratefully received - or if you've found a better way...(at minimal cost)
Cheers - Gordon.

Some lathes, (Colchesters for one) have a pair of tapped service plate holes low on the front face of the tailstock and, at the same height on the tailstock side of the cross-slide.

You can mount clevis plates to these, and a tie-rod between them. You can make several tie-rods of different lengths, and you can make them length adjustable.

By locking the tailstock and engaging the cross-feed you get an exact radius cut at a controlled feed rate. Makes for a better finish than even an experienced hand fed example.

One thing to watch: you can't get too close to "TDC" on the tie-rod, it'll put too much load on the whole assembly. And yes, a more robust tool would minimise chatter/harmonics. Lots of top rake for aluminium.

[speedpro]

Originally my sidecar had an electric fuel pump and water pump powered by a battery. I converted to a vacuum fuel pump but left the water pump electric. On my MB100LC engine the water pump is electric but happens to be powered by the generator. I don't really see the difference between an electric water pump and a petrol powered fan to force air over fins. Both are cooling systems where the cooling medium is moved by an external power source.
I 100% disagree with the idea that water injection provides any sort of measureable engine cooling and would love to read about that.
About the battery versus generator debate - A battery is heavy, generally more than a generator, but does not absorb power from the prime motivator, as minimal as that would be. If there is a difference it would be only measureable in a lab surely.
As usual I expect bucket racers will continue doing exactly what we want to with a good dose of common sense.

[Frits Overmars]

I 100% disagree with the idea that water injection provides any sort of measureable engine cooling and would love to read about that.Here you go: http://www.pit-lane.biz/t1666p90-technique-rossigrm-2strokes-boat-engine


A battery is heavy, generally more than a generator, but does not absorb power from the prime motivator, as minimal as that would be. If there is a difference it would be only measureable in a lab surely.If you can make such a statement just like that, then who still needs a lab? Or a test bench?
A crankshaft-driven cooling fan will absorb over 1 HP, so if you are allowed to drive that fan through an auxiliary engine, you have an unfair (in my opinion) advantage of over 1 HP.
If you take a look at model airplanes, you'll find 4 HP motors that you can hold in the palm of your hand. They could drive a huge cooling fan. Or a blower connected to the inlet system. And what about converting the engine's flywheel generator into an electric motor and hooking it up to a battery pack hidden somewhere in the frame? Batteries are getting lighter and smaller all the time and sooner or later it will become necessary to regulate the amount of battery energy you are allowed to start with.

As usual I expect bucket racers will continue doing exactly what we want to with a good dose of common sense.I sincerely hope so. But you cannot rule out the existence of black sheep...

[speedpro]

Fair comments. I don't see in that link where it mentions cooling the "engine".
A 1hp fan is going to draw a bit of current and I can't see any commonly used battery supplying the power required for the time required, generally, which leaves the fan attached to the crank, OR powered separately as Rob is thinking of.
The newer LiFe batteries are pretty good I must admit, as evidenced by the performance of the electric models flying at the airfield next to the Tokoroa kart track when we've raced there. A small light electric motor providing that sort of power all loaded up and not ripping through the air at 70+mph for cooling would have a shortened life as well I would think. As far as storing generator power goes you don't need a battery just a good ol' capacitor, like I'm already using.
It's all theoretical of course as it hasn't been done yet.

[husaberg]

Fair comments. I don't see in that link where it mentions cooling the "engine".
A 1hp fan is going to draw a bit of current and I can't see any commonly used battery supplying the power required for the time required, generally, which leaves the fan attached to the crank, OR powered separately as Rob is thinking of.
The newer LiFe batteries are pretty good I must admit, as evidenced by the performance of the electric models flying at the airfield next to the Tokoroa kart track when we've raced there. A small light electric motor providing that sort of power all loaded up and not ripping through the air at 70+mph for cooling would have a shortened life as well I would think. As far as storing generator power goes you don't need a battery just a good ol' capacitor, like I'm already using.
It's all theoretical of course as it hasn't been done yet.

A 1 hp Fan will as you say draw at lest 1 hp from the engine powering it probably a fair bit more...... as you say a battery wont last long.........And there's the rub.
I posted a while back how much the VW coling fan absorbs, but i can't be arsed looking for it........but it was a fair bit of HP.
Even if Billy says he can't see an issue, i do, it doesn't add up.
SO i don't quite agree the with the theory on the losses being tiny esp for a power greedy fan rather than a water pump.....
for instance try turning the lights or air con on an older car without the stepper controlled idle (or why they have stepper control on the idle..)
Also muse why cars now have electric fans and viscous coupling fans.

PS Frits was talking of glow aircraft engines rather than electric ones i guess.

Hats off to billy for making a considered opinion but i don't think he quite considered the possible ramifications in regards to a controlled cylinder capacity liquid vs air cooled class correctly.
i wonder what would happen if Honda turned up at Moto GP with an Auxiliary petrol engine. I do have to wonder what would the FIM say?

PS Wob you must dust off that engine and send down, i am taking some time off work soon.

[rgvbaz]

Well I'd been looking out for the latest issue to see how they are doing (mag takes months to get to NZ so we're out of date - yeah yeah;))

Ran to 106mph on the dyno at 12,000 which I think was well past their peak power. Net result so far; 87mph but unable to hold 6th gear. They had jetted down a step to try improve (where they got 87) & it nipped up. Apparently was just getting too hot between runs & not jetting fault.

I'd argue that aircooled bike is petrol cooled & it has to run that bigger than optimum jet.

Either way they are cleaning it up & rechecking on the dyno so we have to wait another month (unless we get a spoiler from overseas guys). They will try gear it down if they can't pull 6th this time. Frankly I think it was crazy they didn't have a range of gearing for a top speed attempt on a Tiddler.

I still predict 92mph. I am not trying to knock them, it is a good effort & the bike looks great for what it is, true to the original idea rather than a liner attempt (they drafted a kid to ride it). I just think a bigger carb & some more revs would have helped their cause somewhat.



[edit] July issue, just looked on site & Aug issue advertised so we're not that far behind, but no mention of it in blurb.




Last issue I saw they retested and got it to 95mph but it wouldn't pull 6th. They are getting a non-standard size sprocket machined to try and get the gearing right. The next issue should be out here soon!

Cheers

Dave

[Frits Overmars]

Frits was talking of glow aircraft engines rather than electric ones i guess.Usually I am, Husa, but not in this case. That's why I called them motors and not engines.



I don't see in that link where it mentions cooling the "engine".It mentions "inject water into the combustion chamber, exchanging temperature for steam pressure."
Guess what lowering the combustion temperature will do to the engine temperature.


As far as storing generator power goes you don't need a battery just a good ol' capacitor, like I'm already using. It's all theoretical of course as it hasn't been done yet.It has been done, a couple of years ago, by Harald Bartol, on the 125 cc works KTM roadracers.
In braking mode the generator/motor on the crankshaft charged a supercap; in acceleration mode the supercap fed the stored energy back to the crankshaft.
Of course rear wheel braking in a road racer does not amount to much. But imagine a light, powerful generator/motor front hub. In braking mode you would be able to recover a huge amount of energy, and in acceleration mode you could have all wheel drive (very useful, with the front wheel off the ground :D).

Joking apart, I've been doing some brainstorming regarding a Freetech50 design. It should have continuously variable transmission, but without the losses of a scooter belt drive.
The efficiency of electric motors is already very good. The efficiency of generators still leaves something to be desired but assuming we can correct that, a generator + motor could handle all the functions of clutch, gearbox, brakes and energy recovery. We could have a 50 cc engine on full song all the time, charging a supercapacitor, even while braking. That would about double the available amount of power over a race distance.

As a rulemaker (yes, I do that too) I would have to add just one line to the rulebook: 'any battery or supercapacitor should be empty at the start of the race'.
How well the energy stored in the fuel is used, should be up to the constructor.

[Strokerhaus]

def not my idea's just regurgitated them.:yes:
I was thinking more ducted fresh air for the heatsink like the JPS Norton (ie Peter williams cut up oil can) duct to cool the troublesome fuel pump overheating (suffered because of the heat soak from the aircooled engine apparently) The mechanical Fuel pump worked of the swingarm pivot (very clever) They also tried it running of the engine vibration and it worked well other than when the vibes smoothed out a peak revs due to the balance factor and it stopped pumping enough fuel.;)

If you add ducts round the engine like Peter Williams, then add an ejector like the Rotary Nortons that may well help cool the top end. The rotary Nortons used the ejector to cool between the twin rotars driven by exhaust gass flow, the only question I have in my mind is how will it effect a 2 stroke exhaust performance?

[TZ350]

Some photos I was asked for.

286284

A 3/4" Mallory metal slug, Mallory metal is soft Tungsten (Tungsten is alloyed with other metals to make it hard). Mallory can be machined easily and weighs about twice as much as steel. Wob recommends a bit of Tig weld to secure it in place. Alloy plugs in the balance holes near the crank pin.

286285

2mm of the inside face both sides, I would take more but I fear the counterweights would become to light. 0.2mm from the thrust washer faces so there is sufficient side clearance on the rod and it also gives you something to come and go on to get 1mm clearance minimin between the flywheel and case.

286286

The boost port is mostly cut into the crankcase on the magneto side.

286283

The magneto side needs gluing up here, I didn't bother with the carb crankcase side as you hardly cut into it.

286287

The original boost port was just a trench in the rear wall of the cylinder, now its more or less a proper port and duct.

286288

[wobbly]

Im sitting on the edge of my chair waiting for a huge shipment from Ignitech that has taken months to be delivered, due they finally said, to summer holidays and some sort
of death disaster withinin the company.
When it arrives I can run up the ignition dyno and check the power consumption on no load with a digital clamp, add the flywheel with magnets spinning, then add a battery/reg/ running ignition.

[F5 Dave]

Last issue I saw they retested and got it to 95mph but it wouldn't pull 6th. They are getting a non-standard size sprocket machined to try and get the gearing right. The next issue should be out here soon!

Cheers

Dave
Well I'm wrong already, Thanks Baz.

[F5 Dave]

. . .On my MB100LC engine the water pump is electric but happens to be powered by the generator. I don't really see the difference between an electric water pump and a petrol powered fan to force air over fins. Both are cooling systems where the cooling medium is moved by an external power source. . .

and the reason 100ccs are restricted to that size is they are allowed that extra cooling.

ooh look a CR250 flywheel has just turned up from UK. Getting hard to find. Another piece in the puzzle for upgrading the 50 ign.

[senso]

Sorry to ask, but does anyone have a nice book/literature/website where I can read about the balance factor of crankshafts, and how to calculate how much mass is needed to add(or remove) to achieve the desired balance factor?
Thanks.

[jasonu]

Here is the MNZ RR Commissioners reply to my two questions.






With regards to the cooling fan motor questions, if Billy says it is 'so' then does that mean it is in fact 'so'? Is this response his personal opinion or does it actually carry some MNZ 'weight'? If TEEZEE uses the fan set up and because of it gains a significant advantage would a (potential) protest even be heard?

[ac3_snow]

Sorry to ask, but does anyone have a nice book/literature/website where I can read about the balance factor of crankshafts, and how to calculate how much mass is needed to add(or remove) to achieve the desired balance factor?
Thanks.


BF=(A/B)*100

A is the flywheel counter balance weight and B is the reciprocating mass (weight).

238097

The lower half of the rod and big end can be considered rotating mass and disregarded and the upper half and little end reciprocating mass, along with the complete piston assembly.

Ballance Factor in % is A/B * 100 and is the amount of reciprocating mass counter balanced by the flyweel counter balance weight.

238096

Finding "B" the reciprocating mass. 231.9g

238095238098

Finding "A" the flywheel counter balance mass. 73.4g

In this example BF = (73.4/231.9)*100 = 32%

A will need to be 231.9 * 0.55 = 127.5g for a balance factor of 55%

238099

Adjusting "A"

This crank needs some mass added to the flywheel counter balance and this is being done here by removing mass from around the pin, and that effectivly makes the counter ballance heavier.



There has been a lot posted on ballance factors, you can use "Thread Tools" / "View Images" to find them.

There is more scattered throughout this thread however that post sums it up quite nicely. Can search by going to the top right and clicking on 'search thread' if you wish to look for more.

[husaberg]

Sorry to ask, but does anyone have a nice book/literature/website where I can read about the balance factor of crankshafts, and how to calculate how much mass is needed to add(or remove) to achieve the desired balance factor?
Thanks.

Try tuning for speed or the Villers tuning book.


Fan hp requirements
• fan air delivery varies directly as the speed varies (linear relationship)

cfm2 = (rpm2/rpm1) x cfm1
• fan pressure varies as the square of the speed

SP2 = (rpm2/rpm1)² x SP1
• required fan horsepower varies as the cube of the speed

hp2 = (rpm2/rpm1)³ x hp1.

So i estimate to power an equivalent electric fan to the petrol one Rob is suggesting would tally around 800-1200 watts at least (which would also tally with it's cc's of the petrol engine plus a little leeway) which is a fair bit more than a water pump draws on a 100cc bike from its battery and or charging circuit or directly from it's own engine.

35 liter /minute pump i guess would be 35 watts at most?

The liquid cooled bike also as Dave said is restriced to 100cc

People often overlook the 125's are resticed in two major ways the 24mm carb eq and the air cooling...........


