Running Hot When Not Moving

[billybronco1]

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?

[solidaxle]

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.

[Bored&Stroked]

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, ???

[flatjack9]

Do you know if your temp gauge is accurate?

[woodiewagon46]

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.

[billybronco1]

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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.

[50fordcoupeman]

Originally Posted by woodiewagon46

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.

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.

[jayvee34]

Originally Posted by billybronco1

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?

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.

[1931 flamingo]

What condition is your radiator in. Even moving it should not be that hot. JMO
Paul in CT

[billybronco1]

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.

[V8COOPMAN]

Originally Posted by 1931 flamingo

Even moving it should not be that hot. JMO
Paul in CT

I have to agree! You have more problem there than meets the eye. Think about it.....realistically, it DIDN'T run that hot back in '36, IF as said above....your temps are accurate. DD

[billybronco1]

So, no shroud not sure where it would fit really.

[billybronco1]

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.

[19Fordy]

Does your radiator need to be cleaned out. Is your system pressurized or original OEM?
What pound cap are you using?

[billybronco1]

Everything is original or at least stock.

[V8COOPMAN]

Originally Posted by billybronco1

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.

Just to be clear, are you IN FACT saying that without thermostats, it will run at ~130º on a 90º day? DD

[billybronco1]

No, it was running at 130 degrees in the spring no therms, temps about 60-70 outside

[Ford Freak]

I would try a 6 blade fan , if you can get one on there. - F F

[flatjack9]

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.

[drolston]

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.

[JSeery]

The 180 thermostats should not run a lot hotter than 185-190 deg on a clean engine with a proper radiator good flow from the pumps and good air flow through the radiator. So, IMO there are one or several issues here contributing to the higher temps. As already posted, ignition can be one of them.

[aussie merc]

fan shrouds are not always the answer a badly designed shroud can actually cause over heating when moving check rad if its clean inside and out make sure the fins haven't been folded over [blocking air flow] low speed or idle overheating is generally low coolant flow so check pump to housing clearance and test thermostats before anything else remember henry didnt put a shroud on it and it ran fine not to say there wasnt room for improvement

[billybronco1]

I'm running 50/50 anti freeze right now, I do remember the previous owner saying he ran straight water with water wetter in the summer and it would run cooler, I need to try that, with just a little anti freeze. The system does hold a lot of fluid for sure.

[VeryTangled]

Hi Everyone. Billybronco, It sounds hurtful but maybe gently explore a safe scenario where you actually get a boil-over condition?

You don't say you've been to that place yet.

That could define some boundaries. I learned things when it has happened to me.

You've had it less than a year. C'mon join the club!

[koates]

Fit two new water pumps which have the sealed bearings and greatly improved impellers for increased water flow. Dropped the temp on a warm day by about 8 deg approx. on two cars I fitted them to, a 34 & a 36 V8. .Also a 6 volt fan will pull about 20 amps current which you would not be able to have turned on for very long because your original third brush generator would not cover that. Water wetter is good also. Check the water flow through your radiator tubes. Regards, Kevin.

[billybronco1]

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If I drain an flush the system completely and fill with distilled water, how much antifreeze would you add just for corrosion inhibitor? The way I see it is the system holds 22 quarts, water wetter says run 15% antifreeze so that is about 1 gallon antifreeze and 4 gallons of water.

[Bored&Stroked]

You mentioned that it only went up to 130 degrees without the thermostats - during cooler weather. This got me to thinking a bit . . .

If it was mine, before I'd start trying all sorts of things, I'd pull the thermostats and see what temps it runs at on hot days with no thermostats. If it can maintain a good temp at idle on hot days, then you know your system has the cooling capacity to handle the heat.

You need to know that the system can handle the engine's cooling requirements - before you start changing things.

Once you've proven this, then you may want to look at your thermostats and potentially the amount of restriction they bring into the system --- maybe there is an issue there? I've never ran 21 stud engines with head-mounted water pumps, so I have no practical experiences to share - but I always try to work from a baseline situation (removing as many variables as possible) - when looking for answers to hard problems.

