[TheForge] OT - A Sterling-cycle outboard motor? Any Sterling engine experts out there?

[Bruce Freeman]

A friend of mine has a classic 2-stroke outboard motor that is forever
giving her trouble.  This made me wonder whether there might be a more
reliable engine type for this application.  External combustion came
to mind, and Sterling-cycle quickly followed.

The thought is to use the beta design
(http://en.wikipedia.org/wiki/Stirling_engine) with the hot end up and
the cold end in the water along with the crank and flywheel, the
latter being the prop.

Using external combustion, diesel or other fuel could be used,
enhancing safety.  The burner could be as simple as a kerosine heater,
making maintenance simple and obvious.  No valves, no carburetor, no
fuel filter, no electrical system at all.

Ignoring corrosion issues for the moment, does this seem feasible?

What working gas would be used in such a thing.  (Non-toxic,
non-flammable, and readily replenishable would be desirable
characteristics.)

Anyone know of a Sterling-cycle engine using a supercritical fluid as
the working fluid?  I don't know whether there'd be an advantage or
not.

-- 
Bruce
NJ