>Date: Mon, 27 Apr 1998 19:04:38 -0400
>To: ritchie@mcn.org (Armand & Lorie Ritchie)
>From: Anita Barrett <anitabrt@mindspring.com>
>Subject: Re: under hood heat (dumb idea number101)
>
>At 09:22 AM 4/25/98 +0100, you wrote:
>>Hi all I was thinking about our under hood heat problem with these tigers
>>and I got an idea this morning. What if we install and electric fan that
>>can be reversed by a dash board switch. So when we are stopped in traffic
>>we could reverse the fan and blow that hot air from under the hood out the
>>front of the radiator. Then when we get going again we could change
>>directions of the fan so it works normaly. I think it would be better to
>>remove the stock fan altogether so it doesn't interfere with the reversing
>>of the electric fan. Any thoughts on this, do you all think this might
>>work?
>>
>>regards Armand Ritchie
>>
>>ritchie@mcn.org
>
>Armand & Lorie Ritchie,
> The rate of heat transfer from the radiator to the air
>depends on the difference in temperature between the air and the
>radiator. The bigger the difference, the higher the transfer rate.
>If you pull air over the motor prior to passing through the
>radiator, then the air temperature will be hotter than the air
>that is normally passed from outside through the radiator.
>Therefore the rate of heat transfer with reversed air (hot) should be less.
> The need for moving air through the radiator is to remove the
>heated air from contact with the radiator. Removing the air previously
> in contact with the radiator allows cool air to come in contact with the
> radiator and therefore have a higher heat transfer rate.
> Secondary problem is that most fans are very inefficient
>when running in reverse due to the shape of the fan blade
>being designed to efficiently pass air in only one direction.
>A fan blade running opposite the designed direction would provide
>even less air through the radiator than the normal direction of the fan.
> You would have more luck by putting an exhaust fan in a
>hood scoop to remove the heated air from the rear of the radiator
>(and from the motor somewhat) to allow cool air to flow through the
>radiator from the front.
> I have found that a light spray from a water hose will keep
>my 351C cool when I am running it for long times in my driveway.
>Maby you could rig up a few gallons of water in the trunk and
>use a windshield wiper spray motor along with some sort of nozzle
>in front of the radiator to keep your Tigers Cool in bad traffic.
>Could add a pump switch, manual or thermal, that is on only when
>your Tiger starts to get overly hot. You may need a needle valve
>to limit the quanity of water sprayed. The correct amount of water
>will be the maximum that the radiator can evaporate, so that no water
> gets your motor wet.
> ( While you are at it, there are also water injection kits available
>to reduce the need for high octane gas)
>.
>Jim Barrett Tiger II 351C and others ( all cool in Florida)
>
>
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