Just got back from the IMACs at my field today and wow. I feel almost ashamed that I'm getting a profile plane after seeing these 50% scale beasts harrier roll like 8 inches off the ground. lol. The mojo 40 is on it's way here so I'm looking at engines and I'm thinking of getting the aviastar .53. It's like crazy cheap at $70 for a .53 and it has some good reviews. The .46 aviastar is only $50 and it was in Fly RC mag with a rave review.