Re: 5 blade cooling fan mod

[Robert Houk - WorkGroup Server Firmware <Robert.Houk@East.Sun.COM>]

   >Good point now I am curious.  The only difference in the two application I
   >can see is the Spitfire and P-51 mustang props are designed to be used at a
   >variety of RPM's.

   I may be wrong on this one, but I believe these props were designed for a
   single rotational speed but had adjustable prop pitch.  A higher pitch
   requires a higher power output from the engine and produces a greater air
   speed.

Aircraft (gas/piston) engines are pretty much designed (well,
"optimized") to run a one particular RPM (a fairly narrow RPM range --
kinda like a TURBO F1 engine...) and don't do particularly well at
lower speeds. By using a varible-pitch propellor, you can run the
engine at its designed operating speed, varying the actual
power-delivery by varying the bite (pitch) of the prop -- kinda like
a CVT...

					-RDH