HOW MUCH ANTIFREEZE in Radiator??
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 857
Likes: 1
From: Morrisonville Illinios
HOW MUCH ANTIFREEZE in Radiator??
WE have a 71' coupe with a 350. I have filled the radiator to the top of the filler neck several times and each time after a couple of drives we find that the level has dropped about 2" in the top tank of the radiator and the top hose no longer what appears to have no fluid in it. We have changed the thermastat with a 165deg and seems to have no leaks and the water tempis looking fine. Is this level normal we have seen somew moisture around the overflow house but remember this car has no overflow tank.
Thanks wro87
Thanks wro87
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
2" sounds kind of low to me but 1" would not, why not put an overflow tank on it? the radiator will purge itself when it gets hot? what pressure rating is the radiator cap?
Drifting
Joined: Apr 2008
Posts: 1,305
Likes: 2
From: Lewisburg WV
thegazman
Install a coolant recovery system and you'll be money ahead. The tank will collect your over flow when the engine heats up and recover it as it cools. Plus it will help purge the air out of your cooling system and provide better coolant flow as your radiator will be full to top.
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
You are ignoring the purpose of the expansion space in the radiator and getting the predictable result. There should be a fill line embossed on the fill side of the radiator. If you go above this line with a cool radiator, when the system comes up to temp, the expanded coolant has to go somewhere, which is the purpose of the spit tube; to purge the liquid that exceeds the space it's confined to. On some Corvettes (pre-'73) there is a divorced expansion tank. The same rules apply here. If you don't leave the expansion space, it will just purge out the spit tube. Even on modern cars with closed cooling systems, there is a cold fill line on the expansion tank. If you over-fill these, they too will purge the excess coolant.
For the system to function properly (assuming the cooling capacity is adequate) you need the expansion space in the radiator and a fully-functional pressure cap of the proper design.
For the system to function properly (assuming the cooling capacity is adequate) you need the expansion space in the radiator and a fully-functional pressure cap of the proper design.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Is your car an automatic? If memory serves, only the AT cars did not have a surge tank on the right fender skirt. For AT cars without the tank, coolant level will drop a little after filling and a drive, but should hold a consistent level after that.
Are you finding antifreeze on the driveway? White smoke in the exhaust?
Are you finding antifreeze on the driveway? White smoke in the exhaust?
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
You are ignoring the purpose of the expansion space in the radiator and getting the predictable result. There should be a fill line embossed on the fill side of the radiator. If you go above this line with a cool radiator, when the system comes up to temp, the expanded coolant has to go somewhere, which is the purpose of the spit tube; to purge the liquid that exceeds the space it's confined to. On some Corvettes (pre-'73) there is a divorced expansion tank. The same rules apply here. If you don't leave the expansion space, it will just purge out the spit tube. Even on modern cars with closed cooling systems, there is a cold fill line on the expansion tank. If you over-fill these, they too will purge the excess coolant.
For the system to function properly (assuming the cooling capacity is adequate) you need the expansion space in the radiator and a fully-functional pressure cap of the proper design.
For the system to function properly (assuming the cooling capacity is adequate) you need the expansion space in the radiator and a fully-functional pressure cap of the proper design.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
Whether the radiator or an expansion tank, whatever has the pressure cap on it must have space for water expansion when it heats up. The '71 radiator has a cap (like mine); it needs at least 2 inches of air space in the upper tank to keep from 'relieving itself' after you fill it.
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 857
Likes: 1
From: Morrisonville Illinios
Thanks gang!!
Looks like I will not worry about it as much since we don't have an expansion tank and I just don't think I need to put one in. Seems like the space left in the tank just might be what the doctor ordered.
wro87
Looks like I will not worry about it as much since we don't have an expansion tank and I just don't think I need to put one in. Seems like the space left in the tank just might be what the doctor ordered.wro87
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