Gary,
If the fan blades were flat, I agree, there would not be much difference,
other than just being wrong.
My assumption is that since the fan blades are curved, even though they still
move the air in the same direction, either-way-round, they are substantially
less efficient when the more highly curved and tapered (normally trailing)
edge becomes the leading edge. Sort of the same result you'd get if you had
air flow across a wing, but backward-----no lift.
The blades are designed where the leading edge is straight and not tapered,
and the air is accelerated rearward by the curve of the blade, rather than
just by the angle, as on a flat blade.
If the trailing edge is made to lead, as in putting the blades on backward,
the curved (now leading) edge would mainly create turbulence.
My vapor lock problems occurred at highway speed, so I can only assume that
the turbulence was keeping the air flow from cooling the carbs and fuel line
properly. ...I turned them right way 'round, and never had the problem again,
in 20+ years.
See, no flames....I said the same thing you did, when a local Healey guru
pointed the blade problem out to me. For me at least, turning them around
proved his theory right.
David W. Jones
'62 Mk II BT7 tricarb
Cumberland, RI USA
----- Original Message -----
From: G. Brierton
To: davidwjones
Sent: Thursday, April 21, 2005 8:01 PM
Subject: Re: Vapor Lock Symptoms?
Now I'm going to be the one that sounds stupid, but here goes....
How can you put a fan blade on backwards?
As long as the blade is spinning in the one direction, the blade moves the
air in the same direction no matter how you flip it around. You have to
make a different blade to move the air in a different direction.
I will now hunker down and prepare to be flamed. ;<)
Gary "I'm no engineer" Brierton
----- Original Message -----
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