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Author Topic:   HOT PONTIAC
posted January 09, 2000 01:44 PM           
Can anyone help me cool down my 350 & 400 Pontiacs. They run about 240-260 degrees at 5000 rpms on a 3/8 track. We got our Chevy to run 200 degrees. Thanks for your help!

posted January 09, 2000 02:29 PM
Well, there are a few things to check, one is the pulley diameter. The pulley diamter needs to be at least 1:1 for gas. If you run a underdriven pulley, it will run hot, simply because there is not as much air being pulled in thru the radiator, and the block hasn't got enuff water pressure to keep the block full of water all the time. Second, look at your fan in relation to the shroud. Feel where the air comes out of the fan in relationship to the fan blades. If it comes out that the top of the blade, either the shroud is wrong or the radiator is plugged up. The fan shroud needs to cover about half the fan blade. Make sure the radiator cap is the highest point in the cooling system if its not, there is probably an air pocket in the hose above the cap, this will cause over-heating. Excessive timing, and leaning a motor out are two more. There are several possibilities here, just take them one at a time.

Hope this helps.

posted January 27, 2000 12:16 PM
you may want to put a water restrictor plate in the water neck. we had to do this because the water was not spending enough time in the rad to be cooled down.

posted January 27, 2000 02:48 PM
one other thing you might try is to lean your radiator in at the top try to get about 4in. difference from top to bottom.Does your motor have a steam hole for the factory heater if so drill it tap it and plug it,if it has one it will be behind the water pump on the block its self.

hope this helps,

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