If you add ducts round the engine like Peter Williams, then add an ejector like the Rotary Nortons that may well help cool the top end. The rotary Nortons used the ejector to cool between the twin rotars driven by exhaust gass flow, the only question I have in my mind is how will it effect a 2 stroke exhaust performance?

I think i have a pic of the ducting for the JPS750 engine somewhere. If i recall correctly it looks a lot like a Scooter set up.
With regards to the shroud the later Norton Rotary as i recall used to bletch massive flames on over run..........
here is a pic of the air ejector that used the vacuum from the EX (i think) to draw cool air threw the engine i think Hele or Creighton? came up with it.
http://farm4.staticflickr.com/3124/2874385573_ce6a5317f8_z.jpg?zz=1

[TZ350]

226307226306226303226305226308226302

As there is no one universally "correct" balance factor, there is only the one that works in your bike and it has to be found by trial and error.

More info here .... and Tuning for Speed can be down loaded for free from here :- tuningforspeed.com

[TZ350]

... if Billy says it is 'so' then does that mean it is in fact 'so'? Is this response his personal opinion or does it actually carry some MNZ 'weight'? ...

The questions were sent through the official MNZ email address to Billy in his capacity as MNZ's RR Commissioner.

[TZ350]

<iframe width="420" height="315" src="//www.youtube.com/embed/kBg86bjr8l0" frameborder="0" allowfullscreen></iframe>

Norton Rotary, not exactly slow.

[husaberg]

Norton Rotary, not exactly slow.

At 588cc swept cylinder volume and depending on wether the car or bike formula is used...
it is either 999cc or 1176cc and the size and weight of a 250 gp bike so it went as well as would be expected.
But still impressive and a lovely bike based on an engine designed in the 70's shame they never got it into production earlier.
Plus shame the classic/police bike was such an ugly troll......
Why didn't john Bloor adopt Norton instead of Triumph.....why why.......:wait:

PS insert mikes joke re rich under here..........

[richban]

Hi Guys

Looks like I will need to get my RGV cylinders re coated. Can anyone recommend a good professional outfit to do the job well.

[husaberg]

Hi Guys

Looks like I will need to get my RGV cylinders re coated. Can anyone recommend a good professional outfit to do the job well.

I think there is only one place here in NZ Rich.
Its seems much much cheaper in Euro-oporsis.http://www.emot.nl/specials.php
What is the Crank like?
Remember what someone said earlier about those other cylinders likely cheaper than getting yours re-plated too.

[Grumph]

Hi Guys

Looks like I will need to get my RGV cylinders re coated. Can anyone recommend a good professional outfit to do the job well.

NZ Cylinders in Ashvegas seem to have a reasonable rep. Kev's probably dealt with them or has a BMW client who has....ask him.

[richban]

I think there is only one place here in NZ Rich.
Its seems much much cheaper in Euro-oporsis.http://www.emot.nl/specials.php
What is the Crank like?
Remember what someone said earlier about those other cylinders likely cheaper than getting yours re-plated too.

Crank seams ok.

Yeah there are options on other cylinders. Just sorting that out. I would be nice to have some mint ones.

[richban]

NZ Cylinders in Ashvegas seem to have a reasonable rep. Kev's probably dealt with them or has a BMW client who has....ask him.

Yeah Kev said the only really good places were in the UK. Might just go with some second hand not so munted one for now and send mine off on the slow boat to blighty.

[F5 Dave]

I've used US chrome, they were good. This nz post youshop system is supposed to work well. just got something on the way with it. Actually my second set of CPI barrels from Millennium were better than the first and came with qa measurement of taper/ sizes.

[Kickaha]

NZ Cylinders in Ashvegas seem to have a reasonable rep. Kev's probably dealt with them or has a BMW client who has....ask him.

I've dealt with them for my Ducati cylinders, one week turnaround and good to deal with, Diesel Pig has also had one done there

I know of guys having some done at what was supposedly one of the best UK places and having problems with them, good luck dealing with a place that far offshore if it does go wrong

Imdying did post up of a place far cheaper than the local guys that had a good rep with the NSR guys, fuck knows who it was though

[richban]

Cheers Guys for the Cylinder info.

So I just popped out and picked up the heads from Glen. AKA custom components. Job went super smooth and Glen, as usual was super helpful. Thanks again.

So here it is my first attempt at any sort of 2 stroke tuning. It was fun. Hope it works.

286343

[timg]

Cheers Guys for the Cylinder info.

So I just popped out and picked up the heads from Glen. AKA custom components. Job went super smooth and Glen, as usual was super helpful. Thanks again.

So here it is my first attempt at any sort of 2 stroke tuning. It was fun. Hope it works.

286343 Yep, that definitely looks like your forte. Best you send your FXR to me to look after. No, no problem. You can thank me later :bleh:

[richban]

Yep, that definitely looks like your forte. Best you send your FXR to me to look after. No, no problem. You can thank me later :bleh:

Not sure about forte. I am winging it from info gained from smart people that know what they are doing. I know nothing really!

You wouldn't want the FXR now. I have tuned it into a 2 stroke.:msn-wink:

[FastFred]

.

Black Sheep

286346


you cannot rule out the existence of black sheep...

<iframe width="560" height="315" src="//www.youtube.com/embed/z4PkMPAlMFo" frameborder="0" allowfullscreen></iframe>

[wobbly]

The down South guys do very good work and are really helpful.
Especially if you want the coating removed first to do the porting properly - only way to go.
The USA Aptec guys probably have the best coating/cost and USPS is easily the best shipper on the planet.
Looks like we should all start sending work off to Rich for tuning.

[F5 Dave]

Glens new setup looks great for what is a converted garage, didn't look like the same place. smart lad esp considering his age. Think I had mastered the file by then. Dremel I was still dangerous with.

[speedpro]

Dremel I am still dangerous with.

Sorted . . . . .

[kel]

So I just popped out and picked up the heads from Glen. AKA custom components.
Looking good, but what about the outer o-ring? What squish, compression and fuel did you decide on? Is the piston flush with the top of the barell? As I alluded to before we had to machine the barell to pick up the required squish but this caused the chrome to flake off.
We have a couple of RGV heads which need modifying, looks like Glenn's the man :niceone:

[jasonu]

Yeah Kev said the only really good places were in the UK. Might just go with some second hand not so munted one for now and send mine off on the slow boat to blighty.

If you find an outfit in the States you want to use I would be happy to act as middle man/shipping agent.

[richban]

Looking good, but what about the outer o-ring? What squish, compression and fuel did you decide on? Is the piston flush with the top of the barell? As I alluded to before we had to machine the barell to pick up the required squish but this caused the chrome to flake off.
We have a couple of RGV heads which need modifying, looks like Glenn's the man :niceone:

.75 machined Squish. The piston will be flush and Avgas. Compression, I will get back to yah when I measure everything. 14:1 I hope. I had to make a few concessions with what I was working with. Outer o-ring will come later maybe. Glue will do for now.

Next will be stock heads converted to take inserts so I can really get things dialled.

I am really doing this quick and dirty and will try a few things but for me its about getting the bloody thing going and on the track.

[richban]

If you find an outfit in the States you want to use I would be happy to act as middle man/shipping agent.

Thanks Man will be in touch if need be.

[wobbly]

Rich, ya know how to cc toroids properly??

[richban]

Rich, ya know how to cc toroids properly??


I made a solid of the of the cylinder and then read the Volume of the file. Then just subtracted it form another solid to get the the cylinder working file for CNC.


But real world CC with engine built I would think it would need to be almost upside-down. Whats the trick master?

[F5 Dave]

Ooh there's a trap I hadn't thought about.

[F5 Dave]

. . .Outer o-ring will come later maybe. Glue will do for now.
. ..
My 50 has an inner ring & Loctite red Hi temp goop for outer seal. Never had a leak in. . .erm, 3 different cylinders & 15 years.

[TZ350]

286369

Making progress, its starting to go back together again with the Boost Bottle and Ball Valve fitted for the EFI setup.

286370

This is the dyno graph of the single exhaust port cylinder when it was last run (with a carburetor) it also ran reliably at Taumuranui.

I am going to use it for the EFI tests, so there is something of a base line to compare the boost bottle and EFI with. At some point I will plug the boost bottle pipe near the inlet to see what difference the boost bottle is realy making.

[Drew]

I have to be honest. At 28 horses reliably, I'd be leaving the thing alone from there. Or at least that set up with injection.

Now you're just being greedy!:bleh:

[wobbly]

Measure the cc with piston at TDC to the top of the plug hole.
Stop about 5mm from the top of the threads and rock the piston to get exactly the highest level.
Then fill flush to the top.
If you have 1mm of a 10 plug protruding then 2.2cc = the plug vol.
Take the head off and turn upside down LEVEL on the bench.
Fill the recessed toroid with fluid till it just creeps over the edge to the flat around the plug.
Take the original cc less 2.2 then add the extra fluid that represents the trapped air pocket within the head.
Remember with all these measurements, leave the burette sitting for 10mins to allow the clinging fluid on the glass walls to drop down and give accurate readings.

[TZ350]

I have to be honest. At 28 horses reliably, I'd be leaving the thing alone from there. Or at least that set up with injection. Now you're just being greedy!:bleh:

Yes you are right, I will leave this cylinder alone other than the EFI bit and you right again, I am greedy and will make another cylinder with the aim of low 30's and the same spread of power, and in the end, like Wob I think 36 at the rear wheel is possible.

OK it might be a big ask for an air cooled 125 with a 24mm carb equivalent but EFI should give me better control over the fueling and if things start detoing then I can have it chuck in more fuel to save myself. And the programmable ignition with a few gubbons like switching on forced air cooling at the right time, and an ATAC valve might be a help too.

[Drew]

Yes you are right, I will leave this cylinder alone other than the EFI bit and you right again, I am greedy and will make another cylinder with the aim of low 30's and the same spread of power, and in the end, like Wob I think 36 at the rear wheel is possible.

OK it might be a big ask for an air cooled 125 with a 24mm carb equivalent but EFI should give me better control over the fueling and if things start detoing then I can have it chuck in more fuel and save myself. And the programmable ignition with a few gubbons like switching on forced air cooling at the right time, and an ATAC valve might be a help too.

I am envious of course. I just don't have the patience to learn all the shit to do it. Or the brains to be able to apply it.

[TZ350]

I would be very interested in the roof angle of the 6th transfer port thats under exhaust.



This is where I have got to tonight, cylinder prepped and ready to go.

284574

The floor of the exhaust port is higher than BDC. I have no idea how high the exhaust port floor could be and I would dearly love to know more about it and what sort of angle a 6th transfer port there should be.

284575284576

The alloy stuffer plate and Belzona glue.

284573

All assembled, and compression tested OK so ready for a run up on the dyno, hopefully tomorrow night.

I want to get a good base run with the carb setup then switch to fuel injection. I have no idea how long the stuffer plate and Belzona will last, I guess we will find out soon enough.

The glued and screwed in port floor dam held up OK and the dyno results were better.

285043285044285045

Raised port floor Blue line.

285042

But I wouldn't read to much into it as this triple exhaust port cylinder made much better power before I "improved" it.

285046

All I did was tidy up around the inside of the main exhaust port area where the side ports converge and after I had finished that I found that some of the horses had bolted.

What was a stable of 29 became less than 20 ??????? ... http://www.kiwibiker.co.nz/forums/images/smilies/scratch.gif

Originally the the exhaust timing was 203 degrees duration, lowering the cylinder to 200 exposed the bottom of the exhaust port, the floor dam fixed that.

I was also going to try a power valve like piece in the top of the port but in the end a glued solution was not going to be satisfactory in the long run.

Messing with this has held me up so I have switched to working on fuel injecting a known good single exhaust port cylinder. I will try making another triple exhaust later.

Thanks Drew, but I am not sure about the brains bit.

286389

I initialy thought the triple exhaust port cylinder was not performing because there was so little piston skirt left to seal the exhaust port floor at TDC.

286387

And it improved when I put in the exhaust port dam but now I think that improvement is a red hearing. It may not have been leaking there after all and the improvement is due to exhaust port dams being a good idea and not a lack of sealing there.

286388

The ports on a Suzuki GP are not on the center line, they are rotated a bit relative to the piston and when you look at the side exhaust ports you can see one of them extends back past the piston center line.

286386

And these pro-light pistons with the side cutaways, when at TDC the piston cutaway would allow the side exhaust port to communicate directly with the transfer port and crank case.

I am sure it was pointed out to me as a possibility but I just didn't pick up on it.

So not so smart.... :facepalm:

I have another piston that does not have the sides cut away, I guess the old triple exhaust port cylinder is worth another try.

[Kickaha]

but I am not sure about the brains bit.

No Drew was right,he doesn't have any

[F5 Dave]

Thanks wob. Was lying awake last night and thought just flat clear plate the bugger (with drill hole for burette) , use that tech to machine sometimes having gotten the full measurement on engine, but with flat top piston could be added to deck height with no crazy math. Never had flat pistons on an engine I'm running yet.

rob yeah those suzi engines can be crazy like that, the VJ23 is like that too!

[TZ350]

286410

Original Suzuki GP 125 100mm rod on the right, the RGV250 105mm rod I currently use and the RD400 115 rod on the left that I am going to use in my new engine.

286411

Interestingly these 1986-88 YZ125 pistons both have the same Wiseco part number stamped on top. I think the one on the left was connecting the side exhaust port to the crankcase, I am going to try the one on the right in the triple ex port cylinder next.

