Heres a picture of the foam I used, if you put aluminum foil between the hood and the foam on the rad you see it gets compressed flat. PG.

[IMG]local://upfiles/2883/B6D097A393564146B743116210082D37.jpg[/IMG]

 

Hi PG,

I have checked again my radiator and it miss lot of foam sealings in respect to your pics. If it's so effective, I'll go for those foam pieces soon.

I haven't checked carefully but I think that my thermostat starts the water flow before 180°. I felt the upper water cooling hose hot before getting 180°. I have to check better, but possibly my car already has a 160° thermostat , or an off specs OEM thermostat

I would like also to more carefully check the fan clutch...
It seem to work ( at cold engine, when i turn off the engine, the fan stops almost immediately).
but probably I should check if the clutch really engages when the engine is hot.I haven't still heard my fan making the louder roar when the clutch engages at high temp.
I have read also that the fan looses about 200rpm per year...

 

Do you have a five or seven blade fan? The five blade fans don't seem to roar like the seven blade ones do when the clutch engages.

 

I have the stock fan , 5 blades i suppose ( can't check now).
is the 7 blades an improvement in cooling?

 

Seven blade fan was used on cars with A/C. However when I put A/C on mine, I left the five blade and never had a cooling problem and don't have to deal with the fan roar.

 

Where is the fan switch mounted on a 79. My fan works when wired direct, but not when it's hook up to the wire harness. So I would believe it's the switch.

Thanks for your input.

 

Welcome to the forum.

While I don't know, I suspect that the electric fan is controlled by a relay which in turn is controlled by a temperature sensor. Of that's the case, you need to check those components.

 

Thank you to many toys,

I went to NAPA,Auto Zone and was told that a 79 didn't have an electric fan. I then went to the Chevy dealer and was told only 79&80 were the only C3 class that came with an electric fan, but the engine temp switch is discontinued.

 

Well you still need to determine if the temp. switch is bad. Also still think there will be a relay involved and that's the first component I'd check as they have a habit of getting burned contacts and fail to conduct even tho they still operate.

Schematics are available in the Factory Service Manual which can be ordered from Helm, Inc or some of the Corvette aftermarket suppliers.