Open vs. close coolong
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Melting Slicks
Joined: Sep 2004
Posts: 2,655
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Open vs. close coolong
I'm considering going to a griffin radiator. The old cooling system was open, ie air flowed into the cooling system via the tank. A surge tank was used because the radiator is lower than the radiator, and that allows the air to flow to the highest spot, the tank. If I go to a griffin raiator with a cap on it and closed cooling with the radiator cap on the tank, can I seal the system and use the surge tank as an overflow. I would use the bottom inlet as the reservoir for the radiator. Thanks.
Gary
Gary
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Joined: Sep 1999
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From: Plano TX
Yes, you can do this and it works much better than the factory setup. This is actually the way all later C3's were done from the factory. I'm running a BeCool radiator with a cap on the radiator. From there I have a hose to an overflow tank. Rather than using the stock expansion tank I opted to swap it out for a 78 plastic tank. It's still available from GM for $15. You can retain the expansion tank but you will have to plug any unused fittings. The expansion tank ties into the heater hose (atleast it did on my LS5) and you have to bypass that.
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Joined: Mar 2001
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From: Living in the Hartland
No it does not have to be higher since the system is using pressure/vaccum to purge/draw air/fluid back in. As long as the inlet tube is below the recover/over flow fluid level in the tank the system will draw fluid back in when it cools. After the system goes through a few cycles all the air should be gone out of the system including the overflow line.
EDIT The cap should be at the highest point for the closed end of the system but the tank can a little above or below.
EDIT The cap should be at the highest point for the closed end of the system but the tank can a little above or below.
Last edited by Fevre; Mar 7, 2005 at 10:53 AM.
Team Owner
Joined: Feb 2003
Posts: 30,183
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From: Lake Norman NC
Great question...i did this with my Griffin radiator and stock radiator tank. I cut off the bottom outlets that crosses over the heater hose, and i'm running the overflow tube straight to the tank. I don't have heater hoses on the engine, but if i wanted, i could run them straight to the heater core and not have to bypass the expansion tank.
Thread Starter
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
Thanks for the info guys.
I just ordered a griffin 27.5 X 15.5, rated for 400hp for my 68 small block. The radiator cap with the overflow hookup looks like it will be slightly lower than the top radiator hose.
I want to plumb the heater hoses direct from the heater to the water pump and manifold. I'll then use the surge tank as an expasion tank and plumb the line from the radiator overflow to the bottom opening of the surge tan.
My only concern was that until the air is purged, I might get an air lock problem since the top hose will be dry after filling. Maybe parking it with the front right up a steep hill will help get the air out.
Gary
I just ordered a griffin 27.5 X 15.5, rated for 400hp for my 68 small block. The radiator cap with the overflow hookup looks like it will be slightly lower than the top radiator hose.
I want to plumb the heater hoses direct from the heater to the water pump and manifold. I'll then use the surge tank as an expasion tank and plumb the line from the radiator overflow to the bottom opening of the surge tan.
My only concern was that until the air is purged, I might get an air lock problem since the top hose will be dry after filling. Maybe parking it with the front right up a steep hill will help get the air out.
Gary
