ESE's works engine tuner

[husaberg]

No not really, its a fairly rare engine I'm working on and don't want to sacrifice any of its originality... Really the only option it to modify the low compression pistons I have or wait until the right ones pop up, and that's fairly unlikely.

Gazza Pm me the measurements of the piston you have and what you need.
I have had a low HP old britsh dungar piston welded when it spat a land but it was only done when the piston was truly unobtainable and i was young and impetuous. But it was not an ideal solution.

[RomeuPT]

Hello everybody.


The most powerfull Honda type exhaust duct, for the T port, that I dyno developed for a customer in Belgium, was a 41 wide by 32 high oval at the flange face.
This went out to a 41mm header diameter via an oval to round transition.
The stepped transition, with simply a round 41mm spigot ID lost around 1.5 to 2 Hp comparred to the CNC lofted shape.


I filled the spignot with high temp epoxi to try oval to round transition, the epoxi will burn slowly but give enought time to test.

First test makes me feel a bit better power before peak... The plug looks a bit leaner but still ok. Wish I have a dyno.

Thanks Wobbly.

Regards

[cotswold]

Just a quick question but I'm sure some one out there may know the answer.
With out gong into models and things is it possible to add height to a piston crown by welding? Just to head off one reply, for various reasons I can't work the head to get the required compression, really need it to be the piston being altered if possible.

You can, I had a kawasaki klr piston built up and re machined to suit a cam and valves we fitted, you do have to be careful not to over cook it though as the 1st attempt failed dismally.

[Grumph]

Just a quick question but I'm sure some one out there may know the answer.
With out gong into models and things is it possible to add height to a piston crown by welding? Just to head off one reply, for various reasons I can't work the head to get the required compression, really need it to be the piston being altered if possible.

As others have said, the answer is yes...but ! I've done it on both 2 and 4 stroke pistons. I'm going to assume that you're talking 2 stroke on this thread. First you need to find a TIG welder who knows his alloys...and has access to the right rods. Then it's done slowly and carefully to try and avoid distortion....good luck.

Can i assume you've looked at alternative pistons ? Most bore sizes have been used at some time when you include oversizes. Failing that see sketchy's thread on CNC work wanted....

[wobbly]

I did it to a piston in a world champs winning chainsaw on Alky that had an integral head.
Used high silicon rods, and preheated the piston in the oven.
Worked fine, I think only due to the fact the saw made bugger all bmep, and the Alky kept it cool.

[Kickaha]

and preheated the piston in the oven.
The engineer who did one for me preheated it and then cooled it in an oven, this was in a 125 National Kart running to 12,000, lasted all season but when we stripped it there was a crack by the edge of the weld

[Ocean1]

The engineer who did one for me preheated it and then cooled it in an oven, this was in a 125 National Kart running to 12,000, lasted all season but when we stripped it there was a crack by the edge of the weld

I've not done a 2T piston, but the ones I have done have been done like that. In the more modern pistons I found it almost impossible not to blow through into the top ring groove, in which case I just welded that up too and recut it later. Another thing I think helped is a plug, to keep the skirt shape true. They're not round, but the machined surface inside the skirt usually are, so I made up a heavy wall tubular plug to fit. It stayed in there through the heating and welding cycles and seemed to do the trick. Might have worked OK without it, who knows, but I also used the plug to hold the piston in the lathe.

Oh, and as Wobbly said, 10 to 15% silicon rods flow much better, easier to control.

[RAW]

I've not done a 2T piston, but the ones I have done have been done like that. In the more modern pistons I found it almost impossible not to blow through into the top ring groove, in which case I just welded that up too and recut it later. Another thing I think helped is a plug, to keep the skirt shape true. They're not round, but the machined surface inside the skirt usually are, so I made up a heavy wall tubular plug to fit. It stayed in there through the heating and welding cycles and seemed to do the trick. Might have worked OK without it, who knows, but I also used the plug to hold the piston in the lathe.

Oh, and as Wobbly said, 10 to 15% silicon rods flow much better, easier to control.

Firstly what is the piston ? Cast or forged ,
silicon is a grain refiner, it's assists with edge wetting ( fluidity along the edges of the welds ) it also assists with the cleaning, if the piston is high in silicon content then a high silicon filler metal is desirable
The added benefit of the available high silicon Alluminium filler wires are that they have a large mangenise content, this is particularly desirable as this is the element that supplies the toughness to material ( not hardness, but toughness ) therefore it's ability to withstand sustained cyclic loading.
Final note, small weld beads, a large weld requires large heat inputs, this inturn leaves the component with large grains, ( for a given area the grains will be flowing accordingly as per the manufacturing process, if we super heat this area as applying a large weld we will have an item with large grains for a given area ) if we apply small weld beads we do not require the high heat inputs therefore the grain growth is minimised, Yes you will need to have more weld beads to comlete the same buildup, but the greater benefit to this is that each subsequent weld applied along the edge of the previous weld has the ability to refine the grains of the preceding weld if done correctly, this in turn has a direct effect upon the toughness of the finished item,

[Gazzza]

Thanks for the advice re the piston, I have to admit I knew the right people to ask are on this forum, in all fairness the pistons and bike in question is a restro project of mine... The problem is its a 1962 Honda CB92, as you can imagine parts for these are fairly scarce. The bore and stroke are 44 x 41, and I'm guessing cast for that era??? With out taking the head off I think we had it rebored .50 over but could only source C92 pistons, thus the lower crown height. Going from what I'm reading yes it can be done, but I need to find some one who knows the business, so would any one who has replied be willing to tackle the job or recommend some one? It's not something that is needed to be done for a bit as its still a way off being finished.
I have tried to attach a pic, but this isn't mine, mine as is all complete but looking a bit sad awaiting its resto.

[RAW]

Thanks for the advice re the piston, I have to admit I knew the right people to ask are on this forum, in all fairness the pistons and bike in question is a restro project of mine... The problem is its a 1962 Honda CB92, as you can imagine parts for these are fairly scarce. The bore and stroke are 44 x 41, and I'm guessing cast for that era??? With out taking the head off I think we had it rebored .50 over but could only source C92 pistons, thus the lower crown height. Going from what I'm reading yes it can be done, but I need to find some one who knows the business, so would any one who has replied be willing to tackle the job or recommend some one? It's not something that is needed to be done for a bit as its still a way off being finished.
I have tried to attach a pic, but this isn't mine, mine as is all complete but looking a bit sad awaiting its resto.

If you want to send it to Australia & you are prepared to wait , PM me

[husaberg]

Thanks for the advice re the piston, I have to admit I knew the right people to ask are on this forum, in all fairness the pistons and bike in question is a restro project of mine... The problem is its a 1962 Honda CB92, as you can imagine parts for these are fairly scarce. The bore and stroke are 44 x 41, and I'm guessing cast for that era??? With out taking the head off I think we had it rebored .50 over but could only source C92 pistons, thus the lower crown height. Going from what I'm reading yes it can be done, but I need to find some one who knows the business, so would any one who has replied be willing to tackle the job or recommend some one? It's not something that is needed to be done for a bit as its still a way off being finished.
I have tried to attach a pic, but this isn't mine, mine as is all complete but looking a bit sad awaiting its resto.

Send me the measurements that you want Honda will have something to suit.

<tbody>
OEM Ref No
Model
HP
No Cyl
Cyl Dia
Piston
Ring
Pin


Head Type
Length
Comp Dist
Comp
Oil Comp
Dia
Length


13101-230-040
CB125 CD125
125cc
2
44
85
53.1
21+5.6
1.2-2
2.5-1
13
35


13101-303-000
CD125K3
125cc
2
44
85
53.5
21.7+5.3
1.2-2
2.5-1
13
35


13101-200-020
C92 C90
125cc
2
44
130
52.9
23+6.9
1.2-2
2.5-1
14
35


13101-216-000
CB93
125cc
2
44
18
55.3
21.2+8.1
1.2-2
2.5-1
14
35


3101-KCI-003
CB-125T RM-125
125cc
2
44
18
48.5
21.5+3.5
1.0-2
2.5-1
13
34

</tbody>




IF these figures are close you may be better off skimming the C92 pistons around the squish band, to suit rather than welding the dome?


"Chimney effect" i 'd never heard of it?
http://www.raerdesign.com/article_1.html

The page designer has heard of Jan and Frits though
http://www.raerdesign.com/images/p010_1_02.jpg


cough cough......

Mr Waynewright, the question for you and Mr Frits it was about air cooled cylinders with rear facing ex port.
I didn't word it that clear though, so my fault.
With air cooled (or water cooled for that mater)I can see how the straighter ex would be beneficial the weight distribution can be improved the sheilding of the exhaust pipe can be beneficial.

But i have often seen it written that the cooling of the cylinders is better and more uniform with the rear facing exhaust on a air cooled cylinder

Which is counter intuitive to me as the hotter part of the cylinder around the ex port would receive preheated air, so intuitively it seems that the cooling would be less uniform. With the cooler part of the cylinder getting better cooler airflow with this set up

But this isn't the case..... or is it?

[Frits Overmars]

"Chimney effect" i 'd never heard of it?
http://www.raerdesign.com/article_1.html
The page designer has heard of Jan and Frits though...But apparently he has never heard of the Aprilia RSA250:

The Bimota V Due broke the first rule of two-stroke engine design by having a downward pointing front cylinder.282398

Nevertheless he goes on about " the only successful version of the world’s most advanced production engine, the Bimota ‘V-Due".
There is a reason this Bimota is usually called the V-Didn't ....
Now I am going to read everything else on this RaerDesign Website. I wonder what other brilliant ideas are in there, waiting to be discovered.
Maybe I will even change my job description from engine designer to chimney sweep :msn-wink:.

Later:
It cost me an hour, but at least now I am sure I did not miss a single piece of valuable information. I also discovered that the web designer "borrowed" several engine sketches from my friend Martijn Stehouwer ( www.emot.nl (http://www.emot.nl) ). I very much doubt whether Martijn was even informed...

[husaberg]

...But apparently he has never heard of the Aprilia RSA250.

Or the YZR500 either. Honda also have some explaining to do.

Someone else would do too... LOL.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=251583&stc=1&thumb=1&d=1322335042

[speedpro]

It reminded me of the marketing for the Yamaha 750 when they first came out with the downdraught intakes and the forward sloping cylinders. Gravity was supposed to be helping fill the cylinders, It would have been of course but I'd like to see someone measure it.

[senso]

Good night folks, hope you don't mind I ask my first question.
I hope to one day(hopefully still this year) to have a running two stroke engine with injection, and I want to start measuring a good engine running on a carb, and I would like to measure crankcase pressure(before and after reeds), can someone tell me what are the ball-park/expected maximum and minimum pressure values, so that I can narrow the sensor selection?

Best regards.

[wobbly]

Here is the intake pressure traces of RZ400 at 10,000 rpm.
The case goes to approx 0.6 Bar, the intake +/- 0.25 Bar if my reading of pressure ratio is correct.

[TZ350]

http://i854.photobucket.com/albums/ab102/GerbilGronk/Mr VMX 10th Anniversary Series 2012 - 2013/Round 5 Wanganui 20 April 2013/IMG_6687_zpsbda45d16.jpg

Fuel injected twostroke second in national MX series. EFI performed seamlessly through out the whole series.

It will be interesting to see how TZ's EFI works out.


There should be a brass band playing and ticker tape parade up main street for Flettner. As a fuel injected racing air cooled EFI 2-Stroke that has been competitive and reliable over a whole race series, is a very, very good effort.

I too think Flettners EFI 2-Stroke is a very remarkable effort that hasn't received the positive recognition it deserves.

I have heard that the other 2T EFI project Wob and Flettner have been working on is up and running and I would love to hear from anyone else, who have had success with raceable 2-Strokes running EFI. Like Flettner's project, it would be good to see how others have gone about it or even to hear of any other privateer who has managed to build a successful racing EFI 2T.

I have now sorted some base maps to get started with for my own EFI project using simulated dyno graphs generated using EngMod2T. And now feel comfortable with how the EFI programming software works so the next step is to start fitting the EFI hardware to the Beast and then its dyno and track time.

[gamma500]

I have built several inertial dynos for 40 Hp engines ( engine dyno, not roller for a bike ) and the steel wheel were all sort of around the same dimensions.
Depending on what scrap I could beg ,borrow or steal.
Last one was 525 by 60 thick, new one is 450 by 80 thick.
Depending upon what gear you use you can vary the spin up time, thus the acceleration rate very easily to get the test length in the ballpark.
One thing not mentioned in many build descriptions is that you must use an overun clutch to prevent the inertia wheel from driving the test motor forward, after a test or
more importantly, if it fails on the dyno.
Imagine the mess if it siezes, and it is forced to keep running whilst you are frantically jumping on the brake.
Im just about to assemble my new setup, so will take some pics when its up and running.


I've been reading some old posts, and found wobblys post about engine dynos.
Wob, could you post some pics(and maybe specs?) of your engine dyno setup?

[wobbly]

Here are some engine dyno shots.
SportDevices software is very easy to setup and use, so is 3rd dyno I have built using it.
Gives appox 10 second run time from 8,000 to 15,000 in 4th gear with 46Hp.
Had everything from 50cc scooter to 100Hp RZ500 on it, repeatable to 1/10ths of Hp easily.
And the engine is at my easily accessed level of crippledom.

[TZ350]

OK?but why change it?(the shaft)
The basket will likely have a press-in steel female spline in the alloy Clutch hub
Just a thought?
If it is anything like Honda's the drum/hub will be fairly generic casting with a different primary gear riveted on and steel spline adapter pressed in for different models.
You will likely need to rivet on the correct gear but it may be easier. Worth a crack anyway?
Some Hondas have rather wide shoulder behind the drum in the casting to accommodate different shaft lengths with the same basic hub casting shared between models.
Could also be an opportunity to get rid of those funny clutch springs pressure plate at the same time.
Have a look for cross over clutch plates from a aftermarket cattledog to see what drums are likely to be very similar say Dr125 etc.
Rob was going to get one off Kicka at one stage to see how they match up i recall.

These all share similar plates
GP 100 C/UC 78 CK3319
RM 100 A 76 CK3319
RM 100 N/T/X 79-81 CK3319
GP 125 C/N 78-79 CK3319
RG 125 CG/CH/J (NF12A) (Gamma/Rear Drum Brake Model) 86-90 CK3319
RG 125 UCG/UCH/UCJ/J/BUJ (NF12B) (Gamma/Rear Drum Model) 86-90 CK3319
RG 125 FN/FP/FR Gamma (NF13A / Rear Disc Model) 92-94 CK3319
RG 125 FUN/FUP/FUR Gamma (NF13B/Rear Disc Model) 92-94 CK3319
RG 125 UN - Wolf (NF13E / Naked) 92-94 CK3319
RM 125 N/T 79-80 CK3319
RM 125 G/H 86-87 CK3319
TS 125 XUE/XUF/XUG/XUH/XUJ 84-90 CK3319
TS 125 RK/RL/RM/RN/RP/RR 90-94 CK3319
GT 185 K/L/M/A/B/C/EC 73-79 CK3319
TS 185 K/L/M 73-75 CK3319
TS 185 B/C 77-78 CK3319
TS 185 ERN/ERT/ERX 79-81 CK3319
DF 200 EV/EW/EY (SH42A) 98-99 CK3319
DR 200 G/H/J 86-89 CK3319
DR 200 SEP/SER/SES/SEV/SEW/SEX/SEY (SH42A) Djebel 93-00 CK3319
DR 200 SE Trojan CK3319
DR 200 SEK1-SEK9 01-09 CK3319
GT 200 EN/EX X5 79-80 CK3319
RV 200 K2/K3 02-03 CK3319
SB 200 N/X 79-80 CK3319
SX 200 R/R-Z/RJ/RM 90-91 CK3319
GSF 250 N/ZM/P/NP/ZP/R/NR (GJ74A) 92-96 CK3319
GSX 250 RCH/RH (GJ72A) CK3319
GSXR 250 CJ (GJ72A) CK3319
GSXR 250 CK (GJ72A) CK3319
TS 250 XE/XG/XH/XJ/XK 85-89 CK3319

Scraped of another thread (Thanks Husa) as its a good list of clutch plate possibilities. I am not sure about the 250's as I haven't thought to look at them before, but the others look like they will fit the GP. Kevlar clutch plates can be purchased of Ebay for a reasonable price, its usually just the number of friction plates that varies between the smaller Suzuki models.

[diesel pig]

This isn't really anything to do with this thread per say but I reckcon that if anybody has tired what I am going to ask about it would be the people on this thread.
Talking with my old man about the programmable ign it is hard work out what's happening with the engine all the time with the curves and powerjet and what nots
in relation to the power curve. So we wondered if we made a graph starting with a dyno HP curve and then overlaying it with ign advance curve and powerjet off
and on times and other things the programmable ign is doing it using the revs as the common baseline maybe easier to "see" what is going on. Since this would take some work I thought I would ask has
anybody done this? was any help?

[gamma500]

Here are some engine dyno shots.
SportDevices software is very easy to setup and use, so is 3rd dyno I have built using it.
Gives appox 10 second run time from 8,000 to 15,000 in 4th gear with 46Hp.
Had everything from 50cc scooter to 100Hp RZ500 on it, repeatable to 1/10ths of Hp easily.
And the engine is at my easily accessed level of crippledom.

Thanks Wobbly!

What is the diameter of the inertia wheel shaft?

[wobbly]

The top shaft with the sprockets/starter gear and the overun clutch is 30mm.
The main shaft is 40mm, and the bearings for this have no trouble supporting the 80Kg odd static load.

[TZ350]

Talking with my old man about the programmable ign it is hard work out what's happening with the engine all the time with the curves and powerjet and what nots in relation to the power curve.

So we wondered if we made a graph starting with a dyno HP curve and then overlaying it with ign advance curve and powerjet off and on times and other things the programmable ign is doing using the revs as the common baseline.

