ESE's works engine tuner

[F5 Dave]

What is all this intake/Exhaust valve stuff? My reed intake valve opens when it damn well pleases & stays out as long as it wants. I have an exhaust valve on my YPVS but not on the bucket.

Print that out so it's like 200mm di & will need to be on a stiff former so you can bolt with a few clamping nuts to the end of the crank.

[Buckets4Me]

pffft..... b-grade riders are hardcore!, id rather be at the front of b-grade than the back of a-grade, thats why b-grade riders arnt ashamed of being in b-grade its all about close racing and getting challenged by other riders.

you have now upset me !!

they are at the frount of the B grade because they are either
#1 Burglers
#2 to scared to ride with real racers
#3 want to knock me off ???

they would be mid pack A grade with there times

[Henk]

pffft..... b-grade riders are hardcore!, id rather be at the front of b-grade than the back of a-grade, thats why b-grade riders arnt ashamed of being in b-grade its all about close racing and getting challenged by other riders.

Wrong, being in B grade is about not being an unpredictable wobbler creating a hazard to the guys at the front of A grade and the problems that the speed differential can cause. I'd rather be mid pack to tail end A grade than burgling the B grade. No chance of that happening soon but when / if I do get the speed up I won't wait to be kicked up a class.

[TZ350]

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This is not about B grade riders its Team ESE's thread about engine development.

Bugger off you guys and have your spat some place else. and come back when you have a picture or story about some development work you have been up to on your Bucket.

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[DELLORTO]

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This is not about B grade riders its Team ESE's thread about engine development.

Bugger off you guys and have your spat some place else. and come back when you have a picture or story about some development work you have been up to.

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i made a ram air

[TZ350]

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Thats what we want to hear. Pictures?

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[speedpro]

I have a ram air, made by IHI

[DELLORTO]

I have a ram air, made by IHI

who's IHI ?? im think about putting my ram air on the cbr, ive been too scared that the EFI wont like it and start to be a pain,

also my ram air is still in development, im gong to fit it with a fan {borrow without permission from electro tech at school} that will hopefully spin and blow air into the engine, therefore making the ram air much more efficiant. -max

[bucketracer]

who's IHI ?? im think about putting my ram air on the cbr, ................im gong to fit it with a fan............therefore making the ram air much more efficiant. -max

IHI......is a make of turbocharger, perfectly legal for Buckets

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[SS90]

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Well its official, the simple setup is the best bang for bucks. Spent a very enjoyable afternoon with Buckets4Me dynoing his RS/GP125 team ESE bike, for a solid wide phat 18rwhp. He has always had the better bike at Mt Wellington and at Taupo it finished 2nd in one of the races.

The mode’s are:- 1.5mm from the top of the barrel, 2mm “O” ring for a head gasket, std head, kX80 ignition fixed at 22deg, std exhaust port, std inlet and timing, std carb, 100 main jet and a RG250 pipe and bingo you have 18rwhp.




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I was wondering Teezee, what are the exhaust port specs of an original GP125?

I suspect that the exhaust port won't be anywhere near as wide as it could be (although, I suspect the OEM piston rings may be too thick for the 72% than you know you can run with you more modern piston)

With the Polini 130cc engines I do, I am able to run 70% safely (original piston) and get my time area where I need with-out raising the duration.

Using a "racing piston" I can run 75%

As you know, widening a port will increase it's time area, not it's duration, and while it will have a slight effect of raising the RPM where maximum power is delivered, it is FAR less that raising the height of the port alone to gain more time area......

I wonder if you could run the original set up that Chambers bike has, and simply widen the exhaust port as much as is safe, and calculate your exhaust port time area from that.

My experience has been simply widening the exhaust port (assuming the port is reasonably narrow to start with) to get the time area I want has time and time again proven to be the biggest single gain in power as far as cylinder modifications go.

I guess it come down to the thickness of the rings on the original piston.

This is the reason I used a bridged port on the cylinder I made.

Apparently there is a 4% reduction of flow in an exhaust port with a bridge, compared to one with-out, but the extra width the bridge allows you is well worth it in my opinion, as you are only limited by the risk of short circuiting of the transfers and exhaust, and (possibly) localised heating of the exhaust side of the piston crown.

I recon you could see the same power as your current engine with the application of some lessons from your development.

I believe you could see 20 PS and 17NM from slight modifications to Chambers engine, all below 9000 RPM.

That's what make Speedpro's engine so interesting too me, he has the time area with-in "norms", but with his set up, I just see his duration as too short, especially considering that more duration on the transfers will increase his torque.

I guess a dyno will tell the story!

I really think you can make the tractor you want from a GP125, but still making 20PS!, but at lower revs.

[F5 Dave]

Most modern bridged ports don't look like older ones so are likely to flow better & maybe meet that 4% you talk of. They aren't straight edged like earlier ones.

[TZ350]

I was wondering Teezee, what are the exhaust port specs of an original GP125?

I wonder if you could run the original set up that Chambers bike has, and simply widen the exhaust port as much as is safe, and calculate your exhaust port time area from that.

Your post is encouraging, and its where our thinking is now. Its pretty much what barrel number two was supposed to be but I cut the ports to big/high.

Would you call the Kawasaki KX125 motocross piston I use a "race piston" suitable for an exhaust width of 75%? I have been running 71% with it OK and see Blair also talks about 75%.

I will now start on barrel number three and base it on Blairs book.

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[TZ350]

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Another interesting pipe design program:- http://www.mh-aerotools.de/airfoils/javapipe_en.htm

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[F5 Dave]

Pussies, I've run close to 80%. But I'm 'special'

[Buckets4Me]

Pussies, I've run close to 80%. But I'm 'special'

is that run close to
or ran close till