[Flettner]

http://youtu.be/1YG9ko8-Nwk

TZ, the EFI YZ is getting used at trail rides, three now, trouble free.
Why are there not more EFI twostrokes out there? This bike is a lot of fun to ride. We are experimenting with injection timing changes, interestingly this changes the way the power is delivered.
So far a 14% fuel saving over my carbed YZ 250. Same track, same times, same rider. This must go to show there is less fuel spillage out the exhaust.

I am keen to see that ball valve working on your 125. I like the boost bottle idea, best way to beat that restriction so far.

[TZ350]

... the EFI YZ is getting used at trail rides, three now, trouble free.

So far a 14% fuel saving over my carbed YZ 250. Same track, same times, same rider. This must go to show there is less fuel spillage out the exhaust.

It sounds good and very responsive on the throttle too.


I am keen to see that ball valve working on your 125. I like the boost bottle idea, best way to beat that restriction so far.

Its going back together now but next week I am away for work, so the week after I should be able to start wiring the EFI and maybe get to see if it starts. One of the issues will be the EFI and Ignitec electricaly sharing the same TPS. The problem being they have different source voltages and therefore different voltage ranges to represent 0-100% throttle position, hopefully I can figure a way around that.

[speedpro]

The Ecotrons system learns 0% throttle when you power it up so that shouldn't be a problem. As far as the max throttle goes, one system will detect 100% while the other may detect only 80%. The remaining 20% won't matter. It will just be a portion of the map that is not used. Effectively you will have lost some resolution. Or is it a bit more complex than that.

[TZ350]

Not everything goes our way....

286457

Chambers and I have been tweaking his 50 and we have virtually tuned it to a standstill..... http://www.kiwibiker.co.nz/forums/images/smilies/laugh.gif

Started with the red line and after much hard work got to the blue line, looks like someone left the barn door open and the ponies escaped..... http://www.kiwibiker.co.nz/forums/images/smilies/scratch.gif

[F5 Dave]

That's a lot of revs if you're still running the std suzuki rod. they'll live all day long at 12k, but ticking if you're at 13.

[FastFred]

I think at one point they had it running to 15k with an even shorter power spread...... :facepalm:

[RomeuPT]

Been reading and watching post's mostly waiting for news about the raised exhaust port floor.... could be a new kick in the a** for the 4 joke fans and industry.

Meanwhile bought a KTM 250 SX, 2002 model to ride with my buddies at the weekend. The exhaust has some dents and I am thinking about filling it with water and put in the frezzer watching the dents go out....

Of course already thinked about building a pipe for it. Wobbly, what should be a start for it? I am thinking about 1000mm total lenght (9000rpm peak power), 135 belly max diameter, long swallow baffle like the stock ones!?

Thanks

[F5 Dave]

Nah nah, he's already split the good oil back page 817.
11600. Rpm. If a stinkn $onda can do it can't let it beat a pumpkin huh?:cool:

[Frits Overmars]

... bought a KTM 250 SX, 2002 model to ride with my buddies at the weekend....Of course already thinked about building a pipe for it. Wobbly, what should be a start for it? I am thinking about 1000mm total lenght (9000rpm peak power), 135 belly max diameter, long swallow baffle like the stock ones!?Let's pretend I am Wobbly: a 135 mm belly diameter sounds fine if you can accommodate it. But the angle.areas of the 250SX cylinder are insufficient for 9000 rpm.
If you force the engine to run at that rpm by means of the pipe, it won't deliver the power that can be had at lower revs.
You can enlarge the blowdown angle.area and gain a lot of peak power, but that will make the engine character too vicious for terrain riding and spoil all the fun.
Now I am eager to see what the real Wobbly has to say about it :shifty:.

[Frits Overmars]

Chambers and I have been tweaking his 50 and we have virtually tuned it to a standstill.....Detuning tends to be easier than tuning. If you can't improve engine power, then try to reduce it. You will probably succeed and it can be just as instructive :D.

[RomeuPT]

Let's pretend I am Wobbly: a 135 mm belly diameter sounds fine if you can accommodate it. But the angle.areas of the 250SX cylinder are insufficient for 9000 rpm.
If you force the engine to run at that rpm by means of the pipe, it won't deliver the power that can be had at lower revs.
You can enlarge the blowdown angle.area and gain a lot of peak power, but that will make the engine character too vicious for terrain riding and spoil all the fun.
Now I am eager to see what the real Wobbly has to say about it :shifty:.

I know that Frits, saw this dyno, but not sure that's correct. I pretend to do a pipe for the same peak rpm as the stock pipe, the stock one has maybe a 120 belly diameter...

http://images.motorcycle-usa.com/PhotoGallerys/fmf-exhaust-1.jpg

[Frits Overmars]

The above torque texts do not correspond to the graphs....

[RomeuPT]

The above torque texts do not correspond to the graphs....

Can you say why? I looked and didn't conclude anything.

I dont know why the riders say so good from the fmf pipe. The stock is better mostly.... at least taking this dyno in consideration.

[Muciek]

Look close , it says under the picture that factory pipe 49HP and fmf 45 but scale of graph ends at 45 and looking at it you can see that factory pipe is around 42HP and FMF 41 or sth close to it. IMO it lacks a second scale for torque on the other side too :P

[Frits Overmars]

Can you say why? I looked and didn't conclude anything.Can't you see that the orange 40.6 Nm torque curve has a higher maximum than the red 47.6 Nm torque curve? And that the orange maximum torque is not produced at 8500 rpm as the text says, but at 7500 rpm? And that the red maximum torque is not produced at 8250 rpm but at 7000 rpm? And that the quoted rpms for maximum power do not correspond to the graphs either?

[RomeuPT]

Can't you see that the orange 40.6 Nm torque curve has a higher maximum than the red 47.6 Nm torque curve? And that the orange maximum torque is not produced at 8500 rpm as the text says, but at 7500 rpm? And that the red maximum torque is not produced at 8250 rpm but at 7000 rpm? And that the quoted rpms for maximum power do not correspond to the graphs either?

Yes, I have seen that. I was just looking at the graphs and not the numbers bellow, big bullshit, does anyone have a decent ktm 250 dyno graph?

[tdc211]

Frits, what do you think on the raised exhaust floor and comparing it to overlap?
I know I can not compare a 2 to a 4stroke. But it seems to act like overlap when floor is raised.

[motoholic71]

I reason what could be happening is that the top half of the exhaust port is where it all happens so raising that "useless" floor results in less volume of the port which improves cylinder/exhaust gas exchange.Why I don't know.Speed?
I thought valve overlap is to transfer the exh. inertia to the intake, help clear the cylinder and control exh.valve temp.
The question was not addressed to me I know But I couldn't understand the relation of port floor and 4 stroke valves,so I posted my take to see if I got it wrong
Also would like to know what could happen if a raised floor port is implemented on a exhaust valve cylinder, will it conflict the valve effect?
Any ideas,Frits, Wobbly, or anyone?thanx


Just 1 last q.:
anyone knows average running power consumption or current draw, and total system weight of an Ecotron or similar 2 stroke EFI ?
Thanx,very interesting Keep it going please

[tdc211]

[QUOTE=motoholic71;1130598286]Also would like to know what could happen if a raised floor port is implemented on a exhaust valve cylinder, will it conflict the valve effect?


That was done a while back on here with a graph and yes it does, or is the valve conflicting with the floor?
I just asked this cause this engine required less timing at lower rpms after raising the valve with a raised floor.
In the end I had more cylinder filling/less short circuiting at these rpms.

[TZ350]

286514

We have had a TF125 on the dyno today, green line is the base run, red line is dropping the main jet from 230 to 200 and blue line is opening the air correction jet out to 1.1mm and back up to a 240 main jet. Just shows that the air correction jet is worth looking at.

[husaberg]

286514

We have had a TF125 on the dyno today, green line is the base run, red line is dropping the main jet from 230 to 200 and blue line is opening the air correction jet out to 1.1mm and back up to a 240 main jet. Just shows that the air correction jet is worth looking at.


I am a bit torn myself the oko's seem to be a leap ahead of the old PJ Keihins. as bucket mentioned above most of the Keihin tuning was on the taper only as the needle jet system was an integral part of the carb and not available as a separate part hense the frustration of tuning a worn Keihins where fatter needles with differing taper's were required to compensate for worn carbs.
But Tz seems to have it close and adjusting the air correction jet is quick and easy esp if it is tapped for a jet and would seem from the symptoms Rob describe to be worth a go because it will affect the area of carburation that rob says is out.
Oh fiddling with the Air correction is something practically every one who had a decent running Rotary Mazda had to do to their IDA Webbers.


PS doesn't the evil empire own Keihin as well as Showa



10 carrots
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=266989&stc=1&thumb=1&d=1343383815



I am keen to see that ball valve working on your 125. I like the boost bottle idea, best way to beat that restriction so far.


My thoughts based on gut instinct is the boost bottle would be quite beneficial esp with the restricted size carb.
I hazard a guess that it would be more beneficial than the original plenum certainly it should be a lot less problematic with the fueling.

.

[jasonu]

:
, does anyone have a decent ktm 250 dyno graph?

Probably not on a Buckets tuning thread.:Offtopic:

[TZ350]

Great Day at Mt Welly, fine and sort of warm. Team ESE rider Rick52 peddling his RS/TF125 took both A grade wins, and Tim on the 50 he is developing was going quick enough to keep Dave D, honest. Garry on a bike sporting a cylinder and head from Speedpro holds the lap record in both directions. FarmaKen had a good day with his MC18/TF125 but packed up early to get back to Rotorua. Its good to see some more 2-T's up the the front of F4.

http://www.kiwibiker.co.nz/forums/showthread.php/153656-Chris-Bucket-photo-thread-Bandwidth-warning?p=1130599037#post1130599037

[goose8]

Any video of today's a grade racers just wondering if someone got my high side save coming out of the infield? Number 3

[kel]

Any video of today's a grade racers

There was a drone hovering above the track for the A grade races, Im guessing it was being used for video as it didn't seem to take anyone out?

[Rick 52]

Great Day at Mt Welly, fine and sort of warm. Team ESE rider Rick52 peddling his RS/TF125 took both A grade wins, and Tim on the 50 he is developing was going quick enough to keep Dave D, honest. Garry on a bike sporting a cylinder and head from Speedpro holds the lap record in both directions. FarmaKen had a good day with his MC18/TF125 but packed up early to get back to Rotorua. Its good to see some more 2-T's up the the front of F4.

Absolutely over the moon with today's results, Im glad I could give the ESE team the results they deserve with All the hard work they put in to help me get the best from the bike :)

[speedpro]

The engine in Gary's bike today was basically made up of pieces from his and Dave's motors I had lying on my bench. The cylinder is a barely modified H100 and really pretty horrible. Gary does like that bike though and seems to have it well set up.

Big thanks to Gary as well. My son's bike is making a noise I need to investigate and Gary offered his bike to Cricket. Cricket's comment when he came in after the first ride is that it was better than his bike and he liked it. Looks like another 2T convert.

[speedpro]

How flash is bucket racing now, we have our own clothing label, WiFi for live race results is available in the circuit for those with smart phones and ipads etc, and we have a drone recording video. I'm thinking our own brand of port next!!

[wobbly]

I have not tried to do an MX design for a 250, only fully ported Open class 250 karts.
We ran 1080 pipes on these but i found no advantage in steep angles that ended in anything fatter than 135, and besides I doubt even that diameter would fit on the bike.
A belly that fat on the MX ported setup I believe would overscavenge and loose important low/mid power for little gain in top end that is hardly used during a dirt based race.
Here is a comparo of 250 - 2T and the 4T competition, showing what is needed to be competitive.

[Drew]

I have not tried to do an MX design for a 250, only fully ported Open class 250 karts.
We ran 1080 pipes on these but i found no advantage in steep angles that ended in anything fatter than 135, and besides I doubt even that diameter would fit on the bike.
A belly that fat on the MX ported setup I believe would overscavenge and loose important low/mid power for little gain in top end that is hardly used during a dirt based race.
Here is a comparo of 250 - 2T and the 4T competition, showing what is needed to be competitive.

By crikey those Austrian mofos have their shit in one sock!

[RomeuPT]

:

Probably not on a Buckets tuning thread.:Offtopic:

Ok sorry


I have not tried to do an MX design for a 250, only fully ported Open class 250 karts.
We ran 1080 pipes on these but i found no advantage in steep angles that ended in anything fatter than 135, and besides I doubt even that diameter would fit on the bike.
A belly that fat on the MX ported setup I believe would overscavenge and loose important low/mid power for little gain in top end that is hardly used during a dirt based race.
Here is a comparo of 250 - 2T and the 4T competition, showing what is needed to be competitive.

ahhh, a decent dyno comparison, KTM and 450 4t cleary superior.

The stock belly from my ktm seems to be around 120+.

Thanks

Sorry for a bit of offtopic.

Here in Portugal race bucket's are becoming popular too..

[RomeuPT]

Woobly, to make a pipe fitment in this case If I remember it was said earlier in this topic that each cone intersection robs power without all the work to make it clean inside and round, so a hydroformed header instead of a lot of cones would perform better right?

I was looking at this photo of this header, don't remeber where it was from.

This is made with two flat sheet's pressed agaisnt a mold and then welded together right?