282546

I have not actually done what your trying to do with the graph before myself, but because my ignition advance on WOT covers pretty much the same range as the hp, ie 0 to 30 on the Y axis I mocked up this EngMod2T dyno graph to see what it might look like.

Yellow for ignition advance and blue for power jet on/off.

My graph has the power jet shutting off just past max power to compensate for the natural enriching effect as the air velocity increases through the carb.

And over advancing the ignition at the bottom on WOT is for enhancing drive out of corners, retarding back to normal at peak torque and extra retarding of the ignition past peak power rpm to dump more heat into the pipe for extending the over rev.

I know its just a mockup but graphing manualy WOT ignition and the power jet onto a dyno graph printout could be fairly doable.

[Grumph]

This isn't really anything to do with this thread per say but I reckcon that if anybody has tired what I am going to ask about it would be the people on this thread.
Talking with my old man about the programmable ign it is hard work out what's happening with the engine all the time with the curves and powerjet and what nots
in relation to the power curve. So we wondered if we made a graph starting with a dyno HP curve and then overlaying it with ign advance curve and powerjet off
and on times and other things the programmable ign is doing it using the revs as the common baseline maybe easier to "see" what is going on. Since this would take some work I thought I would ask has
anybody done this? was any help?

Do it Neil, bring it along on Saturday and let's all look at it.....

[husaberg]

Some random Yam TZ125 Crankcase (first 3 pics) is it an illusion or is the main bearing oiling holes actually proud?
Re the Crankcase crankshaft shielding. I have seen Wob do something similar to the Yam cases shielding before (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130142699#post1130142699). Which i presumed at the time was for primary comp on Yow's RG100.I guess that's not what its entirely for?
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=245979&stc=1&thumb=1&d=1314839200
(http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282550&d=1368011444)http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282550&stc=1&thumb=1&d=1368011444 (http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282550&d=1368011444)http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282551&stc=1&thumb=1&d=1368011533 (http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282551&d=1368011533)http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282552&stc=1&thumb=1&d=1368011533 (http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282552&d=1368011533)
For giggles i have thrown in Some NX4 cases.(last 3 pics)
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282553&stc=1&thumb=1&d=1368012173 (http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282553&d=1368012173)http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282554&stc=1&thumb=1&d=1368012317 (http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282554&d=1368012317)http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282555&stc=1&thumb=1&d=1368012317 (http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=282555&d=1368012317)




Maybe if Wob feels so inclined he can post a pic or the of the NSR125 inlet and crankcase mouth.

[RomeuPT]

Hi everybody.

Wobbly, can you say the port timings of a typical Honda 125 A-Kit?

Is there any radius raising the exhaust time like on Aprilia?


Many many thanks

[2T Institute]

Hi everybody.

Wobbly, can you say the port timings of a typical Honda 125 A-Kit?

Is there any radius raising the exhaust time like on Aprilia?


Many many thanks

Something like
Exhaust 80-83
A transfer 113-115
B 113-115
C 117-119

Open ATDC

No radius I don't think HRC were that clever or go hold of an Aprilia cylinder long enough to copy.

[wobbly]

In reality only factory engineers have ever seen a real A kit cylinder - let alone actually measure one.
But the B kit parts available to teams are a very different setup to the customer bikes.
Several close copies have been made and the setup is Ex 80 with dead flat top edge,A Tr 114.2 B Tr 115.5 Boost 115.8.
The high Exhaust port is difficult to get the powerjet and ignition timing working properly.
But the added blowdown makes alot more power in overev.
Here is a B Kit power curve.

[rgvbaz]

Something like
Exhaust 80-83
A transfer 113-115
B 113-115
C 117-119

Open ATDC

No radius I don't think HRC were that clever or go hold of an Aprilia cylinder long enough to copy.

I had a measure up of a RS 125 cylinder once, It had the a big radius on the top of the exhaust port (like the RSA) and high axial angles on the A transfers. The one thing I did note was that every transfer and the top of the exhaust duct were finished with a file with the score lines in the direction of the gas flow... This is something I saw mentioned by Frits on here, finishing ports with hand tools.

It wasn't a HRC cylinder mind, but a Seel cylinder.

Cheers

Dave

[chrisc]

Rob, this was the link I was talking about this evening. You posted it back on page 230.

http://www.dirt-bike-tips-and-pics.com/future-of-two-strokes.html

and here's another one. The second one talks a lot about injection

http://www.dirt-bike-tips-and-pics.com/the-experimental-motorcycle-association.html

[TZ350]

Thanks ....

[RomeuPT]

Something like
Exhaust 80-83
A transfer 113-115
B 113-115
C 117-119

Open ATDC

No radius I don't think HRC were that clever or go hold of an Aprilia cylinder long enough to copy.

The "crapy" information I have in shows that the good cylinders come with the A transfer much higher, like a 1mm or so than the B transfer. Giving about 136/137º for A and 133/132 for B.

In the photo there are the values to top of cylinder, if we give 0,7 squish deck making tdc 0,7mm below top of cylinder than the transfer timings are way above 130, giving 26,5, 40,5 and 41,5mm from the top of ports to tdc.

[wobbly]

Crappy info for sure.
Assuming a 0.7mm deck then that cylinder has the Ex @ 81, combined with a 112 main transfer it would then have so little blowdown that a stock customer bike would be way faster.
All of the RS125 types have the A port between 0.5 and 1mm higher than the B, but I can assure you no GP race winners would have had anything like 112 on the transfers.

[RomeuPT]

Crappy info for sure.
Assuming a 0.7mm deck then that cylinder has the Ex @ 81, combined with a 112 main transfer it would then have so little blowdown that a stock customer bike would be way faster.
All of the RS125 types have the A port between 0.5 and 1mm higher than the B, but I can assure you no GP race winners would have had anything like 112 on the transfers.

Thanks for this info.

It leaves my experience and knowlegde a bit against each other.

Regards

[TZ350]

Sorry it's been a while... hope this provides interesting info for all.

301 -Regan Griffiths
266 -Richard Ford
195 -Scott Griffiths
138 -Richard Ban
129 -Brian Steffensen
123 -Henk Zeeven
118 -Ken Douglas
93 --Mike Kyle
71 --Gary Cunningham
71 --Malcolm Nabbs
60 --Nathanael Diprose
58 --Grant Nicolson
56 --Leigh Tidman
52 --Finn Keogh
50 --Adrian Mitchell
49 --Gavin Veltmeyer
48 --Dave Manuell
38 --Kieren O'Neill
34 --Cory Peck
29 --Steve Booth
29 --Tyler lincoln
26 --Kamil Chodor
26 --Tyler Firn
25 --Warrick Head
23 --Tim Coopey
23 --Shaun Parker
20 --Cameron Page
19 --Dave Trustrum
18 --Chris Cain
17 --Dean Miller
15 --Aaron Hassan
15 --John Steer
15 --Luke Johnston
15 --No5 Kaitoke
11 --Glen Skatchill
10 --Neil Robertson
10 --Clive Banks
8 ---Gareth Pywell
7 ---Adrian Lee
5 ---Joshua Head

North Island Series 2012-13 Final Results .......

[TZ350]

Page 770 ....

[Forgi]

Wobbly!

We have talked over how important the blowdown and it's size are, but what about the blowdown's intensity? If the aux exhaust ports are opening later as the main exhaust port, the peak of the pression is smaller, meanwhile the blowdown lasts longer. Of course the STA is always the same. Here is an example 'One Half'

http://kepfeltoltes.hu/130510/heha_www.kepfeltoltes.hu_.jpg

In case of almost every race cylinder the aux exhaust ports are opening later, and this can be observed in systems with or whitout a power valve. In case of a T port the top edge radius is not 0, but pretty much bigger.

Is it important? Why don't we open the ports the widest possible? That way the ports could be positioned lower what would be optimal.

[Buckets4Me]

http://www.trademe.co.nz/motors/used-cars/other/auction-590730737.htm

Have i got an idear for you TZ350 :)

[jasonu]

http://www.trademe.co.nz/motors/used-cars/other/auction-590730737.htm

Have i got an idear for you TZ350 :)

A class at Buckets called Formula Simca perhaps...

[TZ350]

Talking with my old man about the programmable ign it is hard work out what's happening with the engine all the time with the curves and powerjet and what nots in relation to the power curve.

So we wondered if we made a graph starting with a dyno HP curve and then overlaying it with ign advance curve and powerjet off and on times and other things the programmable ign is doing using the revs as the common baseline.

282546

I have not actually done what your trying to do with the graph before myself, but because my ignition advance on WOT covers pretty much the same range as the hp, ie 0 to 30 on the Y axis I mocked up this EngMod2T dyno graph to see what it might look like.

Yellow for ignition advance and blue for power jet on/off.

282624

Yesterday I received an email from Neels, the author of the EngMod2T simulation software to tell me that EngMod can graph what Diesel Pig was looking for and how to do it. EngMod2T is a very well supported package.

[wobbly]

There are two factors in play with the tripple port setup.
You have drawn them correctly with 68% main port width, as this allows greater blowdown area to be gained via the aux ports.
Out at 72% that has proven to be approx the reliable max width, you loose some blowdown, and gain total area. ( not relevant at all ).
The problem is that even at 68% you cannot run a flat port roof with 8mm corner radi, as the ring life will be zero.

Secondly is that it has been proven in many dyno sessions that having all 3 ports open together looses power.
I can only explain this as a function of the fact that the effective duct length from the outer corners of the Aux is alot longer than that from the main port
mid point to the header.
Thus you get a smearing of the initial wave amplitude ( wider but lower intensity ) as it exits the cylinder into the duct during blowdown.
This reduces the effectiveness of the expansion phase, creating less depression around BDC, and less plugging efficiency as the piston closes the port.

It would appear that having a 68% main port opening first gives a good, high amplitude wave action in the pipe, then the Aux STA gets the blowdown pressure dropped as much as is possible prior to the Trans opening.

A few pages back was a drawing I did years ago of a T port with the outer edges higher than the mid point, thinking that this would ameliorate the duct length issue, but later
testing proved it didnt work well at all.
So by inferrence even lifting the Aux higher than the main wont fix this issue either in a 3 port.

[rgvbaz]

Thanks, being a fellow air cooled traveler and all, in my heart I would like them to succeed.

So it looks like they have half a chance, if the challenges F5Dave mentioned dont catch them out.

If your following their progress please keep us informed as I think its realy interesting.

Mag has just come out, 21.4 bhp after a few runs on the dyno... .

On Facebook if anyone is interested, here:

https://www.facebook.com/groups/practicalsportsbikes/permalink/525170764195858/

Dave

[Flettner]

http://youtu.be/hOGZ5llowoU

I have ridden the future today! YZ250 twostroke EFI round the back yard. Video was taken, I'll post a link when it's on line. It's a little more civilized than the Bighorn. Nice and clean power spread. No dyno run yet, just seat of the pants. We have only had about an hours worth of tuning so far.

[Flettner]

Who knows what about carbon / carbon pistons? Wobb?

[Frits Overmars]

Who knows what about carbon / carbon pistons? Wobb?About zero thermal expansion; good dry friction; because of the lower specific mechanical strength wall thickness needs to be so much higher that any weight advantage is lost. The biggest problem: because of the lower thermal conductivity the crown cannot git rid of its heat, which provokes detonation.

[crazy man]

Who knows what about carbon / carbon pistons? Wobb?l have this book somwhere about a japanese guy making pistons for 500 gp bikes . wish l could find the wright up. 1500 dollars each around 15+ years ago. also made conrods

[Flettner]

Thankyou, Frits, crazy man, thought as much. I tried ceramic coated pistons some years ago and that's what they did , get hot and help detonation. I wonder about these modern metal sintering ( laser welding metal layer by layer ) apparently you can change the metal as the component is built up. A piston could start off aluminium alloy and end up with say a copper finish layer on top, flash chrome over that. Perhaps?

[husaberg]

Thankyou, Frits, crazy man, thought as much. I tried ceramic coated pistons some years ago and that's what they did , get hot and help detonation. I wonder about these modern metal sintering ( laser welding metal layer by layer ) apparently you can change the metal as the component is built up. A piston could start off aluminium alloy and end up with say a copper finish layer on top, flash chrome over that. Perhaps?

Along these (http://www.mxcomposites.com/) lines

Nice Yamaha twins site (http://erlenbachracing.net/index.htm) also has the race kit info for the RZ500

[TZ350]

Today was the Dominic Howe, 20 laps one way then 20 laps in the opposite direction.

282664

Glen riding Gigglebuttons, from the "Dark Side" Team ESE RS-FZR150 took the honors.

[TZ350]

282671

Garry riding Speedpros 30hp MB100 in leg two looked to be the likely winner of the Dominic Howe and was laying down some super quick times until the rear shock came apart, dumping oil onto the rear tyre.

During the day Garry smashed the previous lap record of 29.4 with a bunch of 29's then a couple of 28.8's.

[TZ350]

282678

This Honda GL145 engine in a RGV chassis would have to be the best presented bike there today.

The field was mostly FXR150s but there were some Suzuki, Honda and Yamahas too.

[TZ350]

282680

This is the winner of the F4 GP at Tokoroa ridden by Nat D, 88. Today Nathanael won the first leg of the Dominic Howe but dropped it chasing Garry in the second.

282682

One of the fast boys who can peddle an FXR like there is no tomorrow.

282684

There were a few FXR's that have had 100cc Honda engines fitted for F5, they are seriously good and handle very well.

282683 282685

Interesting side cars.

282681

The great thing about Buckets is that everyone pitches in and helps out. Yep that's the opposition helping their main competition get going again.

[TZ350]

Some Pit secrets, how to mount an FXR150 into a FZR250 3LN frame. Very nicely done and the owner says it handles well and changing to wet wheels is very easy. The FZR 3LN comes std with 2.75x17 front and 3.5x17 rear wheels and 320mm front disk.

[TZ350]

More Pit secrets, a FZR150 in a TZR frame, these specials are seriously fast.

[TZ350]

And the one I liked most of all, a RG50 in a Honda RS frame. One of F5 Daves engines fitted by RMS engineering.

The RG50's rear engine mount slotted straight into the RS rear mount and the front RS frame mounts used simple brackets to hold the front of the engine.

It also used a light weight hydraulic Mountain Bike rear break with a thumb operated master cylinder on the left handle bar, very clever.

[kel]

It also used a light weight hydraulic Mountain Bike rear break with a thumb operated master cylinder on the left handle bar, very clever.
I would have thought Max was a bit young for buggered ankles

[crazy man]

thanks for the pic rob , looks like a good days racing

[Moooools]

One of F5 Daves engines fitted by RMS engineering.


Actually the dodgy engineering to hold the engine in is Dave's or one of Dave's bum buddies. From what I understand RMS Eng employs a higher standard of engineering. :laugh:

RMS engineering did the tuning work on the engine. And quite a nice job he did. Few more things I would like to change but reliable track time is still more valuable at this stage.

[RMS eng]

And the one I liked most of all, a RG50 in a Honda RS frame. One of F5 Daves engines fitted by RMS engineering.

The RG50's rear engine mount slotted straight into the RS rear mount and the front RS frame mounts used simple brackets to hold the front of the engine.

It also used a light weight hydraulic Mountain Bike rear break with a thumb operated master cylinder on the left handle bar, very clever.

Hi rob i think max fitted the motor in this frame,i did some motor work fitted the pipe and made the seat sub frame,but i did fit the FXR150 motor into the FZR frame for Nick.

[RMS eng]

Actually the dodgy engineering to hold the engine in is Dave's or one of Dave's bum buddies. From what I understand RMS Eng employs a higher standard of engineering. :laugh:

RMS engineering did the tuning work on the engine. And quite a nice job he did. Few more things I would like to change but reliable track time is still more valuable at this stage.

Hi Max you got your reply in before me,what time did you get down to on your 50.
chris

[Moooools]

Hi Max you got your reply in before me,what time did you get down to on your 50.
chris

32.64 I think. Needs some more over rev. Or maybe just some more gear shifting. Or something. It would be good to get it on a dyno so I can see what I am starting with and where it is lacking. Even getting a tacho would be a damn good start. Could have taken elder diprose with a bit more power.

[TZ350]

but i did fit the FXR150 motor into the FZR frame for Nick.

282701

The way the motor is mounted is a very clever bit of engineering, I think better than the way we did ours ......


looks like a good days racing

It was a great day.

[RomeuPT]

Hey everybody.

Wobbly, can you talk a bit about diffuser angles, ok, we are searching for the widest, lowest pressure around bdc, but in a pratical way...

For example, Mota Software (even the demo) when calculating a 3 stage header/diffuser will start the second divergent section "difuser" by 37%, and easily give ultra step sharp final 11 and 12º diffuser cone angle. If they work fine? Yes, they are not bad at all. Is the most used program here in Portugal.

For example, an exhaust calculated for Honda RS specs with 800mm of lenght will have 88 mm of mid section lenght, much more then typical Honda pipes.

What usualy happens when playing with the mid-section lenght?
Max pressure at the exhaust port, should arrive sharply as soon as the transfer close or more progressive until the exhaust close?

Many many thanks

[TZ350]

Mt Wellington Round 7 Results and David Diproses summary for the series so far.

[TZ350]

282715

Avalon on the 600 at Mugello.

http://www.nzsuperbike.com/2013/04/avalon-biddle-takes-third-place-in-italy.html

282716

Former New Zealand 125GP and 125TT champion and 2012 Italian Womens Championship Runner up Avalon Biddle decided to enter a round of the "Masters Cup" at famous Mugello circuit in Tuscany. This was Avalon's second race for the year at the famous circuit. The previous outing ended up with a crash , but this time was different. Starting from 15th on grid the Auckland charger cut her way to fourth place , then was awarded third after the winner was disqualified due to failing a tech check. Here is Avalon's report.


