Cooling issues for an 80 Shark.

[MakoDRVR]

I have an 80 L-48 with about 215K miles on it. I am fighting heating issues with the old girl right now. Temps are in the 230-240 range and I don't know what else to change out. We have done radiators, water pumps, hoses, thermostats. I am at a lost. We are planning on pulling the old L-48 and replacing it with a 383 stroker with about 400-415 ponies. Any thoughts on what I can do for the cooling system or what else we can replace or fix?

 

[Bob Chadwick]

When does it heat? Around town or at speed?

Did you replace all the seals around the radiator when you had it out? Is the chin spoiler still in place. These two items direct the air to the proper place and are essential to cooling the Vette.

Do you still have the original fan clutch? Mine seemed to be working ok but when I took it out it was leaking so obviously it wasn't.

 

[Copdogcorvettes]

Do you have A/C; If so is the condenser clean and clear? If it is plugged the air flow is reduced a lot. Just something that I have noticed on C3's in the past.

Gary

 

[MakoDRVR]

I replaced the entire AC unit to R-134 standards and it seems to do fine. The heating issue takes place at weird times. Around town for the most part it is ok. But at speed (65-85) on the interstate it really shows it self. Now living in Alabama and being summer time might have a little to do with it but during the summer I am forced to only drive at night just to have some cool air in the nose of the car. Chin spoiler is there and in good shape.

 

[MakoDRVR]

Also, has anyone used electronic fans or even a BeCool alum. radiator?

 

[Hib Halverson]

Is the stock front air dam in place?

Are all the seals between the radiator and core support and between the core support and the hood in place?

Is the temperature gauge accurate?

Is the spark timing set to factory specs and is the timing mark accurate?

Is the air fuel ratio and part throttle cruise correct?

The engine has very high mileage. I'd verify that the block and head cooling passages are clear and not heavily coated with scale, rust or stop-leak residue.

A stock 80 radiator should support 400hp as long as the rest of the cooling system is operating properly, however, many people convert to an aluminum radiator. In my 71, I use a Griffin.

 

[Eric R.]

Do you have little bubbles in the radiator with the cap off and running? Just a thought as sometimes a blown head gasket can cause issues like this. If this is suspected, you can go to most any auto shop and have a simple cylinder gas test done. If they look at you funny then you can buy the test kit from MAC or Snap-On.

 

[MakoDRVR]

The next question is should I think about converting over to an electric fan setup? If so....does anyone have any thoughts on this?

 

[steves1980]

http://community-2.webtv.net/MATTGRU/doc/index.html

http://performanceunlimited.com/illustrations/thermostats.html

i found this it may help

 

[dragstar]

usually getting hot at freeway speeds is caused by a bad fan clutch......you have a flex fan on there? if so go back to stock.

 

[80convertible]

Is your temp gauge erratic at all. I once had what I thought was an overheat problem which turned out to be trapped airbubbles. I drilled two very small holes along the outer edge of the thermostat that would allow air thru but very little coolant. I also now disconnect the upper radiator hose and remove the thermostat from the intake manifold while filling the radiator. When I start to see coolant about to overflow the where the thermostat sits, I reinstall the thermostat and hose and continue to fill. This will help to insure that no airbubbles are trapped in the system. I could not believe the problems it was causing me in the hot summers of North Carolina. This may not be related at all to your problem but this cost nothing to try. Just my .02 worth. Good luck.