Originally Posted by
1967brutus
On request of Rob.M, first flight vid of his rendering of Chris' throttle body design.
https://www.youtube.com/watch?v=d3z5-EGyYXw
He has, in the mean time drilled a 1,1 mm airbleed port according Chris' drawings, and reports a very much improved idle in flight: Without the airbleed hole he saw an irregular idle in flight, the airbleed hole stabilized that.
Personally, I am a bit confused by that, because Dave way back when he converted his Boxer had issues trying to use the airbleed that was OEM present in the carb of his engine, and in earlier experiments of mine, the airbleed adjustment also was problematic and that was putting it mildly. My experiments back then were pre-solenoid admittedly, but Daves tests were WITH the solenoid.
Whatever the case, to me this sounds like a pretty good running engine, and according to Rob, top RPM in level flight has remained the same (12K) but throttle response improved in that it is more accurate and predictable (and it was allready pretty good previously if you ask me).
Thats what I think OS had done with their EFi solenoid, except their airbleed draws through that square plug with the orifice in the solenoid housing. That orifice is most likely a one way valve controlled by the fuel pressure as the solenoid valve is modulated.
That doesn't run half bad though, you don't see glow engines run much better than that, not at out field, with the majority pilots being misfits, and not really putting a whole lot of effort into tuning their engines. Their aircraft's look like they've been dragged behind the car in transport, real patch work quilts.
