Subject: Re: Radial engines in Automobiles

From: [email-masked]
Date: 7 Dec 1996 03:06:07 GMT

>The rotary engines ran quite well and provided a lot of power for their
weight compared to other aircraft engines of the time.  They lost a lot
of their advantage because of their poor fuel and oil efficiency.

The basic problem with rotary aircraft engines (crankshaft bolted to
airframe, crankcase rotates) is the gyroscopic effect. Some pilots could
use this to advantage when turning, but only in one direction. Sopwith
Camel is a classic example. 

Pete

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From: "John R. Johnson" <[email-masked]>
Date: Mon, 9 Dec 1996 10:24:47 -0600

> Camel is a classic example. 

Actually, Pete, the gyroscopic problem wasn't that serious.  It could
be dealt with.  It war rather like a P-factor on steroids! :-)  The
real limitation of the rotary engines, and what finally caused their
downfall when we were able to cool the cylinders without spinning them,
was the poor fuel and oil efficiency.  It was not feasible to increase
the compression ratio above about 4 or 5 to one without melting the
pistons and they could not get the oil comsumption down.  Flight
durations were limited to an hour or two by the high fuel and oil
consumption.  That was ok for a fighter, but less than desireable
for air commerce that became more important after the war.

When they figured out how to cast aluminum head and fins onto a
steel barrel without having the differential expansion when it got
hot separate them and overheat the cylinder, then they were able to
build radial rather than rotary engines and recover the oil and
gradually increase the compression ratio and RPM as they improved
the bearings, the lubricants, and the heat dissipation.

John

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From: [email-masked] (Norman Yarvin)
Date: 11 Dec 1996 02:43:49 -0500

"John R. Johnson" <[email-masked]> wrote:

>								The
>pistons and they could not get the oil comsumption down.

My impression was that at that time (WW1), gasoline was around 55
octane, and cars all had compression ratios of 4 or 6 to one.  So the
quoted compression ratio doesn't sound like it'd give too big a
disadvantage by itself.

--
Norman Yarvin						[email-masked]

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From: [email-masked] (J Phelps)
Date: 13 Dec 1996 15:42:45 GMT

At one time there was a motorcycle with a rotary engine.  If 
I recall correctly it was called a Meguiar and was made 
someplace in Europe.  The engine was mounted in the front 
wheel (the cylinders splayed out like spokes) and was a 
direct drive.  The cycle itself looked like a lounge chair 
on wheels and was steered with long, tiller like handlebars. 
 As one would expect, it was bump started and stopping meant 
killing the engine.  The magazine article that described it 
showed several pictures of the bike being ridden and noted 
that there must have been a lot less traffic when it was 
built.
Regards - Joel

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From: Rick Cook <[email-masked]>
Date: 16 Dec 1996 02:44:23 GMT

>I recall correctly it was called a Meguiar and was made 
I think there's a picture of one in Floyd Clymer's Motorcycle Scrapbook.

--RC