ESE's works engine tuner

[mr bucketracer]

Frits, on the Ryger facebook they write this
"and yes ! we do have 70 bhp and 30k rpm and 80% less emissions....it is the result of 10 years of development and a lot of hard work.
BUT ! it is NOT about rpm or horsepower it is about a clean twostroke engine with superb characteristics !"

Are you able to confirm these are all from the same engine or from several different engines

and also it will last 5 mins

[Frits Overmars]

Frits, on the Ryger facebook they write this: "and yes ! we do have 70 bhp and 30k rpm and 80% less emissions....it is the result of 10 years of development and a lot of hard work. BUT ! it is NOT about rpm or horsepower it is about a clean twostroke engine with superb characteristics !" Are you able to confirm these are all from the same engine or from several different engines

When Facebook announced they would disrespect all privacy rules as of 01-01-2015, I stopped logging in, so I haven't got a clue what is going on there nowadays.
I do know that avoiding facebook saves me over an hour, every day, so I do not intend to go back there.
Who wrote the lines you are quoting? If it was Harry Ryger, you can take his word. And yes, the power, the revs and the emission values are all from the same engine.

[husaberg]

When Facebook announced they would disrespect all privacy rules as of 01-01-2015, I stopped logging in, so I haven't got a clue what is going on there nowadays.
I do know that avoiding facebook saves me over an hour, every day, so I do not intend to go back there.
Who wrote the lines you are quoting? If it was Harry Ryger, you can take his word. And yes, the power, the revs and the emission values are all from the same engine.

Frits has anyone done any work in the field of using the cylinder pressure present (prior to the exhaust port opening) to pressurise the crankcase. two birds one stone.

[Frits Overmars]

Frits has anyone done any work in the field of using the cylinder pressure present (prior to the exhaust port opening) to pressurise the crankcase. two birds one stone.

Not too long ago I posted drawings from the Curtil-patent ( http://www.freepatentsonline.com/4091775.pdf ) wherein cylinder pressure was employed to stimulate transfer. Suzuki tried something similar in their 50 cc RM62 racer, with a B-transfer port that had the same timing as the exhaust port.
I tried to find that post back via the search function and as usual I failed, so you'll have to do the searching yourself, Husa.

[husaberg]

Not too long ago I posted drawings from the Curtil-patent ( http://www.freepatentsonline.com/4091775.pdf ) wherein cylinder pressure was employed to stimulate transfer. Suzuki tried something similar in their 50 cc RM62 racer, with a B-transfer port that had the same timing as the exhaust port.
I tried to find that post back via the search function and as usual I failed, so you'll have to do the searching yourself, Husa.

In 1962 Suzuki even gave the B-port (there were only two A-transfer ports and one B-port) the same timing as the exhaust port.
Attachment 312434

I was meaning more modern and perhaps more indirect to keep the pressure but not transfer the unwanted heat.
edit looked at the patent I think I understand it?

[Muciek]

Re the old Yamha port setup.The B ports can be widened alot despite the stud holes as these drillings are smaller where the port goes around the corner.
But with no PV the A port at around 25* and stock width, with the B port lower at 10* as wide as you can get it ( watch the ring pins ) will always work alot better
but usually needs welding of the B port roof to get enough material for this angle.
Of course the A port can simply be epoxied up to for the 25* angle.
The boost port is easily re-angled to 55*.
Old model RS125 cylinders had 28* and 15* but I dont know if this really made more mid power or not.

Forgot to ask, in this combination B ports should "look" straight at each other or should I try put there some "kicker" so they are pointed downwards at 1/2 bore (no way of doing proper radius because of stud hole).

[peewee]

Not too long ago I posted drawings from the Curtil-patent ( http://www.freepatentsonline.com/4091775.pdf ) wherein cylinder pressure was employed to stimulate transfer. Suzuki tried something similar in their 50 cc RM62 racer, with a B-transfer port that had the same timing as the exhaust port.
I tried to find that post back via the search function and as usual I failed, so you'll have to do the searching yourself, Husa.

frits have you looked through some of them patents ? all kinds of crazy ideas. pnumatic valves and sliding sleeves over the piston and all kinds of other stuff. http://www.freepatentsonline.com/5205245.pdf

[peewee]

muciek i think a sharp kicker is not the best idea. besides that, if you look at the drawing frits has posted many times it has the rear wall of B aimed more about 3/4 bore. do you have another photo from the top side to see how long the stud is and where the nut is ? its difficult to say but maybe you can have the tunell go up and then reach over the top of the stud.

