Running Hot When Not Moving

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billybronco1

Well-known member
My ford runs at about 190 - 200 degrees on these hot days as long as I'm moving. I'm running 180 degree thermostats (Subaru) with a little bypass leakage. When I stop at a light for more that a minute once up to temp she quickly red lines, has not boiled over but I'm sure it would if I sat too long. Has anyone had experience installing an electric fan in front of the radiator, do they make six volt fans? Do you think that would help?
 
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Yes they make 6 volt fans. I have no experience with mounting one on a 36. When I had one on my 32 it was controlled by a bi-metal thermostat glued to the upper tank on the rad. You could also just have a switch to turn it off and on.
 
More airflow might help, but my guess is that you don't have enough water flow or radiator capacity. You might consider having Skip Haney rebuild your pumps - but first ask him if he has higher flow impellers for your year of pumps (I don't now this to be true).

Also, you may not have enough cooling capacity in your radiator? Is it old, new, brass, ???
 
Are you running a fan shroud? The more air you can pull thru the radiator will help your cooling issues. The symptoms you describe are telling me that you don't have a shroud. Moving and there is no problem but sitting still, the air is being tossed everywhere and not funneling thru all of the radiator.
 
Running the original radiator flow looks good by eye. I installed a temp gauge on the right side and have the original on the left. Checked several times with a infrared thermometer and everything seems pretty accurate.
 
woodiewagon46 said:
Are you running a fan shroud? The more air you can pull thru the radiator will help your cooling issues. The symptoms you describe are telling me that you don't have a shroud. Moving and there is no problem but sitting still, the air is being tossed everywhere and not funneling thru all of the radiator.
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Agree with you. I was told by an old radiator repairman that heating problems at idle or very low speeds is an air flow problem and heating at highway speeds is a radiator capacity/flow problem.
 
billybronco1 said:
My 36 runs at about 190 - 200 degrees on these hot days as long as I'm moving. I'm running 180 degree thermostats (Subaru) with a little bypass leakage. When I stop at a light for more that a minute once up to temp she quickly red lines, has not boiled over but I'm sure it would if I sat too long. Has anyone had experience installing an electric fan in front of the radiator, do they make six volt fans? Do you think that would help?
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Speedway and Summit have 6 Volt fans, IMO it would help to also have a shroud. I hand a like experience with my 40 Merc and 46 Ford coupe. I first
removed the thermostats which helped, then added a 6 blade fan. that solved
the over heating problem, ran at 190 degrees in traffic, 195 at the light, and
165 on the highway. Never did try the shroud.
 
I'm not sure about the shroud, I will have to take a closer look. Was the shroud original stock from the factory, I know the 36 radiator is special where the blade goes up under and inside the top part or the tank. I don't think there is an after market radiator for this car.
 
When I bought the car it did not have thermostats and was running at 130 degrees, way too cool. Keep in mind the day I was out and concerned it was 90 degrees outside.
 
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Does your radiator need to be cleaned out. Is your system pressurized or original OEM?
What pound cap are you using?
 
billybronco1 said:
When I bought the car it did not have thermostats and was running at 130 degrees, way too cool. Keep in mind the day I was out and concerned it was 90 degrees outside.
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Just to be clear, are you IN FACT saying that without thermostats, it will run at ~130º on a 90º day? DD
 
How is your ignition timing? Retarded spark will cause overheating. Also could try increasing the idle speed to move more air. I installed a shroud on my 39 and really helped low speed cooling. With 180 stats, 190 is not out of reason. Fabricating a shroud would be a really good idea.
 
First advance your timing a bit at a time, until the engine pings while accelerating hard in second gear, then back off a tad to minimize or eliminate the pinging.

Next step would be to do a thorough flush with one of those products that you drive with it in the system for a few hours. Then consider that in 1936 people used alcohol as antifreeze in winter and it mostly all evaporated out during the summer, so they were running straight water. 50/50 glycol based antifreeze costs you about 17% of your cooling capacity, so when you refill after the flush, use maybe half a gallon of antifreeze just for its corrosion protection, plus a bottle of water-wetter. I bet you will find that your '36 will stay much cooler in traffic.

I had problems similar to yours and switched to Dennis Carpenter water pumps, which are advertised to improve flow at idle. Did not seem to help much by themselves, but in combination with switching to very weak antifreeze mix, I can now get stuck in traffic without blowing steam.

Like you, I am using Stant thermostats for a Subaru, with two one-eighth inch holes added to let some flow get up to the thermostat bimetal part during warm up. Tried running without thermostats, and it did not help at all in traffic or at highway speeds.
 
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