RE: Help Me Pick the Engine
I have the RCM Magazine which contains the review of that airplane. The manufacture didn't recommend installing anything
larger than a 91 in the airframe. The reviewer installed a YS 120AC. I think that particular engine is a suprecharged 4 stroke engine.
He gave it rave reviews but didn't use more than 1/2 throttle during most of the flights due to the large displacement engine and power.
I would agree with the review in that you need to limit the amount of power installed to ensure that you do not overpower the flight
controls during high speed manuvures.
I've got a TT 91 4 stroke, a YS 91 AC, and just picked up a OS FS 91. The YS is the most powerful but it is also the heaviest. It also requires tuning during
the flying season. The others engines are reliable powerplants, produce good power, and are almost set and forget engines.