[Muciek]

muciek i think a sharp kicker is not the best idea. besides that, if you look at the drawing frits has posted many times it has the rear wall of B aimed more about 3/4 bore. do you have another photo from the top side to see how long the stud is and where the nut is ? its difficult to say but maybe you can have the tunell go up and then reach over the top of the stud.

Bolt goes from the bottom of cylinder to the top and it uses ordinary nut at the top of the head, not like that special ones from other yamahas. There is approx 3mm between hole and port channel. Aiming for 1/2 I got find in other Wobbly post:

Easy - double the A and B port axial angles.
Move the B port front edge as far forward as you can to make a narrow bridge - and grind it perpendicular to the front/rear axis.
Move the B port rear wall around as far as you can ( limited by the ring pins generally ) and get a hook in there pointing 1/2 way to bore centre.

[Frits Overmars]

frits have you looked through some of them patents ?

Some? Thousands. It's part of the job. You never know when you'll find a gold nugget in the mud. I haven't found many nuggets yet....

[Lef16]

Hey guys.
I design (amateur) exhaust pipes for a while.
My question is about the temp on the exhaust pipe.Untill now I calculated this number by luck.Do I need an EGT?I think I need one.
However I design an exhaust pipe for a 130cc bike now and for 14000rpm.But the engine is not a full racing engine,so in my mind that means lower temp.
EngMod suggests 500-700c.
I will go 650 for the moment wich makes the tuned length about 740mm..it seems too short to me
What't the way to find the right temp?
Enlightenment please

[Frits Overmars]

My question is about the temp on the exhaust pipe.Untill now I calculated this number by luck.Do I need an EGT?I think I need one. However I design an exhaust pipe for a 130cc bike now and for 14000rpm.But the engine is not a full racing engine,so in my mind that means lower temp.
EngMod suggests 500-700c. I will go 650 for the moment wich makes the tuned length about 740mm. it seems too short to me. What't the way to find the right temp?

A 130 cc bike won't do 14000 rpm unless it's full-race spec, Lef16. And I assume the 14000 rpm is your maximum rpm, not the rpm of maximum power.
It would also help if you told us what you told EngMod: port timings, areas and directions, compression ratio, ignition timing, that sort of stuff.
For starters you can use the simple concept shown below, where I left out most of the variables I just mentioned. You will only need to enter the exhaust timing
(from your 740 mm I gather that you entered about 180°, but that is way too low for the revs you have in mind) and estimate the speed of sound.

650 m/s will probably be too high, but it will result in a relatively long pipe, so maximum power will be developed at a more moderate rpm that may be in synch with your angle.areas. And once you know where the engine produces its max.power, it's fairly simple to find the actual speed of sound by reverse calculation.

[Lef16]

Frits all I can say is that the exhaust timing is 203*(I think its low because its an oversquare engine) with 17/1 comp ratio,unfortunately the bike it's not mine,so I can't share info without permission
My inptup in EngMod for max power rpm was 14000 and the temperature 650 celsius.
The engine is designed for drag racing but it have some characteristics from the factory that dont help to reach 14000 at all.Maybe I should try something like 13000 or 13500..
Also I dont want a fat pipe because the transfers and crankcase volume is relatively low,so the pipe/engine volume ratio is about 22.5/1.
What wave speed should I start with as a benchmark?
Cheers!

[Frits Overmars]

The engine is designed for drag racing but it have some characteristics from the factory that dont help to reach 14000 at all. Maybe I should try something like 13000 or 13500.

EngMod can tell you what to try; in the absence of relevant data I can only guess.
Think of it this way. A 125 cc state of the art engine produces its max.power at 13000 rpm. Yours has a bigger cylinder capacity, it's short-stroke (undesirable for a two-stroke) and the specific angle.areas probably won't come close to state of the art, so I'd aim for max.power at 11.000 to 11.500 rpm. More revs will only give less power.

What wave speed should I start with as a benchmark?

Try 500 to 550 m/s.
But I wonder: you say the engine is designed for drag racing, but earlier you wrote 'the engine is not a full racing engine'. They don't come any fuller than drag racing...

[Lef16]

The engine is designed for drag racing but as I say earlier it have some disadvantages like small transfer port and crankcase volume from the factory.You can increase that volume but still you're under some restrictions from the engine manufactor!
Also,I don't say that it will make more power than the Aprilia's(I would be crazy if I told so)..not even close.But because it is an oversquare engine at 14000rpm the piston velocity is less than 25m/s so I think it's possible with this speed,but maybe unpossible from the port anle/areas......
The pipe looks like Honda-KTM-Derbi style in Motogp,but with steepest angles in the header and first diffusor,and relatively smaller baffle(~115mm) than it should(?),because im thinking that bigger diameter here and bigger volume won't cooperate with the small(and maybe not with the right direction) tranfer ports.