Thanks Dave for your quick response and insight. I think the 91 would more than do the trick, however, I was looking for a two stoke solution. Its too bad YS does not make a big brother to the .45, say about 75 -90. I know of the YS helicopter engines, but I am unsure of their application inside airplanes - any thoughts.

Thanks
ScaleME

PS. The model is a scratch built ME-163, 73"WS