I did one a while back. I put it on a big Kaos. It did the plane with dope and dacron. It tuned out great. Best flying airplane I ever made. Unfortunately it was jinxed. Once I took of with the radio set on the wrong plane. The ailerons were reversed. I repaired it. Next flight the wing departed the rest of it in flight. Lawn dart.

The engine ran great, still does. I experimented with compression ratios by making different head disks. I did not make much difference.