Thanks

[wobbly]

No,No,NO.
The hydroforming method works very well in headers where normally there are sharp radii and may cut sections.
But as soon as the angle deltas increase dramatically, getting into the diffuser section, the smoothing and smearing effect of the continuous progressive angle change looses power.
This is most dramatic when changing angle each side of the belly section.

The best combination of methods is hydroforming the front section followed by individual cones.
The pipe in the pic has no sharp angle changes - thus likely is a blown up type.

Honda has used the die formed method for years, with two halves pressed in a CNC machined form tool.
This also gives good sharp angle changes, but with no weld finishing needed.

I spent - wasted - months of time at JL building pipes for 250 Superkarts learning how to do really beautiful formed shapes.
But even with the mid section clamped in a ring,to at least keep that parallel, we lost around 2 Hp per pipe against the best hand built section method.

KTM did a nice job of this, but sadly they were stuck in a Bartol time warp with the actual design elements.

[F5 Dave]

Woobly, to make a pipe fitment in this case If I remember it was said earlier in this topic that each cone intersection robs power without all the work to make it clean inside and round, so a hydroformed header instead of a lot of cones would perform better right?

I was looking at this photo of this header, don't remeber where it was from.

This is made with two flat sheet's pressed agaisnt a mold and then welded together right?

Thanks

What is concerning is the Manx Norton sketch behind with the minimoto wheel concept.

predated 16" wheels I guess;) might be a bit of flex in those forks


http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=286593&d=1376881582

[fatbastd]

Looks more like a 750 SOHC Honda sketch...the Manx would have an oil leak designed-in! (from the cambox).

[F5 Dave]

meh I was just looking at the pinstriping on the tank, but yes there are some extra pipes shown than a single requires. Silly bloody things, - look where the carbs are mounted. Ridiculous!

[Farmaken]

286514

We have had a TF125 on the dyno today, green line is the base run, red line is dropping the main jet from 230 to 200 and blue line is opening the air correction jet out to 1.1mm and back up to a 240 main jet. Just shows that the air correction jet is worth looking at.

Huge thanks to TZ350 and the ESE boys for the Dyno time - a bit of time and a lot of experience made a huge difference - one happy camper right here :2thumbsup

[marsheng]

I need to replace my petals. The original ones are fiberglass and 0.5 mm thick. What is the best Carbon fiber ones to replace these with. They have 0.3 0.35 and 0.4.

The reed block has two sets of reeds. One for low flow and a bigger one sandwiched between it and the block for high flow. Can to run Carbon to Carbon petals or must one be fiberglass ?

[Bert]

We have had a TF125 on the dyno today, green line is the base run, red line is dropping the main jet from 230 to 200 and blue line is opening the air correction jet out to 1.1mm and back up to a 240 main jet. Just shows that the air correction jet is worth looking at.


Huge thanks to TZ350 and the ESE boys for the Dyno time - a bit of time and a lot of experience made a huge difference - one happy camper right here :2thumbsup
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=286514
Well done Team.

That's a great result. :2thumbsup
Looks like there is still something holding it back (possibly transfer duration or is it the 28mm restriction & intake design?) in the top end (26-27 looks very possible).
It would be very interesting to compare porting to a old RM125 cylinder (late 70's vintage).

The North Island series is going to be interesting this year.

[F5 Dave]

Eh? You know what boysen reeds are huh? Google it. Either way for road race just plain single reeds will be the go, none of this sandwich ports in the reeds stuff. Or has someone piggybacked some?

[Grumph]

I need to replace my petals. The original ones are fiberglass and 0.5 mm thick. What is the best Carbon fiber ones to replace these with. They have 0.3 0.35 and 0.4.

The reed block has two sets of reeds. One for low flow and a bigger one sandwiched between it and the block for high flow. Can to run Carbon to Carbon petals or must one be fiberglass ?

You'd better come clean as to just what the motor is, and it's intended use,Wallace. Someone here will know what to use i'm sure.

[marsheng]

Maico 250 1982 for road race.

[F5 Dave]

Ahh, dirty ol' Boysens. Throw them. There is often a bit of testing to get best performance to suit a reedblock on a certain engine with certain carb size etc. Cut some & try, if they flutter like buggery try stiffer. 0.3 is a common thickness. I have some old software to estimate but just found trying it easier & more accurate. No doubt engmod2T will know for sure, but I don't have that,

[wobbly]

Use the softest carbons you can.
Make a " rev plate " from the old reed 0.5mm material ie a strip say 6mm wide, this sits on top of the carbon under the screws.
Then take the original thin fibre reeds, cut them to 1/2 length then cut them to make 3 pointed hats,these are backups that sit on top of the 0.5mm spacer.
Next take the old radius plate and cut it to 1/3 its original length,this sits on top of the backups with the screws going thru all 4 elements.
Best reed setup known to man.

[F5 Dave]

Pointed hats? Maybe I should be wearing one. Still trying to picture exactly what you mean by that.

Do you think single reed will ever work as well as individual fingers? I've had reasonable success with that setup, but really limited testing.

[wobbly]

The backups are tapered from full width at the clamp, to a point with a small rad on the end.
These pointed backup plates are 1/2 the reed petal length.
I have tested several full width petal plates, and some made better power - I believe due to the fact they were slightly stiffer than the original petals
and this is what was needed.

[RomeuPT]

I have not tried to do an MX design for a 250, only fully ported Open class 250 karts.
We ran 1080 pipes on these but i found no advantage in steep angles that ended in anything fatter than 135, and besides I doubt even that diameter would fit on the bike.
A belly that fat on the MX ported setup I believe would overscavenge and loose important low/mid power for little gain in top end that is hardly used during a dirt based race.
Here is a comparo of 250 - 2T and the 4T competition, showing what is needed to be competitive.

The 1080 you mention is from piston to restrictor right, and is the same peak rpm as stock?


No,No,NO.
The hydroforming method works very well in headers where normally there are sharp radii and may cut sections.
But as soon as the angle deltas increase dramatically, getting into the diffuser section, the smoothing and smearing effect of the continuous progressive angle change looses power.
This is most dramatic when changing angle each side of the belly section.

The best combination of methods is hydroforming the front section followed by individual cones.
The pipe in the pic has no sharp angle changes - thus likely is a blown up type.

Honda has used the die formed method for years, with two halves pressed in a CNC machined form tool.
This also gives good sharp angle changes, but with no weld finishing needed.

I spent - wasted - months of time at JL building pipes for 250 Superkarts learning how to do really beautiful formed shapes.
But even with the mid section clamped in a ring,to at least keep that parallel, we lost around 2 Hp per pipe against the best hand built section method.

KTM did a nice job of this, but sadly they were stuck in a Bartol time warp with the actual design elements.

I do want to make pressed or hidroformed header for my pipes, do we really need a mold to make the pressed or can we hammerit against radiused pipes?

Many thanks



The backups are tapered from full width at the clamp, to a point with a small rad on the end.
These pointed backup plates are 1/2 the reed petal length.
I have tested several full width petal plates, and some made better power - I believe due to the fact they were slightly stiffer than the original petals
and this is what was needed.

I didn't quite understand, you mean like those?

Sorry if many questions

[marsheng]

Use the softest carbons you can.
Make a " rev plate " from the old reed 0.5mm material ie a strip say 6mm wide, this sits on top of the carbon under the screws.
Then take the original thin fibre reeds, cut them to 1/2 length then cut them to make 3 pointed hats,these are backups that sit on top of the 0.5mm spacer.
Next take the old radius plate and cut it to 1/3 its original length,this sits on top of the backups with the screws going thru all 4 elements.
Best reed setup known to man.

Is this what you mean ?

[wobbly]

Yes, but I think the 0.5mm material from the original reed is too thick to use as a backup.

At JL we made a form tool from solid bar the header dimensions, and heated it bright red to bend it to the correct shape to make headers for RD/LC/TZ.
Then cut it in 1/2 for LH/RH sides.
Then sat each of these horizontally in a mold box and poured molten alloy into it to form the female press cavity.
The alloy shrunk away enough that the 0.8mm cold drawn sheet would be a tight fit between the inner and outer forms we had made.
When we had pressed a pattern into the forms in a press, the excess was easy to slice off with a cold chisel and hammer along the flat face of the 1/2 steel inner.
Then the two 1/2s were easy to seam weld along this cut with no filler rod needed.

Much easier to do these days with cnc inner and outer die sets.

[F5 Dave]

The backups are tapered from full width at the clamp, to a point with a small rad on the end.
These pointed backup plates are 1/2 the reed petal length.
I have tested several full width petal plates, and some made better power - I believe due to the fact they were slightly stiffer than the original petals
and this is what was needed.

Cool, every day's a school day. Nice pic Wallace.

[marsheng]

Cool, every day's a school day. Nice pic Wallace.
I have one of those Samsung Gallexy Note 2s. Really good. It has a stylus so I drew the picture on it, waved my hand over the screen which copies it to the clipboard and then attached the file to the forum. What could be easier?

[F5 Dave]

hmm. . .having someone else do it for you? - Hey wait!

[marsheng]

I have some 0.3 mm carbon on its way and I try Woobly's suggestion. Sounds good.

[timg]

I have some 0.3 mm carbon on its way and I try Woobly's suggestion. Sounds good. So when's my 30hp FXR gonna be ready then? Huh?

[F5 Dave]

I imagine when you've invested 30 hp worth of money

[TZ350]

Rich these are the det sensor posts that I could find.


258175 258176

So that is Aprilia RS250 and RGV250 that have cable operated TPS's, now that is very handy ......



Thanks for the layout, TZ suggested I should stand them all on end and number them according to their length but having a proper layout plan is much better.


Forget the homemade bullshit, get one of these with the extra wire to ground.
When it sees deto it can ground an Ignitech input and retard the timing automatically.
You get flashing lights and engine protection all in one shot, and cheap as chips - made in Czech so it likes being connected to an Ignitech - same lingo..
Works perfectly - when you get it trimmed correctly it will tell you where to manually pull out timing, then it just operates as a failsafe.

http://www.ebay.com/itm/Knock-gauge-for-detonation-sensor-klopfsensor-NEW-/110818862446?pt=Race_Car_Parts&hash=item19cd51a56e&vxp=mtr#ht_1582wt_1297


263028

Ok mine turned up today.

263027

And a couple of two wire sensors I picked up cheap from the local garage.


263081

BOSCH p/n 0 261 231 046

263082

Other sensors can be found here too. http://www.bosch.com.au/content/language1/html/4563.htm


Good luck with the Deto sensing TZ. I like the little warning instrument!

Here's how I mounted my sensor. I drilled-tapped an old head bolt and screwed a stud.

263051263052

My sensor has a PN 0-261-231-001, what's yours?
According to this http://www.phormula.co.uk/KnockCalculator.aspx , deto freq for 56mm bore should be 10.2kHz.
According to Bosch datasheets for PN -047 (http://www.bosch-motorsport.de/en-US/literature/en-US/Knock_Sensor_KS-R_Datasheet_51_en_2779074187.pdf) & -120 (http://www.bosch-motorsport.de/pdf/sensors/knock/KS-P.pdf), sensors are able to catch frequencies from 1 to 20 kHz.
I assume all Bosch sensors can sense knock within this range (?)

edit: As for the pick-up voltage, I think it won't be more than +-10V. I had a voltage test yesterday with a data acquisition device in real time! I spinned the crank by hand and recorder the voltage waveform from the pick-up in the PC. As RPM increase, amplitude (and freq of course) of the pulses increase - by hand-spinning it didn't exceed 3~3.5 VAC. Sure it was a lot of fun to watch! :D


The shock waves from deto will be transmitted right thru the cylinder and the case.
I have seen many times where for no apparent reason the head or barrel studs loosen off - not because they weren't torqued correctly, but due to the
gasket being crushed momentarily from deto.
Many cars have the det sensors on the side of the block,some with multiple sensors for cylinder pairs.
All that happens when the sensor is further away from the chamber is that the shock intensity is reduced, so the sensitivity of the amp must be wound up - not an issue.


Relocated the knock sensor. I found some steel head bolts and faced one off, then drilled and tapped it. And made a standoff that was carefully faced off as the knock sensor likes to be securely mounted on a very flat surface. The black goop (silicon glue) on the blue wire is there as a strain relief and hopefully it will stop the vibration breaking the wire where it is attached to the copper head fin.


The Trumeter 7111 is no longer stocked by RS but they do have something similar.

269009

703TR002N-512D RS part number 183-5952 $63.50 ... 5-12V and less than 10mA so easily self powered and at 500Hz fast enough to count all deto events as seen by the Knock Gauge or similar, as 200Hz in a 2-Stroke equals 12,000 rpm.

269008

And here is something if you want to try your hand at making a complete det counter for your self.

269011

RS part number 185-6090 $45.30

You could box this along with an amp or frequency filter from Jaycar and make you own little compact det counter.

269012

Electrical specs.

269014

Two different ways to go, with an amp you would count the high amplitude deto peaks or you could use a band or high pass frequency filter and count whatever passes through it.


More on the TPS thing.

This is an email I sent to Ignitec.

Hi
We have several bikes with Ignitec Sparker DC-CDI-P2 tunable two channel ignitions.
We want to use the TPS function.
We found that a 5K Ohm TPS unit worked OK but a 25K one gave us trouble.
Is a 25K resistance wrong?
What resistance TPS do you recommend?
Thanks

This is their reply.

