ESE's works engine tuner

[koba]

I guess you are probably thinking of this one:http://www.amazon.ca/Two-Stroke-Tuni.../dp/0851840396

EDIT: New, 1981!

[husaberg]

Nope, no port diagrams. http://www.amazon.co.uk/Two-stroke-P.../dp/0850770076 shows the cover.

Yes its a little pocket one It has a sister book or books. My old man has it
The book I thinking kind of looks like a Hayes manual in Blue I think.Draper?

I got some two stroke tuning stuff from the fifties if you want a laugh
PM me you Email and I will scan a bit for you.

[koba]

Yes its a little pocket one It has a sister book or books. My old man has it
The book I thinking kind of looks like a Hayes manual in Blue I think.Draper?

I got some two stroke tuning stuff from the fifties if you want a laugh
PM me you Email and I will scan a bit for you.

You have been brilliant on the scanning, that NSR article was fantastic.

[TZ350]

From "Two-Stroke PORTS for POWER" by Roy Bacon:

"...while the primary compression ratio determines the maximum engine speed, the transfer ports determine the power output and reliability of the engine by position, timing and direction."

"The transfer port timing and the height of the port are governed by the primary compression ratio and therefore the engine speed."

"Once the primary compression ratio is fixed, the size of the transfer ports and the exhaust lead (Blowdown) can be determined. The use of a high ratio speeds up the transfer process due to the higher crankcase pressures and this enables the size of the transfer passages and ports to be kept down even at high engine speeds. Thus it can be seen that large ports are not necessarily desirable on a high speed engine as the same result can be achieved in a more efficient manner. If a high ratio cannot be obtained, the transfer ports may be made wider increase the total volume of mixture passed but more usually have to be increased in height to give the mixture more time to transfer from the crankcase to the cylinder due to the lower pressure. Should the transfer timing be extended then the exhaust timing will also have to be changed in order to maintain the exhaust lead (Blowdown) This in turn shortens the power stroke and is likely to reduce the torque as well as the maximum power. Thus both acceleration and speed may suffer."

Great stuff Koba

Late 60's, very interesting, particuarly the bit about transfers being low and wide to maximise blowdown, not much has changed, just detail and refinement.

[TZ350]

You have been brilliant on the scanning, that NSR article was fantastic.

Yes me thinks so 2, and the others as well, +1 +1

[husaberg]

Yes me thinks so 2, +1 +1

Post number 5000 (your one) Con grads Team ESE maybe you should bring in Thomas for another photo shoot.

Talking ESE's works engine tuner
This is Thomas a Vietnamese race mechanic, you know that place where they have all those hot 50's and 125's are big bikes.
Thomas, ESE's Race Team's Tuner is fettling number 9. adjusting the port timing for Taupo.
Its hard to see but he has taped a degree wheel to the magneto flywheel so he can mark out the exhaust port height he wants.
None of this raise the port 3.5mm for a gazillion HP nonsense. He knows what timing he needs and sets the crank position there before marking the port and then doing the hells death port job that we all dream of.
You should see him setting up a carb. Talk about pain staking, he starts with a main jet so big the bike floods at about half throttle (apparently this proves the oriface of the needle/needle jet combo is big enough) and then he slowly step by step works back until it runs clean.
Most people start at the bottom with a carb and work up, He starts at the top and works backwards.
Never seen him blow one up. But then he is intelligent with the throttle and does not ring its neck when the engine is in distress.

Boy o Boy am I Looking forward to Taupo.

Will Daves 100 be finished in time?

Last attachment contains past the main jet 3 times I believe this was raised earlier.

I was looking for the book I was talking about an came across this Blair. Has anyone read these I always wondered about the SAE papers. I guess this is where they are.
http://books.sae.org/book-r-161
Here Is a list of two stroke tuning books the one I was thinking about is Draper The sister book to your one is exhaust and?
http://www.2strokeworld.com/forum/in...p?topic=2022.0

[F5 Dave]

I told you, it is finished. . . Its just not really finished in a sense that it runs but needs some serious development. and a modicum of money a large amount would be better, but the small amount is the current stumbling bock.

[TZ350]

Got a complete clutch assembly from Kickaha today, its a six plate unit with the normal spring setup, just what I wanted, looks like it can be made to fit and with a bit of work maybe a seventh plate can be squeesed in too.

[TZ350]

Had a great evening with Buckets4me running up the pumper carb and divider inlet tract on the dyno.

We are now within 1 hp of our previous best useable power (28.9 rwhp) that we got with the side carb. The pumper with the kart air box gave the best results.

The laptop was still not talking to the Ignitec so I expect more improvements when I can adjust the ignition curve. And I still haven't come to terms with adjusting the pumper carb either so there might be a bit more in that too.

We got all sorts of graphs, when the carb was rich and fat down low there was quite a big torque increase at the beginning of the curve but it would go bananas up top.

I can get it to run low and pull then run clean and make power at the top but the transition is still a problem. It might be that I have to play with the pop off pressure.

Currently it pops off at 8psi but leaks back to 6, I am not sure if thats OK or not ....

Of course, in my efforts to get the carb up and out of the way I have made taking the top off hard, so its not that easy to get at the diaphragm and needle spring without taking the carb right off.

Still I am pretty happy with the way things are going, hopefully Buckets4me will post some of the pictures he took.

[Buckets4Me]

First Picture, Red line is the best useable curve managed so far, Blue line is the 24mm pumper carb. Now the laptop is working again TeeZee figures that with some more carb and ignition tweeking he might get 28+.

Second Picture, Red line is the original inlet manifold, Blue line is the same manifold with the divider fitted.

[husaberg]

I told you, it is finished. . . Its just not really finished in a sense that it runs but needs some serious development. and a modicum of money a large amount would be better, but the small amount is the current stumbling bock.

I hope you don't mind Dave but I was talking with a guy who sponsors me about your plight.

Now "Bob" said he could identify with you as he sees you as a kindred spirit.
He was so taken with your story asked me to offer this a a starting point (See below).
He also said he had been following the F4 build for a quite a while.
All he asks in return, is that you give him a vote in the next MNZ elections.
He did mention due to some problems with Visas he might not be able to get to Taupo, but wishes you all the best.
The eggs are not included sorry.

[F5 Dave]

No I think the 100 mill is what buys the eggs.


TZ have you done an all-gears run to see the kart carb transitions nicely when thrown a bunch of gear changes?

[bucketracer]

TZ have you done an all-gears run to see the kart carb transitions nicely when thrown a bunch of gear changes?

Watching it on the dyno and it doesn't transition between low-high jets very well so TZ is a bit doubtfull, we probably need to talk with someone who has some experiance with these carbs.

[F5 Dave]

may be a game changer as KT100s are single gear of course, not that I have aqny kart experience aside from seeing them in the pits at Bike/kart meets.

[TZ350]

Hopefully the carb will work on the track OK, but whatever, its pretty impressive how much hp can be sucked through it.