Cooling System Trivia Question

[Joe L.]

A few weeks ago I posed a cooling system trivia question but it was pretty much "buried" in another post. So, I'll re-pose it here in a new thread. Actually, this should be an easy one.

Here's the background: over the years Corvettes have used radiators with integral tanks and radiators with only external tanks. Until 1991, though, very few have used cooling systems with radiators with BOTH integral and external tanks. John Hinckley pointed out that 1953-55 with 6 cylinder used a radiator with both integral and external tanks. I'd forgotten about that one since I was thinking only about V-8 applications. But, John was correct; 1953-55 with 6 cylinder was the very first use of both integral and external tanks for Corvette radiator.

In 1991, Corvette returned to using both integral and external tanks for the radiator. However, between 1955 and 1991 there was one group of Corvette applications that used both integral and external tanks for the radiator. Does anyone know what it was?

[Tom H.]

Re: Cooling System Trivia Question

I'll take a stab at it............................. 68 to 72 with AC cars ????

[Paul D.]

Re: Cooling System Trivia Question

Joe, I am not certain I understand what you mean by internal and external tanks, but my base engine 71 with aluminum radiator uses a remote mounted tank where you add the coolant. Oddly enough, I think this system was used on the lowest HP, manual trans cars as well as the highest HP (L/88, ZR1) units for several years. Chip.

[Edward J.]

Re: Cooling System Trivia Question

Tom, I think your almost there, 68-72 non a/c cars had remote tanks and 68-72 a/c cars had no remote tanks. so what do you think Joe?

[Joe L.]

Re: Cooling System Trivia Question

Joe, I am not certain I understand what you mean by internal and external tanks, but my base engine 71 with aluminum radiator uses a remote mounted tank where you add the coolant. Oddly enough, I think this system was used on the lowest HP, manual trans cars as well as the highest HP (L/88, ZR1) units for several years. Chip.

Paul-------


ALL Corvettes prior to 1984 with an aluminum radiator used an external supply tank and had NO integral tanks. Some 1960-61 used an aluminum radiator without integral tanks but an external tank was part of the radiator ASSEMBLY. However, it was not an "integral tank" in the context of the meaning of the term. All pre-1984 Corvette aluminum radiators were, basically, just a core without tanks.

[Michael J.]

Re: Cooling System Trivia Question

This is a question I asked when I was changing out my '67 BB brass/copper radiator, I saw no internal "tank", just room at the top of the radiator when you filled it to the "Cold Fill" line. To me, that is not a "tank", just sloppy radiator design. Is that what you are talking about?

[Joe L.]

Re: Cooling System Trivia Question

I'll take a stab at it............................. 68 to 72 with AC cars ????

Tom and Edward------


You're on the right track but no cigar.

1968-72 Corvettes with small block and A/C used a copper/brass radiator with integral tanks but NO external supply tank.

And, Edward, there were some 1968-72 Corvettes without A/C that used the same configuration as above. These were any small blocks with THM400 transmission.

The answer is all 1969-72 Corvettes with big block EXCEPT 1969 L-88 and ZL-1 with 4 speed transmission and 1971 ZR-2 with 4 speed transmission.

With the exceptions noted, all other 1969-72 Corvettes with big block used a copper brass radiator with integral tanks PLUS an external supply tank. From 1956 to 1990, these were the only Corvettes that used a cooling system with BOTH radiators with integral tanks as well as an external supply tank.

[Joe L.]

Re: Cooling System Trivia Question

This is a question I asked when I was changing out my '67 BB brass/copper radiator, I saw no internal "tank", just room at the top of the radiator when you filled it to the "Cold Fill" line. To me, that is not a "tank", just sloppy radiator design. Is that what you are talking about?

Michael------


All Corvettes with copper/brass radiators used a design with integral tanks. Absolutely no exceptions. The tanks on your 1967 are soldered onto the sides of the core and the right side tank has a filler on the top of the tank. This configuration radiator was absolutely not unique to Corvettes. In fact, it's probably the most common radiator configuration out there.

[John M.]

Re: Cooling System Trivia Question

All SHP Big Blocks?

[Joe L.]

Re: Cooling System Trivia Question

All SHP Big Blocks?

John-----


ALL 1969-72 Corvette big blocks except 1969 L-88/ZL-1 with 4 speed transmission and 1971 ZR-2 with 4 speed transmission.

[Edward J.]

Re: Cooling System Trivia Question

Tom and Edward------


You're on the right track but no cigar.

1968-72 Corvettes with small block and A/C used a copper/brass radiator with integral tanks but NO external supply tank.

And, Edward, there were some 1968-72 Corvettes without A/C that used the same configuration as above. These were any small blocks with THM400 transmission.

The answer is all 1969-72 Corvettes with big block EXCEPT 1969 L-88 and ZL-1 with 4 speed transmission and 1971 ZR-2 with 4 speed transmission.With the exceptions noted, all other 1969-72 Corvettes with big block used a copper brass radiator with integral tanks PLUS an external supply tank. From 1956 to 1990, these were the only Corvettes that used a cooling system with BOTH radiators with integral tanks as well as an external supply tank.

Joe,your are right , I was not thinking about 68 they basicly used the aluminun radiators w/ external tanks with and without a/c. When you said the word (group) I put 68-72 as a group and didn't even think about the 68 model year.

[Michael J.]

Re: Cooling System Trivia Question

Michael------


All Corvettes with copper/brass radiators used a design with integral tanks. Absolutely no exceptions. The tanks on your 1967 are soldered onto the sides of the core and the right side tank has a filler on the top of the tank. This configuration radiator was absolutely not unique to Corvettes. In fact, it's probably the most common radiator configuration out there.

OK, thanks, that is what you were talking about then. Just looks like a sloppy radiator design to me , I much prefer the DeWitts DirectFit.

[Joe L.]

Re: Cooling System Trivia Question

OK, thanks, that is what you were talking about then. Just looks like a sloppy radiator design to me , I much prefer the DeWitts DirectFit.

Michael------


The DeWitts Direct Fit is an excellent radiator. In fact, I have one myself. However, by general design it's pretty much the same as the stock radiators----cross flow with integral side tanks. The primary difference is that it's made entirely from aluminum rather than copper/brass. That's a big advantage, though, because it will increase cooling capacity by about 25-30% with absolutely no increase in size.

[Michael J.]

Re: Cooling System Trivia Question

Michael------


The DeWitts Direct Fit is an excellent radiator. In fact, I have one myself. However, by general design it's pretty much the same as the stock radiators----cross flow with integral side tanks. The primary difference is that it's made entirely from aluminum rather than copper/brass. That's a big advantage, though, because it will increase cooling capacity by about 25-30% with absolutely no increase in size.

Absolutely! And it weighs about 1/2 of the original which is also a huge advantage when you are installing it all by yourself . One thing I am curious about in the old style BB "internal tank" radiators vs. others for BB cars (Mopar and Ford); why do the Chevy ones need so much expansion space (cold fill line 3 inches or so below the neck) compared to Mopar and Ford 426 or 428 radiators with the caps in the center where they only need an inch or less?

[John H.]

Re: Cooling System Trivia Question

why do the Chevy ones need so much expansion space (cold fill line 3 inches or so below the neck) compared to Mopar and Ford 426 or 428 radiators with the caps in the center where they only need an inch or less?

Michael -

Because of the geometry of the tanks. The GM side-tank radiator has much smaller (less volume) per vertical inch due to the smaller side tank cross-section; the Ford and Mopar top-tank is the full width of the radiator, and has much more volume per vertical inch than the GM side tanks, to provide the same total volume for coolant expansion.