Forgive my ignorance, but what's a "mechanical gauge"? Are you talking a bi-metallic meat thermometer? I don't think it will pick up the heat sufficiently, and has a pretty coarse resolution.
I have no idea what year stovebolt you have, but mine isn't graduated to temp values. It is either pegged low, at some sweep inside of the range, or pegged high. Mine tends to run fairly close to mid-range, dependent of course on the ambient temps and how much idling I'm doing.
Have you considered taking off the radiator cap, starting the engine and running at idle until reaching stable temp, then using a kitchen thermometer (electronic barbecue tongs with LED readout) to read the temp inside the radiator through the neck? It isn't the exact same as where your temp sending unit is probably located, but it is closer to the thermostat and can be a benchmark.
Are you running a 50/50 blend of coolant/water?
What temp is your thermostat?
Have you confirmed operation of the thermostat with a stovetop test?
Bill
Last edited by TxLaTx; 03/26/2011 3:12 AM.