Starting from the fifth row in the rain for the race on Sunday I managed to avoid the chaos on the opening laps and settle into a rhythm, picking up many positions. Most of the race I was in a great battle with 4 or 5 riders but eventually I made a gap from that group and was comfortably in 5th place. Then on the last lap I started to catch 4th position so I pushed harder and did my fastest lap of the race,catching him just in time to get in the slipstream and overtake him at the finish line to grab 4th place by 0.01 of a second. That lap was only one tenth of a second slower than the fastest lap of the race overall. Later we were called to the official’s office to pick up the trophy for 3rd place because first position had been disqualified after a technical check on the bikes.

282717

[F5 Dave]

Actually the dodgy engineering to hold the engine in is Dave's or one of Dave's bum buddies. From what I understand RMS Eng employs a higher standard of engineering. :laugh:

RMS engineering did the tuning work on the engine. And quite a nice job he did. Few more things I would like to change but reliable track time is still more valuable at this stage.

Yeah that's how I got it as raced by Jay so don't blame me. Glad you've got it going.

[TZ350]

Wobbly, can you talk a bit about diffuser angles, ok, we are searching for the widest, lowest pressure around bdc, but in a pratical way...

I to am interested in that.

There also may be some more interesting pipe info here.

I have been trying to find the posts that talk about pipes and collate and edit them. There is heaps of it and pages 620 630 640 650 660 670 680 690 700 730 740 and 750 have un edited collections of raw material. If your interested in expansion chambers they are worth a look. Pages 710 and 720 talk about crankcase volume and inlet length.

[goose8]

282671

Garry riding Speedpros 30hp MB100 in leg two looked to be the likely winner of the Dominic Howe and was laying down some super quick times until the rear shock came apart, dumping oil onto the rear tyre.

During the day Garry smashed the previous lap record of 29.4 with a bunch of 29's then a couple of 28.8's.
I would just like to point out that the shock is NOT a WP rear shock just a sticker to make it look like one, its a Dnm shock which works really good when the oil stays on the inside.

[TZ350]

Wobbly, can you talk a bit about diffuser angles, ok, we are searching for the widest, lowest pressure around bdc, but in a practical way...

Hi RomeuPT, Husaberg has just now reminded me, that he had posted Frits's pipe design spread sheet before, it could be worth a look.


Anyway this is a better one based on a simplified Frits Overmars design.

[RomeuPT]

Hi RomeuPT, Husaberg has just now reminded me, that he had posted Frits's pipe design spread sheet before, it could be worth a look.

I have looked and readed that info about pipes twice. Very Usefull.

Thing is, when I was using the demo Expansion Chamber Design Prog (http://www.bevenyoung.com.au/mota.htm) that is very used here and having all the Honda desing's in the table I notice that Mota makes ultra sharp final difuser cone, so the previous exhaust's I builded all have around 11º degree difuser angle, the mid section is longer, and the difuser starts later than the 30/33% rule of thumb.

Other thing is all Honda Exhaust have the last difuser the steepest one, and Aprilia uses the other concept of biggest and longest middle difuser, I would like to know if anyone used a pipe in Honda RS with the Aprilia type.

I don't want to force everthing you know, just discuss the angles and lenght's.

Here Mota example
Regards

[TZ350]

I am interested in this too, as I am a bit of a beginner at pipe design and would like to know more.

[wobbly]

Here is the hell RS125 pipe design that has basically everything I know embedded in its concept, the 800mm length is for a 200* Ex only with a
proper ignition curve and powerjet switching..
The first 25 mm is an oval transition flange ( 41 by 32 ) in the duct, out to a 41 header.
The stinger nozzle is 23.2 with 25 stinger pipe.
Dual stage header, and steep mid diffuser create the deepest and widest depression around BDC at 13,000, with tons of overev power.
The 120mm Honda and Mota pipes wont even get close, especially with the final diffuser being the steepest,it creates the Ex port depression way too late in the cycle
to help at the natural peak of a 200* Ex around 13,000 and into the all important overev past 14,000.
Several details can be jigged to work better than this design, but thats for you guys with a good code to work with to figure out from looking closely at the pressure ratio traces.

[RomeuPT]

Here is the hell RS125 pipe design that has basically everything I know embedded in its concept, the 800mm length is for a 200* Ex only with a
proper ignition curve and powerjet switching..
The first 25 mm is an oval transition flange ( 41 by 32 ) in the duct, out to a 41 header.
The stinger nozzle is 23.2 with 25 stinger pipe.
Dual stage header, and steep mid diffuser create the deepest and widest depression around BDC at 13,000, with tons of overev power.
The 120mm Honda and Mota pipes wont even get close, especially with the final diffuser being the steepest,it creates the Ex port depression way too late in the cycle
to help at the natural peak of a 200* Ex around 13,000 and into the all important overev past 14,000.
Several details can be jigged to work better than this design, but thats for you guys with a good code to work with to figure out from looking closely at the pressure ratio traces.

So this work on the Honda too. One less confusion. Thanks Wobbly.

For this top bmep engines we use 14º baffle angles, right, and if we go for slower less reving bikes, should we decrease this angle right? I have seen an amount of longer pipes (both handmade and aftermarket), like 950 and 1000 mm lenght for bikes who get peak power around 9k/10k rpm that have short baffles, like the ones of RS lenght, and the YZ and CR 125 have very long baffles. So I guess someone is doing a really bad job.

Made an Exhaust for a friend with a DTR 125 (peak at 9500/10000), using one 235mm 12,1º baffle, worked better against a known good aftermarket exhaust, my friend already solded the aftermarket pipe.... :cool:

Now we are having fun making some drags on sundays

Regards

[wobbly]

The position of the start of the mid diffuser is the key to making top end and overev power.
Earlyer Aprilia and Honda designs had the steep diffuser starting right after the header, but this pulls the Ex depression down too early around BDC.
It works alot better for power production to space the main cone further along, and make the angle steeper to promote higher depression values by using a shallow last diffuser angle.
This also increases the main body volume.
I have been making the first and last diffussers around the same angle, just coz it feels right, and the sim says fill your boots.
Steep rear cones will work on any engine needing a high specific output, but you must have a digital ignition and powerjet switching, to stop the fast powerdrop off past peak
that the short cone will naturally create.
A longer rear will suppress the peak value and allow more natural overev characteristics without digital trickery.

[Dutch Fisher]

Wobbly,

Say if you had a single angle header and a steep first diffuser and then made that section by blowing it, do you think that the smearing of that angle would help make the wave "stick" thru that section change.

Have you tried it?

[teriks]

Thanks Wob, two really interesting posts there :niceone:

[wobbly]

I also believed what I had been told previously ,that large changes in initial diffuser angle would cause flow separation and massive turbulence due to choking.
I built a heap of pipes to come up with a new design for CR125 Moto in SKUSA racing.
One of the tests was to try a design similar to the older Aprilia, with a very steep diffuser directly after the header.
This pipe made good power, but i was sure that if I added a short 25mm section ( the length of a bend segment in the U bend ) between the header and the main diffuser, with
only 1/2 the angle change - it would make more power.
Sadly no free lunch, it was worse by a small margin - bugger, another wives tale down the dunny.
I went on to discover the relationship of best power production, to the shape of the depression waves amplitude around BDC - was super critical to where the main diffuser started.

[Dutch Fisher]

Looking at the RSA125 tubo-102 pipe, Jan Thiel has gone for a three angle reverse cone.

What's your thoughts on the thinking behind that?



Have you got an example of a critical BDC depression wave?

[Forgi]

There are two factors in play with the tripple port setup.
You have drawn them correctly with 68% main port width, as this allows greater blowdown area to be gained via the aux ports.
Out at 72% that has proven to be approx the reliable max width, you loose some blowdown, and gain total area. ( not relevant at all ).
The problem is that even at 68% you cannot run a flat port roof with 8mm corner radi, as the ring life will be zero.

Secondly is that it has been proven in many dyno sessions that having all 3 ports open together looses power.
I can only explain this as a function of the fact that the effective duct length from the outer corners of the Aux is alot longer than that from the main port
mid point to the header.
Thus you get a smearing of the initial wave amplitude ( wider but lower intensity ) as it exits the cylinder into the duct during blowdown.
This reduces the effectiveness of the expansion phase, creating less depression around BDC, and less plugging efficiency as the piston closes the port.

It would appear that having a 68% main port opening first gives a good, high amplitude wave action in the pipe, then the Aux STA gets the blowdown pressure dropped as much as is possible prior to the Trans opening.

A few pages back was a drawing I did years ago of a T port with the outer edges higher than the mid point, thinking that this would ameliorate the duct length issue, but later
testing proved it didnt work well at all.
So by inferrence even lifting the Aux higher than the main wont fix this issue either in a 3 port.

Ok Wobbly, I understand...thank You!

Well, I saw your drawing with the T port. It is very strange that it doesn't work although it would be logical.

And what is more surprising to me is that the 3 ports opened together causes power loss. According to your dyno measurements how much is that waste?

In my opinion the problem might be if the aux ports are opening earlier than the main port (in case of a T port the outer edges are higher) the flow goes towards the aux ports and when the main port opens the flow turns to it with a poor efficiency. I don't know is it clear or not but here is a drawing.

http://kepfeltoltes.hu/130514/w4_www.kepfeltoltes.hu_.jpg

This would be an explanation why does the power reduce if the 3 ports are opened at the same time.
But maybe I'm wrong...

Well if the distance between the aux and the main ports is bigger or the angle of the aux ports is bigger then the 3 ports can open together cos there is no effect on each other...

[diesel pig]

Re reading wobbly's posts on tuning with EGT he talked about aiming for a exhaust temperature with leaded gas between 1200 and 1250 *F for best power with temperatures of 1300 *F and above to be avoided as not being good for the motor. Having manage to take this much on broad when tuning on my private test road :msn-wink: I tired to avoid seeing more than 1260 *F in all the rev range at all. But later when re reading wobbly's posts on ignition timing I pick up on what he was saying about retarding timing pass max power rpm to get overrev and this was done by getting more heat into the pipe to trick the motor into acting like the pipe is shorter than it is. So I am thinking have I got the wrong end of the stick with the temperatures? is the 1200 to 1250 the temp for MAX Power RPM and a higher temps in the overrev rpms is a product of getting the overrev and not to be worry about?

[Frits Overmars]

Thankyou, Frits, crazy man, thought as much. I tried ceramic coated pistons some years ago and that's what they did , get hot and help detonation. I wonder about these modern metal sintering ( laser welding metal layer by layer ) apparently you can change the metal as the component is built up. A piston could start off aluminium alloy and end up with say a copper finish layer on top, flash chrome over that. Perhaps?Absolutely. Aprilia GP piston heads were polished to a mirror shine; piston heads for four-stroke competition engines are sometimes chromed. I don't know whether this chroming can be done by selective laser melting, but chroming the piston head in the conventional way has given good results.
If you want to protect the piston from combustion heat, covering its head with a heat barrier is not the way to go because of the detonation this will cause.
The only safe way I can think of is to reflect the heat. That way it won't get into the piston material and as soon as the combustion is gone, so is that heat reflection; fresh mixture won't be heated.

[speedpro]

I think as Wobbly explained it the main port needs to open first as it's bigger and the shape of the top of the port results in a strong leading edge to the pulse. This strength has benefits later in the cycle. Opening the aux ports early or at the same time smears the pulse and reduces it's initial strength thereby losing it's effectiveness.

I've been polishing the tops of pistons for years for two reasons. 1 - to reflect heat back from the piston and 2 - to reduce stress risers in the crap cast pistons I was using. The surface finish on the crowns was utter garbage.

[Frits Overmars]

Looking at the RSA125 tubo-102 pipe, Jan Thiel has gone for a three angle reverse cone. What's your thoughts on the thinking behind that?My thoughts is that you are jumping to conclusions, Dutch. But you are forgiven because I will admit that it is logical to assume that Jan developed that pipe.
In reality he didn't; technical director Witteveen (or The Great Leader as he was called) did; pipes were his hobbyhorse. And each time Jan Thiel had to adapt the cylinder to get it running with Witteveens pipe designs; not a great way to commit development.....

[RomeuPT]

I also believed what I had been told previously ,that large changes in initial diffuser angle would cause flow separation and massive turbulence due to choking.
I built a heap of pipes to come up with a new design for CR125 Moto in SKUSA racing.
One of the tests was to try a design similar to the older Aprilia, with a very steep diffuser directly after the header.
This pipe made good power, but i was sure that if I added a short 25mm section ( the length of a bend segment in the U bend ) between the header and the main diffuser, with
only 1/2 the angle change - it would make more power.
Sadly no free lunch, it was worse by a small margin - bugger, another wives tale down the dunny.
I went on to discover the relationship of best power production, to the shape of the depression waves amplitude around BDC - was super critical to where the main diffuser started.

Thanks Wobbly. It's been a pleasure to talk with people from the other side of the world.

Main diffuser on your Hell pipe start at 43,25% and Aprilia tubo 102 at 41%. So I maybe use 42% as baseline for the next exhaust I build....

We can't say that the wave is traveling at the main difuser after 42% of exhaust opening right? If the exhaust gases are colder at the spignot, and the belly is the hottest point then the 42% is before because the wave might travel slower at the header!? And the wave enters the duct some degrees after exhaust open!?

Regards

[wobbly]

You have to be careful when using retard to heat the pipe in the overev.
If you continue the retard slope too far,especially if the motor then continues to make serious power - the egt will continue to rise with rpm, and you then end up running a richer main to suppress the now too high egt.
This means you are using fuel to cool, not burning it to make power.
You must flat line the ignition retard as soon as you can in the overev, to stabilise the egt when running full throttle at those peak revs.

You have got the wrong end of the stick re pipe temp Romeu, the highest temp is seen just into the header, the lowest in the belly, and it increases again at the stinger.
Lower temps are seen right at the flange, due to unburnt air/fuel sitting there waiting to be shoved back in.
Aprilia used probes in the flange due to reliability issues I understand,but they would for sure have found a correlation between the readings there, and the " normal " one along the header.

Three angle rear cones were a legacy design that Jan was forced to use, as Frits explained.
But it is a long time issue for me that so often a sim will be strongly telling me that the system works well ( and it annoys Neels as well I know ) but in reality I have never been able to get more power on the dyno
than a 14* straight tailcone - believe me I have waisted so much time on this, and have given up.

In a KZ2 125 kart engine with the main Ex port opening at 82.5* you would normally have the Aux about 1.5mm lower - lift them up flat and you loose around 3 Hp at 10,000, 1 at peak 13,000, but worst is
up to 6Hp at 14,000 where the curve is dropping rapidly.
I tested a cylinder with the main down at 84* and the ports all opening flat made the most power there, but sadly that power was well down on what is possible with a higher main and staggered Aux.

Re the diffuser position for RS125 - the Aprilia rotary valve engine was , by design, run to 14500 on track, so was able to use the slightly shorter header end position.
The reed valve Honda is virtually impossible to get to run up there with any effective gains, so makes more power in its useable band with the slightly longer header.

[Flettner]

http://youtu.be/hOGZ5llowoU

Transfer port injection

[F5 Dave]

Mag has just come out, 21.4 bhp after a few runs on the dyno... .

On Facebook if anyone is interested, here:

https://www.facebook.com/groups/practicalsportsbikes/permalink/525170764195858/

Dave

Went to look in shop but silly 'cause we won't see that edition for a couple of months. Not on Farcebook by principle. Either way its a good start, but they won't crack 100 with that in that roadbike chassis I don't think. its an ok effort with what they started with. Given the options & the lack of initial rules I think I'd be reaching for the liquid horsepower to make good the 100mph target. What revs were they pulling? Seemed to be a major limitation in initial calculations.

[Haufen]

Absolutely. Aprilia GP piston heads were polished to a mirror shine

As were the combustion chambers?

[Frits Overmars]

As were the combustion chambers?Yes, the chambers were polished too, but I think the main goal here was to avoid carbon deposition which could cause glow ignition.

[RomeuPT]

Frits I noticed that tubo 55 was slighly thinner at the belly than 102.

Is the energy of the wave going down the exhaust port lineary greater with a raise in HP? So if you have got more horse power you can try increase pipe volume/angles and get even better?

Regards

[RomeuPT]

You have to be careful when using retard to heat the pipe in the overev.
If you continue the retard slope too far,especially if the motor then continues to make serious power - the egt will continue to rise with rpm, and you then end up running a richer main to suppress the now too high egt.
This means you are using fuel to cool, not burning it to make power.
You must flat line the ignition retard as soon as you can in the overev, to stabilise the egt when running full throttle at those peak revs.

You have got the wrong end of the stick re pipe temp Romeu, the highest temp is seen just into the header, the lowest in the belly, and it increases again at the stinger.
Lower temps are seen right at the flange, due to unburnt air/fuel sitting there waiting to be shoved back in.
Aprilia used probes in the flange due to reliability issues I understand,but they would for sure have found a correlation between the readings there, and the " normal " one along the header.

Three angle rear cones were a legacy design that Jan was forced to use, as Frits explained.
But it is a long time issue for me that so often a sim will be strongly telling me that the system works well ( and it annoys Neels as well I know ) but in reality I have never been able to get more power on the dyno
than a 14* straight tailcone - believe me I have waisted so much time on this, and have given up.

In a KZ2 125 kart engine with the main Ex port opening at 82.5* you would normally have the Aux about 1.5mm lower - lift them up flat and you loose around 3 Hp at 10,000, 1 at peak 13,000, but worst is
up to 6Hp at 14,000 where the curve is dropping rapidly.
I tested a cylinder with the main down at 84* and the ports all opening flat made the most power there, but sadly that power was well down on what is possible with a higher main and staggered Aux.

Re the diffuser position for RS125 - the Aprilia rotary valve engine was , by design, run to 14500 on track, so was able to use the slightly shorter header end position.
The reed valve Honda is virtually impossible to get to run up there with any effective gains, so makes more power in its useable band with the slightly longer header.

