Quote:
Originally Posted by FrankieT/A
Not necessarily true. I have FI on my car and one of the breakpoints for engine temp is 170. My car had a 160 thermostat in it from the carb days. My temp would only get to about 156 or 157. Then I brought the car to North Carolina last week and warmest it would get was 152 (40 degrees outside). I was trying to tune the FI and figured I'm never going to get this right unless I get the temp where it needs to be. So, I changed the thermostat while up there to a 180 Stant superstat. Now my car only gets to about 172-174 which I'm good with because it brings me over the 170 breakpoint I was looking for. Point is my car still does not get to thermostat temp even back in S Florida. Both thermostats did the same exact thing and one was about 5 years old and one brand new. In theory it should bring the temp to thermostat temp. I do have a Flow Cooler wp with about a .010 gap, an aluminum radiator, fan clutch and aluminum heads. My temp guage is confirmed by the FI coolant temp sensor.
And let's not forget thermostats don't open and close...they modulate.
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Quote:
Originally Posted by Will
This brings up a question -
Should a thermostat be fully open at its rated temp, or is the rated temp the temp it begins opening at?
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For this to be clear and everyone understand, these aren't set temps. Frankie, My statement above holds true and to the point, engines won't run cooler than the stat rating, that's what they are designed for, but if we want to get technical then some things have to be explained.
I'm sure I'm not the only one here that has watched a thermostat work in a pot of hot water and a temp probe.
We'll use Frankies example of a 160 stat. On the stove I've had a 160 in hot water. 160 is just a general temp rating. It actually starts to open around the 154 mark and isn't fully open until about the 165 mark.
So yes, it is possible to have it run only a few degrees cooler than the stat rating, my chevelle does this on cooler days, it will run 157-158 on the gauge, because the stat is already just cracked open at this point, and coolant is flowing coupled with very cool ambient temps. Usually this can be achieved on a car that has an excellent cooling system.
I explained it the way I did at the risk of generalization for the sake of making things more simplified here.