Hello,
Standard automotive TPS has resistance about 5 kOhm.
25 kOhm is strange. Is it regular automotive TPS ?
276981
We recommended to use automotive TPS.
Jiri Krejzl
IGNITECH

It Looks like a (nominal) 5k Ohm TPS is the unit of choice for the Ignitec.

[F5 Dave]

Well I still have ring seal issues on the mb with it piston. Got my tester going and sez 35%leak which is better than the 36 on another meter a while back. Running std yam bits on a freshly honed bore with a few dyno sessions and a couple of races on it. R30 used to help bed in.
No blowby on piston, bore looks better this time.
Ring gap is 0.7 std yam rings are loose. TK one I have is 0.3 but I lost tips off last one I used.
Very strange and must be losing. Heap of power. Bike used to be harder to push start without skidding with YZ100 piston.

i have a torque plate to use when honing next time, but I can't see any light around side of ring when cold.

[wobbly]

1080 total pipe length gave peak closer to 9000, with overev to 11000 + on a VERY ported setup.
But this was gained using an Ignitech to tailor the advance curve, so would not come close with a stock ignition.

[jasonu]

Well I still have ring seal issues on the mb with it piston. Got my tester going and sez 35%leak which is better than the 36 on another meter a while back. .

Keep trying different testers until you find one that gives you a result you like.

[richban]

Rich these are the det sensor posts that I could find.


Cheers Rob

Going for the EU one with the analogue out for the ignitech. Cheapest engine protection there is. Just not sure if I can get away with just one sensor on the V twin. Will give it bash.

[F5 Dave]

Keep trying different testers until you find one that gives you a result you like.
Thanks yeah I could just seal off one end.

I can hear air leak out the carb & pipe. Its all a bit dumb.

[Yow Ling]

Cheers Rob

Going for the EU one with the analogue out for the ignitech. Cheapest engine protection there is. Just not sure if I can get away with just one sensor on the V twin. Will give it bash.

U sure you want the analog one ? I think the input for retard is a off/on so you want the open collector output on the det box

[richban]

U sure you want the analog one ? I think the input for retard is a off/on so you want the open collector output on the det box

Yeah ummmm. I'm not sure of anything when it comes to wires and little black boxes of magic.

[wobbly]

Yea you need the output to ground option, this earth's the Ignitech input to retard mode.

[Ocean1]

Got my tester going and sez 35%leak.

Tragic. Or is it?

What's "normal" for one of them 2T thingies with all the holes in the cylinder and just the one skinny wee ring?

And what sort of hone did you use?

[F5 Dave]

Was honed by the local kart guy (adjustable stone hone, but manual).

You lock the engine at the top to test. He sez KTs usually run 8% in fresh condition.

Next time I will put the plates either side & torqued & heat the barrel up & try again.

Still think I'm, losing power like this, but not sure how to get better seal if above doesn't work.

[speedpro]

To confirm where it's leaking, or to eliminate possibilities, I'd pull it apart and put it back together with a good coat of grease on the piston, then test again. I would also not assume anything regarding the head gasket and it might get a good coat of grease as well, or the o-ring. 35% is not good especially when you think it'll probably only get worse with heat.

[Kickaha]

Good couple of pages on a fuel injected two stroke Kawasaki thingy in the latest KR :niceone:

[F5 Dave]

To confirm where it's leaking, or to eliminate possibilities, I'd pull it apart and put it back together with a good coat of grease on the piston, then test again. I would also not assume anything regarding the head gasket and it might get a good coat of grease as well, or the o-ring. 35% is not good especially when you think it'll probably only get worse with heat.
I guess it would be interesting. I'll give it a shot when its back together (just cutting the fins off to weld on a water jacket).

The fact I can hear it out the pipe & the carb mean there is a leak past piston ring.

I should compare to some of my other engines but I know my 50 is a bit oval bored as I can see light past the ring, - but then it has done almost 10 years very near 14,000 consistently.
I could try the 496 or the dirtbike but they are both plated 72mm bores so not similar. Should be equal to a KT.

[TZ350]

286699


Yea you need the output to ground option, this earth's the Ignitech input to retard mode.

286698

http://www.ebay.com/itm/Knock-gauge-for-detonation-sensor-klopfsensor-NEW-/181138934401

[RomeuPT]

Use the softest carbons you can.
Make a " rev plate " from the old reed 0.5mm material ie a strip say 6mm wide, this sits on top of the carbon under the screws.
Then take the original thin fibre reeds, cut them to 1/2 length then cut them to make 3 pointed hats,these are backups that sit on top of the 0.5mm spacer.
Next take the old radius plate and cut it to 1/3 its original length,this sits on top of the backups with the screws going thru all 4 elements.
Best reed setup known to man.

This is what we are searching for?

I had talked to some people that used to race Honda RS 125 for years, they say that Vforce 2 reeds for Honda RS 125 give a wider peak power band and a slightly improvement at botton end over stock. I had installed ones on my NSR 125 with the RS cylinder and felt the same. It also seems that carburation goes a little richer. Can you say something about your experiences with Vforce?

Thanks

[TZ350]

http://www.pit-lane.biz/t4072p20-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-3



Does covering the header of the exhaust with some isolating material have any benefit in performance?
286776

No, I don't think so.
But it helps to make the engine reach the same revs on the circuit as it does on the dyno.
And it could help to keep down crankcase temperature.
I would have liked to paint the exhaust with isolating paint.
Preferably on the inside!
Doing so might have made different exhaust dimensions necessary.
It would have been very interesting.
But I never had the time to do it, which I still regret!

Working at the dyno daily, the big-end was changed after about 220 tests.
Each test taking about 6 minutes.
And also the exhaust was cleaned at the inside, removing the carbon deposit.
After this it took about a week for the same maximum power to return.
And you also needed a richer carburation, because with a clean exhaust pipe the engine had more tendency to detonate.
The teams that went to the races always cleaned their exhaust pipes on the saturday evening, before the race.
I tried to convince them not to do this, but nobody believed me!
To a lesser degree the same thing happened with the dampers.
Filling them with new glass fiber always gave less power and more detonation, for about 3-4 days!

[RomeuPT]

http://www.pit-lane.biz/t4072p20-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-3

I had posted that question on pit-lane, and Jan came with very good info about some other pipe concerns. Very good of him..

I no more recomended anyone to clean the exhaust from carbon after that post

[TZ350]

Yes there is lots of good information on the Pit-Lane thread, I hope they don't mind if I re post bits here (with full acknowledgement to the original authors of course) from time to time.

[TZ350]

http://www.pit-lane.biz/t4072p260-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-3




some people still think I'm crazy :laugh:.
But Frits, you're sure that relates to crankcase volume? :bleh:
Not solely, Graham. I've said lots of things that seem hard to swallow. Here is an anthology:

'The part of the exhaust port area beneath the transfer port level is a waste of real estate'.

'A high secondary compression ratio improves power in a four-stroke;
in a two-stroke with an efficient exhaust system it is the other way around'.

'Two-stroke rpm is limited by blowdown and scavenging angle.areas, not by crankshaft reliability issues'.

'Comparisons of differently sized engines should be based on mean piston speed, not on rpm'.

'Piston clearance, coolant flow rate, radiator size and ambient temperature are practical limits to engine cooling,
but in theory there is no such thing as too much cooling'.

'Top speed is the most unimportant thing in racing. Keeping your minimum speed high is the most important'.

The above collection should be sufficient to earn me a reserved place in an asylum, don't you think, Graham? :joker:.

There is some real Gold on that Pit-Lane thread.

[wobbly]

The VF2 from a CR125 makes really good power in the RS125, way better than stock and way better than the later VF3.
I discovered this years ago when I built a TM125 MX motor for karts, I tested 8 different setups and the VF2 blitzed them all.
By product also was that the reeds lasted for 3 seasons with 3 National titles, and around 30 races in total.

[husaberg]

[URL]


There is some real Gold on that Pit-Lane thread.

Not sure if the link will work.
Some of the Jan story in English.
I was Looking for stuff on Herman Meijer and tripped over it.
http://translate.google.co.nz/translate?hl=en&sl=nl&u=http://www.hermanmeijer.nl/herman1/janthiel3.html&prev=/search%3Fq%3Dherman%2Bmeijer%2Btuner%26biw%3D1280% 26bih%3D827

[TZ350]

Page 830 links list to go here..

Looking for the good stuff ....


... some may find this useful. 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 priceless site:www.kiwibiker.co.nz (http://www.kiwibiker.co.nz)
or
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

Plugging piston pins ......


http://www.pit-lane.biz/t4140-2-stroke-how-plug-up-a-2-stroke-wristpin



I have a little question about a Cagiva Mito barrel with large booster; how plug up the wrsitpin, avoiding the "short circuit" between exhaust and transfer?
It's a 16 mm pin, can't fit an Aprilia GP pin!
I'm thinking to put some kneadatite into the pin ID..any suggestions?
Thanks

Aprilia wristpins were made by Pankl.
It was done by welding.
Every different solution we tried was a failure.
Maybe they will make some for you too!

And another approach taken by Wob, if any one is doing the piston pin thing this may be worth a try too.


Why put the plug inside the pin with a "new"" groove,there is already a groove available and also there is a chamfer on the end of the pin that can be used - as it was previously - to force outward, the retainer
into this groove.
Wont say any more as this stuff is Frits intellectual property , but with all the pics flying about its quickly becoming public property.
I made these plastic plugs several years ago using glass reinforced Peek,and tested them with no positive results at all.
But now we have tripple ports reaching around to 1/2 bore, and yes they do work a treat.

Then Wobs thoughts on cylinder heads and plug to piston crown distance.


To do a toroid properly you need to drop the plug tip to approx 6mm from the piston crown.

Means welding the chamber and counterboring the plug seat face.
Very difficult to do repeatable and accurately unless done on CNC.
I model the piston dome and the head shape in SolidWorks to generate a solid then I have an accurate curve the toolpath follows and a calculated volume.


You dont really need the Ex timing to establish the head geometry, and yes the 6mm number seems to work with most " usual " combustion chamber geometries.
Avgas works with anything from around 192 to 202 Ex duration at around 15.8 full stroke.
Smaller bores or lower bmep setups can go 16.2, big bore oversquare or very high bmep like slightly less at 15.5, air cooled of course needs alot less.
As long as you hit the lower mechanical squish depth limit, then adjust the width to hit 38M/Sec MSV you will have good squish turbulence that helps the flame speed - reducing any tendency to deto
the end gasses.
That MSV number is meaningless in the context of all but hitting the head when within the normal rev limits, but as a guide it works every time.
The sharp bowl edge increases the flame speed, and a very deep angle away from that edge into the bowl is synergistic by pulling the turbulence further into the combustion space, again increasing the flame propagation speed,
over a wider band.
Pushing the combustion parameters this hard means a digital ignition is mandatory to balance the timing against the high peak cylinder pressure now being generated.


No free lunch today except that its all been done before and in most cases a guide is available.
It depends upon the stroke length, the piston weight and the crank integrity.
Suffice to say that a 125 single will usually go down to 0.65mm when spinning to 14000
A 250 twin like the RGV with a single middle bearing will go 0.75 spinning to 12,000
A 250MX type with 72mm stroke is OK at 1mm spinning to 11,000.
But I stress again, as I dont want the Honda faggots off their forum abusing me that the NSR wont rev if taken below 0.8mm - the ignition has to be optimised
to work with a combustion chamber that is designed correctly, and does actually do what its supposed to.
A stock PGM simply wont cut it - but then we wont be using HRC parts, so they just cant be any good at all, as everyone should realise.


Yep, looks fine.
The flat squish area should have 0.1mm taper upwards from the bore edge.
As I found the piston will clip the inner edge first when the vertical gap is at the mechanical limit for the rpm.
This is the sort of shape you are after.


There is only one rule grasshopper,NO radius from the squish into the bowl.
The other rule is to pull the squish down to the mechanical limit - ie probably around 0.7mm on an RGV then adjust the width to get around 38M/Sec MSV, usually 45 to 50%.
This generates good response and " torque" as you put it - but for sure will need a digital to retard the top end advance to get the overev back.

[Frits Overmars]

Yes there is lots of good information on the Pit-Lane thread, I hope they don't mind if I re post bits here (with full acknowledgement to the original authors of course) from time to time.Pit-Lane won't mind at all; on the contrary. And Jan and I will love it :shifty:.

[TZ350]

Thanks.....

[TZ350]

286847

Finally found a throttle cable in the junk box's at work that is long enough and with the right sort of fitting for the end. And it took some searching around the shelves to find a twist-grip that would open the ball valve in a quarter turn but everything works OK now.

286852

The MAP sensor is usually plugged into the inlet tract just behind the throttle body but it is subject to a lot of strong pulsation there, particularly on a 2-stroke. So I have plugged it into the Boost Bottle in the hope that it will be able to make a more "average" reading of the absolute inlet tract (manifold) pressure from there.

286846

Next move is to start wiring the EFI and IgnTec.

286851

Looks like both The EFI and Igni use the same 5V source voltage for their TPS so I plan on using the EFI as the source and splice in the IgniTecs TPS grey position sensing input wire to the EFIs white sensing wire so both units see the same variable voltage.

I am familiar with setting the Ignitecs TPS range and expect the EFI should be able to be set in a similar way.

