1936 V8 radiator issue

[ctvpa]

I am a Model A person, but just bought a 1936 Ford V8.

Problem is when I run the car, the coolant pours out of the overflow tube. I can lose a gallon in about 5 minutes.

Could this be thermostats frozen, or a bad radiator? Also most data shows the thermostats located in the upper hose, but others I see mounted with a gasket, (pardon my ignorance) where would they be located?
I am looking for a repair manual, are there any downloadable?

Thanks Craig

[G.M.]

Craig there are two reasons the water comes out the over flow. First you must under stand this is a built in problem with the old Fords the don't have a pressure cap with the over flow off the neck of the radiator. The 144 radiator tubes 2 feet long cause a restriction of flow plus the dirt build up in them. When pumping the water backs up in the top tank and out the overflow. The faster the pumps turn the more water is pumped so at highway speeds the problem gets worse. Your over flow come off the top of the tank and when the water backs up in the tank it flows freely out the over flow. Skip Haney in Fl. developed a 3 lb pressure valve that go's on the bottom end of the over flow tube. This holds the water in the radiator until the pressure gets above 3 lbs then opens as a safety valve. Under normal operating conditions the temperature which causes higher pressures should never get much over 200 degrees. This valve also allows you to fill the radiator up to the filler neck. This give you the full 22 quart capacity that cools the engine better. The other problem of loss of water is a leak of compression into the water by a bad head gasket or small crack. This would be found by filling the water up to the neck and with the engine at idle small bubbles will appear in the water. Increasing the speed increases the size of the bubbles. Small leaks can be stopped with Barr's heavy duty stop leak. Remove any thermostats before testing. G.M.

[Mike in AZ]

link is to MacVP's website, showing the '36 radiator, grille, etc.....#8575 is the thermostat, i think.....goes into upper hose...your overflow could be from overfilling the radiator.....coolant level should just cover the tops of the tubes when cool, allowing for expansion of the coolant and the flow of the coolant as G.M. says.....pretty sure that is where the coolant level should be....maybe a little more, but your coolant will level off after overflowing.....is your engine overheating??...what does temp gauge show??....check with infrared temp. gun??....good luck....Mike

http://www.vanpeltsales.com/FH_web/F...ll_1936car.jpg

[Kurt in NJ]

If you fill it up to the top with the cap off and crank with the ignition off and it pushes water out you could have a head gasket problem or other combustion chamber to coolant system leak

If you drain to below the level of the tubes and look in the top of the radiator with a flashlight ---are the tops of the tubes open?? the radiator from my 36 has most of them closed off, I know I have to fix it before I run it

[ctvpa]

Thanks for the great replies. I understand dynamics of the issue. I backwashed the radiator and got a lot of crud out. Some of the issues are better, but still I can over heat quickly.
Problem is I don't have a standard radiator, I have a Brewster.

I will keep working, thanks.

[ctvpa]

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Update: I backflushed the radiator several times. I uses a commercial radiator flush, I isolated the flush to just the radiator. The car now runs spot on with no boil over. The car had been sitting for a few years, and I think it just needed an enema.
Thank you for all your help.