ORIGINAL: dsk
Bill, thanks for the rapid reply. Well, I'm not much into wild......yet.......so perhaps I'll put something else on.....I have a Towers gift cert thats burning a hole in my pocket so perhaps I'll spring for an OS 50 SX. I think this might be a superb engine for this plane. I had another Four Star months ago.......RIP.......and it also had a .46 AX in it. You're right, it did great. I have one .50 SX that I've used in other 40 sized planes and it really is a nice setup
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Whatcha wanna bet that the OS.50SX can kick that .60FP's butt in every power production use except maybe swinging a 14x6 the fastest? I'm not even sure it would lose in that case, to be honest with you.
Like you said, throttle management would definitely be required. The 4*40 is not a robust airframe in the first place, but it is adequate for its intended purpose. I don't think that hovering at half throttle was in Bruce's list of intended purposes, though.
I scratch built a model some years ago (dubbed The Hail Razor - you had to be there) that was in the forty sized class of airframe. However, I built it with some provisions so that I could fly it with an ST Bluehead G60. As one modeler told me, "Ed, that model doesn't takeoff, it explodes off the ground". It was a lot of fun to fly, but I had to be constantly vigilant on keeping the throttle at 1/2 or below. No, that model would not come apart at full throttle, but it would turn into a speck about as fast as you blink your eyes.
Experimentation is one of the reasons that I chose to stay with model aviation instead of full scale aviation. Give the .60FP a shot. Build a battery box behind the wing so you can bring it into balance and have a ball.