ESE's works engine tuner

[Flettner]

Power 40 or 110%? When I fly (gyro) it is important to have a smooth a power delivery as possible ( hence my fitment of the power valve) for when running up the rotors you can not go to full power directly. Or else bad stuff happens, get rotor flap, rotors strike the ground, craft tips over. Standard gyro accident, all to do with rotor management and that comes from throttle control. The last thing you want is an engine that comes on strong, like a twostroke that relies heavily on the exhaust only. Just my observation.

[136kg136ps]

Frits, thanks.That last motor looks like a big chunk of metal.Bet it turns beads.

[Grumph]

Power 40 or 110%? When I fly (gyro) it is important to have a smooth a power delivery as possible ( hence my fitment of the power valve) for when running up the rotors you can not go to full power directly. Or else bad stuff happens, get rotor flap, rotors strike the ground, craft tips over. Standard gyro accident, all to do with rotor management and that comes from throttle control. The last thing you want is an engine that comes on strong, like a twostroke that relies heavily on the exhaust only. Just my observation.

Interesting to hear and it makes sense too. I recall reading about the last of the piston engined fighters which had major torque reaction problems on takeoff.
I think the experimental very highly supercharged versions had major problems till they developed contra-rotating props.

[TZ350]

Ok, so it is a 150cc four stroke Bucket. ..... 4T .....

But posted to show what can be achieved by paying attention to small detailed changes.



Down draft inlet tract length optimized to suit cam and exhaust.



Moved steadily from the red line to the blue line by 10mm then 5mm incremental changes in the inlet tract length.



It will be interesting to see if the low speed torque dips can be filled in with an Exup valve.

[Brett S]

Hey TZ is that a tacho pickup on the low voltage side of the coil on that Foulstroke?

[Nath88]

TZ, what ignition coil is that?
Does it have a separate primary winding ground?
Would it have enough gusto for the YZ250?

I did some experimentation with the piezo sensor on the road yesterday, saw much less signal amplitude than the previous test and DC voltage seemed to vary a bit over time, but I think the hose was kinked and I know the wiring was crap. So I've fixed those things and will see if it's better/back to normal today.
Also leaned it out from where it was on the dyno, target AFR is 14:1 before 5300rpm (anti-resonance point) then 13.4:1 AFR to 8500rpm (peak power) then it slowly leans out to 13.8:1 at 9800rpm. It feels pretty happy, probably more to gain here. I think it still blows a little smoke on full throttle before anti-resonance, might be able to go a bit leaner still.

[Niels Abildgaard]

Power 40 or 110%? When I fly (gyro) it is important to have a smooth a power delivery as possible ( hence my fitment of the power valve) for when running up the rotors you can not go to full power directly. Or else bad stuff happens, get rotor flap, rotors strike the ground, craft tips over. Standard gyro accident, all to do with rotor management and that comes from throttle control. The last thing you want is an engine that comes on strong, like a twostroke that relies heavily on the exhaust only. Just my observation.

It was my intention to ask why You had power valves so thank you for answering.Is the propulsion propeller turning when You spin up rotor?

[Flettner]

It was my intention to ask why You had power valves so thank you for answering.Is the propulsion propeller turning when You spin up rotor?

Yes it is, there is a small cone clutch driving off the balance shaft, through an angle drive. Spooling up the rotor, this is the trickiest part of gyro flying.
Apply brakes, engage clutch, bring rotor system up to about 250 rpm, release brakes and build ground speed as the rotors spool up. Above 300 rpm you can just nail it, stick forward and it will lift off, as at these revs you are outside the rotor flap danger zone. Flys at about 400 rotor rpm.
Sorry, getting off track.
I intend to run the next engine on E85, injected ( with an autolube)

[Frits Overmars]

For a V2 it is not nessecary to sepparate cranks for starting engine and for an aircraft engine it is either idle or 60 to 110% power. At the high end either tuned exhaust or turbocharger.

I would love to see a measured power curve of your V-twin with a common crankcase and tuned exhausts.

Me too but two is too few for crowdfunding

Yeah, I know the feeling.

