<VV> Electric cooling fan results

[Roger Gault]

The only number I've been able to find is, "The 911 fan takes 9 hp".  If
this is correct, that's not much help in getting to the electric motor
range.  I've seen pressure blowers that give around 1700 CFM at 11" in of
water - they run about 5-6 hp.  Still no electric joy.  There is no general
purpose solution down this path, we just don't have enough wattage.

I'm amused by the continual assertion that the 911 fan is "more efficient".
Where's the evidence?  Just because it has a big "P" stamped on it?  Where
are the pressure vs flow vs hp curves?  How does it match up to our pressure
vs flow curve needs?  Does the 911 fan even put out enough pressure to cool
the Corvair?

If you look through a 140 head, it's a miracle the poor fan can push any
useful amount of air through.  I say the reason the 911 fan cools more
horsepower than the Corvair fan is because the Porsche valves are stacked
vertically allowing WAY more open area in the heads for airflow.  Prove me
wrong.

Roger

----- Original Message ----- 
From: <JVHRoberts at aol.com>
To: <mfrancis at wi.rr.com>; <virtualvairs at corvair.org>
Sent: Sunday, July 29, 2007 4:26 PM
Subject: Re: <VV> Electric cooling fan results


>
> The stock fan is horrible and inefficient. However, perhaps a 911 fan?
> Efficient, and since there's an electric motor, its CW rotation doesn't
matter.
> Still, it's reasonable to assume it'll take a BUNCH of HP to spin any
reasonable
>  fan.
> And it's probably simpler, etc., to come up with a  better fan in the
stock
> location with the stock drive. HEck, it's hard to do worse!
>
> In a message dated 7/29/2007 3:33:39 P.M. Eastern Daylight Time,
> mfrancis at wi.rr.com writes:
>
> The main  reason we are all interested in an electric cooling fan is that
> it be  electric, for the obvious benefit of low drag on the engine at top
> speed.  Also, the benefit of achieving aftercooling between runs at an
> autocross,  etc.
>
> Since the fan tested was a bladed fan, which has now shown to be  unable
> to effectively pressurize a Corvair engine cooling system, how  about
> retaining the stock impeller fan and mounting an electric fan motor  to
> the top of the existing fan pulley?
>
> I've found a fan motor  online, made as a factory replacement for the
> current GM V8 line. This  motor could be mounted on a tripod bracket
> above the fan pulley, with a  suitable drive connection between.
>
> It would appear that this setup  might have the benefits of electric
> cooling, with none of the low-pressure  drawbacks of a bladed fan. You
> wouldn't have to modify anything below your  upper shroud either.
>
> Since the testing group already has the test  vehicles still in hand,
> perhaps this mod could be readily done and a second  test performed,
> maybe with better results.
>
> Does this look like a  reasonable alternative to the testers?
>
>
>
>
>
>
>
> ************************************** Get a sneak peek of the all-new AOL
at
> http://discover.aol.com/memed/aolcom30tour
>  _______________________________________________
> This message was sent by the VirtualVairs mailing list, all copyrights are
the property
> of the writer, please attribute properly. For help,
mailto:vv-help at corvair.org
> This list sponsored by the Corvair Society of America,
http://www.corvair.org/
> Post messages to: VirtualVairs at corvair.org
> Change your options:
http://www.vv.corvair.org/mailman/options/virtualvairs
>  _______________________________________________