I need some help sizing a gasser for a Pica 1/5 Mustang. Gonna come out about 20lbs without the powerplant, maybe a little less...I think. My question is what size gas engine to use for realistic scale flight? Don't want to under powered, but don't want to go vertical either.
My problem is I read the threads about spinning such & such a prop @ 7000 RPM, or producing this much HP, or so many lbs thrust. I don't know enough about those to match it with any given weight plane. In fact, I'm not sure that the weight given on the kit box includes the engine or not!! I've always used the kits recommendations.
In this case, I don't have the specs available for gas, and I don't know how to convert from glow to gas as far as power goes.
Is there some rule of thumb for engine size vs aircraft weight?

Signed...Helpless in Louisville

I would guesstimate something in the 60cc range should be adequate. Check out the ZDZ or 3W. There are other manufactures such as Taurus,FPE,Zenoah but I am not familiar enough with their engines to recommend anything. I have an 80cc installed in a 26lb aerobatic plane, this motor is more than enough for unlimited vertical. A 60cc with a 3 blade prop should fly your plane with authority.
I would also take a look at www.rcwarbirds.com they have a wealth of info on warbirds.

Thanks for the web site tip. I think I can get my answers I need from that site from info already posted.

See ya...flukester