"Charles Vincent" wrote

In the end, it still doesn;t matter as GM is not to my knowledge selling
reciprocating aircraft engines certified or otherwise and I have not seen
any evidence many of the uncertified engines for sale are testing their
engines at this level.

I guess the point that we were making, is that although GM is not selling
uncertified engines for airplanes, a number of them do find their ways into
experimental airplanes, thus the reaction about the reliability of auto
engines.

Interestingly, it is most always not the core auto engine that experiences
failure when an auto engine conversion has problems, but the prop speed
reducer, or fuel system, or non original fuel system, or whatever else has
been added or re-engineered by the experimenter.

I hope this sheds light on why your comments got such a swift and
enthusiastic rebuttal by some here. It sounded as if you were condemning
those that used auto engines for airplanes, as a unsatisfactory, not as
tough engine as what is made as a certified engine.

After all of the major metallurgical crankshaft problems that some of the
certified engines have had as of late, it is hard to accept that just
because it is certified, it is completely reliable.
--
Jim in NC