I have a couple of these engines and they are wonderful engines. They run very smooth and they are between the 3W42 and the 3W50 in power. They turn a 20 x 10 around 7500-7700 rpms.

I had one on a 80" cap and the plane had unlimited vertical at 2/3 to 3/4 throttle and my cap was on the heavy side.

Hope this helps

Elson