Re: Diesel aircraft engines

From: (Tim Takahashi)
Organization: University of Rochester, School of Engineering
Date:         01 Aug 96 13:34:27 
References:   1 2
Followups:    1
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Louis A. Ramsay  <> wrote:
>Falke_Charlie phone dist ) writes:
>>Yup.  There were some German Diesel engined patrol seaplanes during
>>WWII.  There are some intrigueing turbodiesels running in R&D
>>environments here and there.

>     When I had Aircraft Engine shop in High School (1948-1950), we had
>a set of drawings of a radial diesel aircraft engine.  Can't remember
>for certain, but I think the engine had been designed, and possibly
>built, by Packard.  One of the instructors told us two of the engines
>had been mounted on either a Beech D-18 or a Lockheed Lodestar.

What made the Junkers Aircraft Diesels so unusual was the unique
configuration : an opposed piston two-stroke turbo-supercharged
diesel. Unlike a Subaru or VW auto engine, there were 2 pistons
in each cylinder (driven from opposing sides via synchronized
crankshafts). The 2-stroke design gives high specific power,
the turbocharging increases that, and the opposed piston
layout is benecficial for scavenging.

They seemed a pet project of Junkers (who advocated the
configuration as early as the teens), but werent all that
common among short range planes in the WW-II timeframe.

There were some more conventional aero-diesels made during
the 1930's but non approached the power/wt and SFC of the
Junkers motors.