ESE's works engine tuner

[jbiplane]

I estimating if it is rational make 3 cylinder star of cylinder I have. It should be alternate to Koenig SC430
I make 3d assembly of crankshaft in 3d CAD and play with crank geometry to reach the best balance.
Planned use Yamaha DT175 connecting rod with center to center 100mm, bottom hole 28mm, upper hole 20mm

This assembly fluctuate centre of gravity about 0.14mm


But crankshaft with common 22x80 mm pin looks a bit fragile and may be I change intent to 4 cylinder V90.


If I will make 4 cylinder V90 I want simplest possible intake with one manifold and one drum valve in the centre of the engine.
Dont want reed valve which badly behave at -40C in Siberia.

[F5 Dave]

Why would you be doing anything in those conditions? This doesn't sound like leisure activities.

[wobbly]

Flett, as I have stated several times, there has to date only been two actual dyno confirmations to my knowledge that the 3mm floor lift on a 54.5 stroke
actually works.
Jan did it on the last RSA , he made one higher , but then retired and had that recut back to 3mm.
I did it on a TM homologation test engine and that worked as well - but it was kept as a" factory special " mod only.
There are two issues at play that make things difficult.
One is that Jan stated the mod only worked at all , when the Blowdown had been fully optimized ie the Aux around to bore center and made as high as possible
before loosing power band width.
The second issue is that its easy to say - make the dam higher then grind it down if its too high , but the ground bore port edges are only reliable enough for a short dyno test session
and then it has to be replated.

[Flettner]

I got plenty of blow down time / area / flow, like I said exhaust almost round to half way round the cylinder with onlt one bridge and a relatively straight port outlet from each port wndow (water cooled one will be straight) .
I guess its just a shit farm bike moter, apart frim Nikasil cost, I'll leave it at 3mm.
195 - 130 (might actually be closer to 129, shitty castings&#128513

[Flettner]

Made a couple of these the other day, I guess a little less now, some actual numbers 😁

[jbiplane]

Anyone know if exist V90 2cylinder or 4cylinder 2-strokes with rotary intake valve?
I saw only ones with piston and reed valve intakes.

JBB250 use rotary valve but a bit exotic way with 2 karbs

[Peter1962]

Anyone know if exist V90 2cylinder or 4cylinder 2-strokes with rotary intake valve?
I saw only ones with piston and reed valve intakes.

JBB250 use rotary valve but a bit exotic way with 2 karbs

There is an enormous amount of info on the JBB saga, the V2 250cc and his other endeavours, at Pitlabe.biz. http://www.pit-lane.biz/t5627p175-ol...e-une-histoire.

Go directly to page 8 for the first reactions concerning the V2

Jean-Bertrand Bruneau was a genius.

[Pursang]

Why would you be doing anything in those conditions? This doesn't sound like leisure activities.

Altitude of 4000m with a -15C ground temp. Flettner could probably advise on the degree of leisure that would be in an Autogyro.