Another reason for the widespread use of electric fans is emissions.
Manufacturers have found that running engines at much hotter temperatures
helps in the reduction of them darned ozone depleters. It is not at all
uncommon for a modern engine to run at temperatures above 220deg F. Of
course at these temps it is very important not to let them get too hot and
the use of an efficiently designed fan allows the engines to run within
probably 5-10 deg. of their best emissions output temperature. Of course
then the engineers found out that if they ran them much hotter then the
emissions of NOX (probably the worst of the big 3 bad gases) went through
the roof. For what its worth both VW and Audi have both started using belt
driven viscous (SP) coupling fans along with electric fans side by side. I
dont think that cost was the reasoning for this as the coupling and related
bearings to make the thing work price out to over $500.00 and the great
debate rages on........................ Craig
-----Original Message-----
From: Bwfox <Bwfox@aol.com>
To: triumphs@autox.team.net <triumphs@autox.team.net>
Date: Sunday, March 29, 1998 5:18 PM
Subject: Elec Fans vs Efficiency
>
>Fellow Listers:
>I have been following the thread re electric vs directly driven fans on our
>beloved
>Triumphs. Someone made the observation that electric fans must be more
>efficient as all new cars use them. I do not believe efficiency has
anything
>to do
>with newer vehicles using electric fans as much as the fact that almost all
>newer vehicles have transversely mounted engines. As the Corvair engineers
>(and owners) learned, V belts do not like to make 90 degree corners. You
are
>forced to either put the radiator in the wheel well or leave it in its
usual
>spot and use an electric fan. I vaguely remember back in the 60s a Fiat or
>Renault or Simca or somesuch with a rear mounted transverse engine with the
>radiator squarely in front of it, crank driven fan and all, with lots of
>ducts/louvres to get air back there.
>
>BTW, I plan to add an electric fan to my TR4A.
>
>Cheers,
>Barry W. Fox 65 TR4A CT51681L
>W1HFN
>N. Central Mass.
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