Customs 1962 327 blowing water but not overheating

Ok, I have a 1962 327 in my 1957 Bel Air. It has a new radiator, no hose or heater core leaks and every time I drive it it blows water out the radiator overflow tube. I installed a new thermostat (185 degrees) and it never gets above 190 degrees. I have a 13 psi radiator cap which is what the specs call for in 1962. The engine runs great and not seeing anything like water in the oil so don't believe I have internal engine issues.

Any ideas?

 

Pressure test the system. Pull plugs, pump it up & let it sit overnight. Next morning, crank it over ..... don't forget to test the cap, especially if it's new.

 

Some 'new' radiators don't let the cap seat properly. Might be bad cap also.

 

When you fill the Radiater up How far do you Fill it Too.????
if you fill it all the way to the Top of the Rad. its Wrong
Let it be about 2" from the Top

Just my 3.5 cents

Live Learn & Die a Fool

 

new radiator? check for air lock.

 

Let it blow out what it doesnt want, then let it be.

 

I would replace the thermostat with a 160 degree Stant Super Stat thermostat. I would drill a very small hole into the base of the thermostat to relieve any air pockets that might otherwise form..

Next I would drill a small hole into the radiator cap to keep pressure from building up. You will also need to run a decent size over flow with this.. I have been doing this to all my cars and trucks for 40+ years.. They just run better without that pressure...

 

A friend of mine had the same problem on his model A hot rod.
Turns out the radiator caps bottom seal wasn't making contact with the top of the radiator fill tube!
Found a radiator cap that had more length, problem solved!
KK

 

Well seems that it was a bad radiator cap. I knew not to fill it all the way but You figure that new equipment should be good. China is really falling down on their quality!..... Just kidding... not sure where the cap was made but the replacement worked great.

Thanks for all the suggestions! This site is amazing with all the knowledge and experience that is available here.

 

I am like anybody else on this Board that Does not Like
China's Junk But they Do make some Good Stuff.
Did You Know that Cars are Made in China
along with a lot of Big Mfg. Co have Items made there.

Just my 3.5 cents

Live Learn & Die a Fool

 

Yep, as far as I know they build Volvo, some Buicks, some Cadillac's and Ford Focus. They also make a lot of parts for cars. Some cars and parts are made Mexico and Canada. Do I wish that American cars could be completely built in America? Yes. But the name of the game is profit and not patriotism.

 

Without an overflow recovery tank the radiator should be kept 1” low. That was factory there were no overflow tanks until years later. I kept my 56 1” low for 9 years before just adding an overflow. I use a 7 psi cap and never pucked any coolant..

 

Jimmy is right. If you don't have an expansion tank, the radiator cannot suck the fluidback in when it cools so just let it seek it's own level.

Sent from my 9024W using The H.A.M.B. mobile app

 

Thanks guys. Running like a charm now.

 

Good to hear you solved your issue.

 

You would be wise to install an overflow tank. I should have done it years ago. It keeps the system
free of contamination. I made one from an aluminum water bottle I got at a car show the AAA had a display. Put a fitting on the bottom an an breather holes on the top. Painted it black and as inconspicuous as I could. Places like Summit and Jegs sells some nice tubular ones that fit beside the radiator.

 

I run a 7 lb. cap on my 56 chevy, it is my understanding that a higher pressure cap may cause the heater core to fail - worth double cking, good luck!!