"Mike Rapoport" writes:

But do you agree that components that require maintenance (propeller,
cylinders, engine mounts, ...) can cause/accelerate crankshaft
failures?

I suppose that I agree to a limited extent, but virtually all
crankshaft/connecting rod failures are caused by a flaw/fault in
design/manufacture or installation. Once the crank or connecting rod is
installed, nothing is done to it and it is unseen until overhaul time. A
failure of either of these components is not going to put much, if any,
metal into the oil until the bitter end either..

I was thinking less of metal in the oil than the forces exerted on the
crankshaft. An out-of-balance prop or even a faulty spark plug can
cause out-of-spec. impluses to be exerted on the crankshaft.

I sure don't know how significant that is likely to be though. ('course
you can consider the stories of pilots taking off after prop. strikes as
an extreme.)

--kyler