Anyway, I wonder about a couple of things. I think the trailing cylinder will receive less mixture and do less work than the leading cylinder.
When the leading piston is moving upward from BDC towards transfer closure, the trailing piston is still moving downward, increasing the scavenging pressure in your common crankcase. But by the time the trailing piston is moving upward from BDC towards transfer closure, the leading piston will already have moved up quite a bit, noticeably lowering the crankcase pressure.

And to what extent will your scavenging depend on exhaust suction? A tuned exhaust needs strong primary pulses. Exhaust ports can provide these, because they open with a speed of about 1,5 x mean piston velocity. But exhaust valves, as shown in your drawing below, can't, because they open with an initial speed of zero.
Exhaust valves will also make it difficult to achieve sufficient blowdown time.area, unless you plan to stick to really low rpm numbers. But that would mean a low power-to-weight ratio, which is not desirable, especially not in a light aircraft engine.

[jbiplane]

I think the trailing cylinder will receive less mixture and do less work than the leading cylinder.
...

Simple idea
V-2 with stepped pistons and isolated crancase, like Ryger or similar

60 years ago in Soviet union produced 2-stroke star engines, 23...500 hp range. They had good reputation.
Sorry for picture with russian comments, seems clear enough without translation.


Design with numerous exhaust pipes and transfer ports... A bit remind FOS

[Frits Overmars]

60 years ago in Soviet union produced 2-stroke star engines, 23...500 hp range. They had good reputation. Sorry for picture with russian comments, seems clear enough without translation. Design with numerous exhaust pipes and transfer ports... A bit remind FOS

Russian is not exactly my first language, but I managed to decipher most of the 'skhema raboty dvigatelya' .
I don't suppose there is a video or a soundtrack from these engines? I'd love to hear them.

[TZ350]

Hey TZ is that a tacho pickup on the low voltage side of the coil.

Yes

TZ, what ignition coil is that?
Does it have a separate primary winding ground?
Would it have enough gusto for the YZ250?

I think so, but not totally sure as its not my bike and other than recording the dyno runs and trying to keep people from changing to much at once I don't know very much about it. I will see what I can find out.

I did some experimentation with the piezo sensor on the road yesterday, saw much less signal amplitude than the previous test and DC voltage seemed to vary a bit over time, but I think the hose was kinked and I know the wiring was crap. So I've fixed those things and will see if it's better/back to normal today.

Also leaned it out from where it was on the dyno, target AFR is 14:1 before 5300rpm (anti-resonance point) then 13.4:1 AFR to 8500rpm (peak power) then it slowly leans out to 13.8:1 at 9800rpm. It feels pretty happy, probably more to gain here. I think it still blows a little smoke on full throttle before anti-resonance, might be able to go a bit leaner still.

Totally looking forward to hearing how your piezo sensor experiment goes. I have been trying to re map my CPU for all low throttle fully on pipe running in the hope I will be able to get a piezo sensor switch from you sometime to see if I can use it to switch between low throttle on and off pipe maps.

[katinas]

Simple idea
V-2 with stepped pistons and isolated crancase, like Ryger or similar

60 years ago in Soviet union produced 2-stroke star engines, 23...500 hp range. They had good reputation.
Sorry for picture with russian comments, seems clear enough without translation.


Design with numerous exhaust pipes and transfer ports... A bit remind FOS

Thanks, very interesting, Valentin Poliakov was great engineer.
Found very interesting russian experimental aviation engines forum


http://www.reaa.ru/cgi-bin/yabb/YaBB...1180373404/all

[katinas]

Russian is not exactly my first language, but I managed to decipher most of the 'skhema raboty dvigatelya' .
I don't suppose there is a video or a soundtrack from these engines? I'd love to hear them.

Will be glad to help you, this was my second language ( learn in school from the fourth grade, long long time ago)
Read that this engine had some problems with overheating pistons (holes in dome) because no cooling from fresh mixture under dome.

[Frits Overmars]

Thanks, very interesting, Valentin Poliakov was great engineer. Found very interesting russian experimental aviation engines forum
http://www.reaa.ru/cgi-bin/yabb/YaBB...1180373404/all

Thanks Katinas. Very interesting indeed; I found Ryger-type engines with 4 and 5 cylinders, dated 2010 (the recent Ryger patent was filed in 2015...).