The last kit built one I saw had an OS .32 in it and it hauled it like a pattern plane. I had experience with two in high school in the early 80s. One was an orignal with an OS .15 built by a friends father in the 60s and never flown until we had it. Very nice plane. The other was my best friend who built his with a K&B .40 FIRE. Fast was not the word for it. On the first flight, I did a low pass at 100+ and said it is going to blow the wings off it; 6 flights later they did.