Re: Largest piston engines

Date:         19 Apr 99 02:22:30 
From:         Steve Lacker <no@spam.thanks>
Organization: Applied Research Laboratories - The University of Texas at Austin
References:   1
Followups:    1
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Don Stauffer wrote:

> I am working on a book on the internal combustion question, and wonder
> about two questions.
> 1) what was the largest piston engine ever used on an aircraft?

By almost any measure you choose, it was the Pratt & Whitney R-4360. This
was a 4-row radial with 7 cylinders per row, and was used in aircraft
such as the B-36, B-50, KC-97, and Boeing Stratocruiser, as well as many
of the "Guppy" cargo haulers built on Stratocruiser airframes. It
displaces 4,360 cubic inches, and in various forms delivers over 3500
horsepower. There was allegedly a program in the works to develop a
turbo-compound version of it for the B-36, but this was shelved because
the B-36 would have to have been converted from pusher to tractor layout
to sufficiently cool the engines, which would have been capable of around
5000 HP each.

The turbo-compound version of the Wright R-3350 (which used 3 exhaust gas
driven power-recovery turbines that  couple power back to the crankshaft-
a sort of half-turboprop half-piston engine design) produced about as
much power as the R4360's that were built, but this was a notoriously
persnickety and complex engine that drank oil by the gallon, and had a
significantly smaller displacement at 3350 cubic inches. It was used in
the Douglas DC-7C and in Lockheed Super Constellations and Starliners.

> 2) what is the largest aircraft piston engine still in production?

Sorry, I don't know that one!

Steve Lacker,
Applied Research Laboratories
slacker@arlut. uutexxas.eduu (make the doubles singles to reply)