LowVoltage, I still say the Saito .82 is a fine choice for the FK. I've been flying my original prototype this summer with an old Saito .80 and it has plenty of pep for me. Doesn't climb like a rocket, but it certainly loops and rolls without effort, will hold inverted no problem, and the sound is a perfect match for the style of plane. That said, it's a great choice for the V60 too. The V60 is a much lighter design than the FK, so you'll have lots of power for aerobatics. If I were picking an engine for a V60 today, it would probably be the Saito .82.