ESE's works engine tuner

[ief]

Picture says more than a 1000 words





(got them from kreidler.nl forum )

Couldn't find the info you wanted except it's suposed to give some improvement all over the range.

[breezy]

IEF , thanks for the pictures, i guess its all about having a go and hoping for the best. spent alot of time on the barrel im using now, gonna take a lot of bottle to let loose with a grinder and drill my lovley piston.........

[SS90]

ss 90, way back, in this long thread ,you mentioned and showed pitures of old cast twin transfer ported barrels that you added piston controlled boost/ transfer ports to. is there anywhere on the net which gives any more result based info i can read / down load. thanks in advance...

While it is certain that piston controlled boost ports are neither new nor high tech, I am pretty sure I only mentioned them to illustrate some point or another.... possibly the importance of crankcase scavenging I suspect..... All good when it comes to modifying an old, cramped design.

Web based info?

Meh......

While there are some profoundly experienced clever buggers casting wisdom out on the web, my experience is that the best stuff comes from small "cliques" situated in Europe, very little of which finds it's way onto the web. The real smart ones (not only males by the way) are the 50cc brigade around the Nederlands.

[TZ350]

... spent alot of time on the barrel im using now, gonna take a lot of bottle to let loose with a grinder and drill my lovley piston.........

Some photos of the std Suzuki GP125 gully boost port, I would not be to worried about cutting ports into the piston, its fairly easy to do neatly and you can practice on an old piston first.

With the piston in the bore we mark the position of the ports then drill a pilot hole we then use a bigger drill the correct width and by pulling the drill over we get a nice elongated hole, afterwards we clean the hole up with fine paper, its easy to do.

Pictures of a std Suzuki GP125 cylinder and piston and one of our 31rwhp cylinders (estimated 34 crank hp) where the gully boost port has been opened up, the piston is from another motor but you can see how drilling a hole then pulling the drill over makes a nice shaped port.

[ief]

Funny looking cylinder somehow, why did't they make that gully port crank fed in the first place? Am I right in assuming u still use the holed piston with the crank fed boost port, wouldn't that be counter productive flow wise?

And what i was meaning to ask for some time, did u ever get around to using the defconned cylinders as somehow i've got the feeling there might be even more improvement there seeing your 30 hp cyls.

ps: for the record, count me out on the genies part of the dutch tuning community, just here to learn and find inspiration for my mostly theoretical tuning efforts

[Grumph]

Holes in cast pistons which didn't have them originally are all about the radiuses and finish....poor finish equals superb stress raiser.

It pays to lift the barrel frequently and keep a record of the hours run when using a perforated piston.
Once a crack is seen, you've got the figure for piston life.

Don't ask how I learned...it's embarrasing.

[TZ350]

Am I right in assuming u still use the holed piston with the crank fed boost port, wouldn't that be counter productive flow wise?

One of the other engines does not have the hole in the piston, but mine does, we are not sure whether it helps or hinders, might do a back to back test some time. But I like the idea of some wind and oil cooling the underside of the piston and lubricating the little end.

And what i was meaning to ask for some time, did u ever get around to using the defconned cylinders as somehow i've got the feeling there might be even more improvement there seeing your 30 hp cyls.

If you mean the cylinder on the right, no, it needs a re-bore, so I have not tried it yet. The cylinder on the left is the one currently on my bike.

I am in the process of making a new short 24mm carburettor from a modified EI flatslide and the next move is to make an engine with a bigger diameter rotary valve so that I can have an inlet port thats fully open for longer.

[breezy]

Thank you all for your time and efforts in showing me how to go about this and maybe i can find and translate some of the dutch web sites to learn more......Im currenty trying a tz350 inspired project to keep myself busy... when i learn how to show pictures on the forum ill let you see, truly bucket style come scrap heap challenge with a bit of "im sure i can get that end mill bit in my wood router"......


(where theres a will theres a way)

[Frits Overmars]

...I would not be to worried about cutting ports into the piston, its fairly easy to do neatly and you can practice on an old piston first.

A priceless tip. Never perform a modification you haven't done before on a part you still intend to use.

With the piston in the bore we mark the position of the ports then drill a pilot hole we then use a bigger drill the correct width and by pulling the drill over we get a nice elongated hole.

"If it ain't electric it can't be good" hmm? Sure, you can do all kind of tricks with drills, grinders, milling cutters etc. But there is nothing wrong with a file.
Two golden rules when modifying cylinders, pistons, etc:
One: stop before you reach the inscribed lines.
Two: wherever possible, do the finishing touch with a hand file. It will save you a lot of errors. And if you are looking for a more 'technical' reason: grinding and milling will in general remove material perpendicular to the direction of flow; you risk producing a surface with a lot of pot holes. Filing removes material in the direction of flow; it will automatically offer a smooth surface to the flow.
Filing is a slow process compared to the various 'electrical' operations. But that is an advantage, not a disadvantage. The goal is not to finish a part in a hurry; the goal is to avoid having to redo it.

