Bill Freeman wrote:

             SNIP

Packard in the US also built diesel aircraft engines in 1928
and it was as light as a gasoline engine at the time. They did
this by using only one valve  that served for both intake and exhaust.
Consequently no exhaust manifold was possible. This
meant the exhaust was dumped straight out into the air stream
and "the smell drove drove users out of their minds" :-) according
to Herchel Smith author of A History of Aircraft Piston Engines.

BTW I can highly recommend this book published by Sunflower University
Press in Manhattan Kansas.

Paul Lamar

AHA!   This finally explains the Packard diesel radial that Jeff and
I were examining last year in San Diego's air museum.  We really
couldn't figure out the wierd spool valve system dumping into a
tube which ran parallel to the crankshaft (perpendicular to the bore,
and was open to the air on both ends.  Now it makes sense - it
took in air from the front on the intake stroke and dumped the
exhaust thru the same valve on the exh stroke.  Jeff and my friend
Mike and I puzzled over this one for about 5 minutes and couldn't
quite figure it out, esp without dissassembly and we were not
sure if there was some sort of manifold which was missing from
the display engine.

Bill
Long EZ builder & pilot
mechanical engineer

You should have asked me Bill :-)

Paul Lamar
 
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