RE: 33cc 4*120??
I can't speak about the 33cc Homey, i have no idea what it weighs after conversion, what prop it will spin and at what RPM, so it is hard to say. 33cc in general is not too much for a 1.20/1.40 sized plane. I can talk about two planes: Quique Somenzini Yak 54, 72", 11 lbs, Zenoah G26 converted to EI, Mezjlik 18x6 @9000, and it will do everything it did before with the YS 1.40 on it, unlimited performance. Hangar 9 Funtana X100, 69.5", 10 lbs, Zenoah G26 converted to EI, Mezjlik 18x6 @9000 and APC 17x6 @9400, again unlimited performance, the same as the YS 1.20 it replaced. Zenoahs are known for running really well at higher RPMs, where other small gassers don't love it so much. At least here you have some plane sizes, weights, rpm and prop measurements to help you decide on power for your model. Good Luck!
Chad