John Govich

63 -327\340 running hot, replaced clutch fan (bad) decided to flush system,got 2 gallons concentrated coolant,added but only ablt to add 1\2 gallon distilled water afterward. will too much concentrated harm it. drained from petcock as well as removing thermostat hose and fushed. i did remove thermostat,95 degrees outside all the time.

Hitch

With more coolant less water your heat rejection capability is reduced. This could cause higher operating temperatures. Why did you remove the tstat? That will not help it only regulates the operating temperature.

Is this a new problem? Have you recently done any other work to the engine? Is this the original radiator?

Hitch

John Govich

took t-stat out,old school theory. I did check it out and it works. Bought from my Uncle in 05,he restored,doesn't look original. always had issue with temp.,always around 200+,starts to stall out when hot. In winter in Tampa area,runs fine

RestoMike

Your making a mistake by taking the thermostat out. Coolant will constantly roll from engine to radiator back to engine. Without the tstat coolant isn't given ample time in radiator to cool down. Secondly and probably most importantly, have you pressure checked your radiator cap? If cap will not hold pressure, system will not cool to maximum capacity.

JohnZ

Not a good idea. You might want to read this so you understand how your Corvette cooling system works, and how to diagnose it.

http://www.lbfun.com/warehouse/tech_...em/cooling.pdf

Powershift

What radiator is currently in the car?? Is it an original aluminum radiator or a brass replacement??

If it is the original aluminum radiator, it may be corroded and fouled from years of use or neglected antifreeze.

If brass replacement, it may not have sufficient capacity to keep the car cool in the summer.

Put a 180 F thermostat back in the car, adjust the antifreeze to around 50-60 percent glycol (buy a tester if needed) and then use a IR gun to verify the radiator inlet and outlet temperatures and compare to your car temperature gage.

Also check your ignition timing against spec and make certain that the vacuum advance is working correctly.

There are other things to do/check.......but I would start with these first.

Also, for what it's worth, I recommend Zerex G-05 antifreeze as the best out there for these older cars. MANY others agree.

Larry

John Govich

Ok, read the article,will put tstat back,I have a 160 degree,think its ok? Instead of checking cap,I will replace,my book shows 13#, should I put a 15# in?
And thanks for all the help!
Split63

John Govich

I do have a Harrison aluminum radiator as well as the fill tank. It has the numbers 3155416 on it