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From: cdb100620@AOL.COM (CDB100620)
Subject: Re: Cannon v. machineguns
Date: 12 Sep 1997

>October 14 1943, The American aircrews claimed a total of 186 kills, when
>the Luftwaffe actually lost 31 fighters shot down and 12 written off as

The breakdown of losses is interesting:  24 Bf 109 and only 2 FW 190 (plus
3 Bf 110 and 2 Me 410).  There were  more 109s than 190s engaged, but the
fact that the 109s suffered so severely is an indication of the
vulnerability of the Bf 109 to .50 cal projectile strikes in particular and
the liquid-cooled engine in general.
It's worth noting that the liquid-cooled reciprocating aircraft engine
disappeared abruptly with the end of WWII while the, air-cooled
reciprocating aircraft engine is with us still.  Big radial and corncob
engines powered the postwar prop airliners such as the Constellation,
Stratocruiser, DC-6 and DC-7 and boxer engines are found in practically all
of today's general aviation aircraft.  The liquid-cooled reciprocating
aircraft engine is one bit of WWII-era technology that had a very short

From: (CDB100620)
Subject: Re: Radial vs liquid cooled (was Cannon v. machineguns)
Date: 15 Sep 1997

>One Douglas airliner (don't remember which one, but I think the DC-4) was
>marketed in Canada with Merlin engines...

That was the DC-4M.  A couple of other British airliners used the Merlin,
the Tudor was one.  But customers were limited to BOAC and Trans-Canada.
The R-2800 was a much more economical engine--and a quieter one, important
in passenger applications--so other airlines weren't interested.

Incidentally, in 1941 Pratt & Whitney installed an R-1830-SSC7-G radial
engine in a Hawk 81A-2 (export version of the P-40B).  This experiment
resulted in an airplane with a top speed of 389 mph at 22,700 ft. (critical
altitude).  Time to 20,000 ft. was 7.5 min.  Even with armor and more guns
added, it's likely, had such a variant been produced, to have had superior
performance to the liquid-cooled edition.  And--most importantly--been much
less vulnerable to battle damage and been easier to service.  It probably
would have had a little bit better range, as well.
It's likely that with routine further development the round-engined
version of the P-40 might well have become a 400 mph airplane.
One can only wonder at what the performance of the P-38 would have been
had Lockheed actually built its proposed variant with P&W R-2800s.  That
would have given the plane 5,600 horsepower!

From: (CDB100620)
Subject: Re: Radial vs liquid cooled (was Cannon v. machineguns)
Date: 15 Sep 1997

>A principal reason for the popularity of liquid-cooled engines in European
>air forces and the USAAF was that their small frontal area made possible a
>greater degree of streamlining and therefore a higher top speed

That was the idea, but, as it turned out, the fastest allied
piston-engined fighter was a variant of the radial-engined P-47, the J,
which had a measured top speed of 500+mph.  While it didn't see production,
it certainly could have had conditions warranted it.  The P-36/P-40
probably would have been a better plane had the army pushed Curtiss to bolt
on a more powerful radial rather than the Allison in-line.  Lockheed
proposed putting P-W radials on the P-38.
Properly cowled, the radial engine actually produced more thrust from the
hot air that had cooled the cylinders than there was drag from the frontal area.
The liquid-cooled aircraft engine was a dead end side branch of aircraft
development.  Had the US Army joined the U.S. Navy (and the airlines)  in
favoring the radial and pushing its development, a lot of young men who
died in air combat in the early 1940s would be alive today to infest
internet newsgroups.

From: (CDB100620)
Subject: Re: Cannon v. machineguns
Date: 14 Sep 1997

>I think you misunderstand the reasons why liquid cooled engines
>were not used in new designs

Actually, you're making my point for me.  The liquid-cooled (definitely
NOT "water-cooled") aircraft engine was perfected in the WWII era and did
not survive it because it was complex, unreliable and vulnerable compared
to the air-cooled aircraft engine.  Ultimately, of course, the turbine
replaced both the radial and liquid-cooled reciprocating engines.  But the
air-cooled recips played a major role in aviation for 15 years after the
end of the war.  The liquid-cooled aircraft engine did not.  Twenty years
after the end of WWII, radial recips were being used in combat in Vietnam
(T-28, AD-1, A-26, AC-47, AC-119, E2A, even EC-121).  There was nary a
liquid-cooled job in sight.

Incidentally, during WWII, Lockheed, recognizing the problems inherent in
the liquid-cooled engine, proposed re-equipping the P-38 with R-2800s.

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