Running Hot When Not Moving

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.
 
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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
 
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.
 
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!
 
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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.
 
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.
 
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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!
 
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.
 
aussie merc said:
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
Click to expand...

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.
 
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.
 
How hot is the outside temp ? And how long did you let it run and how hot does
it get? G.M.
 
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.
 
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.
 
mumpsimus said:
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.
Click to expand...

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

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