Stock radiator im changing the sensors one sensor 185 the other 180 which sensor should go at the top.Believe it or not this particular pantera runs too cool just bought a Robert shaw 180 stat.
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the original switches should be 176F and 158F. with the original radiator baffling, they were both on the "cold" outlet tank. the 176F was the upper and the 158F was the lower position.
there was a recomendation to rebaffle the radiator. this put the 158F in the "hot" inlet tank and left the 176F in the cold outlet.
there was a recomendation to rebaffle the radiator. this put the 158F in the "hot" inlet tank and left the 176F in the cold outlet.
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Actually in the original configuration with the vertical baffle, it's interesting that they felt that they needed two temps sensors because one would believe that the water temperature would be relatively constant top and bottom. Maybe it's just a limitation of the current required to switch the fan relays?
Two sensors only makes sense in the horizontal Baffle case and in that configuration the outlet lower one should be the cooler one.
Rocky
Two sensors only makes sense in the horizontal Baffle case and in that configuration the outlet lower one should be the cooler one.
Rocky
I was thinking, the original thermostat, radiator baffle and fan switches would work like this;
Assuming a “cold” moving situation…
When the engine reaches 195F, the thermostat opens and a small flow of 195F coolant enters the radiator. Given the car is moving, the low flow of coolant passing through the radiator is cooled below 157F and returns to the engine and no fans are needed.
The car now slows and the coolant leaving the radiator increases above 157F and first fan comes on to provide air flow. With the returning coolant hotter, the coolant exiting the block exceeds 195F and the thermostat opens to allow more flow. With the increased coolant flow and the single fan the coolant exiting the radiator should stay below 176F and the second fan not be needed.
The car stops. The single fan cannot cool the exiting coolant and its temperature increases to 176F and the second fan starts. With the warm coolant entering the engine, the coolant exiting the thermostat exceeds 195F and the thermostat provides full coolant flow to the radiator
The car begins to roll again and the air flow cools the coolant exiting the radiator below 176F and the second fan stops. With the cooler coolant returning to the engine, the thermostat reduces the coolant flow to keep the thermostat at 195F.
Once back at speed, the coolant exiting the radiator drops below 157F (even with the coolant entering at 195F) and the first fan stops.
In my thinking (which differs from others) with the horizontal baffle, the lower switch on the inlet is not needed. Trying to match the inlet switch setting to the thermostat does not make a stable control loop.
And then there is my thought that at speed, the fans are being driven by forced air flow and if “on” they would supply current to the battery and thus no reason to cut them off anyway, thus making the switch in the radiator inlet a good option.
Now if I just had a running car to connect a couple thermometers on the radiator and an amp meter ….
Assuming a “cold” moving situation…
When the engine reaches 195F, the thermostat opens and a small flow of 195F coolant enters the radiator. Given the car is moving, the low flow of coolant passing through the radiator is cooled below 157F and returns to the engine and no fans are needed.
The car now slows and the coolant leaving the radiator increases above 157F and first fan comes on to provide air flow. With the returning coolant hotter, the coolant exiting the block exceeds 195F and the thermostat opens to allow more flow. With the increased coolant flow and the single fan the coolant exiting the radiator should stay below 176F and the second fan not be needed.
The car stops. The single fan cannot cool the exiting coolant and its temperature increases to 176F and the second fan starts. With the warm coolant entering the engine, the coolant exiting the thermostat exceeds 195F and the thermostat provides full coolant flow to the radiator
The car begins to roll again and the air flow cools the coolant exiting the radiator below 176F and the second fan stops. With the cooler coolant returning to the engine, the thermostat reduces the coolant flow to keep the thermostat at 195F.
Once back at speed, the coolant exiting the radiator drops below 157F (even with the coolant entering at 195F) and the first fan stops.
In my thinking (which differs from others) with the horizontal baffle, the lower switch on the inlet is not needed. Trying to match the inlet switch setting to the thermostat does not make a stable control loop.
And then there is my thought that at speed, the fans are being driven by forced air flow and if “on” they would supply current to the battery and thus no reason to cut them off anyway, thus making the switch in the radiator inlet a good option.
Now if I just had a running car to connect a couple thermometers on the radiator and an amp meter ….
quote:In my thinking (which differs from others) with the horizontal baffle, the lower switch on the inlet is not needed. Trying to match the inlet switch setting to the thermostat does not make a stable control loop.
My (unstudied) opinion on this is that they did less scientific diagnosis. They just figured if the coolant exiting the radiator was hotter than 157, then they needed more blowage, therefore the second fan kicked on.