ESE's works engine tuner

[Flettner]

Profile, left and right. Wiring time.

[F5 Dave]

Couldn't have used an old KTM Tshirt?

[Flettner]

Couldn't have used an old KTM Tshirt?

Yeah, should have. ����. certainly if I had a KTM Tshirt I would have no problems cutting it to little peices wirh the sizzors or razor or just stab it with a screwdriver.
Too much?

[Flettner]

Frits, you talked about how the blowdown requirement was different for methanol / ethanol engines, once. Model aircraft engines. Or was I mistaken?

[husaberg]

Yeah, should have. ����. certainly if I had a KTM Tshirt I would have no problems cutting it to little peices wirh the sizzors or razor or just stab it with a screwdriver.
Too much?

Do you have sheep or alpacas flet that fence looks well higher than the average Romney.
Is it due to alpacsas being more fire retardent due to the lack of lanolin
Nice Stuff, I especially like the repackaged pipe

[ken seeber]

Do you have sheep or alpacas flet that fence looks well higher than the average Romney.
Is it due to alpacsas being more fire retardent due to the lack of lanolin
Nice Stuff, I especially like the repackaged pipe

Jeez, as an Ozzie I thought it would be so much more politically correct to not take the piss out of kiwis about the ?sheep on the cliff edge? etc. However, it is now clear that this etiquette is no longer necessary.

[rtechracing]

I posted my issues on this site hopeing to get some good feedback. Instead it ends up with a big argue regarding what Luc has claimed or said in the past. Why bother, instead lets spend our time and energy on a good discussion sharing information and knowledge about the fantastic art of 2-stroke.
Let`s agree on that we don`t have to share the same filosophy, some thinks one thing is the right way to go and someone else thinks another route is better.....if someone claims he can make 100HP from a 50cc engine so what! let him think that.
Can some of you guys that keeps asking questions about what Luc have said or claimed give me a good theory why the power drops before entering powerband like the dynograph shows?

Thanks a lot guys!!

[lucf]

I posted my issues on this site hopeing to get some good feedback. Instead it ends up with a big argue regarding what Luc has claimed or said in the past. Why bother, instead lets spend our time and energy on a good discussion sharing information and knowledge about the fantastic art of 2-stroke.
Let`s agree on that we don`t have to share the same filosophy, some thinks one thing is the right way to go and someone else thinks another route is better.....if someone claims he can make 100HP from a 50cc engine so what! let him think that.
Can some of you guys that keeps asking questions about what Luc have said or claimed give me a good theory why the power drops before entering powerband like the dynograph shows?

Thanks a lot guys!!

rtechracing,
If you don't get the right information, I'm ready to make the right calculation for you.
Which will show exactly what is wrong, but only directly and without any information to this forum.

[Frits Overmars]

Can some of you guys that keeps asking questions about what Luc have said or claimed give me a good theory why the power drops before entering powerband like the dynograph shows?

I'm not one of the "guys that keep asking questions about what Lucf has said or claimed" (god forbid!) but I'll give it a try.
When an engine runs at the rpm of maximum torque, the exhaust pipe pulses work in harmony with the port timings. A suction pulse from the exhaust pipe sucks fresh mixture out of the cylinder, filling the exhaust duct with it. After the transfer ports have closed again, a return pulse from the exhaust pipe pushes this mixture back into the cylinder, raising the mass of combustible mixture there. And then the exhaust port closes, capturing the cylinder contents.

But a 2/3 of this rpm it takes longer for the ports to close, while the exhaust pulses still move with about the same velocity as before. When he return pulse pushes the mixture back into the cylinder, the transfer ports are still open, so the cylinder contents flow back into the crankcase. Then the transfer ports close, leaving the crankcase pressure high instead of low, which is bad for the next inlet phase.
Next, the exhaust return pulse is reflected back from the cylinder, turning into a suction pulse, while the exhaust port is still open, so fresh mixture that was still present in the cylinder, is sucked out. And then the exhaust port closes, leaving hardly any combustible mixture in the cylinder. Hence the torque dip at 2/3 of max.torque rpm.

[rtechracing]

I was not aiming at you Frits and thanks a lot for your reply.
I noticed black residues downd the transfer ducts. So the solution will be to back of ex duration? If so, does it make sense to back of a litle each time to sort of find the limit where the duration makes more hp then anglea area.....I dont know if that make sense. 😊😊

[jonny quest]

Finding your optimum ex duration is easy. Start at 190 degrees, dyno, go to 191, dyno, 192, dyno... until things get wacky.

Easy ;P

[jonny quest]

I want to know why some engines lose power when going from a straight pipe to a pipe fit to the chassis. While others don't care how many bends are twists there are

That's a question I've yet to solve, nor heard of the reason

[Flettner]

The tank, suitable for E85 and the last of the mechanical stuff, the left hand kick start / bob weight. Cut the teeth and machine up a case to fit it all into.

Sheep? nah got rid of those fly blown, garden destroying ( when someone forgets to shut the gate) , one even had a drink problem, always trying to suck on the ethanol fuel line to my furnace, bags of wooly sheep poo. Kiwis, we love our sheep aye.

[Frits Overmars]

I noticed black residues down the transfer ducts. So the solution will be to back of ex duration? If so, does it make sense to back of a litle each time to sort of find the limit where the duration makes more hp then anglea area...

Black residue in the transfer ducts usually indicates insufficient blowdown time.area: when the transfers open, the pressure of the spent gases in the cylinder is still above the pressure in the transfer ducts, so exhaust gases enter those ducts. Backing off exhaust duration would only reduce the blowdown time.area, aggravating the problem. Backing off the rpm on the other hand would increase the time.areas. In other words: don't rev quite so high.

Note: backing off the exhaust duration a little each time is like trying to drill a hole smaller... I'd rather follow Jonny Quests proposal of increasing the exhaust duration in small steps. That way you only need to bin one cylinder after you've exceeded the optimum. And you will have to: the only way to establish a limit is to exceed it.

[peewee]

hey frits what about widening the port as much as logically possible before raising the roof to the clouds . perhaps rtech power loss is from the power stroke being reduced a bit to much, which seems like it would meen less cylinder pressure at exh open and less pressure differential between cyl and pipe, (less suction and plugging ) ?