1961 Expansion Tank?

[Carr C.]

We are restoring a 1961 Corvette with the 230 HP 283 and Poweglide trans.

The customer who has owned the car since 1972, sayd that the car never had an expansion tank, and I can find no evidence that it did.

The JG does not state specifically if all had them, or not.

Can anyone clear this up for us?

Thank you!

[Joe L.]

Re: 1961 Expansion Tank?

We are restoring a 1961 Corvette with the 230 HP 283 and Poweglide trans.

The customer who has owned the car since 1972, sayd that the car never had an expansion tank, and I can find no evidence that it did.

The JG does not state specifically if all had them, or not.

Can anyone clear this up for us?

Thank you!

Carr----


I believe that there were 2 different radiators used for 1961 with 230 hp engine. The first one was a copper/brass unit and was used without an external supply tank. The second one was an aluminum unit and was used with an external supply tank. Just when the changeover occurred, I do not know.

[Jeff C.]

Re: 1961 Expansion Tank?

Carr
If you look on pg 350 of vol 1 of Noland Adams book he states that several pictures in Road and Track of 1961 base engine cars show cars with 1960 top tank radiators which do not use an expansion tanks. He also quotes a chevrolet bulletin that states that approx 1700 1961 cars will be built with 1960 type radiators, 192 base engine cars using top tank copper radiators. If you have an early car it is possible that it had no expasion tank. Hope this helps.
Jeff

[Dennis A.]

Re: 1961 Expansion Tank?

Check the build date...If the car was built in 1960, ( up to S/n 1500) It appeared with either a '60 style copper radiator or a '60 style top tank aluminum radiator for . (no expansion tank)
Also the early 1961 and 1960 aluminum date codes were unpainted,

[Tom L.]

Re: 1961 Expansion Tank?

The car is a late, June 61, build.
The current radiator looks to be a replacement.
was there ever an aluminum radiator without expnsion tank?

[Mike E.]

Re: 1961 Expansion Tank?

In June 1961 was there ever a Corvette built with an aluminum radiator without an expansion tank? None of us here followed every car down the line in June of 1961, so never say never. However, it would be difficult to believe, since there is no cap on the aluminum radiators. How would they be filled? How would you pressurize?
I guarantee you that if you arrive at an NCRS meet with anything other than what the judging manual specifies for your 61, you will lose points! (And you'll lose fluid all the way there if you don't have a tank and cap!)

[Mike B.]

Re: 1961 Expansion Tank?

To jump in, my car is an early July 1961 build (110211) and it definitely has an aluminum radiator and expansion tank as originally fitted. To my knowlege they all came equipped with either the top tank (early cars as stated) or with the tank.

You will do the client a favor to convince him to install a correct aluminum reproduction radiator by DeWitt and the correct aluminum expansion tank available in reproduction along with the mounting bracket.

Note that the tank is an integral part of the cooling system, not simply an overflow tank as in later models. Coolant continually flows through that tank during operation helping to cool by providing additional coolant mass and fluid capacity. For around $1100 in parts it will be as good or better than new.

[Joe L.]

Re: 1961 Expansion Tank?

In June 1961 was there ever a Corvette built with an aluminum radiator without an expansion tank? None of us here followed every car down the line in June of 1961, so never say never. However, it would be difficult to believe, since there is no cap on the aluminum radiators. How would they be filled? How would you pressurize?
I guarantee you that if you arrive at an NCRS meet with anything other than what the judging manual specifies for your 61, you will lose points! (And you'll lose fluid all the way there if you don't have a tank and cap!)

Mike, et al-----


I don't know what happened in June, 1961, either. However, I'm very confident of this: there was never any C1, C2, or C3 Corvette ever made with an ALUMINUM radiator that didn't use an external supply tank, either "integral" (as with some C1's) or separate (as with all others).

With one model year range exception, all C4 and C5, all of which are equipped with aluminum radiators, use an external supply/surge tank, too. The exception? 1984-89 did not use the external tank.

[Ray C.]

[Mike B.]

Re: 1961 Expansion Tank?

One more thing...you said that there is no evidence that there ever was an external tank. Does it have a LH exhaust manifold with the extended "ear"? I believe it is part number 3749865. It is via the 3/8" drilled and tapped holes on the ear on which the tank bracket mounted with the bracket stabilizing strap attaching to a 3/8" stud that also doubles as an intake manifold fastener. That would be a good clue although of course through the years the manifold could have been swapped. Below is not the greatest photo but gives some idea of what to look for.

[Richard G.]

Re: 1961 Expansion Tank?

For what it's worth mine's a June 14 build 1961 270 hp and it has alluminium radiator with expansion tank. # 10867S109538