Hey guys I have a 52 flatty its stock and Its getting hot need to track down the problem. the gauge goes to hot after a few minuets weather driving or idling it has never over heated before used to always sit at about the 3/4 mark on original gauge. I have a catch can on it flushed radiator checked for bubbles in radiator so I dont think I have a gasket problem what do ya think.
Could be a thermostat stuck open,Flatheads because of their dual waterpumps actually will overheat because the water flows too fast and does not have time to cool.Back in the day when I raced them we had several things we did to slow down flow like replacing the thermostat with a large washer with a small hole to restrict the flow, also removing every other impeller on the water pump was a common trick.You could have a radiator shop run a test to detect gases in the coolant just takes a few minutes but will tell you if you may have a headgasket problem beginning to surface,you can't always determine that by looking for bubbles.
Also be worth checking your Gauge, is it the stock one or an aftermarket one? may be worth buying a machanical type gauge and run the line into a port on one head just to double check .
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