If the T port likes opening dead flat and the two aux's port likes staggered, I wonder what would an W exhaust port likes....

[F5 Dave]

If the T port likes opening dead flat and the two aux's port likes staggered, I wonder what would an W exhaust port likes....
Eating rings for breakfast?

[Dutch Fisher]

In a KZ2 125 kart engine with the main Ex port opening at 82.5* you would normally have the Aux about 1.5mm lower - lift them up flat and you loose around 3 Hp at 10,000, 1 at peak 13,000, but worst isup to 6Hp at 14,000 where the curve is dropping rapidly.
I tested a cylinder with the main down at 84* and the ports all opening flat made the most power there, but sadly that power was well down on what is possible with a higher main and staggered Aux.


Do you have a rule of thumb for the main and aux differential openings considering different B/S and cyl vol?

[Frits Overmars]

Frits I noticed that tubo 55 was slighly thinner at the belly than 102. Is the energy of the wave going down the exhaust port lineary greater with a raise in HP? So if you have got more horse power you can try increase pipe volume/angles and get even better?All other things being equal, more horsepower goes together with more exhaust gas energy. But the connection is not linear and all other things are never equal.
Exhaust gas energy is mainly effected by squish, ignition timing, flame speed and compression ratio. And as I tried to explain before, you can overdo it with diffusor and reflector angles; there is no maximum but there is an optimum.

[Frits Overmars]

If the T port likes opening dead flat and the two aux's port likes staggered, I wonder what would an W exhaust port likes....Putting three cooling fins inside the exhaust duct; what a Wonderful idea. That must be what the W stands for, innit?
Normal port bridges can at least convey the heat to the surrounding metal at both ends; these one-ended W-fins really are the worst you can think of.

[senso]

Eating rings for breakfast?

They are pretty reliable, they only eat rings when the tuner has the bright idea of removing some width/thickness from them, and then the hot exhaust gas make the nicasil coating to flake and the rings dont really like that nice soft alumium liner at all.

I gets a bit worse, because allmost all the cylinders that have those W shapped exhaust ports don't have cooling all around the exhaust port, only on top and part of the sides, the lower tooth as very marginal cooling.

I don't know if I already said, but thanks Wobbly for the pressure values :msn-wink:

[RomeuPT]

All other things being equal, more horsepower goes together with more exhaust gas energy. But the connection is not linear and all other things are never equal.
Exhaust gas energy is mainly effected by squish, ignition timing, flame speed and compression ratio. And as I tried to explain before, you can overdo it with diffusor and reflector angles; there is no maximum but there is an optimum.

Can we create a rule of thumb for the optimum belly diameter / exhaust volume/cc ratio a pipe should have?

[Frits Overmars]

Can we create a rule of thumb for the optimum belly diameter / exhaust volume/cc ratio a pipe should have?It is included in my 'FOS exhaust concept'.

[F5 Dave]

. . . .he nicasil coating to flake and the rings dont really like that nice soft alumium liner at all.. . .

Sorry I was being a bit silly.

and to continue that theme; I think the rings would love the bare ally, they'd gobble it up in no time.

[senso]

I understood, we can't be serious all the times.

[RomeuPT]

It is included in my 'FOS exhaust concept'.

Sure, it is....Thanks

[Kickaha]

Not strictly Bucket legal but does anyone want a Barton Phoenix? one of the guys on the UK sidecar forum is selling this
http://i458.photobucket.com/albums/qq303/16000rpm/DSCF0985.jpg
I have for sale a Barton Phoenix square four two stroke race engine, it is for re build and is missing one gear shaft/gears but that should not be a problem as there are many people that could make a new part.These engines where used in the Barton 750 race bikes and in the silver dream racer film and of course Nigel Rollason used one to power his sidecar to a win at the TT. How many did Barton make ? no records exist but i am sure it would have been in the low teens at most, Barton sold out to Eric Buell in America and i have seen a dyno sheet showing over 160bhp. I am open to serious offers for the engine. You can have either Barton or Armstrong cylinders.
Contact racing50chris@aol.com Please not this is a complete engine inc dry clutch and cranks and disc valves/covers etc and just missing a gear shaft and some gears.

[F5 Dave]

Kevin Cameron did an article on Buell back in the day describing his folly of buying the Barton concern & spending countless hours trying to fix the F'ups in the design. That said if one won a TT it must have some pedigree.


I like his ltd liability approach to marketing "Barton sold out to Eric Buell in America and i have seen a dyno sheet showing over 160bhp"
Yeah I've seen a dyno sheet for 160hp, it was on a K5 GSXR with a pipe & PC. Or does he mean the Buell ones may have reached 160? Or even perhaps the original. Technically I didn't lie your 'onour.

[TZ350]

Can we create a rule of thumb for the optimum belly diameter / exhaust volume/cc ratio a pipe should have? It is included in my 'FOS exhaust concept'.

282886

........ found it.

[husaberg]

........

Did ya get to read the other link i sent you Rob?

[TZ350]

282889

Yes, thanks Husa

[husaberg]

282889

Yes, thanks Husa

No this one (http://translate.googleusercontent.c...d9NMS6j0oW1tQQ)

[Frits Overmars]

282889
Yes, thanks Husa

No this one (http://translate.googleusercontent.c...d9NMS6j0oW1tQQ)
These XLS-files were made by people unknown to me; they apparently based their files on the above drawing of my FOS Exhaust Concept.
I do not take any responsibility for these files. In the first one I happened to notice that the diameter of the tailpipe restrictor is used for the whole tailpipe, which can hurt the engine. I could not even open the 'No this one'-file.

[husaberg]

These XLS-files were made by people unknown to me; they apparently based their files on the above drawing of my FOS Exhaust Concept.
I do not take any responsibility for these files. In the first one I happened to notice that the diameter of the tailpipe restrictor is used for the whole tailpipe, which can hurt the engine. I could not even open the 'No this one'-file.





Try this one? (http://translate.googleusercontent.com/translate_c?depth=1&hl=en&rurl=translate.google.com&sl=nl&tl=en&u=http://www.tomosforum.nl/uploads/File/2takt_Expansieuitlaat.pdf&usg=ALkJrhhXp1YDO1A5klycd9NMS6j0oW1tQQ)
That was my fault too many Htts i guess.. The pics seem to have disappeared though............


I figured that, but it was fun to play with never the less


Anyway this is a better one based on a simplified Frits Overmars design.

[RomeuPT]

282886

........ found it.

Already have built some pipes in part based on those formulas.

Dunno if is good or bad, what I can say is that gives low header angle, header ends at 34% and difuser ends at 68%. Tail pipe restrictor seems to low compared with others, but maybe because that is just the restrictor.

Not complaining about it, it maybe in fact be very good... :niceone:

[Haufen]

Yes, the chambers were polished too, but I think the main goal here was to avoid carbon deposition which could cause glow ignition.

Thanks, Frits. I am wondering, what would be the best way to keep the edge of the squishband sharp when polishing the combustion chamber?

[senso]

I think that you want to keep the sharp edges, to promote turbulence in the combustion chamber.

[RomeuPT]

I think that you want to keep the sharp edges, to promote turbulence in the combustion chamber.

promote turbulence, or to not promote coanda effect? :drinknsin

[senso]

I would say turbulence, has the combustion occurs in small pockets of burning gas, more turbulence means a better spreading of the initial flame and thus achieve a more even/complete combustion.
That or I'm totally wrong.

[ief]

Although very interesting it seems to totally miss the essence of the question posted by Haufen ;)

[TZ350]

282939

Tillotson HL-360A 24mm carb

Posted as someone was asking about using a pumper carb because they have clearance problems with a conventional carb and they also want a shorter inlet tract.

282942282943

Adapter, the shorter pumper carb can be mounted hard up to the case or cylinder as it does not need a rubber vibration mount. It also does not need the add-on bell-mouth to make good power. I think, on this carb the bell-mouth is just a handy place to attach an air box.

282941

Set up like this, the pumper made 28hp on the dyno and did not make anymore with the add-on bell-mouth and a little less with a KT100 air box.

282944

And ran well at Taupo.

282940

But on the track it needed a wind shield like the rubber one on this OKO carb.

[twotempi]

As positioned as per the photo the "wind shield" is going to act as a venturi and will REDUCE the available air pressure at the carb inlet .

You won't see the difference on the dyno but on the track with air-flow past it you would. Did you try turning it around 180 deg so faced the other way. Some form of still air box would probably be better.

[TZ350]

As positioned as per the photo the "wind shield" is going to act as a venturi and will REDUCE the available air pressure at the carb inlet .

You won't see the difference on the dyno but on the track with air-flow past it you would. Did you try turning it around 180 deg so faced the other way. Some form of still air box would probably be better.

This way when I crashed it folded over the carb and protected it. I had thought of fitting it the other way but expected it would act like a scoop and fill the carb with gravel in the event of a crash which happens a lot in F4 at Mt Wellington.

Although with the regulation KT100 cart air box it made about 2hp less, I agree, your right, a proper still air box would be the story.

[F5 Dave]

So I'm still thinking about the somewhat irrelevant reason that my dirt bike for example will stutter through the first few gears despite a little warming up at least. Once its run through the gears it will pull cleanly, but not before.

How would a drag bike cope with this as they often run from cold?

[TZ350]

282978

I have been trying to figure out where to place the injectors. My EFI setup calls for two injectors, one small and one big so its a bit of a puzzle to figure out where best to put them.

282977

I needed a fuel rail and got this Honda Civic (D16Y8 engine) rail with 240cc saturated high impedance injectors and fuel regulator off Trademe. All sorts of injectors will fit this rail and it can be shortened up to suit my engine.

282976

A bit of info on injectors and spray patterns.

[twotempi]

This way when I crashed it folded over the carb and protected it. I had thought of fitting it the other way but expected it would act like a scoop and fill the carb with gravel in the event of a crash which happens a lot in F4 at Mt Wellington.

Although with the regulation KT100 cart air box it made about 2hp less, I agree, your right, a proper still air box would be the story.


That's always the quandary. It will work better BUT becomes very vunerable to damage when/if things go pear-shaped. A combination still-air box / carb protection fairing may be a good option. A bit like the "riders boot fairing" as on a Britten may work, and look real cool as well. But not pink !!!

[Rick 52]

New Carb is bolted on and the pipes for the pulse are fitted, one into the in let port and the carb diaphragm pipe moved, now all I need to do is make a bracket for the throttle cable.

[TZ350]

Crankcase Compression Ratios Revisited

Primary or crankcase compression ratio is determined by dividing the full crankcase volume including transfers with the piston at TDC by the crankcase clearance volume with the piston at BDC.

For a 125 the ratio will probably be some where between 1.3:1 and 1.5:1, also according to Blair it is very difficult to get a 50 above 1.4:1 and a 500 below 1.55:1.

Pic, the good old Suzuki GP125

282983282984282985282986

Using EngMod2T I simulated up some of the numbers Bucket came up with when he measured the GP's crankcase volume.

282982

Blue line is 1.3 primary compression ratio and Red is 1.4 to 1, no other changes.

1.4 is a crankcase volume including transfer ducts of 517cc using a 105mm rod, 1.3 is 621cc with a 110mm rod.

I remember Frits suggesting using the crankcase as a plenum and Speedpro talking about the crankcase as a place to store air/fuel untill its needed. I guess I will be looking to add some more crankcase volume to the Beasts engine.

[TZ350]

New Carb is bolted on and the pipes for the pulse are fitted.

Good work Rick, I am looking forward to getting it onto the dyno.

[RomeuPT]

282983282984282985282986

Using EngMod2T I simulated up some of the numbers Bucket came up with when he measured the GP's crankcase volume.

282982

Blue line is 1.3 primary compression ratio and Red is 1.4 to 1, no other changes.

1.4 is a crankcase volume including transfer ducts of 517cc using a 105mm rod, 1.3 is 621cc with a 110mm rod.

I remember Frits suggesting using the crankcase as a plenum and Speedpro talking about the crankcase as a place to store air/fuel untill its needed. I guess I will be looking to add some more crankcase volume to the Beasts engine.

That is pretty interesting, before we change con rod lenght we should measure case comp, just to be sure it will not go too low.

being 1.3 the optimun or a baseline for reed induction race engines like was said before.

Regards

[FastFred]

283011 .... :nya:

Just heard, its true, TeeZee brought this Dark Side thing of Trademe.

[TZ350]

283011 .... :nya:

I wanted to see if it can be cut down into a side car platform and "now" your going to be the swinger, so :bleh:

[Frits Overmars]

we should measure case comp, just to be sure it will not go too low. being 1.3 the optimun or a baseline for reed induction race engines like was said before.RegardsBetter make sure your crankcase volume is not too small. I have seen lots of cases with too little volume, but none with too much yet. The optimum primary compression ratio is probably less than 1.3. And in case you really want to start messing with oil and measuring jugs, you will need this special tool, provided by the engine itself:
283043

[wobbly]

In my testing I have found no more power going to a bigger than 1.3 case on a reed engine.
This is a function I believe of the efficiency of the rotary valve intake system being able to better fill the case at high rpm,using the 1.24 as Frits has described , but having said that
I have only just crept over 50 Hp with a 125 reed, and the Aprilia RV made alot more than that, so maybe a huge case simply isnt needed at the lower bmep.

[RomeuPT]

Better make sure your crankcase volume is not too small. I have seen lots of cases with too little volume, but none with too much yet. The optimum primary compression ratio is probably less than 1.3. And in case you really want to start messing with oil and measuring jugs, you will need this special tool, provided by the engine itself:
283043

I Never had burned a hole in a piston... :banana:

That is a really low volume crank, the piston is just saying, measure the sh** you have done :laugh:

[fatbastd]

All,

I might be onto a coupole of bare RS125 frames (with swinging arms) available overseas. I have no imemdiate need (though I wish I did), and could probably get them to NZ with minimal fuss (I get a VERY good deal with FedEx - guessing, but maybe for $120-ish for shipping). What would they be worth to someone? There's no suspension or tanks.

FB

[husaberg]

All,

I might be onto a coupole of bare RS125 frames (with swinging arms) available overseas. I have no imemdiate need (though I wish I did), and could probably get them to NZ with minimal fuss (I get a VERY good deal with FedEx - guessing, but maybe for $120-ish for shipping). What would they be worth to someone? There's no suspension or tanks.

FB


Def be into getting a NX4 frame...........:niceone:

[TZ350]

Made it through to the 2013 proposed changes, so maybe it might fly.

http://www.mnz.co.nz/docs/default-source/regulations/summary-of-all-proposed-rule-changes-for-website.pdf?sfvrsn=2

283082

Bert was talking about single event Licenses but amongst the proposed rule changes is this one that appears to allow unleaded pump fuel with 10% ethanol like Gull 10 (http://www.gull.co.nz/fuel-products/gull-force-10/) and 18% other Oxygenates whatever they are.

[TZ350]

http://toxics.usgs.gov/definitions/fuel_oxygenates.html

Fuel Oxygenates

Definitions

Fuel Oxygenates - "Oxygenates, when added to gasoline, are designed to add oxygen to the gasoline, thereby decreasing vehicular carbon monoxide emissions and oxone levels in the atmosphere." - U.S. Geological Survey, 2006
Fuel Oxygenates - "Fuel oxygenates are a group of chemicals that raise the oxygen content of gasoline. The presence of oxygen optimizes oxidation during fuel combustion, resulting in a more complete burn and a reduction of harmful tailpipe emissions of partially oxidized gasoline components from motor vehicles." - U.S. Environmental Protection Agency, 2009
Gasoline Oxygenates - "Gasoline oxygenates have been used in gasoline primarily to improve octane, reduce vehicular emissions and comply with the oxygen requirements of the 1990 Clean Air Act Amendments. While there are many different gasoline oxygenates the ones most commonly used in US gasolines are methyl tert-butyl ether (MTBE) (http://toxics.usgs.gov/definitions/mtbe.html) and ethanol (EtOH). Tert-butyl alcohol (TBA) is both a trace component found in fuel grade MTBE, and is also a metabolite of MTBE biodegradation." - American Petroleum Institute, 2008
Gasoline Oxygenates - "Oxygenates are man-made chemicals that are added to gasoline to make it burn more efficiently. Adding oxygenates to gasoline increases the gasoline's octane level, and reduces pollutants (particularly carbon monoxide) emitted from motor vehicles ... Most oxygenates are either alcohols or ethers, which are readily soluble in water. Two commonly used oxygenates are ethanol and MTBE (methyl tert-butyl ether)." - New York State Department of Health, 2006.


Ok found this on Oxygenates, good old Google ....... 10% Ethanol plus 18% other Oxygenates, nothing in the rules that say I can't add my own Oxygenates only that there can't be more than 10% Ethanol and 18% of other Oxygenates ...

Hmmm I like this, a high octane fuel that is much cheaper than Av gas and I can run my fuel injection O2 sensor with it, watch this space.

[husaberg]

10.1.3
At all times the onus is on all competitors to ensure their machinery has enough fuel onboard
to complete any race
they start in, including allowance for any restarts that may occur, penalty for running out of fuel during any race, first
offence will be an instant fine of not less than $400.00
Reason: New rule


That's a bit of a interesting rule..............:rolleyes:
Whats the point............

[kel]

[
Ok found this on Oxygenates, good old Google ....... 10% Ethanol plus 18% other Oxygenates, nothing in the rules that say I can't add my own Oxygenates only that there can't be more than 10% Ethanol and 18% of other Oxygenates ...

Hmmm I like this, a high octane fuel that is much cheaper than Av gas and I can run my fuel injection O2 sensor with it, watch this space.

Nope.
24-2-5 Fuel: See 10-17-1
Alcohol based fuel or fuel additives are prohibited.
Stupid rule. Why not change it to "only commercially available pump fuels may be used for this class". Would keep the cost down and the lead out!

