RE: Which engine for GP Viper?
I'm waiting on delivery of a GP Vipor right now. It should be here by Teusday or Wed.
I'm rebuilding a used OS 46FX with high speed bearings and a ringed piston and liner. I've got a Macs tuned pipe and header for it after I get it broken in.
That ought to be plenty of speed for a beginner at speed planes. Even here at 6000' above sea level, I think it will be plenty fast.
If I like it, I'll slap a Jett on it later.
I don't think I can race with this engine, right now. I believe all the races around here limit engine size to .40