Nice link JAW. I am going to re-post it in the "Formula one 1.6L V6 turbo engine formula" thread. Of particular interest is the high pressure ratios selected for the turbomachinery with no detriment to BSFC.J.A.W. wrote:Here is an interesting high-efficiency 2-stroke turbo-diesel design (2.2Ltr/1000hp) done by Garrett for NASA
~20 years ago - as an alternative to gas-turbines for military helicopters..
http://ntrs.nasa.gov/archive/nasa/casi. ... 001160.pdf
A sad fact. There are alternatives but no manufacturer in their right mind would look at developing a twostroke. EFI, direct injection has been shown to work but still has it's problems. Thankfully there is nothing stopping development from the back yard and I think you will find there are many ideas still bubbling away in the back ground.J.A.W. wrote:2-strokes are - sadly - currently banned for G.P. power units, bike or car..
The G.P. 125s were replaced by Moto 3 250cc 4Ts,
& the G.P. 250s were replaced by 600cc 4Ts (which have not bettered the lap times/speeds)..
I'd suggest you check out the Patakon work done by Manolis, he has some innovative answers to your issues..autogyro wrote:The problem with a two stroke light aero engine is that to keep the propeller speed below 4000 rpm requires the engine to be geared down.
This results in negating the weight saving and introducing a gear set which is difficult to prevent backlash vibration at low rpm.
The Wallis AG has been flown on practically all engines available. Flat twins, flat fours, rotaries, inline two strokes etc.
We even cut off two cylinders from a flat four RR to make a flat twin from it.
Hewland built a one off engine as did Weslake just for the Wallis.
There was a crank case supercharged cross two stroke from Italy, subaru flat fours and various VW based air cooled flat fours.
The McCullock flat twin target drone engine of 60 hp was the best all rounder.
The aircraft held over 20 world records at one time.
So I have had a little experience in this field.
I wanted to build an all electric W116 to achieve the first operational all electric rotor craft.
My idea for an ideal engine would be two stroke with only two moving parts.
Cant say anymore.