Well I see nobody had stepped up on this one lol. I'm going to advise against it. RPMs do not mean usable power. The average aerobatic helicopter runs a rotor RPM of between 2,000 and 2,200 RPMs. With an average gear ratio of about 9:1 that puts the engine at about 18,000 RPMs. This is pretty much where the engine port timing is set. So far this sounds great, 18,000 RPMs WOW!! OK the down side, to get the heli engine into it's high RPM powerband, you would have to run about a 8.5X7.5 prop. Now put that on an airplane with aveage drag and the end result would be an airplane that makes plenty noise but dosen't go anywhere. The airplane just wouldn't get going fast enough to unload the engine/prop combination enough to get the engine into the meat of the powerband. You could put on a smaller prop to get the RPMs into the powrband but then you wouldn't have enough prop to overvome the drag of the airplane.