286854286853

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.... such excitement.... :clap:

[RomeuPT]

The VF2 from a CR125 makes really good power in the RS125, way better than stock and way better than the later VF3.
I discovered this years ago when I built a TM125 MX motor for karts, I tested 8 different setups and the VF2 blitzed them all.
By product also was that the reeds lasted for 3 seasons with 3 National titles, and around 30 races in total.


Many thanks Wobbly :yes:

If I remember the stock vforce came with 0.45 thick carbon reeds, and they have a bolt on piece with "high" and "low" in each side, high makes the reeds more pressed against the cage, I always run them in high.... but...

[dmcca]

The basics of good head design have generously been explained here already so I thought id post up this pic to show a new direction that KTM seems to have taken this year with their motocrossers...

Both heads are from a KTM250SX (sorry i know this is a buckets thread!)... in both pics the head on the left is a slightly modded 2011 (same basic shape as stock) and the head on the right is the latest 2014 version (stock)... You can only assume in their testing that its worked for them but it does go against a lot of whats been spoken about here and elsewhere about what comprises a good head design...


286867286868

[wobbly]

The low tension gives a bit more bottom end, but loses overev and the tips shatter real quick.
At the time KTM125s had this reed as stock, I know VeeForce dont stock it any more.

[SwePatrick]

I´ve searched this huge thread, no luck.

but, do you guys talk about pressure in pipe(middle of belly) somewhere?
I´m researching about how high the averagepressure should be.

Rgds
Patrick

[2T Institute]

All the various capacities use a common VF2 cage with the flange mount screwed to the cage is how they get the cage to fit different manufacturers. KTM use the same cage size for 125-380 only the size of the entry hole differs

[Flettner]

Patrick, I too am interested in total average pressure in the chamber. I'm assuming it's probably two or three psi ?

[RomeuPT]

The basics of good head design have generously been explained here already so I thought id post up this pic to show a new direction that KTM seems to have taken this year with their motocrossers...

Both heads are from a KTM250SX (sorry i know this is a buckets thread!)... in both pics the head on the left is a slightly modded 2011 (same basic shape as stock) and the head on the right is the latest 2014 version (stock)... You can only assume in their testing that its worked for them but it does go against a lot of whats been spoken about here and elsewhere about what comprises a good head design...


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That's not very strange, If I remember in a post earlier from this topic (I think was a wobbly post) was said that yamaha test's said the other way about the radius from the squish to the bowl. And most Honda RS head that I have seen use a 2mm radius.

Glad KTM still try to improve the 2 strokes...

[marsheng]

What silicon or similar will standup to petrol and oil in a 2 stroke crank case? I have blanking plates I want to seal in.

[Muciek]

I use Victor reinz it's best IMO http://www.reinz.de/root/eng/aftermarket_1102_ENG_HTML.php this is how it looks http://image.ceneo.pl/data/products/13343380/i-victor-reinz-masa-uszczelniajaca-victor-reinz-70ml.jpg .

[wobbly]

In jetskis we used a much too big stinger to increase the low and mid power, then pumped water into the stinger to squeeze down the effective outlet area
Best power was at 3 psi at full noise, and this was set by a jet under the water solenoid.

[F5 Dave]

What silicon or similar will standup to petrol and oil in a 2 stroke crank case? I have blanking plates I want to seal in.

Yamabond, which is pretty much 3Bond 1215. Most bike shops or gasket places will have it. Std fare for Suzukis & Yams which don't have centre gaskets.

[F5 Dave]

In jetskis we used a much too big stinger to increase the low and mid power, then pumped water into the stinger to squeeze down the effective outlet area
Best power was at 3 psi at full noise, and this was set by a jet under the water solenoid.
That's brilliant. . . But why does too large a stinger increase bottom end?

[wobbly]

I know it seems counter intuitive, but at low speed where the pipes tuned length is too short,the power will come up if you reduce the effects
of the return wave coming back way too early.
Thus by reducing the pressure in the pipe you ameliorate the bad effects by killing how well the pipe system works.
High pressure in the pipe increases the effectiveness of the wave action, so to reduce this additional "performance" at low rpm,you open up the stinger diameter.
Less bad matching of port timing and pipe length = more power.

[F5 Dave]

oh, ok I'd just assumed there was an optimum for output/heat as always chasing top end. So this has a noticeable difference on mid/low?

Pity its not the other way around or I can imagine some simple RAVE type valves on the stingers. So a 2ndry ATAC further down the pipe to release pressure, would have to have some muffling. Too complex I guess.

[wobbly]

On the big bore ski it was around 35% increase in power at the bottom of the used powerband.

[Drew]

Pity its not the other way around or I can imagine some simple RAVE type valves on the stingers. So a 2ndry ATAC further down the pipe to release pressure, would have to have some muffling. Too complex I guess.What does it matter what way round the equation is? If you can increase/decrease the stinger size relative to the revs, the rest is just timing.

[wobbly]

A servo driven by the Ignitech would be the go to progressively throttle down the stinger related to rpm.
Ignitech do a stand alone servo driver that has TPS as well for a 3D map.

[F5 Dave]

What does it matter what way round the equation is? If you can increase/decrease the stinger size relative to the revs, the rest is just timing.

It matters because a simple pressure operated arrangement is, well simple.



Servo option does make sense though. That is huge boost increase, I wonder why it hasn't been applied more often?

Edit, a butterfly arrangement could be a robust easy to seal & make arrangement once you've worked out the area it occupies.

[Drew]

It matters because a simple pressure operated arrangement is, well simple.



Servo option does make sense though. That is huge boost increase, I wonder why it hasn't been applied more often?

Edit, a butterfly arrangement could be a robust easy to seal & make arrangement once you've worked out the area it occupies.I see the pressure driven solution to be harder to set up, of the two basic options. But I get what you meant now.

Something to look into for you guys running dribblers though.

Yours is already very quiet, I noted at the track the other day dave. Why that is?

[TZ350]

The mid chamber bleed re visited .....


Model aero engine carburetor, about 9mm bore.

279495279496

I have been having trouble with detonation in over rev and I hope to cure it by bleeding some of the pipe pressure off when the engine is running in the detonation zone.

Sometimes stingers/mufflers have been attached here at the fattest point on the pipe because the pressure wave is at its lowest amplitude and quietest so I guess I can bleed pressure of from here without upsetting things and being to noisy.

Might get a chance to try it out in a day or two.


Deto in the Over Rev Zone.

279979

The mid chamber bleed.

279980

Tried it open and closed, Red open, Blue closed. The big surprise was how quiet it was when open, hardly any more noise at all, certainly wouldn't need any sort of mufler.

Actually I tried it lots to see if I could join the two curves and if it would kill the high rpm deto. But it was difficult to coordinate by hand and the runs were all over the place. Although the results were good enough to make me very interested in developing a proper ATAC Valve.

279978

Kel gave me a hand to try and figure out where this top end deto is coming from.

I tried to take pictures when the Red light flashed, but all I got was a lot of unfocused blurry photos.

Although I could see the Red light flashing, in all of the shots the green light obscured the Red deto one.

<iframe src="http://www.youtube.com/embed/TYMFOuigEf8" allowfullscreen="" frameborder="0" height="315" width="420"></iframe>

At the end of the runs the engine went into auto ignition and ran on, in the clip you can just see Kel pull in the clutch and thumb the kill button but the engine still ran on for a bit.


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



In jetskis we used a much too big stinger to increase the low and mid power, then pumped water into the stinger to squeeze down the effective outlet area
Best power was at 3 psi at full noise, and this was set by a jet under the water solenoid.


A servo driven by the Ignitech would be the go to progressively throttle down the stinger related to rpm.
Ignitech do a stand alone servo driver that has TPS as well for a 3D map.


That's brilliant. . . But why does too large a stinger increase bottom end?


I know it seems counter intuitive, but at low speed where the pipes tuned length is too short,the power will come up if you reduce the effects of the return wave coming back way too early.

Thus by reducing the pressure in the pipe you ameliorate the bad effects by killing how well the pipe system works.

High pressure in the pipe increases the effectiveness of the wave action, so to reduce this additional "performance" at low rpm,you open up the stinger diameter.

Less bad matching of port timing and pipe length = more power.


On the big bore ski it was around 35% increase in power at the bottom of the used powerband.


Servo option does make sense though. That is huge boost increase, I wonder why it hasn't been applied more often?

Ok the mid pipe bleed didn't work for me as a detonation suppressant but it did show a useful low end boost. The interesting thing was that there was very little noise from it.

286902

Red line is the bleed in the open position, Blue is closed.

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And there was those who scorned me for trying this ....... :D

I will re visit this again, maybe with a bleed system like Frits suggested.




279498

Frits proposed this bleed system, thought I should at least give something like it a try.......

[F5 Dave]

. . .

Yours is already very quiet, I noted at the track the other day dave. Why that is?
It was a bit noisy, so I spent some money & got Damon to make a new sleeve which has a reversal at the end of the muffler made in light ally after the original muffler.

Its made in larger di pipe- it removes sound energy without causing a restriction as there is a little volume for the original to spill into. When I've tested this setup before I've noticed no diff on the dyno.

[TZ350]

286907

OK ... got the EFI wired up and the Laptop talking to it, things looked OK and the TPS was ranged correctly.
Then the USB/Serial communications stopped?????? :brick: ...... Ohooowell another day tomorrow.

[F5 Dave]

Must admit I forgot about the bleed valve. Wonder it's affect vs capacity as implied? Only issue is noise more of a constraint in larger cylinders with bigger stingers.

[SwePatrick]

In jetskis we used a much too big stinger to increase the low and mid power, then pumped water into the stinger to squeeze down the effective outlet area
Best power was at 3 psi at full noise, and this was set by a jet under the water solenoid.

Very kind of you to share the info. great thanks.
I tuned the engine to exactly that before your answer, nice to know i´m on the correct ballpark and playing my game :)

I got 132cc and an 28.5mm stinger and reached these 3psi at about 10500rpm.
And keeps steady all the way to the top at 13000rpm.
Then it 'chokes' out at about 4-5psi

The most amount on GP racers hp output with reeds(wheel hp)
Does somebody know those numbers?

Kind regards
Patrick

[marsheng]

What is the suggested spacing between the crank and case to reduce windage losses?

[teriks]

What is the suggested spacing between the crank and case to reduce windage losses?
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130291499&highlight=viscous#post1130291499

1 mm should be enough to avoid the viscous drag.

[wobbly]

Before he left Derby to go do the Aprilia RSA I believe Jan got nearly 50 Hp from the reed engine, up from the 45 it had when Lorenzo rode.
They do sprocket power, so rear wheel on a Dynojet would be maybe a bit over 45.
Frits has posted a graph showing the reed engine Vs the rotary valve before Jan massaged it upward.

Makes me spit when you think of HRC with a noname on board the RS250 winning the last title due to idiots at the factory and idiots on the bikes for Aprilia.

[Frits Overmars]

Patrick, I too am interested in total average pressure in the chamber. I'm assuming it's probably two or three psi ?About 0.25 bar in real money.

[TZ350]

About 0.25 bar in real money.

About 3.5 psi in old money.

286952

OK ... now I have got the laptop talking properly to both the EFI and the Ignitec at the same time and the TPS input is responding correctly on both and all the gauges on the EFI are reading as expected, so good to go.

I still have a lot to learn about programming the EFI but when I get the fuel system hooked up, I will have a little try to see if I can get it to start.... this is fun.

[Flettner]

TZ 350,yes, isn't it fun. Have you got one TPS feeding the two computers?

Frits, yes "old money" , I've just got my David Brown gear hob going and it's all BSF threads. Hard to find these days, I might have to thread cut these odd ball fasteners on the lathe. It has a few missing and or stripped. We do a bit of work for the US, they still use " old money " , a pain in the ^%$@.

[TZ350]

Have you got one TPS feeding the two computers?

Yes ....

286966

[cotswold]

Over 1million page views

[jasonu]

Over 1million page views

Now that is really cool!!!!!

[wobbly]

Dont know if it will make a difference but TPS has its own sensor ground on the Ignitech - maybe this should be combined with the EFI sensor ground.
May not show up on the bench, but possibly when running.

[SwePatrick]

Before he left Derby to go do the Aprilia RSA I believe Jan got nearly 50 Hp from the reed engine, up from the 45 it had when Lorenzo rode.
They do sprocket power, so rear wheel on a Dynojet would be maybe a bit over 45.
Frits has posted a graph showing the reed engine Vs the rotary valve before Jan massaged it upward.



Thanks yet again, the dyno i was on is an 'mjp dyno'
http://www.mjpdyno.com/images/dyno2200_b.jpg
I had a lot of drivetrainloss due to:,,, forget to check tirepressure and the exhausthose rubbed the rear wheel. :wacko:
I had 0.2bar of tirepressure *lol*
I went to the dyno with no sparkplugs, no jets.. hoping that the dynoer had the things i needed.
He had no jets in the sizes i needed so engine ran a bit rich and the sparkplug(equal to an NGK B6ES) was starting to melt due to overheating.
Received 30.41hp at wheel.
Now at home engine runs way better due to better heatrange of sparkplug(NGK B9ES)
And tuned the fuel a bit.
I´m dreaming of about 34-35hp at the point where i´m at right now, but haven´t dynoed those numbers, just 'buttdyno', the engine runs a lot harder now than just after the dyno. :D
If one could fantasy about sprocket power, i´m in the range of about 37-39hp at the sprocket.
Still a bit to tune. i run an unmodded V-force reed now, but i´m modding an another reed as we speak. takes some days to finish thou, Jb-welding takes it´s time. ;)

My goal is a bit less than Derbi couse i haven´t got the resourches to dyno every now and then.
i´m tuning at home with buttdyno ;)

The engine?
Honda MT5(with kawasaki barrel from 1987) ;)
(50cc version of the Elsinore engine,but mine have grown)

Rgds.
Patrick

[TZ350]

Dont know if it will make a difference but TPS has its own sensor ground on the Ignitech - maybe this should be combined with the EFI sensor ground. May not show up on the bench, but possibly when running.

