I know what certification involves from FAR 33 during development and design of the engine but I've heard that the two engines whether certified or not are pretty much identical. I know that old pre-configuration 3 non-certified engines did not have the overload clutch. I know certified engines are tested for more hours which I think I read on kitplanes.com. Is there any REAL difference in reliability or is putting it in a certified aircraft the only reason ever to buy the 912S?
