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ghost ridder 08-11-2012 08:13 PM

Big Block high speed over heat
I have a 1968 Camaro with a 1969 396 hsp big block. I have a 180 degree thermostate in it that runs at 193 degrees. When I hit the hgihway 55 mph or higher the temperature rises above 200 degrees. I have had the radaitor and cap checked at Ann Arbor Radaitor, no problem. Replaced water pump with high volume pump. Heads have been redone with hard seats to burn the unleaded gas. New Elderbrook carb and aluminum intake. Still the same results.

Any ideas.


RWENUTS 08-11-2012 09:18 PM

Do you have a coil in your bottom rad hose? Could be collapsing stopping flow.
Do you have an airdam or chin spoiler on your car? You need to create a low pressure area behind your rad so the air will flow in the front.

xzero117 08-11-2012 09:47 PM

check your hoses, maybe you should think about investing in a modern cooling system, aluminum radiator and electric fans

ghost ridder 08-22-2012 09:09 PM

Thanks for the input. I will take another look at the lower hose.
I have been looking at the more modern cooling system but I am tryin g t;o stay original if I can. I have played with the I have reduced some of the high temp.

cdminter59 08-22-2012 10:47 PM

Big Block high speed over heat
The radiator you are using is this the original radiator. Did the Camaro originally come with the 396 Cid. Is it a four core radiator? Do you have the fan shroud for a 1969 big block radiator? There are two one is for 23" radiators and the other is for 20 3/4 radiators. Can you get a Infrared Thermometer Gun to check the block temp, temp head, radiator, etc. You can see hot spots in the block and heads. Need some more info such as last time engine was rebuilt, clutch fan. Cast iron or aluminum heads. Have you done a compression test or leak down test for checking the head gaskets.

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