Another thing I forgot to mention is to go for a 46 size engine and put a Master Airscrew 11-5 prop on it. I know its a 40 trainer but the extra power can really come in handy on grass runways or if the wind whips up and you are trying to make it back to the runway. If you check the price is almost the same as well. For me the most reliable standard brands of engine I suggest are Thunder Tiger or OS. There are other brands that may be as good if you get a good one but the quality is consistantly high on these two brands.