Running engine without thermostat

With the combustion temperature several hundred degrees higher than the coolant temperture, running the cooling system cold takes more heat from the combustion and so reduces the output of the engine. So the cold engine takes more fuel for the same load. For this consideration it would be nice to run a coolant temperature a couple hundred degrees warmer, but pistons and rings can't yet hack higher temperatures. Ceramic pistons, cylinders, and rings may allow that higher coolant temperatures in the future. Essentially, the hotter you can run the engine AND still lubricate it (there's be big rub) and take away the waste heat (in a diesel more than 2/3 of the heat energy in the fuel goes to the oil and coolant) the better.

Then there are the side effects on the oil. Water is a combustion product of hydrocarbon fuels (from burning the hydrogen). Cool cylinder walls condense that water that then can run into the crankcase. Inburned fuel follows. Both affect the lubricating oil adversely. Makes sludge and that sludge blocks passages and the water and fuel parts of the "lubricating" oil don't lubricate well so bearings wear. On top of that water with combustion products like those from burning a bit of sulfur makes sulfuric acid that eats bearings.

Running the engine as close to water boiling as possible (180 or 210 degree thermostat with a closed and pressurized cooling system) boils the fuel and water OUT of the oil getting far better bearing and oil life.

Running an engine without a thermostat is ABUSE, don't do it. If the engine doesn't heat up the thermostat isn't closing properly. Put in a new thermostat. If the engine still doesn't warm up, restrict the air flow through the radiator in the winter.

Gerald J.

At 180-195 the cylinder wall, ring and piston wear is reduced. Cold cylinder walls condense unburned fuel on themsleves. And dilute that thin layer of lube oil in the pores of the metal causing accelerated wear. Cold temps also fill and stick rings/lands with carbon/soot. Along with the previously stated port/combustion/valve deposites and "wet stacking." Put that tractor on a pto generator or something and begin measuring the coolant temp entering the rad before warmed up and under pressure. I suspect your IH rarely reaches proper operating temps with the stat.

Also, a properly designed cooling system accounts for the flow restriction of the thermostat. Removing it on some engines increases the risk of cavitating the water pump and other bad things.

There are no advantages to running without a thermostat in your situation. Why on earth would you want to?

John

Leave well enough alone. Take that thermostat out and the old tractor will be slobberin' all over itself.

That 414 needs the heat.

Allan

Will it harm anything by not having one? Hard to say, depending upon the conditions. Put one in and be done with it, and worrying.

Mark

Joe