[Bert]

10.1.3
At all times the onus is on all competitors to ensure their machinery has enough fuel onboard
to complete any race
they start in, including allowance for any restarts that may occur, penalty for running out of fuel during any race, first
offence will be an instant fine of not less than $400.00
Reason: New rule


That's a bit of a interesting rule..............:rolleyes:
Whats the point............

Having been in the control box at minefield (with others on this forum). It was the lowest point (most sickening) in my involvement with motorcycle racing; while not the first time this one had the most impact on my views... This is a good control measure by MNZ to attempt to reduce the possible occurrence of this happening again.

Have a read in the racing section.


Yip,But,That was the coroners recommendation following the deaths of Derek Hill and Phillip Harrison at Puke in 08,No action was taken following that recomendation and since then we've had a similar situation at Manfeild which resulted in another death,Not a good look,Its an easy fix,Just deal with it.

[TZ350]

In my testing I have found no more power going to a bigger than 1.3 case on a reed engine. This is a function I believe of the efficiency of the rotary valve intake system being able to better fill the case at high rpm,using the 1.24 as Frits has described.

283084

Ok with my EngMod2T rotary valve simulations, 1.24 is better than 1.30 but interestingly 1.29 and 1.28 were worse than 1.30.

[Frits Overmars]

I Never had burned a hole in a piston... :banana:Don't worry Romeu, you're still young; you'll get your chance yet. BTW, it wasn't my piston; just a picture I picked up from the internet.

[husaberg]

Having been in the control box at minefield (with others on this forum). It was the lowest point (most sickening) in my involvement with motorcycle racing; while not the first time this one had the most impact on my views... This is a good control measure by MNZ to attempt to reduce the possible occurrence of this happening again.

Have a read in the racing section.

OK makes more sense, but using the same logic it could be suggested that one could ban racing and mechanical failures etc. I would suggest far more people have been injured as a result of a bike spilling it guts an the race track though. Anyway not the place here to argue the merits esp as it's a done deal... but i now see the point. If potentially one life is saved, $400= great deal

[wax]

So tz350. Did you find the pumper carb better than an conventional bike carb

[TZ350]

So tz350. Did you find the pumper carb better than an conventional bike carb

No better or worse, I used it because it is smaller and it can be bolted hard up against the motor in any orientation, so its easier to fit in and get a shorter inlet tract length.

[TZ350]

283082

Amongst the proposed rule changes is this one that appears to allow unleaded pump fuel with 10% ethanol like Gull 10 (http://www.gull.co.nz/fuel-products/gull-force-10/) Nope.
24-2-5 Fuel: See 10-17-1 Alcohol based fuel or fuel additives are prohibited.

Stupid rule. Why not change it to "only commercially available pump fuels may be used for this class". Would keep the cost down and the lead out!

I would be for it.

Av Gas with 2T oil costs Team ESE about $100 a 20 L tin and we get through lots of them, a high octane pump fuel at half the price sounds appealing.

I asked Billy about any proposed fuel rule changes, and this was his reply.

" ... rulechanges outside of those based on safety have been submitted for 2013/14, The only change to the fuel rule, Was to allow the use of Ethanol based fuels with a maximum of 10% Ethanol content, Cheers Billy"

So just a remit, not a rule change yet.

[Frits Overmars]

Av Gas with 2T oil costs Team ESE about $100 a 20 L tin and we get through lots of them, a high octane pump fuel at half the price sounds appealing.Make your engine thermally sound (could be difficult with an aircooler), provide for sufficient (that is: lots of) blowdown angle area, and for effective squish, and lower the compression ratio.
Does 9:1 sound ridiculous? After I managed to convice a friend to change from 14:1 to 9:1 he reported a more reliable, easier to ride bike that was less sensitive to ignition issues and made more power.

Then you can drop the avgas and use pump fuel with a better energy content (more power), a better flame speed (cooler running engine) and a better price (more dow available for after-race celebrations).

[Flettner]

Would it be sound to use an 02 sensor? Injecting at the back port and timing right you will spill air out the exhaust, not fuel air, so your sensor will say to the computer more fuel required when it will not be required.

Make your own rules, use E85 ( or make your own E90 ), bugger MNZ they still have their head in the sand.
And you can dip into the same drum for your after race celebrations ( before the petrol oil mix! )

TZ I have your ball valve ( both halves now ) made, I think it's ended up better than mine!

[Frits Overmars]

Would it be sound to use an 02 sensor? Injecting at the back port and timing right you will spill air out the exhaust, not fuel air, so your sensor will say to the computer more fuel required when it will not be required.Avgas will kill any O2-sensor; pump fuel mixed with two-stroke oil will in theory do the same, but if you take care to heat the sensor to working temperature before starting the engine, and provided the sensor is not too close to the cylinder so it won't be hit by washed-through mixture, the sensor will last a long time.

I can hardly imagine that with the right injection timing you can avoid fuel entering the exhaust, certainly not over the entire rev range.
In order to make real power, the pipe needs to receive and subsequently push back about 40% of the cylinder capacity and I do not think you can separate air and fuel to such a degree that no fuel will enter the pipe. But in order to keep the sensor clean it will have to be fitted well away from the cylinder anyway.
At the end of the day it all depends on how the injection system is instructed to handle the various sensor signals.

[Flettner]

No, I am talking about low speed, bottom third throttle. I don't think an 02 sensor in a twostroke is a very useful tool.
I'm only guessing.

[F5 Dave]

Nope.
24-2-5 Fuel: See 10-17-1
Alcohol based fuel or fuel additives are prohibited.
Stupid rule. Why not change it to "only commercially available pump fuels may be used for this class". Would keep the cost down and the lead out!
Nothing wrong with using Av, heck at the rate a bucket sips it a 20l container lasts at least 3-4 meetings.

Presumably 2 stroke oil isn't a fuel additive?:rolleyes:

[F5 Dave]

. . .
Does 9:1 sound ridiculous? After I managed to convice a friend to change from 14:1 to 9:1 he reported a more reliable, easier to ride bike that was less sensitive to ignition issues and made more power.
. .

Gibgab blubber. ok now you're blowing my tiny mind:mellow: yes it does sound ridiculous, but I'm prepared to listen, although seriously have to sort out the first sentence which is difficult with these old engines. My poor 50 is very hard to get decent blowdown area & can't triple port it due to water jacket, still considering options there.

[F5 Dave]

Having been in the control box at minefield (with others on this forum). It was the lowest point (most sickening) in my involvement with motorcycle racing; while not the first time this one had the most impact on my views... This is a good control measure by MNZ to attempt to reduce the possible occurrence of this happening again.

Have a read in the racing section.

S'funny I was just thinking about Derek & his accident this morning before I'd read this, just one of those random things, I was thinking about my old bathroom which he had done the lino, but I got to thinking about how it must have affected his family. High speed collision is a cruel thing. I'm not sure many people would willingly run out of gas & whether a $400 fine would make them remember to fill up. May alter weight saving gamblers I suppose.

[kel]

Nothing wrong with using Av

Presumably 2 stroke oil isn't a fuel additive?:rolleyes:

Yes there is. Avgas is expensive, hard to get (compared to pump fuel) and it contains lead. Lead is a particular nasty we can all do without exposure to.

Regarding "additive" well a common defintion would be "A substance added in small amounts to something else to improve, strengthen, or otherwise alter it".
Like I said stupid rule, it could be tidied up quite nicely with my proposal but it seems it never made it through to MNZ.

[Frits Overmars]

No, I am talking about low speed, bottom third throttle. I don't think an 02 sensor in a twostroke is a very useful tool.I don't know about that, Neil. Under those circumstances maybe you can inject so well-timed that no fuel will make in into the pipe. But then you could also instruct the injection system to expect more O2 under the circumstances.
I agree that an O2 sensor is not the best tool for governing the injection, but I have found it quite helpful on the test bench. You just have to keep reminding yourself that it does not say lean or rich; it only says 'I see more O2 or less O2'.
Maybe I've told this before but it can't hurt to do it again: during a test bench run the O2 sensor said 'lean' or so I interpreted it at the time. So I fitted a bigger main jet, whereupon the sensor said: 'now it's even leaner!'
What really happened was: during the first run the mixture was so rich that the engine misfired slightly, sending unused oxygen into the exhaust. And after I fitted that bigger jet, of course the misfiring became even worse.

[twotempi]

24-2-5 Fuel: See 10-17-1
Alcohol based fuel or fuel additives are prohibited.
Stupid rule. Why not change it to "only commercially available pump fuels may be used for this class". Would keep the cost down and the lead out!


AvGas is a "commercially available pump fuel" - available at the pump at most airfields !!! And contains lead. This argument has been presented at a protest , and prevailed.

[kel]

24-2-5 Fuel: See 10-17-1
Alcohol based fuel or fuel additives are prohibited.
Stupid rule. Why not change it to "only commercially available pump fuels may be used for this class". Would keep the cost down and the lead out!


AvGas is a "commercially available pump fuel" - available at the pump at most airfields !!! And contains lead. This argument has been presented at a protest , and prevailed.

Hadn't considered that :facepalm:
OK so the wording won't lock out Avgas, which will keep some happy anyways, but it will get rid of the silly alcohol and additive nonsense.

[Flettner]

Frits, yes I used to tune the SUB4 engines we made ( fourstroke four cylinder ) on our dyno at SUB4. Under about 3000 rpm it was impossible to use the 02 sensor ( two mikuni carbs ) as the cam was such that we got a lot of misfire / extra 02 in the exhaust. We used to tune it to what sounded best / smoothest.

I'm only guessing ( you know, enough knowledge to be dangerous ) as I have no "real" idea of what's happening with injection in twostrokes apart from assumptions I've made to date, and tested.

[wobbly]

Banning the use of AvGas simply due to its lead content is short sighted bullshit.
No different to the banning of leaded fuel in GP racing, when you then saw the fuel guy in the pits having to wear rubber gloves and a respirator so the Elf unleaded rocket fuel
didnt kill him with an instant asthma attack, or slowly leach thru his skin and collect in all the bad places to be in his body..
The lead content is so minute and so benign as far as its so called environmental impact is concerned, when compared to the huge amount of killer additives now being dumped into your car gas tank.

[kel]

Banning the use of AvGas simply due to its lead content is short sighted bullshit.

I listed three reasons on why Avgas should go, there are more.
The rule needs tidying up. Alcohol content in pump fuels will only become more prevalent and oil is an additive.

[TZ350]

For me, its not about banning Av Gas, I am not sure how that got into it, but I would like more choice of what can be used from the local garages pumps as Team ESE get through one 20 liter drum of fuel a meeting.

There are only one or two places here that sell Av Gas and they are a bit of a mission to get to, I expect its the same for most Bucket racers. Team ESE would like to be able to use Av Gas or any commercial fuel that can be brought from the pumps at the local service station, we would like the choice.

As we are attracted to Gull 10 or its competitors E10 equivalent, as a much cheaper and potentially just as good an option to Av Gas. E10 is a commercial fuel available from the local pumps that is easily available everyone. Av Gas is not readily available to everyone but E10 is, level playing field for all I say.

[kel]

we would like to be able to use Av Gas or any commercial fuel that can be bought from the pumps at the local service station.

Then "only commercially available pump fuels may be used for this class" works nicely (although not exactly as intended). As we are self policing maybe this should be put forward to the bucket racer fraternity rather than MNZ.
Sorry to tie up the thread.

[Flettner]

Don't be frightened of ethanol, It's a good fuel but you do still need a little petrol in it for starting and flame speed. Just TELL MNZ "the rules have changed" live with it or piss off.

[F5 Dave]

For me, its not about banning Av Gas, I am not sure how that got into it, but I would like more choice of what can be used from the local garages pumps as Team ESE get through one 20 liter drum of fuel a meeting. .
Fair call. But how many bikes is that feeding?

we used to run off 95 leaded pump gas but switched to Av when they brought in the first dangerous batch of ULP. Personally I found the old leaded gas station gas better for my 50 than the Av, but it was consistent & would hardly run on that first ULP. Keep options open & use what you need. Heck why not add the 5% Tol for blending Castor? Its not like a performance super fuel.

[TZ350]

Fair call. But how many bikes is that feeding? Keep options open & use what you need.

Usually feeding three bikes, and yes "keeping options open", that is what appeals.

[Billy]

Yes there is. Avgas is expensive, hard to get (compared to pump fuel) and it contains lead. Lead is a particular nasty we can all do without exposure to.

Regarding "additive" well a common defintion would be "A substance added in small amounts to something else to improve, strengthen, or otherwise alter it".
Like I said stupid rule, it could be tidied up quite nicely with my proposal but it seems it never made it through to MNZ.

As simple as your proposal would seem,In reality it is not,As many fuels are available from a pump that we do not want used in the sport,Oddly enough AVGAS is one of them,So is E85,On the basis that I do not have a huge amount of knowledge in the feild,I left it up to another member(A much earlier previous roadrace commissioner) to deal with,The original proposed rule has been altered and the revised version is on the website,Also as the date for submissions has passed and NONE were received on theis particular change,Then it will no doubt go through as it is

[RomeuPT]

Banning the use of AvGas simply due to its lead content is short sighted bullshit.
No different to the banning of leaded fuel in GP racing, when you then saw the fuel guy in the pits having to wear rubber gloves and a respirator so the Elf unleaded rocket fuel
didnt kill him with an instant asthma attack, or slowly leach thru his skin and collect in all the bad places to be in his body..
The lead content is so minute and so benign as far as its so called environmental impact is concerned, when compared to the huge amount of killer additives now being dumped into your car gas tank.

Really makes me think we are getting backwards sometimes, just because of the convinience (€) of who can impose the rules.

I was looking at exhaust layout's again today, I have a small question:

Why this 50cc pipe has soo long belly (87mm) compared with other even longer exhaust's? It is to give bigger volume? To give a 14º baffle and keep the diffusor ending percentage in the ideal? What can be in play here, lenghtning the belly/shortning the baffle?

Sorry for the offtopic.

Regards

Romeu

[Flettner]

Ok, is there some sort of conspiracy going on? Why not E85? What has MNZ against this fuel? Why do they not understand this fuel? It's been around for a long time now, passenger cars run on it, racing cars world over use it, It's made in NZ from a by product of milk processing. Green ( ish ). No where near as bad for you as Methanol or petrol. Excellent cooling for air cooled engines, high octane rating and you can run it through your EFI system, I do. What more could you want from a fuel? Available in 200L drums. Mixes with castor straight.
Yes you will use it at twice the rate but so what.

[wobbly]

The belly length number is completely irrelevant, getting the correct diffuser end point is critical - no matter what the desired angles or their configuration - as is the rear cone angle.
What connects these two elements is simply there to get the correct phasing of the leftward/rightward travelling wave fronts.

The same logic applies for example to the cylinder duct and header end %.
If there is a long duct, the header then becomes shorter, as long as it ends at the same % of tuned length to get your desired effect, the number matters Jack Shit.

[Billy]

Ok, is there some sort of conspiracy going on? Why not E85? What has MNZ against this fuel? Why do they not understand this fuel? It's been around for a long time now, passenger cars run on it, racing cars world over use it, It's made in NZ from a by product of milk processing. Green ( ish ). No where near as bad for you as Methanol or petrol. Excellent cooling for air cooled engines, high octane rating and you can run it through your EFI system, I do. What more could you want from a fuel? Available in 200L drums. Mixes with castor straight.
Yes you will use it at twice the rate but so what.

Conspiracy????? Hahahaha,Jezz some of you guys really need to get a life,

The member I entrusted to make the call has far more experience in motorsport than most,2 wheeled and 4,He had a valid reason for his decision based on experiences encountered with some who have allowed the use of E85,I am more than comfortable with his decision and the basis for it,If people aren't going to become more involved with the rule making process,Then I guess they just have to put up with whatever we decide,ENJOY.

[Flettner]

Fair enough, but are we able to learn from some of these "experiences encountered with E85"? Would this entrusted person be willing to share?

[TZ350]

Yes I would be interested in what the background story is too.

283093

This is what Billy says will likely become legal fuel for Road Racing which is a good thing as the un leaded petrol allows for 10% ethanol or E10 and its readily available from the local pump and cheaper than Av gas.

But the Bucketeers may still have a problem because, as Kel has pointed out to me, in the supplementary rule in the miniature road race rules it states no alcohol no additives.

So the most progressive performance development class on the NZ Road Race scene with more members than any other, looks to have missed the boat a bit.

[Billy]

Yes I would be interested in what the background story is too.

283093

This is what Billy says will likely become legal fuel for Road Racing which is a good thing as the un leaded petrol allows for 10% ethanol or E10 and its readily available from the local pump and cheaper than Av gas.

But the Bucketeers may still have a problem because, as Kel has pointed out to me, in the supplementary rule in the miniature road race rules it states no alcohol no additives.

So the most progressive performance development class on the NZ Road Race scene with more members than any other, looks to have missed the boat a bit.

I don't doubt that those involved with the most progressive performance development class are a bit dismayed that they have missed out,However,If you don't apply for a rulechange,Then it won't happen,If you require things to change theres a process that needs to adhered to,As others have.

I simply do not have the knowledge or the time required to deal with every rule in every different appendix plus the chapters,I rely on those involved to keep me informed of any changes required.

[crazy man]

think l may take up golf again far easyer to keep up with

[Grumph]

Ok, is there some sort of conspiracy going on? Why not E85? What has MNZ against this fuel? Why do they not understand this fuel? It's been around for a long time now, passenger cars run on it, racing cars world over use it, It's made in NZ from a by product of milk processing. Green ( ish ). No where near as bad for you as Methanol or petrol. Excellent cooling for air cooled engines, high octane rating and you can run it through your EFI system, I do. What more could you want from a fuel? Available in 200L drums. Mixes with castor straight.
Yes you will use it at twice the rate but so what.

Quite agree...way back when alky was legal I vigorously opposed it's banning, pointing out that we could have had a greener sport.
Methanol and synthetic oil - good combination. But they wanted to ban Nitro and threw Meth out with it.