Best of luck!

[Seth Swoboda]

I had a similar problem in a '47 Ford. I removed the radiator and had it thoroughly cleaned. There were many tubes in the radiator that were blocked or partially blocked not allowing coolant to flow efficiently. Your radiator need to be working at 100% capacity.

[flatjack9]

Originally Posted by aussie merc

fan shrouds are not always the answer a badly designed shroud can actually cause over heating when moving check rad if its clean inside and out make sure the fins haven't been folded over [blocking air flow] low speed or idle overheating is generally low coolant flow so check pump to housing clearance and test thermostats before anything else remember henry didnt put a shroud on it and it ran fine not to say there wasnt room for improvement

The obvious answer is use a well designed shroud. I think almost all modern cars have fan shrouds. Before I installed my fan shroud the car would tend to overheat. If my car was in a parade, I would have this problem. As soon as I would be able to drive at normal speeds for a few blocks, the temp came right down.

[Bored&Stroked]

My 32 Cabriolet has a re-cored original radiator, no pressure cap and my engine is a fairly stout 42 Merc, 284 cubic inch stroker. The timing is correct (about 24 degrees total) with about 8 initial. I have Skips water pumps and 160 degree thermostats.

I have been idling in traffic trying to get in/out of the Columbus GoodGuys show at 90 degrees outside. The engine got up to about 192 or so, but never higher.

So, if you have a good radiator and good water pumps and the correct timing, these engines should NOT run hot.

[G.M.]

How hot is the outside temp ? And how long did you let it run and how hot does
it get? G.M.

[billybronco1]

Right now I'm in the middle of flushing out the system. After the first drain of 50/50 water antifreeze I filled it with water and took it for a ride. Temp outside about 87. Went for a few miles so the therms could open. Came home and let it idle for about 5 minutes, temp went up to 200, I shut her down and checked the temp at the gauge connection on the engine with a inferred thermometer and it was at 205, she was very hot but not boiling over. More flushing tomorrow.

[mumpsimus]

Is there a fan shroud that will fit a 1937 with the fan up on the generator? I did a quick search on the www, but didn't see much.

[G.M.]

Originally Posted by mumpsimus

Is there a fan shroud that will fit a 1937 with the fan up on the generator? I did a quick search on the www, but didn't see much.

I think they made one for the trucks. G.M.
This was a larger truck mounted upside down.

[Bored&Stroked]

Have you removed the thermostats and given it the same test as above?

You need to establish a cooling baseline - to know that your radiator, water pumps and fan can cool the engine without any restrictions . . . then go from there. If not, then you'll need to address any/all those issues first.

[JSeery]

I agree with B&S. Remove the thermostats and see where the rest of the system is at.

[billybronco1]

After flushing several times, reducing antifreeze to 15% and a bottle of water wetter, she is running at about 180-190 degrees now. I know she runs way too cool without thermostats, that was a problem before as she was not running at her best and plugs showed it, very black and carboned up. Now running hot very little carbon build up.

[Supertuner700]

If you do not want to run antifreeze you can add a rust inhibitor which is better than the antifreeze anyway for rust. Also purple ice is better than water wetter. Water wetter has problems if it touches oil, which should not happen but can.

A fan shroud always helps the fan move air thru the whole radiator. My 1938 1.5 ton has a fan shroud if you want a picture (it looks factory) I have an electric fan on right now because of 12neg conversion and didn't have the pulley to mount the fan.

Have you cleaned the outside of the radiator, mine was filthy and a good cleaning dropped temps.

[Pat's Ride]

Well I'm a new guy here with my first post. I just bought a 38 with a flathead and know very little and will need to learn a lot.

With that said my 38 has the mechanical fan and an electric fan on the front of the radiator. The electric one is on a switch by itself and the previous owner said "just have it on all the time".

I don't care for that so I turn it on as I feel it's needed, and it does bring down the temp when turned on.

Wish I had more for you, but I'm just stating to learn about these old Fords. ~Pat