I have a 67, with a 327. I have a newer radiator, with an elec fan that is always on. When i'm crusing the temp is around 180 to 190. However when i'm stuck in traffic or at a stop, or evening going up a hill it climbs to about 210. It doesn't die or lose power, but that is too hot for comfort. Im thinking about getting a new Thermostat. What temp should i get? If i get a 160, could it do harm running cold? Thank you!! I'm kinda stuck in Reno, nv right now.

 

With an electric fan setup I'd be checking first to make sure the fan is turning on when it's hot out. Is the fan thermostatically controlled or has a thermofan switch that tells it when to turn on? Or is it just on all the time? That's pretty dang hot. What thermostat are you running in it right now?

You could always yank out the thermostat and drop it in some hot water. I put mine on the stove and slooooowly turn up the temp till it's just about at boiling then drop my thermostat in it to see if it opens on time. If it doesn't your thermostat is sticking.

Running a cooler thermostat isn't going to be a horrible thing, but an engine does run more efficiently when it's warm, and not at a cold temperature (burning fuel more efficiently) but you obviously don't want the engine running crazy hot. Just don't forget to burp the system to get all the air out when ya do.

Do you notice when the thermostat opens (When the temp drops and then regulates?) if it seems too late i'd suspect a sticky thermostat. If it opens on time but still gets hot, could be the fan not kicking on (unless you have it on all the time) otherwise i'd suspect air in the system or something clogging the system.

I'm no expert with your engine, but overheating is overheating, clogs are clogs, air is air and thermostats are thermostats lol. By all means if someone with more insight wishes to chime in, I'm also all ears. Love soaking up more info.

Good luck with the fix and let us know so others can find the answer in case they come across a similar issue

 

Great! Thank you for the info. My fan is on all the time. Im not sure what temp the thermostat is. The OEM is a 195 one. But that just seems too hot. Let me know what others are running. Thanks!

 

I'd try a 180 stat, works great for me. Although I do have an aftermarket radiator, my temp rarely goes above 190 in traffic. 160 is too cold of one to use, and it will just stay open all the time once the coolant gets past that temperature, which it will. That's not going to let the radiator do it's job of cooling down the coolant. A lower rated stat doesn't mean you automatically lower the engine running temperature, it doesn't work that way. Also check your ignition timing, as if it's way off (especially retarded), it will make the engine run hot.