Formula one went pump gas in 1958 from open fuel. But they did it for sound commercial reasons - the fuel companies who were sponsoring wanted it to link race fuel more closely with what they sold at the pump. Don't see any fuel company money here....
At this end of the world there's no reason to follow FIM fuel regs as we have our own local brews.

I've no idea why MNZ - and Motorsport NZ and Kartsport NZ too - all have a downer on alky....ridiculous and ill informed.

[Billy]

think l may take up golf again far easyer to keep up with

Me too !!!They tell me the 19th hole's where it all happens

[crazy man]

Me too !!!They tell me the 19th hole's where it all happenslol tiger:laugh:

[TZ350]

If you don't apply for a rulechange (in time),Then it won't happen ...

There it is in a nutshell ..... Thanks Billy for your input.

[TZ350]

283097

Tonight's effort was to clean up the back of the cylinder ready for the injectors.

[speedpro]

Avgas is expensive, hard to get (compared to pump fuel) and it contains lead. Lead is a particular nasty we can all do without exposure to.

As a percentage of the total cost of bucket racing the "extra" cost of Avgas hardly matters, and who hasn't heard some horror story about a bad batch of fuel from the pump. With all the effort and $$$ I've put into building my engine I want consistency with the fuel I'm tipping in. Even my baggy 1.8 Legnum doesn't like some fills of 96. If you want to use it, the bother of getting a tin filled every couple of months at worst is hardly a problem.

Lead is not particularly good for you I agree. On the other side, Tolulene/Toluene isn't any sort of health tonic either and once burnt the byproducts, if I remember the article I have round here somewhere, are worse than lead. Not too bad if the exhaust is put through a Catalytic converter but who has one of those on their bucket?

[husaberg]

As a percentage of the total cost of bucket racing the "extra" cost of Avgas hardly matters, and who hasn't heard some horror story about a bad batch of fuel from the pump. With all the effort and $$$ I've put into building my engine I want consistency with the fuel I'm tipping in. Even my baggy 1.8 Legnum doesn't like some fills of 96. If you want to use it, the bother of getting a tin filled every couple of months at worst is hardly a problem.

Lead is not particularly good for you I agree. On the other side, Tolulene/Toluene isn't any sort of health tonic either and once burnt the byproducts, if I remember the article I have round here somewhere, are worse than lead. Not too bad if the exhaust is put through a Catalytic converter but who has one of those on their bucket?

Mathanol is not that good for you either, also none of the Ethanol pump fuels are freely available in the South Island.
Avgas is practically everywhere...................
The environmental sustainablity of ethanol is also highly dubious to say the least....
It's also likely more enviromental damage is caused by one green party member flying to a conservation conference, than in an entire year of NZ bike racing..........
the cat will be after the "Envromats" are introduced...........

[chrisc]

Tonight's effort was to clean up the back of the cylinder ready for the injectors.

This is great! Watching with curiosity

[TZ350]

Methanol is not that good for you either, also none of the Ethanol pump fuels are freely available in the South Island. Avgas is practically everywhere.....

Thats why I think it shouldn't be one or the other but a choice, anyway its moot now untill next year.


I rely on those involved to keep me informed of any changes required.

Maybe in the meantime we could take a pole on whether the Bucket community thinks having access to an effective pump gas is worth pursuing.

PS I didn't start this but it has got me interested.

[TZ350]

This is great! Watching with curiosity

I think it was Grumph who suggested fan (forced) air cooling, wait and see what I have in mind for that and the generator required to run the EFI, lots of fun.

[Flettner]

Billy, am I to understand that even if a remit was put forward regarding the use of E85, that E85 would still not be accepted, because the " entrusted member" is not in favor?

[Bert]

There it is in a nutshell ..... Thanks Billy for your input.

Like my annual rant about mx80s as an option (not going there as it hasnt been long enough) I also throw up the idea of a national bucket federation... So here it is again.

Selection of members from around the country (silver backs). a. Help with sorting out the GP and north/south island events (even allocation of numbers). B. Apply or resolve rules and work proactively with MNZ for the betterment of the sport. C. Like the sidecar fed; everyone becomes a member ($20) a year to ensure key events happen and celebrations are what is expected...

Let's engage as a united front and ensure it is the best classes in NZ.:niceone:



Billy, am I to understand that even if a remit was put forward regarding the use of E85, that E85 would still not be accepted, because the " entrusted member" is not in favor?

Flettner, you are never going to get anywhere. As seen in the racing section requests for information / explinations are encouraged to be directed to MNZ and other than turning into shit throwing session (fun to read); little will be achieved other than filling up Mr TZs great thread. Only my two cents though.

[Billy]

Billy, am I to understand that even if a remit was put forward regarding the use of E85, that E85 would still not be accepted, because the " entrusted member" is not in favor?

This is not the right place to be discussing MNZ internal functions.But the short answer is,No the rulechanges in the norm have a due process,In this instance we needed to make some changes to counter the problem that arose during the NZSBK series when we fuel tested a couple of machines that were running E10,A s I have limited knowledge in the area I enlisted the other members help,We did discuss E85 and he identified some problems and as we had not been approached in regard to E85,It was left out.Simple really,If you want to put forward a submission to have E85 included,Do so.

[Flettner]

I know, but I just had to ask:rolleyes:

[TZ350]

Page 780 ... Setting up an IgniTec DC-CDI-Race-2 ignition


http://ignitech.cz/english/aindex.htm

OK I was asked about getting an DC-CDI-Race-2 IgniTec Ignition to fire, this is what I remember about setting one up for the first time.

283909

If there is no spark at all it may be that the Kill switch polarity needs reversing.

ie you have a normally closed switch for ""stop when open"" and the IgniTec might be set up for ""stop when closed"" and ""run when open"", so the Ignitec would need need to be reversed.

Also, from memory the DC-CDI-Race-2 IgniTec does not fire below 300rpm. Push starting is faster than 300rpm but spinning the back wheel over by hand may not be.

A DC-CDI-Race-2 Ignitec is voltage regulated and will not fire below 8 volts (I think) or above 18 volts. Lots of on track miss firing is due to the battery voltage dropping too low when the Ignition is revving out under load.

283915

For accurate timing its important to have the ignition triggering of the back of the lobe, ie on a falling voltage.

You can change the polarity of the pickup here.

283914

For a single with only one coil and pickup and firing once a revolution the setup needs to be changed.

283912

This twin cylinder DC-CDI-Race-2 IgniTec ignition set up will now fire on only one channel, the other side is turned off.

283907

The next step is to work out the base advance.

With the piston at TDC measure the number of degrees between the heal of the lobe and the trigger.

You only need something thats in the ball park to get started with.

An eyeball with a protractor and near enough is good enough here as it gets adjusted later.

Although you are limited to a maximum base advance of 30 deg or 40 on newer software so you might have to move the trigger to get things right.

283911

The 21 deg base advance is entered here.

The next step is to make a flat line graph. Here we have made it 15 deg, only because we know that's what this motor likes.

Next step is to carefully put a timing mark on the flywheel at 15 deg BTDC.

And with a timing light adjust the base advance until the 15 deg flywheel timing mark lines up. When it does, that means the 15 deg ignition line is spot on.

Now when you adjust part of the curve to say 17 deg you can be pretty sure the Ignitec is firing 17 deg BTDC there.

Bucket goes through the setup routine in his post, including a short clip of him using the dyno to spin the engine over while he adjusts the base advance to get his flywheel timing marks to line up.


I got the job of setting up NedKellys IgniTech programmable Ignition.

If your not lucky enough to have a bike that Igni make a drop on ignition for then you have to setup one for yourself.

This is how we went about it with one of Team ESE's bikes and Mt Eden Motorcycles dyno. Chambers is friendly with Mike and was able to get a bit of a deal on some dyno time.

223239

First step is to find TDC.

223240

Mark TDC and the Advance you want, we chose 15 degrees BTDC. and marked them on the fly wheel, the flywheel turns ant-clock wise so the advance is marked to the left of the TDC mark.

This does not have to be that accurate as its only needed as guide so you can see that the ignition is firing somewhere near the right place. The ignition will be optimized on the dyno later.

223236

The next move is to find the base advance.

223238

Ours was about 10 Degrees.

223237

The base advance is entered into one of those little box's in the program and initially the real advance is setup as a straight line in the curve part of the IgniTech program.

223242

With the ignition programed and the spark plug out, (but plugged into the HT lead and resting on the head) you can then use the Dyno's starter to spin the engine over. Then with the motor spinning over you can use a timing light see if you have got the initial advance more or less where you want it.

If the advance lines dont line up, you simply adjust the base advance setting and cylinder correction until they do.

<iframe src="http://www.youtube.com/embed/JKt9OWnYdsQ?feature=player_embedded" allowfullscreen="" frameborder="0" height="360" width="640"></iframe>

With the initial advance setup more or less where you want it, you are ready to rock and roll on the dyno optimizing the ignition curve.

The IgniTech software is very clever as changes to the ignition curve can be made on the fly and the Ignition itself re-programed while the engine is still running............


An Ignitech will fire below 300 rpm if its connected to a battery.You can simply spin the rotor lobe back and forth past the trigger by hand and it will fire.

Also the RACE box has a test page where you can press a screen button and fire each channel to check everything is working electrically - past the trigger input.

Once the rotor is spinning, the input screen will automatically show the trigger polarity, so you can change it, or simply use auto that selects the trailing edge by default.

Again I say for the 1000th time - YOU MUST USE A RESISTOR PLUG AND CAP.

Nearly every day I get to fix these bloody things playing up simply due to this rule being ignored.

The other thing that can cause problems is keeping the coil drive wire away from TPS and power wiring,if not done you get false input triggering that makes the rpm as seen by the ECU double or treble in value - it then invokes the rpm limiter and suddenly we have a " misfire " at 4000 rpm that shows as 12,000 on the screen.

But alot of this can be "seen " on the screen when the engine is running and is easy to diagnose.

Stainless pipes are an absolute bitch to make due to the material stiffness, use 304 as its soft and you MUST use gas purge inside the chamber or the welds will be shit and it will crack.
The material has no performance advantage over mild, it dissipates heat a little differently, but for a road bike it does look nice.


http://i1056.photobucket.com/albums/t380/uniflow/IMG_8860_zpsd6b580d7.jpg

I run an ignitec, fires ethanol under high comp no problem. In fact the unit has been trouble free, not even fouled a single plug in two years of tuning on ethanol.

Only problem I did find is if you use the coils Wobbly supplies just check that they are not open circuit before you use them, although I would say he puts the meter over them now before they are sent out.

Super adjustability, great for engines that are a little bit different. Cost effective too. I'll be trying one of the Ignijet ( EFI and CDI all in one box ) units shortly, can't wait!

Pictures of the Saturday Epic Events trail ride, only EFI twostroke entered, imagine that.
A lot of modern fourstroke bikes lying on the side of the track? F9 never stopped once, this bike is a lot of fun to ride!


The thing that got me was a newbie mistake. I didn't have the "Programming after Change" box ticked so any changes I made were on the screen & not pushed through to the box, unlike the old Zeel programmer I have where you can change on the fly but have to save at the end, the Ignitech you have the choice, but you have to be aware of it.

really the documentation is pants, but as you said, is obvious once you've shagged around.

Hmm, I've just got mine set to Classic, so do I need to set up in special as a single, or just leave the input open never getting a signal?

I'm struggling to get a Baseline sorted. It looks stable spinning the back wheel by hand but adjusting the baseline on the PC doesn't seem to change the position. I've even taken the rotor off & moved it as it seemed to be out of range, even though I have the same setup as Mike's MB (& have to remark 15deg). PS mine is the P2.


You cant leave the " input open never getting a signal ", the P2 will always fire both CDI with a single pickup when in classic mode.

The unused CDI will eventually die if it is run continuously without a coil connected. Thats why I gave everyone the info on turning off the second cdi in the software.

Even easyer is to simply leave the ecu as its programmed, and parallel the cdi outputs into one coil.

That way you get twice the spark energy at the plug, as Niel has used forever on his F9 injection Ethanol burner.

The arc over voltage is the same but depending upon the inductance of the coil you will get up to 4 times the burn time of the arc as the caps discharge into the ionised gap.

As you say you can run program after change, but I prefer to do all the changes, check them,save the file with a new name, THEN program the box and finally hit " verify ".

This does a checksum, to confirm whats in the ecu matches the screen.


So connect both outputs. What about the other input wire?


I leave mine disconnected.....


Easy for anyone to go online to Ignitech and read the manual, but to be fair also they dont, and should, have in big red capitals a line saying

" IF YOU DONT USE A RESISTOR PLUG AND CAP IT WILL SHIT ITS PANTS ".

P2 or Race - or any electronic ECU system needs RF suppression - all TZ and RS race engines have them from the factory.

All plugs including short reach are available in resistor 5K config, and I have seen a 10K resistor cap, that would work without a resistor plug as well.

Another option is to use spiral wound coil wire, made for race CDI systems such as MSD or better, I have run this without a resistor cap on the twin fire system using a race resistor plug and it worked fine.


There are a lot of little things they don't say in the manwell, I wasted a night trying to get a spark just because I didn't click that you needed to push the changes into the CDI. Sounds obvious when you have played with it, but when you are looking at something on a screen & you change it, you assume it is changed. Why no Worky? http://www.kiwibiker.co.nz/forums/images/smilies/wallbash.gif There is no mention of the single set up, so thanks for that info, but what of the other input?


The first changeable point available is 300 rpm, it fires on the base advance up to 300 then switches to the programmed curve.

Its easy to set a straight line at TDC ie 0* advance,as then you can do it just with a DTI in the plug hole - no protractor or calculations needed.

Set it at TDC and mark the rotor and stator with a felt pen line.

Leave the plug connected on the head, but not screwed in , and its easy to spin the rotor with an electric drill and a socket on the rotor nut - no racket involved, kids snore on unaware.

Strobe the lines - advancing the base advance retards the firing point.

I like to keep the base advance near 10* then there is little chance of it kicking back and trying to start in reverse.
All this is super easy on the dyno of course using the starter on the roller to spin it over.

DO NOT run the charging circuit without a battery or a capacitor .

Without a load the rec/reg can fire out up to 80V and then some smoke comes out of the Ignitech.
With no smoke inside it tends not to work at all, and yes I can tell if this nastyness has been inflicted on the poor thing ,so then it will cost money to fix.


The Ignitech DC CDI P2 ( or RACE ) was designed for a 2T ( like a Rotax tandem for example ) using low ohm coils driven by a capacitor.
They make the usual 12V switching units as well, but both can be programmed easily for non waste spark on a 4T by using a cam sensor that identifies cylinder 1.
I have built both systems on old Ducati Bevels and running waste spark on a slow reving 4T works fine without the complexity of having to make a cam sensor setup, just two sensors
in the side cover at 90* with a single rotor lobe.
The CDI system makes identical power to the 12V on a dyno, but the riders swear ( alot ) that the cdi feels better on track re throttle response.
PS - never heard of a tandem twin 4T, enlighten me?


There are several issues that I have worked thru to get the Ignitech to work its best.

Firstly is that they like low impedance coils - that is low DC resistance ( 0.2 ohm or less ) primary and a high inductance secondary.
The Suzuki RGV or Aprilia RS125/250 are the best common coils available, but I have used Crane PS92N cdi coils on Methanol burning Hydros where spark power is super important.

Stock Honda RS125/250 and CR250 coils are way too high resistance/low inductance to work well with this type of DC CDI.
Using both cdi to drive one coil doubles the effective energy available at the plug, and this is the way to get more power from say a RS125 Honda, especially if you swap out the coil.

Lastly using simply a battery alone isnt the go at all.
The voltage drops quickly under load with this setup, the DC CDIs work best when run with a battery that is being charged by the alternator at 14.2V continuously.

There is only one setup of MX rotor and stator that will drive sufficient current into an Ignitech for it to work best when using a cap instead of a battery.
The stator must have a 2 ohm winding and the rotor must be the later type with super strong magnets - you can feel them " clunk " over each pole as you rotate the rotor by hand.

You can see the voltage at the CDI drop ( on the computer screen ) during a dyno run - if the power supply isnt working as it should.
And as usual, the posts reveal that they werent using a resistor plug and cap as Seb4LO also pointed out, along with using the proper NGK race plugs.

So the spark would be all over the shop, not at the correct time to make power.
I dont know the exact calculation sequence the software uses, but I have found by trial and error that the best setup if possible,is to ensure that the addition of the base advance to the lobe duration should be around the max advance used in the curve.

Having said that I have built several CR250 kart engines that have stock 6* of base and around 15* of lobe length, but the engine strobed exactly showing the 32* max advance as programmed.

And lastly I found that a lobe longer than around 20* length makes the calculations go haywire, and it will misfire badly at one rpm, then go perfectly well everywhere else.

There is a software button that says " wide lobe " and also one that says " no lobe length check ", but trying to translate from Czech what these actually do is impossible.

I simply cut the lobe length in 1/2 and it worked perfectly.


- you can use twinfire as I call it, dumping 2 cdi into 1 coil in a twin - by purchasing a DC CDI P4.

This has 4 cdi in one box ( twice the size ) and uses a rather older version of TCIP4 software, but does everything you would need.

You will need some serious power supply capability to keep that system from pulling down the voltage.

Im doing exactly that in the new TZ400 im building with two of the huge Crane coils.


The twin fire setup does not add any voltage at the plug.

The two cdi output capacitors in parallel,simply doubles the available stored energy.
This translates into exactly the same arc over performance but increases the burn time duration, as the caps energy is drained into the ionised gap.

The only other way to increase burn length is to increase the inductance of the coil.

Using a PC based oscilloscope with an ignition analysis app, I saw the burn duration at x4 using twinfire and a Crane coil, over a standard single cdi and RS125 coil.

