C1 62 Coolant Tank purpose / location

[Karl #35089]

I'm advising a friend on his frankenstein project that is essentially using a '62 cooling system. I have advised him that the coolant tank needs to be moved to be the highest point in the system. Before he does a bunch of rework of his neato custom mount, we are just seeking to confirm if I really understand the tank's purpose, especially as it relates to its relative elevation. Can anyone help us out on that?

Thank you,
Karl

[Dennis C.]

Re: C1 62 Coolant Tank purpose / location

Coolant level should be half full in the expansion tank when engine is cold. In order to fill the radiator and get rid of any air, the tank must be the high point.

[Joe L.]

Re: C1 62 Coolant Tank purpose / location

Karl-----

Also, the purpose of the tank is related to the fact that aluminum radiators used for many 1960 through 1972 Corvettes had no integral tanks. They were, basically, just a core with inlet and outlet tubes as well as a connection for an external supply tank.

[Christopher R.]

Re: C1 62 Coolant Tank purpose / location

Don't believe the tank is at the highest point in the system. The top radiator hose (engine outlet/radiator intake) is higher. Go out and look at your 62s. When my '62 is cold, the top radiator hose is full of air. Filling the tank 1/2 at cold, as recommended, puts that level below that of the top radiator hose. When the car reaches operating temperature, the top radiator hose is full.

[Karl #35089]

How does that work?

I guess I was under the impression that among the tank's purposes was to provide a spot for the air in the system to congregate. How does that happen if the tank is lower than some other point? And if it can be "a little lower" than the top, why not a foot lower?

Or, specific to the immediate situation, if my friend has this thing located so the top of the cap neck on the tank is ~1/2" below the top of the radiator core, and the top of the radiator core is about level with the thermostat, will his system perform as intended?

Thank you for all the responses...
Karl

[Christopher R.]

Re: How does that work?

That's about where mine is. Mine's got to be right because I used all the right parts when I assembled it.

When the car is hot, the top radiator hose is full, so I assume the top of the radiator is filled up. There's a small tube from the top of the radiator to the tank. I assume when the coolant gets hot, it expands and pushed the air into the tank, where it is compressed, and some probably escapes. When the car is at operating temperature, the coolant level in the tank is just below the cap. When the car is cold, the coolant level is at the 1/2 way mark. If you start to take off the cap when the car is hot, coolant will start to spurt out. If you take the cap off when the car has cooled down, you'll get a "whoosh" of air being sucked in.

The way to fill these systems is to fill them to the top of the tank and run them up to operating temperature. Do this for a few cycles, filling the tank to the top each time. This purges the system of air. After a few cycles of this, the car will "puke" coolant a little while after shutdown do to the heat soak. It'll "puke" until it finds a level where it'll stop. That'll be about 1/2 in the tank when cold.

[Karl #35089]

Thanks for the responses...

Chris: Thank you for your responses here & on CF. After reviewing the stock location for 61L/62, I don't think I have a disagreement with what you've said. I'm just not communicating well because this tank is significantly lower than that and I still don't see how that will work. In any event, we'll find out in a month or two as he didn't change it and the car's off for paint now.

Thanks again,
Karl