Ted Azito wrote:
The Germans and French have used the VW in production aircraft, but I
wouldn't use one today (and I drive a Meyers Manx). I wouldn't
consider any conversion that doesn't isolate the crank from the prop
loads and provide for inertia decoupling.

Dave Blanton used to be called crazy, but his V6 Fords never had any
torsional resonance problems and in fact you could start and run the
engine without the prop attached. The boat outdrive guys figured it
out a long time ago and no one questions the use of autoderivative
engines in boats today. Other than turbines there are no
aeroderivative engines in boats and to me that says a whole bunch.

I would bet it has to do with cooling. It is a pretty simple matter to water
cool an engine in a boat.