Electric fan question for street rod,,

If your rod has AC just wire it up so fan comes on with ac/defrost no
matter what, then when hookin up, put ac or defrost on.
No ac, well, my next move would be a lower temp. sensor that is
controlling your fan, and if that didnt work, I would try moving the
sensor closer to the heat, if possible.


On Thu, 05 Oct 2006 11:42:31 -0500, hexter.DeleteThis@blazenet.net (Gudmundur)
wrote:

> Hi folks,
>
> I recently took off my belt driven fan and went to an
>electric fan mounted directly on the radiator. It's a
>puller type. The power to the control circuit is always
>on and I like the fact that the fan runs for a while
>after I shut the engine off.
>
> Here is what I see as a problem, and I am looking for
>input,
>
> Let's say I start up cold and decide to idle the engine
>while hooking up to my trailer. The fan is not running
>and there is No air moving under the hood. The heat load
>under the hood from the headers is incredible, and even
>the heat radiated from the heads and block becomes intense
>after 5 minutes.
>
> Would you go with a 'fan over-ride' switch to force the fan
>on in this situation? I was thinking something like a dash
>mounted toggle switch. My '97 Freightliner had such a thing
>right from the factory. I was thinking maybe a thermal
>switch to sense ambient underhood temperature that would
>come on at 140 to 150 degrees.
>
> Maybe just putting a very very small fan back on the water
>pump would be a good thing?
>
> Anyone have any ideas? (Remove the fenders!! hehehe)
 >> Stay informed about: Electric fan question for street rod,, 

Done this twice over the last year. Neither vehicle has A/C so that
doesn't enter my equation but could be a solution you like. Here's my
input.
1) computer-controlled fuel injection: I didn't like that the computer
pushed me well over 200deg, so, I used a thermal switch (grounds the fan) at
a preset temp. I then hooked up a three-way toggle that let's me set to a.
computer-controlled high temp for highway/winter; b. thermal switch lower
temp for traffic/summer; and c. ground for overriding and always-on.
2) old-school carburetion: Got a Hayden adjustable, thermal switch.
My other observations:
-Make sure the thermostat/fan switch don't conflict. Basically, if the
switch comes on at 185 and off at 170, a 195deg thermostat will never let
the fan cycle. Just do the math and find your happy medium that'll agree
with the computer if you have one.
-I like sensors that install in the cylinder head (stop snickering).
They'll better represent the true temp. Installing lower in the block
doesn't reflect the temp I'm concerned with. I don't trust the fin probes
since they just stick external to the radiator (not the temp I'm concerned
with). Last, I'd never use one of the probes that gets stuck into a
radiator hose. How could I trust that to seal?
-An electric puller fan and a belt-driven fan probably won't fit and defeats
the purpose. I assume you have a single fan. If you had a dual fan, you
could get two switching methods. Otherwise, you could get fancy with
another pusher (not my first choice).
The only other thing I'd say is that I don't really like the underhood
thermal switch idea (just my opinion) because of the thermal map and other
stuff.
Drink
"djdave" <noname.DeleteThis@fake.com> wrote in message
news:1igbi25v2ic8amkj2i3dgq684fnmerh4bo@4ax.com...
>
> If your rod has AC just wire it up so fan comes on with ac/defrost no
> matter what, then when hookin up, put ac or defrost on.
> No ac, well, my next move would be a lower temp. sensor that is
> controlling your fan, and if that didnt work, I would try moving the
> sensor closer to the heat, if possible.
>
>
> On Thu, 05 Oct 2006 11:42:31 -0500, hexter.DeleteThis@blazenet.net (Gudmundur)
> wrote:
>
>> Hi folks,
>>
>> I recently took off my belt driven fan and went to an
>>electric fan mounted directly on the radiator. It's a
>>puller type. The power to the control circuit is always
>>on and I like the fact that the fan runs for a while
>>after I shut the engine off.
>>
>> Here is what I see as a problem, and I am looking for
>>input,
>>
>> Let's say I start up cold and decide to idle the engine
>>while hooking up to my trailer. The fan is not running
>>and there is No air moving under the hood. The heat load
>>under the hood from the headers is incredible, and even
>>the heat radiated from the heads and block becomes intense
>>after 5 minutes.
>>
>> Would you go with a 'fan over-ride' switch to force the fan
>>on in this situation? I was thinking something like a dash
>>mounted toggle switch. My '97 Freightliner had such a thing
>>right from the factory. I was thinking maybe a thermal
>>switch to sense ambient underhood temperature that would
>>come on at 140 to 150 degrees.
>>
>> Maybe just putting a very very small fan back on the water
>>pump would be a good thing?
>>
>> Anyone have any ideas? (Remove the fenders!! hehehe)
>
 >> Stay informed about: Electric fan question for street rod,,