The Stovebolt Site Forums The Shop Area Engine Shop Radiator Overflow Tank?

My mechanic suggested to me that i may want to consider installing a radiator overflow tank for my 216 engine. I realize its not original, but its advantages could out-weigh the negatives.

What do yall think? If i get one, i could get an early model overflow tank that doesnt look too modern.

Thanks for your thoughts

A tank will stop coolant losses. I saw an original coolant overflow tank in the swap meet lately but it seemed a bit pricey to me. Let us know what you decide to do and pictures would be cool too.

https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=616193#Post616193

http://www.chevsofthe40s.com/shop/s...p;dept=Truck&searchtype=FT&Go=Go (they have one style that is a reproduction for the original accessory - it's no less expensive than the one at the link above).

I have never had to use an overflow tank with a 216/235/261 engine. You fill the radiator to within an inch of the top and run the engine for 30 minutes after it has warmed up. Let it cool down and then check the level. A little fluid might overflow until the correct level is reached. When cool, the coolant level is about 2-3 inches below the filler opening.

Until 1954, the radiator cap on a truck was 0 pressure; later, they were 4 psi to 7 psi, depending on the year and size/duty of the truck. A high-pressure radiator cap on these trucks would most likely cause leaks at a few weak points in the system. Shops/people who are used to modern, high-pressure, cooling systems almost always recommend overflow tanks for older vehicles.

Be carefull not to use a high pressure cap you'll end up popping your heater core they were never made to take the pressure I put a 4 psi. cap on mine and once I ran the engine a few times it does not overflow anymore.


Pete

Tim,
Will a pre 54 raditor hold the higher pressures of a late model sbc if you put a high pressure cap and an over flow on it?

I was thinking of using the original 41 1.5 ton radiator with an electric fan for my sbc conversion.

Empty 40 and a wire hanger.

Bodyguy,

I do not know. I'd have a radiator shop give it a long-time pressure test.

Better yet: Wait to hear from some one with first-hand experience (and/or who might know if a bigger radiator might be needed with a small black V-8).

It didn't work for me, too much pressure. I bought a 4-core from Champion Radiator off ebay. In hindsight I could have got away with a 3-core.

This good info guys, thanks. So what is your opinion on using one? If i drive my truck often (2-3 times per week), would it be a good idea to have one, or is it unnecessary?

I can handle the 40.....where did ya get the hanger...most I see are now plastic?

Kevin, if all is right with your truck and your not using it to haul a ton of gravel up a hill to the building site, there really isn't any need for an overflow on a stock 216. People tend to over fill the radiator and when it pukes out the extra after warming up they think they need an overflow. Keep the system clean and the level just above the baffel in the radiator when it's cold and you shouldn't have any cooling problems. As was brought up earlier, you can gain a little higher boiling point by running a 4 lb. cap but DON'T go any higher, the system will only take about 8 lbs before the tubes in both cores (heater and radiator) begin to distort.
Denny Graham
Sanwich, IL

Thanks for the insight. I was considering it because a buddy of mine used his old down flow and an electric cooling fan in his sbc conversion in his 49 International.

Anybody else tried this?