They have a long life in a airplane, where cooling air is abundant. OS made two fourstroke models for kyosho cars and they used small belt driven fans to engine temps under control. The OS car engines were based on airplane engines but had high RPM cams and much stronger valve springs to keep valves from floating during high revs. This is where you are going to have problems with a airplane engine, when your car drive train unloads and rpms skyrocket, your engine will be damaged. This rarely happens in a airplane because even a small prop will still load the engine enough to keep the engine from completely unloading.

If you are going fourstroke, you should at least look for one of the OS fourstroke car engines because they are better suited for the punishment of a car.