[Frits Overmars]

While there are some profoundly experienced clever buggers casting wisdom out on the web, my experience is that the best stuff comes from small "cliques" situated in Europe, very little of which finds it's way onto the web. The real smart ones (not only males by the way) are the 50cc brigade around the Nederlands.

Names, addresses, cell phone numbers, photographs! .

[wobbly]

Its a joy having a woman that likes it on her knees, but imagine one that likes to get her knee down.
I can see all you dirty buggers grinning now - stop it, and get back in the workshop.

[husaberg]

Some photos of the std Suzuki GP125 gully boost port, I would not be to worried about cutting ports into the piston, its fairly easy to do neatly and you can practice on an old piston first.

With the piston in the bore we mark the position of the ports then drill a pilot hole we then use a bigger drill the correct width and by pulling the drill over we get a nice elongated hole, afterwards we clean the hole up with fine paper, its easy to do.

Pictures of a std Suzuki GP125 cylinder and piston and one of our 31rwhp cylinders (estimated 34 crank hp) where the gully boost port has been opened up, the piston is from another motor but you can see how drilling a hole then pulling the drill over makes a nice shaped port.

Frits and Wob and Grumph have probably seen them but does anyone have a pic of the Italian designed by Vincenco Piatti
AMC England manufactured motors made for James/Francis Barnet etc.The ones with the funny piston head port cut outs to control the fuel air charge kind of like a non loop scavenged deflector.Pic posted below. but a bit hard to make out detail sorry.
Because i am pretty sure they were all transfer gully ports as well. Just a trench machined into the cylinder with no cylinder wall to support them. Although i understand the motor was a piece of poo it did have a radial finned head.
In the shed at my old mans there is modified Villiers Cylinder that cut through the sleeve entirely and used the pistons skirt for the outer wall of the cylinder.
I am certainly not suggesting it was a great idea but It was done for a time at least once. Probably not that successful other wise they would be more common..
Note these engine were under-square and had real long skirts.No short skirt for you there wob sorry


http://www.motorcycle-usa.com/289/54...t-Cruiser.aspx

In an attempt to break away from Villiers' monopoly supply of engines, AMC commissioned Italian designer Vincenzo Piatti to design all-new two-stroke engines. Piatti was already known to AMC management through his novel, but breathtakingly ugly, Piatti scooters, but the project was a total mess from start to finish. First of all, Piatti's design - constrained by AMC's demands for cost cutting rather than quality - was very conservative. Second, it was poorly made by AMC and soon gained a strong reputation for unreliability.

[Yow Ling]

Frits and Wob and Grumph have probably seen them but does anyone have a pic of the Itailian (pos French) AMC motors made for James/Francis barnet etc.The ones with the funny piston head port cut outs to control the fuel air charge kind of like a non loop scavanged deflector.
Because i am pretty sure they were all tranfer gully ports as well. Although i understand the motor was a piece of poo.
In the shed at my old mans there is modified Villiers Cylinder that cut through the sleeve entirely and used the pistons skirt for the outer wall of the cylinder.
I am certainly not suggesting it was a great idea but It was done for a time at least once. Probably not that successful other wise they would be more common..
Note these engine were under-square and had real long skirts.

Pretty common in chainsaws and weed eaters.

[wobbly]

I built a mini bike when at high school ( got my picture in the paper - really helped my behind the bikeshed activity's ) that had a James motor.
It had the transfers cut as slots in the liner and the angled cuts in the piston.
Great idea for changing the port timing easily,as I found out,in that I "tuned" it so badly that no matter how hard I reved it, I would fall into a torque hole,with only a 4 speed box.
That started my quest to understand how a 2T worked - still havnt got it nailed.

[husaberg]

I built a mini bike when at high school ( got my picture in the paper - really helped my behind the bikeshed activity's ) that had a James motor.
It had the transfers cut as slots in the liner and the angled cuts in the piston.
Great idea for changing the port timing easily,as I found out,in that I "tuned" it so badly that no matter how hard I reved it, I would fall into a torque hole,with only a 4 speed box.
That started my quest to understand how a 2T worked - still havnt got it nailed.

Note to the younger tuners out-there.
My own limited experience suggests when attempting to "nail it" is too concentrate one the upper inlets or "torque hole". Or for some the exhaust port depending on the model brand. Not my thing.
If to much effort is spent with the lower front transfer passage a dangerous spreading of the bottom end curve can result, leading to periods of non working
Wobs bit above with the 4 speed box is intriguing, As my own model A Fancis Barnett (a Fanny B) as they are called) seems to have trouble with the "box speed selector" not functioning i will have to strip it down later and see if i can find the problem.