On my TR6 I have a puller fan that is set to come on with a thermostat.
I also have a manual switch just in case that thermostat fails. I
have an indicator light hooked up so I can see when the fan is running
from inside the car. When traveling down the highway the light glows
dimly indicating that the fan is moving and air is flowing through the
radiator. All other things being equal might the airflow going through
the radiator be less impeded by the non-engaged electric fan if the fan
blads spin with the airflow?
Aaron
Aaron Cropley
71 TR6 (Throttle Body Injection!)
http://www.triumphowners.com/108
Topsham, Maine
-----Original Message-----
From: Kurtis <tr4driver@gmail.com>
To: Triumph List <triumphs@autox.team.net>
Sent: Sat, 27 Aug 2005 12:33:54 -0500
Subject: Re: TR3 running hot
Based on my personal experience...
I have a pusher fan. My car does run hotter at highway speeds
(particularly over 65 mph) than when in stop and go traffic. I have
long suspected that, as Randall states, the fan mounted on the front of
the radiator acts to deflect some of the airflow that would normally
pass through the radiator. I also suspect that a rear radiator mounted
fan would reduce airflow through the radiator as well. However, it
seems to me that there might still be more of a cooling effect by the
air deflected by the radiator,with some sort of obstruction in the
rear, rather than air deflected by an obstruction in front of the
radiator (and thus never actually reaching the radiator).
Of course, it's been a long time since I had thermodynamics (and it
was a summer class at that!). :)
Kurtis Jones
Russellville, Arkansas
1963 TR4 - CT19389L
1959 AH Bugeye - AN5L23250
www.geocities.com/tr4_1963
> >However, unless you remove the original fan and it's extension,
there > >isn't room to mount the
>>electric fan behind the radiator. And mounting it in front will
actually >>reduce
>>cooling at highway speeds, IMO. It may or may not reduce it enough
to be >>a
>>problem, but it will reduce it (by interfering with the ram-air flow
>>through the
>>radiator).
>
> O Randall, Imparter of Great Knowledge, please explain to this
unworthy > Old Airplane and TR3 Guy how putting an electric fan in
front or behind > the radiator would make a difference in how much air
would flow through > the radiator? Or did you arrive at this knowledge
empirically?
>
> Isn't it rather like putting a resistor in an electric circuit in
front > of, or behind, the load? The flow would decrease just the same?
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