[bucketracer]

I don't doubt that those involved with the most progressive performance development class are a bit dismayed that they have missed out ...

Sure the Buckets need to pull finger with their paper work, but I think your right about it being the most progressive performance development class.

Where else can you be totaly involved in every aspect of race bike development and see fields of 40+ on the grid, no not talking about combined classes to make up the numbers but all 40 from one class, F4, don't see that anywhere else in MNZ do you.

[Billy]

Sure the Buckets need to pull finger with their paper work, but I think your right about it being the most progressive performance development class.

Where else can you be totaly involved in every aspect of race bike development and see fields of 40+ on the grid, no not talking about combined classes to make up the numbers but all 40 from one class, F4, don't see that anywhere else in MNZ do you.

So pull finger with the paperwork and problem sorted.If everybody works together,I'm sure it will work out,But don't think for one minute I have all day to run around second guessing everybody elses ideas,If I get some input to work with I can help,If I don't...well simple from there really

[jasonu]

Conspiracy????? Hahahaha,Jezz some of you guys really need to get a life,

The member I entrusted to make the call has far more experience in motorsport than most,2 wheeled and 4,He had a valid reason for his decision based on experiences encountered with some who have allowed the use of E85,I am more than comfortable with his decision and the basis for it,If people aren't going to become more involved with the rule making process,Then I guess they just have to put up with whatever we decide,ENJOY.

How about some info on this person and the reasons behind the decisions. It is all very well to make statements like the above but without knowing the reasons behind the decisions and the hint of 'if you don't like it then tough' ...

[kel]

How about some info on this person and the reasons behind the decisions. It is all very well to make statements like the above but without knowing the reasons behind the decisions and the hint of 'if you don't like it then tough' ...

Slow down Jason. Billy states that MNZ was not approached about E85. He does however encourage us to follow due process if we want a result.
Strangely enough I had followed correct procedure and was of the understanding my proposed rule change would be submitted by the Auckland club, Im guess its still sitting on someones desk.
The no alcohol no additives bit needs to be removed from 24-2-5. The rule would seem to be there to stop bucket racers brewing their own fuels with God knows what, but its out dated. Alcohol, or more correctly Ethanol, is in pump fuel hence the suggestion that all commercially available pump fuels be allowed. Guess I'll try again next year.

Actually, would bucket racers really care what fuel is used if its genuinely pump fuel? After all pump fuel will never match the $12/ltr Elf unleaded stuff which is legal.

[TZ350]

I had followed correct procedure and was of the understanding my proposed rule change would be submitted by the Auckland club, I guess its still sitting on someones desk.

My thoughts too, I think Cully plans on finding out ....

[Grumph]

Slow down Jason. Billy states that MNZ was not approached about E85. He does however encourage us to follow due process if we want a result.
Strangely enough I had followed correct procedure and was of the understanding my proposed rule change would be submitted by the Auckland club, Im guess its still sitting on someones desk.
The no alcohol no additives bit needs to be removed from 24-2-5. The rule would seem to be there to stop bucket racers brewing their own fuels with God knows what, but its out dated. Alcohol, or more correctly Ethanol, is in pump fuel hence the suggestion that all commercially available pump fuels be allowed. Guess I'll try again next year.

Actually, would bucket racers really care what fuel is used if its genuinely pump fuel? After all pump fuel will never match the $12/ltr Elf unleaded stuff which is legal.

That's the problem in a nutshell - who's representing buckets at the MNZ conference this weekend ? Deafening silence here....

If the SI boys would take the next step and affiliate as an MNZ club instead of hanging on the coattails of other clubs there's one voice. I assume there are enough up North to form another club for affiliation. Just do it.

[Buddha#81]

That's the problem in a nutshell - who's representing buckets at the MNZ conference this weekend ? Deafening silence here...

If the SI boys would take the next step and affiliate as an MNZ club instead of hanging on the coattails of other clubs there's one voice. I assume there are enough up North to form another club for affiliation. Just do it.

Problem is no one wants to run the club let alone drive it forward. There now seems to be at least two groups and other than the odd cams meeting or street race its that disjointed it would take a lot of effort to sort it out. For a laugh i suggested we finish the club and spend what we have in the bank, i think it got two replies, no one cares as long as we get to ride.
How many of the north island meets are run under a MNZ permit anyway?

[FastFred]

Billy states that MNZ was not approached about E85. I had followed correct procedure and was of the understanding my proposed rule change would be submitted by the Auckland club, Im guess its still sitting on someones desk.

This is what I know:-

Because the Auckland club sectary was away the proposal was entrusted to the club president to pass to the club sectary on their return so it could be submitted in the proper manner to MNZ, there was plenty of time.

Maybe it made it to MNZ, it would be interesting to know.

[Buddha#81]

This is what I know:-

Because the Auckland club sectary was away the proposal was entrusted to the club president to pass to the club sectary on their return so it could be submitted in the proper manner to MNZ, there was plenty of time.

And this is how I see it:-

1) Buckets at Auckland make up more numbers (read club fees) than any other class.

2) Bucket meetings make a profit and always return money to the club.

3) A lot of big bike meetings run at a loss, therefore Buckets subsidizes them.

4) Its only tradition that Bucketeers associate with the Auckland club.

5) Bucketeers run their own meetings with no input from the wider Auckland club.

6) Buckets could quite easily fit in with a MX club affiliated with MNZ. We only need the organizational structure as an umbrella for our racing, we are used to organizing meetings for ourselves.

7) If the remit did not get to MNZ it would add weight to the perception that the Auckland Motor Cycle Club does not seem to value their Bucket members enough to promote their cause.

8) The Auckland club likes the steady income from Buckets.

9) But Buckets as a racing concept does not really need the Auckland Motorcycle Club, and as a group could probably go somewhere else.

Any MX club out there that would like 40 - 60 new members and a steady income from Miniature Road Race events.

We have had a simular situation down here with the bears club taking the money they got from the 40 odd bucket guys turning up to their meetings and treating us like something that grows on the bottom of a boat. Some of us moved on after trying to change things and getting burnt off doing it. Motorcycling Canterbury Inc welcomed us that left with open arms and continue to treat us as equals. Good luck but some organisations just dont see a good thing and willmake any excuse they like when they lose it!

[Billy]

This is what I know:-

Because the Auckland club sectary was away the proposal was entrusted to the club president to pass to the club sectary on their return so it could be submitted in the proper manner to MNZ, there was plenty of time.

Maybe it made it to MNZ, it would be interesting to know.

Hell I can answer that for you....NO,It did not come through my inbox,Either of them,The only discussion I had was with a guy from R&R Motorsports I think was the name he put forward,But no submission was ever recieved,Doubt that Graham Bastow would have left it out if it was presented too him in the correct time frame.Not suggesting your telling porkies,But it may have been to late

[Billy]

How about some info on this person and the reasons behind the decisions. It is all very well to make statements like the above but without knowing the reasons behind the decisions and the hint of 'if you don't like it then tough' ...

Hi Jason,

Heres a tip,If you don't think I'm doing my job or are somehow thumbing my nose at the bucket scene,Lay an official complaint with the MNZ office,Don't forget to quote your licence number.

[FastFred]

Not suggesting your telling porkies,But it may have been to late

No no, I am not suggesting your telling porkies either, I have just related what I know so far, and the process had a few steps to it before it got to MNZ, lets see what unfolds.

[kel]

Actually, would bucket racers really care what fuel is used if its genuinely pump fuel? After all pump fuel will never match the $12/ltr Elf unleaded stuff which is legal.

How about we take this over here http://www.kiwibiker.co.nz/forums/showthread.php/158831-Buckets-fuel-rule?p=1130551111#post1130551111
Sorry, haven't bothered to find out how to link between threads

[TZ350]

How about we take this over here http://www.kiwibiker.co.nz/forums/showthread.php/158831-Buckets-fuel-rule?p=1130551111#post1130551111


I am off to vote on Kels poll.

[RomeuPT]

The belly length number is completely irrelevant, getting the correct diffuser end point is critical - no matter what the desired angles or their configuration - as is the rear cone angle.
What connects these two elements is simply there to get the correct phasing of the leftward/rightward travelling wave fronts.

The same logic applies for example to the cylinder duct and header end %.
If there is a long duct, the header then becomes shorter, as long as it ends at the same % of tuned length to get your desired effect, the number matters Jack Shit.

Thanks again.

I am finnaly puting this concepts into three real pipes that will be tested within the next week.

They mostly have dual stage header, three stage diffusor, single stage baffles. With the middle diffusor the steppest one. The percentages are within 32/66

Hope it will work great :yes:

Regards

[husaberg]

Technical question For Frits.

Here in NZ we have the F4 class
125 Air cooled 2 strokes (24 mm carb max)
100cc Liquid cooled 2 stokes (open carb)
150cc four strokes (open carb)


Which subgroup would benefit the most from a move to change the fuel rules to allow a fuel.
E85 that was 85% ethanol 15% petrol 110+ RON octane.
The current legal fuels are
Avgas (RON is 103-112)
FIM unleaded (RON of 95-102)
Pump fuel (God knows about 98?)

Apologies for the RON numbers only but it was for consistency

As it stands currently the 3 class are pretty much evenly matched, on Avgas or on Pump unleaded.(Don't know who or if anyone runs the FIM unleaded)

Would it be fair to say the potential performance and reliability gained would be equal across the board. For all three Subgroups

[richban]

Technical question For Frits.

Here in NZ we have the F4 class
125 Air cooled 2 strokes (24 mm carb max)
100cc Liquid cooled 2 stokes (open carb)
150cc four strokes (open carb)


Which subgroup would benefit the most from a move to change the fuel rules to allow a fuel.
E85 that was 85% ethanol 15% petrol 110+ RON octane.
The current legal fuels are
Avgas RON is 103-112
FIM unleaded is a RON of 95-102
pump fuel Good know about 98?

As it stands currently the 3 class are pretty much evenly matched on Avgas or on Pump unleaded.(Don't know who or if anyone runs the FIM unleaded)


Even better question.

Which out off these engine types has the biggest hp advantage in a tuned form for road racing.

125 Air cooled 2 strokes (24 mm carb max)
100cc Liquid cooled 2 stokes (open carb)
158cc Air and Liquid Cooled four strokes (open carb)

[goose8]

Fuel isn't really gonna change much
Well at the gp the bike with the least amount of power out of the top 7 bikes won so I think we other things to worry about than fuel I think nathaniel has 20hp maybe 21hp
Which out off these engine types has the biggest hp advantage in a tuned form for road racing.

125 Air cooled 2 strokes (24 mm carb max)
100cc Liquid cooled 2 stokes (open carb)
158cc Air and Liquid Cooled four strokes (open carb)[/QUOTE]

[Frits Overmars]

125 Air cooled 2 strokes (24 mm carb max)
100cc Liquid cooled 2 stokes (open carb)
150cc four strokes (open carb)
Which subgroup would benefit the most from a move to change the fuel rules to allow a fuel. E85 that was 85% ethanol 15% petrol 110+ RON octane.The current legal fuels are
Avgas (RON is 103-112)
FIM unleaded (RON of 95-102)
Pump fuel (God know about 98?)
As it stands currently the 3 class are pretty much evenly matched,
Would it be fair to say the potential performance and reliability gained would be equal across the board. For all three SubgroupsI only have experience with FIM-allowed fuels (and pump fuel should qualify) so I can't really say. But 125 cc two-stroke GP-bikes could wipe the floor with 250 cc four-strokes, so if your 150 cc four-strokes are evenly matched, it is about time someone wakes up your two-strokes.
OK, your 125 cc smokers are handicapped, but even so a 150 cc four-stroke should not stand a chance.

[richban]

OK, your 125 cc smokers are handicapped, but even so a 150 cc four-stroke should not stand a chance.

Love your work Mr Frits. But like the snails and the tortoise we keep on trudging on. Coz engine's blow and people make mistakes and racing is racing. And we love it.

[husaberg]

I only have experience with FIM-allowed fuels (and pump fuel should qualify) so I can't really say. But 125 cc two-stroke GP-bikes could wipe the floor with 250 cc four-strokes, so if your 150 cc four-strokes are evenly matched, it is about time someone wakes up your two-strokes.
OK, your 125 cc smokers are handicapped, but even so a 150 cc four-stroke should not stand a chance.

Well Maybe then i will owe someone an apology......
As i see the cooler running 85% ethanol to be a huge advantage on the thermally inefficient air cooled 125cc 2 stroke vs the liquid cooled open carbed 100cc 2 stroke.
In fact i see it as a major thermal restriction exploiter.
The air cooled being given a 25cc leg up (but only allowed air cooling and a 24mm carb)
I base this on the 85% ethanol mix (using my maths) to have a assumed latent heat of evaporation of around 368 BTU/pound (ethanol is assumed to be 410 BTU/Pound.
with petrol being around 135 BTU/pound.
The may not seem significant, but the correct E85 mixture will end up burning 1.53 times as much fuel.
So it will be removing the EQ of 4.17 times as much heat as petrol
Yet only adding from its burning 8.5% more heat than petrol.
This same thermal advantage would also be exploitable by a forced induction engine.

[Frits Overmars]

like the snails and the tortoise we keep on trudging on. Coz engine's blow and people make mistakes and racing is racing. And we love it.Engines do blow, it's true. The other day I had a conversation with an acquaintance who used to build his own successful 125 cc two-stroke machines. His son now races a 250 cc Moto3 Honda. "It is not true that Moto3 is three times as expensive as GP125. That should be five times. Our first Moto3 engine blew after 40 km while running in. In the second one the piston split vertically after 470 km. A bare piston (no rings, no pin, no clips) costs over 800 euros and I am not even allowed to fit it myself. Great class, Moto3". As far as he is concerned, the people making the mistakes are called Dorna and he doesn't love it.

PS: the Honda piston pin costs 340 euros. "Let's make racing more affordable and ban those two-strokes":argh:.

[RomeuPT]

Engines do blow, it's true. The other day I had a conversation with an acquaintance who used to build his own successful 125 cc two-stroke machines. His son now races a 250 cc Moto3 Honda. "It is not true that Moto3 is three times as expensive as GP125. That should be five times. Our first Moto3 engine blew after 40 km while running in. In the second one the piston split vertically after 470 km. A bare piston (no rings, no pin, no clips) costs over 800 euros and I am not even allowed to fit it myself. Great class, Moto3". As far as he is concerned, the people making the mistakes are called Dorna and he doesn't love it.

PS: the Honda piston pin costs 340 euros. "Let's make racing more affordable and ban those two-strokes":argh:.

We need to be rich to barely run a high end 250 4t :facepalm:

The Honda piston cost more money than the average, and I really mean the average Portuguese montly income.

For long fast tracks wouldn't a revving 100cc liquid cooled be the best? And the 125 air cooled for slower tracks?

Regards

[kel]

For long fast tracks wouldn't a revving 100cc liquid cooled be the best? And the 125 air cooled for slower tracks?Regards

Yes I believe you are correct but - our slow tracks (kart tracks) have some very tight corners, the four strokes drive out of these corners much better making them very hard to beat. We have only one 2 stroke rider that can reguarly beat the four strokes

[richban]

Engines do blow, it's true. The other day I had a conversation with an acquaintance who used to build his own successful 125 cc two-stroke machines. His son now races a 250 cc Moto3 Honda. "It is not true that Moto3 is three times as expensive as GP125. That should be five times. Our first Moto3 engine blew after 40 km while running in. In the second one the piston split vertically after 470 km. A bare piston (no rings, no pin, no clips) costs over 800 euros and I am not even allowed to fit it myself. Great class, Moto3". As far as he is concerned, the people making the mistakes are called Dorna and he doesn't love it.

PS: the Honda piston pin costs 340 euros. "Let's make racing more affordable and ban those two-strokes":argh:.

Yes that sux for sure. And 2 seasons in they just sound wrong. Crazy money being spent I am sure. I am sure they don't smell as nice ether.

Even though I race a 4 stroke I grew up on 2 strokes. They are great.

[richban]

Yes I believe you are correct but - our slow tracks (kart tracks) have some very tight corners, the four strokes drive out of these corners much better making them very hard to beat. We have only one 2 stroke rider that can reguarly beat the four strokes

Now that my friend, sounds like an excuse of some sort. The problem is not the engine. If its running good and making the power they are in your end of the country. It's the rider and the handling package that Needs work.

[kel]

It's the rider and the handling package that Needs work.

Ouch :laugh:

[speedpro]

I've come to the same conclusion about the package required. So far the solution seems good. My motor, Dave's bike, and currently Gary riding it. Despite the power it makes, currently less than 30hp, it seems to not have any real advantage over a lesser 4 stroke. It takes a moment to get up and boogy even when well into the powerband revs if the throttle has been closed. In a similar situation the 150 4 stroke has a more immediate transition to power. The result is that in between corners where you could give it a little squirt the 4 stroke pulls away a bit. Gary and Dave ride pretty good and Gary is sorting the handling nicely so they manage to keep up. Now that Gary has sorted out how to start races with the bike he is in a lot better position on the first lap. Last meeting he was noticeably quicker than pretty well everybody but just needed to ramp it up a bit for getting past people. Dave has less problems sneaking past other riders so I'm looking forward to him getting fit again. I think there's a reasonable possibility of Gary resetting the lap record again next meeting and Dave should be a bit faster again.
Just gotta keep it together for an important race, like a GP.

[TZ350]

- our slow tracks (kart tracks) have some very tight corners, the four strokes drive out of these corners much better making them very hard to beat. Now that my friend, sounds like an excuse of some sort.


My motor, Dave's bike, and currently Gary riding it. Despite the power it makes, currently less than 30hp, it seems to not have any real advantage over a lesser 4 stroke. It takes a moment to get up and boogy even when well into the powerband revs if the throttle has been closed.

In a similar situation the 150 4 stroke has a more immediate transition to power. The result is that in between corners where you could give it a little squirt the 4 stroke pulls away a bit.