Good point, my thinking was that with the Ignitec and Ecotrons there is no measurable DC resistance between sensor ground and battery ground so I expect the sensor ground is connected directly to battery ground through the earth plane on their circuit boards.

So as it stands the Ignitec CDI and Ecotrons EFI are both tied to a common potential by their battery wires.

286978 The active voltage range of my TPS is 2690mV or 2.69V.

I agree it works OK on the bench but like you say, its worth keeping in mind the effect that any noise in the ground plane might have on things and tying the Ignitecs sensor ground to the 0V side of the TPS looks like a good idea and I think I will do that before I try to run this thing seriously.

286982

Up date as suggested by Wobbly.

[husaberg]

The most amount on GP racers hp output with reeds(wheel hp)
Does somebody know those numbers?Kind regards
Patrick

Before he left Derby to go do the Aprilia RSA I believe Jan got nearly 50 Hp from the reed engine, up from the 45 it had when Lorenzo rode.
They do sprocket power, so rear wheel on a Dynojet would be maybe a bit over 45.
Frits has posted a graph showing the reed engine Vs the rotary valve before Jan massaged it upward.

http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=261462&d=1333621581


When Jan Thiel went to Derbi to design the bike we now know as the Aprilia RSA125, he encountered the 125 cc reed valve Derbi ridden by Lorenzo the previous season. Jan played around with the reed valver as well, because he wanted to find out the differences between reed valve and disk valve power. He managed to extract 2 HP more from the reed valver than anyone else had ever done before (never mind the fairy tales of reed valve 125s producing over 50 HP; those Horses must have been Shetland ponies, probably measured at the piston ring).
My graph shows the power curve for the Aprilia RSA, the Aprilia RSW and that best-ever reed valve Derbi. It's not quite in the same league as the rotaries, hmm?

EDIT: Shame on me; I discovered that I posted a wrong graph (and I do not have the correct one at hand here in Holland). Power curve DERBILOR shows the reed valve Derbi as Lorenzo rode it. After Jan finished playing with it, it had 49 HP. Still, the best-ever disk valver produced 10 % more power than the best-ever reed valver.

[TZ350]

http://www.pit-lane.biz/t4140-2-stroke-how-plug-up-a-2-stroke-wristpin



I have a little question about a Cagiva Mito barrel with large booster; how plug up the wrsitpin, avoiding the "short circuit" between exhaust and transfer?
It's a 16 mm pin, can't fit an Aprilia GP pin!
I'm thinking to put some kneadatite into the pin ID..any suggestions?
Thanks

Aprilia wristpins were made by Pankl.
It was done by welding.
Every different solution we tried was a failure.
Maybe they will make some for you too!

And another approach taken by Wob, if any one is doing the piston pin thing this may be worth a try too.


Why put the plug inside the pin with a "new"" groove,there is already a groove available and also there is a chamfer on the end of the pin that can be used - as it was previously - to force outward, the retainer into this groove.

I made these plastic plugs several years ago using glass reinforced Peek,and tested them with no positive results at all.
But now we have tripple ports reaching around to 1/2 bore, and yes they do work a treat.

[cotswold]

Marques, Sykes ,Rossi and Av

[bucketracer]

TeeZee your posts have got me interested in reading the Pit-Lane thread.

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

Frits
I prefer not to talk about a stinger because that would imply a tube of some length. And length is not the issue here; the issue is flow resistance and diameters are far more decisive than lengths in that respect. Therefore I always apply a venturi as the flow-controlling element at the end of the reflector cone. It can be made exchangeable which allows experiments, and because the flow is controlled by the venturi, it allows for a tailpipe with a much larger diameter that is less susceptible to dents and deposit build-up. It also allows for a longer tailpipe in case you need to move a silencer out of the way.

You may be wondering about waves running up and down the tailpipe. Don't. Those waves will never be able to influence the events in the exhaust pipe because the flow through a correctly dimensioned venturi is sonic. Those waves are like birds flying against a storm: they will lose all their energy but they will never make any progress.

Your experience is correct: more flow restriction causes a higher average pressure in the exhaust pipe, hence less expansion and a higher average temperature of the gas in the pipe, and hence a higher speed of sound and a higher resonance rpm. And if you create too much flow restriction, the exhaust gases in the cylinder will not completely have left the building by the time the transfer ports open; they will enter the transfer ducts and that flow of hot gases will severely heat up the cylinder, the piston and the fresh mixture in the transfer ducts.

287048

The required flow restriction depends solely on the amount of generated exhaust gas, and that is directly proportional to the generated horsepower. I am almost certain that somewhere on this forum I already posted a simple exhaust concept that included the venturi calculation. But I can't find it through the search option (forum search options and I never seem to get along) so here it is once more, together with a sketch of the exchangeable venturi (red in the sketch).

287047

Brian, you are right about the flow restriction influencing the mixture strength of the MB40 model aero engine. For those of you who are less familiar with it: these model airplanes keep their fuel in a bladder. That bladder is contained in a tank, and the exhaust pipe pressure is fed to that tank. The pipe pressure tries to squeeze the bladder and the fuel is pushed to the inlet port via a regulator needle. But since the needle setting is optimized for each flight anyway, it doesn't matter if the fuel pressure is not always the same.

The cross-over connecting tube is connected to both inlet tracts between the carb and the reed valve, so the reeds will make sure that one crankcase cannot steal directly from its neighbour. What it can do, is steal some of the ram pressure that occurs at the end of each inlet phase. On the other hand, breathing will become much easier for each crankcase because the combined cross-area of both carbs is always available.
Air flow through each carb will become more uniform, so the suction signal at the carb's needle tube will be weaker. That means the mixture will become leaner unless you compensate with larger jetting. Did you work in that direction?

Jan Thiel
Temperatures at the exhaust flange were usually between 500 and 600°C if I remember well after 4,5 years!
Mid-exhaust temperatures were not taken,but I think they are higher.
The temperature sensor in the exhaust flange might have been cooled a little by escaping fresh charge!
We sometimes measured under-spark plug temperatures, they proved too high so we modified the head insert,
bringing the water nearer to the plug. This was very succesful, afterwards we never bothered with the sparkplug temperature anymore!

Some time ago engines mostly breathed air warmed by the radiator.
And do'nt forget the exhaust pipes!
Inside the fairing they heated the air quite a lot.
Putting them outside the fairing you lost revs.
The best solution was outside the fairing, but shielded from the airstream.
A friend of mine once tested his MBA 125 on a dyno. With and without fairing.
With fairing he lost 7HP!
So when I once had the opportunity of wind tunnel testing we looked at this.
There proved to be a quite big depression at the carburetors, at a wind speed of 120km/h.
This depression would of course have been even bigger had the engine been running!
The airbox resolved all these problems.
The bigger the better I heard at Aprilia!
Mostly there is not enough room at the bike however!

On the Aprila RSW the airbox was fitted on the spigot, of course with the air vents inside it.
On the RSA the carburetor was totally enclosed inside the airbox.
I would have liked to test with a ventilator giving real airspeed, but was told it to be too expensive.
Approximately 40.000 Euro!
You need a real big ventilator to simulate 240 km/h!
And of course it should have simulated airspeed going through the gears!
Then we could have mapped the ECU for all gears!
It proved to be cheaper to do this on-track and using telemetry.

When EGT goes up and up there should be some serious problem with the engine.
We never had pistons seize during our steady state tests.
Working on the dyno continuously 5 days a week!
I am 100% convinced our engine could have run for 6 hours at max power without seizing.
The problems arise when you close the throttle, or run part throttle!
The piston is mainly cooled by the transfer flow.
And at part throttle there is less transfer flow, causing detonation (auto ignition)
The entering fresh charge is ignited by the remaining, hot, burned gases!
You can see very severe damage to the piston after maybe 10 seconds at 20% throttle.
This still is an unresolved problem! I was thinking about a way to reduce engine power without closing the throttle. But how can you do this? I did not find a solution before I retired.
And nobody else was really interested.
At 100% throttle the engine was undestructible!
By making the transfer ports as wide as possible we had very good piston cooling.

As Frits has written, I would have liked to have also a dynamic testing possibility, with a flywheel.
In my opinion you should simulate a straight, starting at around 10.000 rpm, and shift through the gears
until you reach top speed. And with the airbox as used on the bike, with a ventilator that simulates the raising
air speed as it would be on track! Maybe it is interesting to know that without a ventilator the engine gave
less power with the airbox fitted.

I was told that such a testing system was too expensive.
And unnecessary as we won anyway!

I can also see a disadvantage of 'dynamic' testing.
Because the duration of the test is so short you can get away with very extreme (too extreme?) settings,
without damage.

Mic
How about much larger travel on the exhaust power valve.

Jan Thiel
This causes detonation (auto ignition)
The problem is that the burned gases do not exit the cilinder!
Retarding ignition also does not make sense.
As you have an AUTO-inition problem!
So the engine does not 'listen' to its ECU anymore!
What you would need is the same fresh gas flow, but with less HP!
Not easy to achieve!
A variable tailpipe might help.

Frits
Like Jan wrote, a shorter exhaust duration will worsen the detonation. What happens is this:
During normal operation, the blowdown time.area of the exhaust ports is sufficient to drop the cylinder pressure below the crankcase pressure before the transfer ports open, even at high rpm.
At part-throttle that cylinder pressure will drop to the same level, but now the crankcase pressure is much lower and exhaust gases will enter the transfer ducts, contaminating and heating the fresh mixture even before it enters the cylinder.
A theoretical solution would be a power valve that enlarges the normal exhaust timing instead of lowering it. But that is impractical as it would ruin the shape of the exhaust duct and it would cause cooling problems in the cylinder's exhaust area.
A variable tailpipe area, like Jan says, can be a more practical approach. I designed a simple solution, shown in the drawing below, but then two-stroke development at Aprilia was terminated because of Dorna's ban on two-strokes.

287050

Jan Thiel
This could very well have been the solution.

Frits
As Jan pointed out, once you have auto-ignition, the engine does not listen to its ECU any more. So you would have to start skipping sparks well before the onset of detonation.
In a foul-stroke your proposed system does work, but a two-stroke would react far from linear. For example, if you skip 1 in 4 sparks, you will loose much more than 25% of engine power because that one missing spark will cause the gasdynamics processes to collapse. The main problem would be to realize a smooth transition from intermittent to full ignition.

[husaberg]

Mcbeth.........
http://www.mororacing.com/documenti_scheda.php?iddocumento=2

[Flettner]

Took the EFI YZ out for another trail ride, 20% fuel savings this time over my standard YZ. It depends on the type of riding, the closer to full throttle the less the savings. This was a tighter track, Tarawera. Last time out it was measured at 14%, Epic events fast and open. Thought it was interesting.

[TZ350]

Took the EFI YZ out for another trail ride, 20% fuel savings this time over my standard YZ. It depends on the type of riding, the closer to full throttle the less the savings. This was a tighter track, Tarawera. Last time out it was measured at 14%, Epic events fast and open. Thought it was interesting.

Thats very impressive and in line with Husabergs post. With this sort of improvement you would have to think 2-T's will make a comeback and have a bright future.

Below is Google Translates best efforts with Husa's post.

In the face of the patent dated December 2004 , in 2005 I took a bit ' to heart . We began to work with the various motors , 50, 100 , 125 and 250 also have to cross a range of different types to understand in various applications as it was going to require, if there was homogeneity of technical result between the various engines or not. In the end it turns out that in broad terms the benefit is the same on all engines , from fifty to 250 cross there was always a 40% consumption less, 60 % less HC and CO with respect to the carburetor ; engines that were marked 70 % less but the minimum was always 60 % and 40-50%. With the great advantage that the two-stroke engine layout is not as had to be changed , the system could and should be applied on engines already in circulation, there is probably a need to update the mergers ( and maybe cylinder head ) but it is very different at the project level and constructively address such issues as the pressures 4T of the internal gas or the need of the distribution system, the two-stroke remains in all respects " our beloved two-stroke " , there are in more of a pump oil (preferably electric ) and a fuel , the whole , however, also works on batteryless mode , without battery , because the supply pressure is slightly higher compared to an indirect 4T .

With the electronically controlled oil pump can give quantitative of lubricant right at any time with the result in statistical terms of an average consumption of less than 1 % , very lower than consumed today by a fifty (as well say that the quantity of oil engine series is far too high ). The oil for the lubrication is sent as in engines with mixer
a nozzle upstream of the slats. Technically, the solution is very nice because with the electric pump can send oil according to the real conditions of work , you can consider all the parameters and decide accordingly .

Another advantage of the system is the CCID internal and external cleaning of the head. The injector in the rear of the cylinder shoots against the roof of the combustion chamber which remains "clean" , then is cleanliness in the sense of accessibility mechanics , you have nothing lìoltre the candle so the maintenance Typical Fast the racing keeps the speed of the motor current . Obviously with the injector on the cylinder some complication with respect to a cylinder present there , but it is more than acceptable. The idea: to inject from bottom to top.

