But as Scoubie has alluded to, the problem with these engines is the power to weight issue for the engines. I've had an MVVS 1.60 engine. The engines are heavy for the power that they put out. Because of the engine weight and size issue it is hard to get a properly (read that weighted) sized plane that will perform well in a full aerobatic envelop. I think it's a losing proposition until they figure out how to get more power out of these 20-30cc units. Currently it seems that 50cc is about the breakpoint were power to weight ration gives you a good 3D engine. I tried my MVVS 1.60 in a couple of planes. In both cases either the plane the motor fit and balanced in was to heavy overall for the horsepower or the plane came out way to nose heavy - all related to the engines power output versus it's size. Stick with the 50cc size planes for now.