Rick Girard wrote:

Paul et al, I've been reading this thread for some days. Those that
postulate that small runner diameters some how overcome their size with
greater velocity might do well to review Formula One Grand Prix engine
development in the late fifties. I remember looking at a picture of the
Coventry Climax engine (a fire truck engine raced on the world stage) of
a whopping 91 cubic engine displacement with a pair of 48 IDA Weber
carbs hanging off the side. The commentator marveled at the fact that
the engine would not only produce copious power for racing, but also
idle quite civilly. That capability was attributed to the venturi shaped
manifold designed to couple those giant carbs to the limited port size
of the Coventry. It kept the intake velocity up so the mixture wouldn't
stagnate at idle and, along with the velocity stacks that effectively
increase runner length, prevented stand off at high RPM's. Wish I still
had the picture of that engine sitting in the Cooper, it was a beauty.

Rick Girard

Vance W Jaqua wrote:

A slight correction Rick, that makes the story more relative. The Coventry
Climax engine
was designed as a portable firepump (not fire engine)  engine, utilizing a
single o head cam
I believe, and much aluminum, making it quite suitable for racing. A similar
US Navy
application called the "Handy Billie "(I believe) was developed around the
60 in
opposed four Evenrude  2 stroke - which ended up in a lot of US "Midgets",
where it could beat V8 sixties, and challange Offys if it was not abotaged
into
fouling plugs by balked starts. - A bit of engine racing trivia for gray
heads - Vance

Vance don't forget that torque verses HP article. I really need that
and I know you will do a good job.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.