Speaking of small case >= .50's, I was impressed by the Evolution 60NX I inherited, with the Jett muffler that is. I would guess in my meagre understanding of these things, that the timing of this .40 size engine, i.e. intended rpm range, is probably well selected to make good use of the available breathing abilities of the small case front intake format. It pulls real hard on an APC 10-7. The firewall on the P7 it was on stared working loose pretty quick so it will be spring before I know more about it. It's on my original Screamin Demon now. I bet it launches like a bottle rocket on the 10-7. My instinct is to try the APC sport 9-9 next - based on the almost universal good results with .46's and .50's on 9x8's on various sport speed models, combined with the extra displacement and perhaps slightly milder timing than an SJ50 or the like. Probably be fun to try an APC 9x10 on the Demon, the NX won't spin it so fast that the safety limits will be threatened.

It would be a good powerplant for the Magnum or a Q500 ARF for the guy wanting all around briskness - for test flying you could slow them down to 75% of fast with a 10-7 and probably pull two of either aircraft vertical at the same time.

I've never seen a EVO .60 run.
Is this the engine that uses the crankshaft as the inner race for the ball bearings..?
If so, that would free up extra room to make the crank journal's diameter larger and allow more air to enter the engine.
The bigger piston in a relatively small case would increase pumping efficiency.

No it's just a regular BB. It's probably set up for best power around 17k or so from the specs and behaviour, but I haven't got enough time on it to know it well. At $150 plus the aftermarket muffler it's attractive.

The engine with the inner ballrace ground into the crank? MB....28.000 rpm four stroking during break-in....

Thanks Rudeboy.
That feature probably makes the cranks tricky to produce because you need very tough surface for the bearing, but the rest of the crank needs to be tough but not brittle.

And the Profi F2A TOP 2.5cc engine. I was told it is good for a couple more k rpm or so.

Here you go, F3D break in.. https://www.youtube.com/watch?v=FJqxX0f0XcI#t=25