After getting my 1967 SS-350 running after sitting a few years, it seems to run hot.
Water pump, radiator, fan, and fan shroud are all original, or as was on the car in 1976 when I bought it.
The temperature gauge (that I added in 1977) indicates that it runs about 210-240F.
On a hot day (+90F) it runs about 240F on the highway and about the same on the street.
I donít recall it running much above 180-190 in the past.
The fan is a fixed pitch, direct mount, no clutch. The fan shroud is in place and seems to be located properly. I don't see any way to adjust the position.
I have replace the thermostat with another 180F. No improvement.
I have take then radiator and had it boiled out. No improvement.
New Antifreeze is ethylene glycol about 50/50 mixture.
With the radiator cap off I have seen the following:
Thermostat opens up at 180F, meat thermometer indicates 180F
At idle, very little coolant flow.
At 1000-1500 rpm, flow seems adequate.
When rpm goes from idle (450rpm) to 1500 rpm the level in the radiator drops an inch or two.
Heater core was recently replaced, but it still ran hot before being replaced. Heater does work.
Does anyone have any ideas as to where the problem may be and how to find it?