C2 Expansion Tank

[Dave C.]

I just finished replacing my heater core on my 66 - 427 with the help of NCRS members (thanks for all the advice) I filled the radiator and then started the engine and then topped it off. Took it for a 1/2 hour ride and parked and noticed a good amount of fluid on the ground. After a scare, it turns out it was coming from the overflow on the radiator. Which brings me to my question. Why didn't big blocks come with the expansion tank?

[Michael W.]

Re: C2 Expansion Tank

The expansion tank is integral with the radiator, no external tank is required. Sounds like you simply overfilled your radiator and it dumped the excess.

'73 and up Corvettes had no expansion tank at all and relied on an overflow and recovery tank.

[Joe L.]

Re: C2 Expansion Tank

Dave-----

Some big blocks did come with an external supply tank. These were 1965 L-78, 1967-69 L-88, and all 1969-72 big blocks. It just depends on the design of the radiator as to whether an external supply tank is used. An external supply tank is NOT THE SAME as a coolant recovery resevoir. In other words, coolant escapes from the overflow on any Corvette with an external supply tank just as it does from the overflow of any 53-72 Corvette radiator used without external supply tank. A coolant recovery resevoir captures overflow and returns it to the cooling system. As Mike mentioned, these were used for all 1973 and later Corvettes.