Just remember... the first goal is to have fun. There are many engines that will fit the bill for the Rascal but don't get so caught up in getting the perfect engine that it ruins your flying experience and enjoyment. Any one of the smaller engines that have been mentioned will work unless you are hoping to get 3D performance. If you want to fly 3D, this is not the plane for it nor is it going to be a high performance aerobatic bird with that 110" wing. I've heard it will knife edge well though