OK and airplane engine on an R/C car. But how about the other way around?

I plan to use a OFNA Force engine .21 (rated at 22,000 RPMs, 2.1 HPs) to use it in a Ducted Fan 3.5 inch diameter. So far manufacturers agree that the specs of the engine will do. But how about the way it is built & the purpose it will serve.

For example:
I think that most of the stress in an airplane engine is made pulling the shaft out of the engine, thus forcing the inner bearing (axial movement), but on a car engine the stress is made perpendicular to the shaft of the engine.

Will my plane loose the engine in the sky? I don't want to risk it...