A problem long ago with the copper radiators was that they would get a pinhole leak under one of the mounts. This let pressure drop, so temperature would rise. The pinhole let so little coolant out, it could evaporate before you noticed it, it still let the pressure drop.

Remove each top radiator mount and check for leaks.

 

Everything seems to be OK... No apparant leaks... T-stat.. new... water circulation good... Engine timing good... Still getting over 210 on the move...The only thing I can think could be left is that the twin fans (Flx-210) are not pulling enough air to keep the enging cool. They "Say" that the unit is rated at 2500cfm... not sure how exagerated that is but I think moving more air through the radiator should resolve this. I have read alot about the Lincoln Mark VIII electric fan conversion... I think I am going to go that route ...

Anyone have a good used one that they may want to part with or a suggestion on where to buy a new unit??

Thanks again!!!!

 

Pay attention! This may be your problem. If you do not have the specific Corvette sender with the proper resistance to match you temperature gauge, you will get an incorrect, (too high) reading. You said you have a rebuilt 350, were the sending units changed?

I'm speaking from experience. Go to one of your Corvette suppliers like Eckler's and order the proper Corvette sending unit. If you want to know if your engine is actually overheating, (unless it's boiling over), check it with a heat gun or a heat stick.

Good Luck,
Yellovette

 

You said you are getting 210° down the road.

-Did you verify the accuracy of the stock gauge with another method?
-What temp tstat did you install?
-What temp are you at idle?
-What rpm and what road speed when getting 210° "on the move"?
-did you install the original spoiler?

Answers would help to pinpoint your concern.

 

I've been a bit busy at work and getting ready for Carlisle so sorry for the delay.

you siad earlier in response to my previous post that you have an aftermarket copper radiator. There is an excellent chance that it doesn't have the same BTU cooling capacity as the factory unit and it's less than a good aftermarket aluminum unit such as the DeWitts units.

you mentioned there is no spring in the lower radiator hose - you may be having the hose collapse under the pressure thereby restricting coolant flow. you should definitely replace that hose with a correct one with the internal spring.

you also said there is no stock airdam. These cars get their air for cooling from underneath and the airdam is integral for this as it directs the air up to the radiator to flow thru it and cool things down. Without that airdam you are significantly reducing the amnount of airflow thru the rad. Even with an electric fan that you say you have it still needs air directed up to the radiator area. No air coming up and that expensive fan you installed is next to useless.

Last, have you actually checked the real operating temps via an IR temp gun or are you simply going by what the factory guage is saying? In other words, are you SURE you actually have a real issue with high temps or just that the gauge says so? Believe me, you wouldn't be the first one to chase their tails fighting a problem that doesn't actually exist (been there, done that one myself!) IR temp guns are not very expensive and have many uses and this is a good one for it.