My 77 has aftermarket radiator with dual electric fans. The 401 has electronic FI and ignition and likely a more aggressive cam. It also had a thermostat that was locked wide-open when I got it. The thermostat has been replaced with a stock open-temp (205F?). When observe it warming up, I can feel when the thermostat opens - first I can feel the flow in the hose and then the aluminum radiator warms almost immediately where the coolant enters the radiator. The electric fans came on a minute or two before the thermostat opened. This implies to me that they are set to come on a lower temp than the thermostat. Also implies that they will always run - including at highway speed and even if the thermostat were to close partially - such as getting on the highway with colder air temps. I think they would only ever stop if the ambient was so cold that the engine could not reach operating temperature?
I would have thought that the fans should not come on until the coolant temp is a little above the thermostat open temp.
Am I off-base?
TIA!
Chris