I have noticed the same thing with my stroker, a 4-Stroke that was behind when we are apexing a corner can just get a wheel in front when we both start turning the power on again.

Frits has talked about the wave action in the 2-Strokes pipe collapsing when the throttle is shut and the revs drop and when you open the throttle again you get the sound back straight away but it take a few moments more for the wave action and power to build up again, I guess its that, that is allowing the 4-Strokers to edge a wheel in front exiting corners and is most evident on a cart track.

[TZ350]

283224

Ok ... I have machined the cylinder up for the injectors and now figuring how to mount the common rail. The piece of common rail was cut from a Vtec Civic.

The current plan is to use three IWP048 215cc/min injectors, the ECU will fire the middle one only until it starts coming onto the pipe then the ECU will swap over to the out side pair untill peak torqe when it will bring the middle one in again.

283226283225
http://competitionsystems.co.uk/product.php?id=145

283227

Maximum fuel flow is about 250cc/min but as we have to deliver it in 120 deg or 1/3 the time available we need about 750cc of injector flow. This set up will have a variable common rail pressure, as the power goes up so does the pressure in the expansion chamber and with the fuel pressure regulator connected to the chamber the common rail fuel pressure will also go up during peak demand.
(http://competitionsystems.co.uk/product.php?id=145)

[richban]

I have noticed the same thing with my stroker, a 4-Stroke that was behind when we are apexing a corner can just get a wheel in front when we both start turning the power on again.

Frits has talked about the wave action in the 2-Strokes pipe collapsing when the throttle is shut and the revs drop and when you open the throttle again you get the sound back straight away but it take a few moments more for the wave action and power to build up again, I guess its that, that is allowing the 4-Strokers to edge a wheel in front exiting corners and is most evident on a cart track.

Anyway enough of the four stroke banter rubbish. Whats the best fuel pre mix for me to run my new un restricted RGV 250 on. Stock everything at the mo. Just un restricted controller. Aprilia version.

[speedpro]

This set up will have a variable common rail pressure, as the power goes up so does the pressure in the expansion chamber and with the fuel pressure regulator connected to the chamber the common rail fuel pressure will also go up during peak demand.

I'm not fond of that idea. You have introduced a variable that is outside the control of the ECU.

[richban]

I'm not fond of that idea. You have introduced a variable that is outside the control of the ECU.

Ahh ok. I just figured I should not rely on the oil pump. Save weight and all that. OK then best oil to use?

[Frits Overmars]

As i see the cooler running 85% ethanol to be a huge advantage on the thermally inefficient air cooled 125cc 2 stroke vs the liquid cooled open carbed 100cc 2 stroke. I base this on the 85% ethanol mix (using my maths) to have a assumed latent heat of evaporation of around 368 BTU/pound (ethanol is assumed to be 410 BTU/Pound with petrol being around 135 BTU/pound.
The may not seem significant, but the correct E85 mixture will end up burning 1.53 times as much fuel. So it will be removing the EQ of 4.17 times as much heat as petrol Yet only adding from its burning 8.5% more heat than petrol.I cannot find anything wrong with that, apart from you forcing me to think about air-cooled racing two-strokes, which I intended to avoid forever :p.

[Frits Overmars]

.... This set up will have a variable common rail pressure, as the power goes up so does the pressure in the expansion chamber and with the fuel pressure regulator connected to the chamber the common rail fuel pressure will also go up during peak demand.What if the engine has one single misfire?

[Frits Overmars]

I have noticed the same thing with my stroker, a 4-Stroke that was behind when we are apexing a corner can just get a wheel in front when we both start turning the power on again.
Frits has talked about the wave action in the 2-Strokes pipe collapsing when the throttle is shut and the revs drop and when you open the throttle again you get the sound back straight away but it take a few moments more for the wave action and power to build up again, I guess its that, that is allowing the 4-Strokers to edge a wheel in front exiting corners and is most evident on a cart track.Scooter riders have a similar problem: when they close the throttle, the transmission goes into a longer ratio, so crankshaft revs drop. My advice to them: do not close the throttle completely, keep the engine pulling, and take engine power away by using the rear brake. Not every rider can master it, and not every rear brake can endure it, but it does give better corner exits.

[Flettner]

Frits, whats the real reason twostrokes have been pushed out? I don't bother watching GP any more.
Same in MX, now same at trail rides, the twostroke is becoming an endangered species! All the young guys now only ride fourstroke and subsequently have no idea how the engines work because they just pay someone else to rebuild them, perhaps the rules should be that the rider must rebuild their own bikes. Soon twostrokes would be back. Where are we headed? Or am I just old and got my head stuck in the sand?

[Flettner]

I pipe my pressure reg to the chamber, just don't misfire!
Just like the in a car where the pressure reg is connected to the inlet manifold, which is influenced by the turbo exhaust pressure / load.

[TZ350]

What if the engine has one single misfire?

Not a lot I expect, I expect any pressure variations can be damped out.

[TZ350]

283230

Had Buckets4me's RG50 on the dyno today.

283229

14 rwhp at 13,500 rpm.

[jasonu]

Fuel isn't really gonna change much
Well at the gp the bike with the least amount of power out of the top 7 bikes won so I think we other things to worry about than fuel I think nathaniel has 20hp maybe 21hp
Which out off these engine types has the biggest hp advantage in a tuned form for road racing.

125 Air cooled 2 strokes (24 mm carb max)
100cc Liquid cooled 2 stokes (open carb)
158cc Air and Liquid Cooled four strokes (open carb)[/QUOTE]

It is not all about the hp numbers. Nathaniel and his bike have a combined weight of around 50kg less than the opposition. Nathaniel rides pretty good too.

[Flettner]

Use a pressure wave modifier.
A small hole out of the chamber.

[TZ350]

Good idea, thanks.

[TZ350]

I'm starting to come to the belief that the limiting factor in air cooled 125 development may be the ability of an iron linered barrel designed for a commuter bike to handle the heat rejection levels required for those power levels. A safe level may actually prove to be around 27 - 28 hp....unless you go to fan cooling....

Fan cooling, it must be a good thing when you look at how little fining those hotted up fan cooled scooters have.

This is how I am thinking of doing it, leaf blowers throw out quite a bit of air, and with a bit of ducting and with one each side of the cylinder should do it. They are not that heavy and there is quite a bit of space behind the engine where I could mount one or maybe two.

The rules talk about the bikes motor size and configuration but there is nothing I can see forbidding separately powered accessories or that the accessories like superchargers or electric power generators must be driven by the bikes own motor. If I was supercharging a bike I would be thinking about driving the supercharger by its own separate motor too.

283243283242

These leaf blowers have 39cc 2-T engines and there are others with Lithium Iron batteries.

[Frits Overmars]

Frits, whats the real reason twostrokes have been pushed out? I don't bother watching GP any more.
Same in MX, now same at trail rides, the twostroke is becoming an endangered species! All the young guys now only ride fourstroke and subsequently have no idea how the engines work because they just pay someone else to rebuild them, perhaps the rules should be that the rider must rebuild their own bikes. Soon twostrokes would be back. Where are we headed? Or am I just old and got my head stuck in the sand? Politics:argh:.
Honda got fed up with being beaten by bikes from a little italian factory. Honda have sworn never to build two-strokes again. Honda has good contacts with GP-organizer Dorna.
283249


The official reason was that 125 cc and 250 cc Aprilias were becoming too expensive. But what can you expect when no other manufacturer offers competitive bikes any more? As it turns out (and as everybody could have seen happening in MX a couple of years before) switching to four-strokes sent costs through the roof.

But there is hope: http://www.youtube.com/watch?feature=player_embedded&v=99HRU7At8QA#

The video shows dutch KTM works rider and reigning world champion Jeffrey Herlings testing his 2014 bike: a 150 cc two-stroke with which he can compete in the 250 cc four-stroke class. He loved it!

[Frits Overmars]

I pipe my pressure reg to the chamber, just don't misfire! Just like in a car where the pressure reg is connected to the inlet manifold, which is influenced by the turbo exhaust pressure / load.Turbo revs and inlet manifold pressure won't drop very much within one engine revolution. Pipe pressure can.
But you can dampen the effect by inserting a small orifice and a buffer volume (a long or wide hose) between pipe and pressure regulator.

[TZ350]

283246 283247 283248

In fact by using a high volume leaf blower it might be possible to air cool a normally water cooled cylinder by passing a large volume of air through the water jacket space. The water jacket itself is a cooling surface that is also a duct around the cylinder.

I have some RGV250 cylinders and might give it a go.

[husaberg]

Fan cooling, it must be a good thing when you look at how little fining those hotted up fan cooled scooters have.

This is how I am thinking of doing it, leaf blowers throw out quite a bit of air, and with a bit of ducting and with one each side of the cylinder should do it. They are not that heavy and there is quite a bit of space behind the engine where I could mount one or maybe two.

The rules talk about the bikes motor size and configuration but there is nothing I can see forbidding separately powered accessories or that the accessories like superchargers or electric power generators must be driven by the bikes own motor. If I was supercharging a bike I would be thinking about driving the supercharger by its own separate motor too.

283243283242

These leaf blowers have 39cc 2-T engines and there are others with Lithium Iron batteries.

I see no problems provided they meet the Cylinder capacity limits and the Carb reg's.
using the MNZ formula of bore and stokes X the total number of Cylinders............
You Might need to run a 47mm bore and a 20mm carb on the Gp motor though. The electy one seems to comply without such drastic measures
I do see an issue sneaking it under the noise regs they aren't that quiet are they.

Remember KISS........ you have a spinney thing to mount the Fan on to cool the motor, you might as well use it...

That's my two cents. Check out the attachment for how the airflow is directed and the louver exit above the spark plug......lots of R&D time spent there

[Frits Overmars]

In fact by using a high volume leaf blower it might be possible to air cool a normally water cooled cylinder by passing a large volume of air through the water jacket space.Do the math: what is the mass of air that you will have to chase through the cylinder in order to get the same amount of cooling you get with water? What is the volume of that air mass? What flow velocity will this volume flow require? (don't bother with meters per second; Mach numbers will tell you enough).

[Frits Overmars]

Fan cooling, it must be a good thing when you look at how little fining those hotted up fan cooled scooters have.Fan cooling is a good thing for 5 HP scooters moving in 5 km/h traffic. We used to have a 50 cc air-cooled scooter racing class in Holland; plastic fans sometimes exploded above 12,000 rpm....

[TZ350]

Do the math: what is the mass of air that you will have to chase through the cylinder in order to get the same amount of cooling you get with water?.

Kg for Kg I need 4 times as much air.

From my rough estimate for my cylinder it looks like 1m3 of air a second for a 30 deg delta t.

A leaf blower might put out that much volume chasing leaves but could it force 1m3 a second through a cylinders water jacket.

[TZ350]

I see no problems provided they meet the Cylinder capacity limits and the Carb reg's. using the MNZ formula of bore and stokes X the total number of Cylinders.........

I thought the MNZ regs only applied to the bikes motor, must have missed the bit where it said accessories too.

[husaberg]

I thought the MNZ regs only applied to the bikes motor, must have missed the bit where it said accessories too.

It doesn't mention auxilary engines powering leaf blowers. (Which is odd) but it does say total engine capacity or words to that effect. (in the technical section)
You could ask for clarification, but bucket are self policing arn't they.;)

[chrisc]

http://www.youtube.com/watch?v=5gVeqix2Yc4

[Yow Ling]

Fan cooling, it must be a good thing when you look at how little fining those hotted up fan cooled scooters have.

This is how I am thinking of doing it, leaf blowers throw out quite a bit of air, and with a bit of ducting and with one each side of the cylinder should do it. They are not that heavy and there is quite a bit of space behind the engine where I could mount one or maybe two.

The rules talk about the bikes motor size and configuration but there is nothing I can see forbidding separately powered accessories or that the accessories like superchargers or electric power generators must be driven by the bikes own motor. If I was supercharging a bike I would be thinking about driving the supercharger by its own separate motor too.

283243283242

These leaf blowers have 39cc 2-T engines and there are others with Lithium Iron batteries.

I think if you want to use battery powered accessories thats fine, however when you cross the line to internal combustion engine powered accessories I think that the engine capacity rules

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

would need to be taken into account, if you used a 39cc engine to power the fan then you would need to subtract 39cc from the prime mover, because in normal circumstances the fan would be absorbing power from the std engines crankshaft, also as Husaberg says you would need to take into account the carburation equivelent of the blower motors carb

24.2 Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro and Go Kart motors and transmission parts are not permitted. There shall be no restriction on the make, type or design of carburettor, ignition, exhaust, piston, cam, valve springs or cooling system except for class eligibility. All engines must be normally aspirated except F4 4 stroke engines of less than 100cc capacity, which may be turbo or supercharged. F4 2 stroke engines over 104cc are restricted to carburation equivalent to a single 24mm carburettor


Seems the rules could work as intended, so if you wanted to use a 39cc blower , you would be at 86cc with a carb restriction , might as well run 103cc with water cooling and unlimited carb and no weight penalty

[Flettner]

Chrisc, just more proof cylinder / transfer EFI works.

[TZ350]

Fan cooling, it must be a good thing when you look at how little fining those hotted up fan cooled scooters have.

This is how I am thinking of doing it, leaf blowers throw out quite a bit of air, and with a bit of ducting should do it.

The rules talk about the bikes motor size and configuration but there is nothing I can see forbidding separately powered accessories.

283243283242

These leaf blowers have 39cc 2-T engines and there are others with Lithium Iron batteries.


I see no problems provided they meet the Cylinder capacity limits and the Carb reg's.


I think if you want to use battery powered accessories that's fine, however when you cross the line to internal combustion engine powered accessories I think that the engine capacity rules would need to be taken into account.

So a battery powered accessory like a water pump is ok but one driven by a model airplane motor would need to have its capacity included as part of the Bikes engine.

Buckets is pretty open as far as novel ideas go, so I think its wrong that a battery motor is OK but model airplane motor is not without including it with the bikes engine. Buckets is about imagination and building hp using innovative solutions, to do this the rules were simple and left as much as possible open.

If battery accessory motors are ok, then I think so should any other means of driving accessories be treated like battery motors and ok too.

I think the engine capacity rule only applys to the engine that moves the bike. I will see if we can get some clarification.

[Buckets4Me]

So a battery powered accessory like a water pump is ok but one driven by a model airplane motor would need to have its capacity included as part of the Bikes engine.

Buckets is pretty open as far as novel ideas go, so I think its wrong that a battery motor is OK but model airplane motor is not without including it with the bikes engine. Buckets is about imagination and building hp using innovative solutions, to do this the rules were simple and left as much as possible open.

If battery accessory motors are ok, then so should any other means of driving accessories be too.

I think the engine capacity rule only applys to the engine that moves the bike. Lets see if we can get some clarification.


how about an electric motor for powering the bike :) :lol: no carb no cc limit
and no racing parts

[TZ350]

The text of a letter which also includes links to Husaburgs and Yow Lings posts that I have sent seeking some clarification of the rules.

Re posted here for transparency.

""
Some clarification required please.

Independently powered accessories like water pumps have been used on Buckets for a long time. I propose using a small independently powered accessory (fan) driven by a small petrol motor.

Some maintain that independent battery power is ok but independent petrol powered devices need to be included in the bikes engine capacity, it seems for no better reason than it’s another internal combustion motor and not a stored energy device like a battery motor.

I think any accessory should be able to be driven independently of the bikes motor, or to be fair to everyone, everything including all things electrical should be powered directly by the bikes motor.

I guess the rules never really anticipated independently powered accessories but battery-powered motors have become accepted and the concept of independently petrol-powered accessories like a cooling fan is a new concept.

Would you please shed some clarification on how the rules should be interpreted regarding independently powered accessories.
Thanks
""

[Yow Ling]

The text of a letter which also includes links to Husaburgs and Yow Lings posts that I have sent seeking some clarification of the rules.

Re posted here for transparency.

""
Some clarification required please.

Independently powered accessories like water pumps have been used on Buckets for a long time. I propose using a small independently powered accessory (fan) driven by a small petrol motor.

Some maintain that independent battery power is ok but independent petrol powered devices need to be included in the bikes engine capacity, it seems for no better reason than it’s another internal combustion motor and not a stored energy device like a battery motor.

I think any accessory should be able to be driven independently of the bikes motor, or to be fair to everyone, everything including all things electrical should be powered directly by the bikes motor.

I guess the rules never really anticipated independently powered accessories but battery-powered motors have become accepted and the concept of independently petrol-powered accessories like a fan is a new concept.

Would you please shed some clarification on how the rules should be interpreted regarding independently powered accessories.
Thanks
""

Why not fit a model aeroplane jet engine to your bucket ? You could connect the shaft to the waterpump, how convenient just have to duct the exhaust somewhere.
Why not use a 250cc engine , just uncouple the cranks use 125cc to run the geartrain and use the other to run your generator or your fan, thats almost what you are suggesting just in different packaging

Battery power is a finite resource on a bike , petrol is a virtually unlimited source of energy, i think the battery blower is fine as it will probably exceed the power available and then need to get additional power off the crank, which crank is in question.

[TZ350]

I like your thinking, you must be a Bucket Racer.


Why not fit a model aeroplane jet engine to your bucket ? You could connect the shaft to the waterpump, how convenient just have to duct the exhaust somewhere.

But to be fair, its not what I have been saying.

My case is, that if it does not turn the back wheel or propel the bike forward it need not be counted as part of the bikes motor.

There is nothing in the rules that say the bikes motor has to run the accessories and I am seeking clarification on that.

I have posted everything including links to opinion that disagrees with mine in the interests of transparency and now you can put your case too and assist with clarification from the right people, nothing hidden.

[Ocean1]

This could get interesting.

What's the stoichiometric limit on pressure for a E85 fuelled, direct injected four stroke with an independently powered blower? :shifty:

[chrisc]

You guys sound like the freaking FIA on F1