I have one of these engines I purchased used. I haven't stated it yet, but it has very good compression and looks to be in great shape. I also have the 3M TMM-106 twin that is brand new still in the box that I plan on installing in my Meister FW-190A swinging a 25X12 threebladed prop. I've seen several youtube videos of these engines in action on 3D aerobatic planes and although videos can be deceiving, I was quite impressed with the power and performance. I hope my Wolf has nearly the same performance keeping in mind that hovering/vertical climb will be replaced with speed and maneuverability.