My son has supercharged 1996 Z28 with around 50K miles. He recently had the car start to overheat on him and when I got there it was boiling over a little. I refilled the coolant (it was VERY low) and when he started it, it was leaking horribly at the front of the block. I refilled it again with water and when he started it this time the coolant started to pour out of the radiator (cap off). I tried to purge the air but since it was dumping so much coolant I stopped. I used a pressure tester and the leak was coming from both gaskets on the water pump, badly from the driver side. I did a oil analysis and shows no coolant in the oil and it didn't smoke. I have the car apart right now and am replacing just about everything on the front of motor but am really getting nervous that the head gaskets may be bad. Don't want to get this back together and have to do it again.

Can a really bad water pump cause pressure in the radiator? I believe I got the air out on the bleeders but like I said stopped because it was leaking so bad. Ideas? Thanks for the help!

 

Yes, a bad water pump can cause that. I'd also flush the heater core.

 

I too have a 97 SS S_charged. Very modded. The water pump uses a bypass circut type T_stat. Some don't seal very good. I would go with a 160F unit.

I have modded my cooling system with a be-cool alum unit and evans NPG poly_gly. No T_stat. I had to make my own bypass seal in the water pump. Cools much better.
Consider an electric 55 gal/min Mezz pump.
I also run my fans on constant.

FI always will cause high heat load.
Check out Evans cooling dot com.
B.

 

I've been involved with an 1,125HP Vortech S/C'd 383 LT1 buildup in a 30th Anniv convertible (car ran 9.05@156MPH, at 4,000# race weight way back in 1999) and the only real change that was made to the cooling system was a Be-Cool aluminum radiator. Stock water pump, Dex-Cool, 160* t'stat w/ revised fan on/off temps. Car ran unbelievably cool.

I run an 800HP nitrous 381 LT1 motor with the stock system, except for a Griffin aluminum radiator - stock water pump, Dex-Cool, 160* t'stat, reprogrammed fan on/off temps. Engine runs 190*F or less under all conditions.

Both setups ran a fan assisted outboard auto trans cooler, because both of them were originally 6-speeds.

 

If I run a 160* stat, wouldn't I need to have it tuned for it?

 

It won't do anything unless you revise the fan on/off temps in the program. With the lower operating temps you may be able to run a bit more spark advance.

 

Thanks!