Now I want to discuss the idea of the patent. The direct injection is proposed by definition to send fuel in the combustion chamber , as it is easily imaginable with an injector placed coarsely beside the candle ; the common idea at that point is to inject a drain that is closed during the ascent of the piston for the maximum time allowed by the geometry of the motor and fairly high pressure necessary to throw gasoline little time in the environment already under pressure. Moreover it should be noted that systems with the injector over head to clutter in the area candle, fire station against the sky piston which is the hottest area of the entire combustion chamber , and I think this does not go so well because gasoline goes to evaporate in a non- controllable.

Nino in the system , the concept is different , the injector shoots from below the upwards towards a certain area of the head ; the mixture exits the unloading, even if it is open , and if a little ' air pumped by decanting maybe comes out , it should be well and good , cleans the gas . The timing of work is uncoupled from the geometry of the engine. apparently seem to lose time on the possible length injection because I lose the ability to inject when the piston is in the vicinity of the upper dead point , in reality the possibilities Splash in open drain proposes the reverse situation , times lengthened . The injector on the head as a system has to deal as the limit with the position of the piston , the injection that shoots from below against the head offers injection times doubled because the path for fuel to get to the discharge would be double , goes against the head and bounces towards the piston.

Throttle body : is not essential If you noticed at the main picture you may have noticed that there is no body throttle , just a suction cone . This system is in fact was initially developed to work without a valve, with air Suction always open ( controlled slat ) as with the gas ideally 100 % . In this configuration acts a bit ' as the Diesel engine , the performance is controlled by the amount of fuel dosed by the injector as a faucet: because the air flow remains constant , is the fuel to determine the ascent or descent
speed. Nothing guillotine or butterfly to control the passage air but only a " fuel cock " managed by the control unit on basic information of the gas sensor . It ' a system that works well, there is a lot of air under the piston to cool the crank species in closing of gas , the operating temperature detected during the tests was always less high in comparison to the solution with air control . The braking effect on the brakes is there anyway , depends to 95% on the compression ratio and combustion .

The CCID version without throttle body is particularly suitable I think the racing where the engine can be "open" . It has a "Small" problem, there is an intake noise higher than
the presence of the throttle body that among other things reflects the noise. So where there is a need to respond to homologation requirements with evidence around at idle , you should put a system choking air that helps in those situations. depends by motor and engine , is so average and we had experimental verification. Ready for the market
I close the presentation of Direct Injection -fuel Combustion Control reporting that after doing all the various tests we mounted on a motor Minarelli enduro 50 cc. developed in mechanics to reach nearly 13 horses and at 14,000 rpm . Once more we have seen that the performance is similar to the carburetor , with the same benefits in terms of consumption and pollutants reported before , ready to try to demonstrate the effectiveness of all the work. We did it first without and then with the throttle body body throttle because of the noise in the intake system with batteryless ( power generator from the original) because it seemed to us just to prove that it works fine without a battery.

In the face of all this I would say that today there is on the market a solution patented technique applicable to all engines two times useful to arrive with the pollutants more or less at the level of the four- time of performance (ie that all engines are not the same ) , obviously it is not correct to compare a 250 with a 250 2T 4T and compare the performance when the pollutants are different. We put the system on engines as well as hang-gliding and other search engines finding the same benefits , so for the future of the news is that there is the possibility for the two times to be competitive in the years to come with 4-stroke engine while keeping all advantages that very constructive know it. Then there is no possibility for the market to go back to how was once with the two-stroke in the foreground , then each Manufacturers may choose to develop it and use it specifically . Because today , we could get there first? I would have liked to get two or three years ago but the time in these activities is hardly controllable. Today there is the need, the components industry has made available what is necessary to build the facility , twenty years ago there were no such injectors righteous and right sensors , Now with the development of 4T injection has become easier to make a certain type of plant on the two times , and if observed , for example the pattern of patent drafted in 2004 you can see that injector and headquarters occupy a certain space on our prototype engines went drastically reduced.

State of the art If it is true that this direct injection could go in series as components in the morning , it is equally clear that a fifty Today the injection is not essential , to meet Euro 2 can be achieved with the carburetor with the current state of affairs do not need any change, but with the future introduction the new standards , sooner or later, this need will be there. On the other displacements of 125 and we are already at Euro3, and here some models pass with difficulty with electronically assisted carburetor , the 4T same way as you can imagine with this handle with facility performance for fun on the track and switching to mode code to return home. MANAGEMENT INJECTION 4T
ON MECCANICA2T I thought during the development that the development point would have been criticism , there is a problem "Sensitivity" of each the new engine technical solutions , instead despite combustion lasts less compared to a four- times and the ratio of actual compression is less high ( better if it is high) , I have not seen critical in behavior between engine and motor to vary environmental conditions and applications. I think this is positive because if a engine is very sensitive you're always playing catch up optimal tuning : Today when I say that the consumption is less than 40 % , I say the worst figure that are sure to find even in conditions less favorable. The oil is mixed with the air in the duct suction . Given the presence of various sensors , it needs to be an oil quality , which lubricate and it burns without leaving deposits. with consumption we are not far from the blow-by of the four-stroke : when we say that the 4T do not consume oil make a statement incorrect , the smoke at the discharge is more or less marked , and even if there is a certain amount of oil goes away for unloading . With careful management the discharge of oil can be obtained with the 2T results neighbours.

Thanks to ... Throughout the development activities have always been followed by engineer Henry Nino with his staff and the work of the workshop was executed by Franco Moro Moro Racing , after which the patent at the end of 2010 it was purchased by Athena that with Get Benedini was led by Antonio development partners electronically.
Each of us has had I think its satisfactions . Henry Nino , head of the Faculty of Mechanical Engineering at the University of Potenza and his staff has been
glad that I was interested in him and his system has seen in a very interesting idea , especially for high-performance engines , for my part I think I gave the impetus
decisive to achieve a certain result and now I can use the patent for racing ; Athena in turn is placed in a home where we're going to make use of technology in
years. At the moment, out of the two-wheeler sector , in the absence of specific regulations for use The use of this injection is linked to the costs and hence the delta of carburetor is in line with the four-stroke , renounce the carburetor but serve the fuel pump , control unit, various sensors etc . , plus here is the oil pump . We should not expect lower spreads compared to what we have already seen with the four times but on balance will remain the mechanical advantage of the two-stroke than a 4-stroke is certainly not cheap.
018

[TZ350]

287148

The wiring is a bit of a rats nest and with its fuel header tank the poor thing looks like its on life support but it has passed its first EFI test. I connected in the plumbing and fuel pump and turned it on, and there were no fuel leaks. So onto the dyno when we get a chance to see if we can get the Beast started.

[RomeuPT]

I have a question about plug to piston top distance.

I had measured the 125 head and domes I got for domed pistons, two hemi head's with 0.7 squish would have about 8.7 distance from plug to piston dome top. But the domes I got have more volume and they would make 10.3 mm of distance, toroidal head's have a lower distance and I have one stock toroidal Honda RS 125 head but my bike does'nt seem to like it with the domed piston.

Aprilia RSA head drawing show a 7,6mm distance.

Is there an optimun for this distance? I understand that the volume and squish width needed would play with the distance, or even it can be corrected with proper ignition.

fast 125 engines running unleaded run low compressions, how much is the distance in them?

Is there any good baseline for this?

Thanks

[F5 Dave]

That's a good question, what I can tell you is if you get too close (which on a 50 is easier) it shrouds the spark with a conventional plug & a side ground to electrode racing plug opens the spark area up helping greatly. But yer probably not running a B8ES in it anyway;)

[TZ350]

287185

Not mine, not Dave D's not Av's (but there are plans) but another soon to be out there Auckland 50, so who's could it be?

[speedpro]

Gotta love Toots' safety boots

[TZ350]

Gotta love Toots' safety boots

Yep ... Steel Cap Jandals. Grandma OSH would have a fit .... :laugh:

[F5 Dave]

Well the pic sez Ned Kelly:innocent:. GPR50 from the looks. Dave Ds old Techo mags at a guess too.

[TZ350]

Well the pic sez Ned Kelly:innocent:. GPR50 from the looks. Dave Ds old Techo mags at a guess too.

Yes Neds ... and No the wheels are original to the bike. First start up tonight, serious dyno time Thursday and then hopefully Mt Wellington at the next meeting.

[F5 Dave]

Good Greif my poor old 1985 Suzuki is going to be obsolete one of these days with all these new fangled engines.

[FastFred]

Good Greif my poor old 1985 Suzuki is going to be obsolete one of these days with all these new fangled engines.

Maybe not, well not an orphan anyway as I hear Chambers might be making a RS/RG50 combo for Av.

287196

Originally posted by Cotswald, Av riding in Italy top right corner, her bike (A1 ???) has the white faring.

[wobbly]

I read the extract above from Pit Lane and one comment I am at odds with.
Disagreeing with Frits in public is fraught with danger but in this case I feel something needs more input from those cleverer than I
"You may be wondering about waves running up and down the tailpipe. Don't. Those waves will never be able to influence the events in the exhaust
pipe because the flow through a correctly dimensioned venturi is sonic. Those waves are like birds flying against a storm: they will lose all their energy but they will never make any progress."
This seems wrong to me so I checked the stinger flow conditions in several engines that could be considered to be successful in that they made serious power and were reliable.
All of the results showed fow in the venturi after the rear cone to be just short of sonic.
If sonic conditions prevailed than the flow would be termed to be choked, and a shock wave would form,creating havoc with the pressure conditions in the pipe - ie death deto.

The statement also seems at odds with what I have been working with in KZ2 kart engines.
These 125 engines have a U bend stinger dumping into a large muffler.
Two mufflers are available, one with the muffler perf a couple of mm bigger than the stinger ID, the other around 50mm ID.
The larger muffler would in effect create the conditions at the stinger end replicating dumping into atmosphere.
It also happens to add around 6 Hp at 14000 - so if the wave action within the stinger due to its length is having no effect, then what is causing this.
It certainly isnt the small muffler simply affecting the pressure in the pipe due to a flow restriction.
The length appears critical, so i am going to try adding length to the stinger inside the big muffler to see what happens ( this isnt a tech item by the way, and yes I put a venturi inside the stock stinger as well ).

When I found out about stinger venturi from the inventor - Helmut Fath, my 2T hero, he said they ameliorated the differing return wave effects on the pipe action due to having one long stinger and one short one.
This was an early version of Honda's RS250 that had one stinger 450 long the other 150 long.
What he thought may not in fact be true, but creating equal pressure in the pipes by using a venturi would be a plus, and just maybe the return wave action is reduced by the restriction as well.

Below is a plot of Mach number due to having the flow conditions checked by the simulator within a " correctly designed " stinger venturi.

[TZ350]

Maybe not, well not an orphan anyway as I hear Chambers might be making a RS/RG50 combo for Av.

287196

Originally posted by Cotswald, Av riding in Italy top right corner, her bike (A1 ???) has the white faring.

Av's race number is usualy 21. attached is an email received this morning. And it looks like Av's RS/GP125 bucket will be getting a dust off in preparation for the 2-hour.

Hey guys,
Hope everything has been trucking along well at ESE.

I just realised you haven't been receiving my race reports from over here in Europe so a couple are attached. How rude. Sorry! Presume facebook has been keeping you in the loop at least a bit..

Would love to hear how buckets is getting on? And the rg50, Cully?
I will be home in time for the two hour this year!! Should we give it a crack on the two smoker?

Catch ya soon
Av


287198 287199 287200

[marsheng]

This is some interesting reading on detonation.

http://www.avweb.com/news/pelican/182132-1.html

[RomeuPT]

I have a question about plug to piston top distance.

I had measured the 125 head and domes I got for domed pistons, two hemi head's with 0.7 squish would have about 8.7 distance from plug to piston dome top. But the domes I got have more volume and they would make 10.3 mm of distance, toroidal head's have a lower distance and I have one stock toroidal Honda RS 125 head but my bike does'nt seem to like it with the domed piston.

Aprilia RSA head drawing show a 7,6mm distance.

Is there an optimun for this distance? I understand that the volume and squish width needed would play with the distance, or even it can be corrected with proper ignition.

fast 125 engines running unleaded run low compressions, how much is the distance in them?

Is there any good baseline for this?

Thanks

I would like this a bit of discussion around this. I guess is important for everyone here.

[Drew]

I would like some video updates on the injected GP125.

GET TO WORK FUCK YA! It's the most interesting mod to date!

[husaberg]

<img src="http://www.crp-racing.com/portal/images/stories/Kit-Honda-Lamellare/honda-disco-rotante-1.jpg" height="300px"/><img src="http://www.crp-racing.com/portal/images/stories/Kit-Honda-Lamellare/honda-disco-rotante-3.jpg" height="300px"/><img src="http://www.crp-racing.com/portal/images/stories/Kit-Honda-Lamellare/honda-disco-rotante-2.jpg" height="300px"/><img src="http://www.crp-racing.com/portal/images/stories/Kit-Honda-Lamellare/honda-disco-rotante-4.jpg" height="300px"/>

This has been posted before...... but there is another similar version.. maybe Indian or Chinese but i can't remember what it was......
http://www.crp-racing.com/portal/en/kit-honda-disco-rotante.html