Thermostat temperature recommendations
- Thread starter Ron Grubb
- Start date
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If your cooling system is in good shape, a 180° would be perfect. Your 273 shouldn’t overheat with it. You want it to get to operating temp.
doug 371
Well-Known Member
I run a 160 works for me
I have been told that a car will run warmer than 160 with no thermostat at all. Is this true? I was told that the thermostat kept the water in the radiator longer with a thermostat actually cooling the water better than no thermostat at all. Cooling system is new. Radiator, water pump hoses.
A car will run warmer than 160 even with a 160 thermostat. The thermostat controls when the water is allowed to start cooling, not what temp it will stay at. you want to get your temp up to "operating" temp as soon as you can, oil works better up there, engine efficiency is better, and you burn off crud better. Thats why modern engines run much higher (my truck runs at 210). I was always of the cooler is better camp until I started doing some reading.
here's but one article, but it isn't the one I was looking for, but there are others out there.
https://www.motortrend.com/how-to/engine-oil-temperature/#:~:text=Cold engine oil causes excessive,between 230 and 260 degrees.
If your car runs hotter than you want, a lower temp thermostat isn't going to change that, it might buy you a couple minutes before it gets to that temp because coolant will start flowing sooner, thats all. If you want it cooler, you need to beef up the system- Radiator, fan, shroud, pump, proper hoses, air flow,(into and OUT of the engine compartment). Notice the hood vents just behind the radiator on Jeeps when they put the 5.9 in the grand (98), thats a low pressure zone, so it would "suck" the air out of the engine compartment. The back of the hood is a high pressure zone, (think about how much air comes through your floor vent boxes) so vents far back will try to jam more air under the hood, with no place to go.
here's but one article, but it isn't the one I was looking for, but there are others out there.
https://www.motortrend.com/how-to/engine-oil-temperature/#:~:text=Cold engine oil causes excessive,between 230 and 260 degrees.
If your car runs hotter than you want, a lower temp thermostat isn't going to change that, it might buy you a couple minutes before it gets to that temp because coolant will start flowing sooner, thats all. If you want it cooler, you need to beef up the system- Radiator, fan, shroud, pump, proper hoses, air flow,(into and OUT of the engine compartment). Notice the hood vents just behind the radiator on Jeeps when they put the 5.9 in the grand (98), thats a low pressure zone, so it would "suck" the air out of the engine compartment. The back of the hood is a high pressure zone, (think about how much air comes through your floor vent boxes) so vents far back will try to jam more air under the hood, with no place to go.
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Thermostats are there for control. I have tried without and it didn't overheat or overcook either. Most race engines have restrictions which act like a Thermostat but they don't regulate temp. The most important thing is there is nothing mechanical there to fail. Billions of cars run thermostats. Put one in and get on with your crusing.
Thermostats control the minimum operating temp, not the maximum, so if a thermostat is marked 180 for example, that has zero to do with how hot the engine will run. All it means is the thermostat begins to open at 180 degrees. The maximum operating temp is a function of the rest of the cooling system, not the thermostat. For a stock application, I would stick with the stock thermostat (probably 192 or 195) or use a 180 as an option, although whichever degree opening I chose, I would use a high flow thermostat, regardless.
The FSM actually states do not use a 160 deg thermostat.
The clearances in the engine are designed for a particular operational temp range. Too hot or too cold and the parts will be too tight one way or another.
The clearances in the engine are designed for a particular operational temp range. Too hot or too cold and the parts will be too tight one way or another.
TrailBeast
AKA Mopars4us on Youtube
Try it without and then with a 160 and see what results you like best.
There are multiple reasons why you shouldn’t run an engine too cool, but is obviously your choice.
What temp your engine runs at will be determined by the engine.....& cooling system.
Never run without a stat; it is the restriction in the system & it creates pressure [ by deliberately causing a restriction ]. This suprressses localised boiling in hot spots [ eg, near the exh ports ].
If you have an extremely efficient cooling system, & a 160 stat, the engine will run just slightly higher than 160 [ the opening temp].
If the engine runs hot, the temp rating of the stat will have little impact on the actual temp the engine runs at.
Never run without a stat; it is the restriction in the system & it creates pressure [ by deliberately causing a restriction ]. This suprressses localised boiling in hot spots [ eg, near the exh ports ].
If you have an extremely efficient cooling system, & a 160 stat, the engine will run just slightly higher than 160 [ the opening temp].
If the engine runs hot, the temp rating of the stat will have little impact on the actual temp the engine runs at.
doug 371
Well-Known Member
mine will run at 160 all day and creep to 170 when u shut it off
I've been running without a thermostat for years, never had a problem. Car gets up to 190 fast and doesn't go over 195 sitting in traffic, even on 100 degree days.
69hemibeep
Well-Known Member
If you do get the engine to run near 160 make sure you change the oil a little more often because the temp isn't high enough to get the condensation out of the crankcase via the PCV. There is a reason for the factory putting higher rated stats in.
I agree AND make sure you TUNE the engine when it;s up to operating temp. When they run cool like that, it's important to retune them for it. Most will take some more timing and can be fattened up at the carburetor a little.
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