i just bought a helipro blackhawk 500 gp. they recomend a engine between 0.10 and 0.15 size. can anyone recomend a heli engine in that size range.i cant seem to find one. or can i use a bigger engine like a 0.32 , will it fit?OK i cant use a bigger engine so were can i find a heli engine that size or does it have to be a engine for heli's can i use a car or truck nitro engine. is there a differnce?