Just wondering if there is an STC to install higher compression pistons (more than 8.5:1) in a certified O-320 or O-360 powered Cub. Obviously no auto fuel.

This STC for the Mooney 201 (angle valve IO-360) is what got me wondering.


While their numbers may be optimistic, this mod does seem to make a noticeable difference. The group I used to work for had two different Mooney 201s. One had the 10:1 and a power flow exhaust and it noticeably out performed the other plane, especially in climb to altitude at gross weight.

If an STC like this exists for Super Cubs, I've missed it.

What about an STC to put an O-340 on a PA-18? Anything in the works?