A member in our chapter has a '62 327/340 hp which he feels is running hot. He has replaced everything including the water pump; hoses; thermostat; radiator (new Dewitt); and fluid, including adding a bottle of "Red Line's Water Wetter". He has a 160 degree thermostat installed and the temp gauge reads 180 to 190 degrees. He has checked the gauge with another and with an external thermal unit. All indicate that the 180 to 190 degree readings are correct. Is there anything else that should be checked or should this have to be the acceptable reading for his engine?
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Re: 62 Cooling Inquiry
The 61/62 radiator design has significant gaps (1-1/2") at each side of the radiator. There are a couple of flat rubber seals designed to cover these gaps. Available from the vendors for about $10-15. Sealing these gaps on my 62 327/360 made a marked difference in cooling. As a test, obtain a length of 3/4" foam pipe insulation. A length of this material on each side of the radiator will seal it and direct all the air flow through the radiator instead of around it, and can be accomplished in less than 5 minuets. If it works, order the seals. -
Re: 62 Cooling Inquiry
I have a 63 not a 62 however I believe the engines are set up the same. My 63 is designed to have a 180 degree t stat. I would think a 62 should also have the 180. If the car is running 180 to 190 this is normal. I don't think anything is wrong.Comment
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Re: 62 Cooling Inquiry
'62 340s don't have a vacuum advance, and this will tend to make them run hot at idle and low speeds; 180 to 190 is not abnormal. With the 13 psi cap the boiling temp of a 50/50 water/antifreeze mixture is about 260F and 265F if you up the cap to 15 psi. The thermostat sets the minimum engine operating temperature, and 180 is best to keep the engine warm enough to prevent excess condensation of blowby in the crankcase.
My advise is to reinstall a 180 degree thermostat and seal the radiator gaps as suggested by Ed. If I had a '62 I would install a single point distributor set up to '65 FI specs with the 8" vacuum can. This will reduce the thermal load on the cooling system at idle and low speeds and improve fuel economy. GM did this for me on my '63 340.
You didn't mention if the car pukes coolant out the overflow after shutdown. If it does, this could indicate a weak pressure cap. Either way, the cap should be tested. Most autoparts stores have pressure testers at the counter. Also, don't waste your money on Water Wetter.
A check of initial timing is also in order. It should not be less than spec, but if it was retarded to keep the engine out of detonation it will run hotter. Increasing the initial timing will make the engine run cooler, but the limiting factor is detonation and total advance should not exceed 38-40 degrees. Don't know the centrifugal advance spec for the '62 340 configuration, but if it is 24 degrees you can run 14-16 initial as long as it doesn't detonate.
Duke
Duke
DukeComment
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Re: 62 Cooling Inquiry
It sounds like there may be some confusion as to the purpose of the thermostat. The thermostat does not act as a controller. It is nothing more than a valve that in this case opens or closes at approximately 160 degrees. The rest of the cooling system components are going to determine the ultimate cooling capacity and the operating temperature of the system. I think many people mistakingly expect the thermostat to limit the maximum temperature of the cooling sytem.Comment
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Re: 62 Cooling Inquiry
Doug -
Absolutely correct - the thermostat controls the MINIMUM operating temperature (assuming the cooling system has the capacity to cool the engine below the rated thermostat temperature, which many don't); the condition, efficiency, and heat rejection capability of the radiator and the volume of airflow through it determine maximum temperature.Comment
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