RE: Electric equivalent of 50cc Gas engine
I have a feeling buying the HC-motor is a waste of money... You propably have to buy a good motor after trying to make it work.
I would suggest an Actro 60-175. 12S LiPo and a 26x12 Mejzlic propeller would give you suitable performance. In addition you get a superb motor, no loose magnets flying around, no vibrations and a motor which stay cool and last a looong time.
Motors I haven`t tried myself but think should be good: Neu.