Fevre

I run very little anti-freeze % with distilled water in the summer with water wetter, running a 350 hp 350 and rarely turn on my fans

ThunderMaker

Forget water wetter, if it does anything at all it won't be noticable, just pull out your thermostat, it worked for me !

shawn_cake

I also noticed that both my big (~540 CID) and small (~406 CID) block 1980 Vette ran hot. I upgraded to dual Spal fans, Griffin Black Ice rads and Edelbrock water pumps. I also made sure the air dam was functional and the radiator foam surrounds were in good shape. Yet I still ran a little too hot.

I then looked at trapped air in the cooling system. As it turns out, the filler neck on the Vette rad is lower than the water neck on the intake manifold -- making it very cumbersome to purge any air from the cooling system. I found a part from Moroso that replaces the water neck on the intake manifold -- and it is a water neck with a rad cap fitting on top. I installed this Moroso part instead of the original water neck. The original rad cap (15 psi Stant Lever-Vent) was put on top of this Moroso part, and the Moroso part was connected to the radiator and the overflow tank just like a normal water neck. The radiator was sealed with a 30 psi rad cap.

After idling the engines up to operating temperatures, I used the Stant Lever Vent to purge the tapped air from the cooling systems. After some highway and city driving, I repeated the purges. Using 195 degree thermostats, my engine temps never went beyond 210 degrees on both machines.

The air entrapment issue is not the total solution to the overheating problem -- but it was the final factor that I had to fix along with the other cooling system upgrades in order to make my Vettes more "summer friendly".

Hope this helps...

brimcc

Thanks for all the solutions. I drained all my anti freeze and replaced it with water. I also add water wetter, it does run cooler now. I haven't had it on the high way yet and am courious to see if it worked. With 356 rear end I don't do alot of highway driving anyway.

Fevre

You need to run something along with water to lube the wp bearing, believe WW has a lube additive.

71406

I tried a number of things to get my 406 cool...but I got the most impact on the part that costs the least...the thermostat. But not any stat, the Robertshaw / Mr Gasket 180 degrees. It allows water to pass through before reaching 180 (which delays heating up) and the high flow design you get more water into the radiator quicker. I now think my car run too cool. Before this install I could not sit in traffic with the ac on in 90+ degree weather...even after installing a DeWitts alum radiator. I may not get great heat in winter, but for now, its the best improvement for the fewest bucks.