'66 V-6 Normal Operating Temperature?

The previous owner installed an additional aftermarket temperature gauge before figuring out the original gauge still worked. Both sensors are installed on a pipe nipple on the front of the intake manifold where I believe a heater hose was mounted. The heater and all hoses have been removed.

We don't drive much, just around the ranch or sometimes my grandson takes it down the road a little. Usually neither temp gauge moves. Yesterday we drove into town and back, a 12 mile round trip, at a blazing 35 - 40mph, and the original gauge moved about a third of the way between C and the middle line. The aftermarket gauge didn't move off the peg. The air temperature here at the time had cooled off to about 97.

The previous owner said he had put a 190 degree thermostat in it. I put a test light on the power wire at the sensor and it blinks off and on. I don't know if this is normal or if it should be getting steady power. The other sensor is mechanical.

What operating temperatures have y'all seen?

 

I would not put a test light on the sender wires, it can overload the power supply. You need to read resistance in ohms at the sender.

I'ld expect 195 or 200 with a 190 thermostat.

 

At 110 and up i have hit 220 degrees. Between 80 and a 100 around 190. At 70 to 80 runs at 180 the thermostat setting. Below that it won't
reach temp. The new heater valve may not be closing completely and the bypass hose may allow too much water past. Replace the mechanical
gauge so you have two points of reference.

 

Mine is brand new - rebuilt motor, aluminum 3row radiator, and electric fan. It has a 180 thermostat and an aftermarket mechanical gauge drawing from a port in the Offenhauser intake. The temp always goes up to about 220 at first warmup then drops to about 170-180 and holds there.