Hot Rods Thermostat accuracy?

So how accurate are thermostats supposed to be? I just checked my 160 degree 'stat and it did not start opening until 172 degrees or so. Is there a spec for this, or is this one shot? BTW, the car is not yet drivable, so I don't know if its overheating yet.

 

Was the meter you checked it with guaranteed to be accurate?

 

Thermostats are not created equal , you pretty much get what you pay for.

 

Did you do the pot of hot water and a meat thermometer test?

 

What might "start" to open @ 160 might not be "fully" open 'till the 172 you are seeing.

 

I'm using a nearly new digital meat thermometer, the last mechanical one I got caught using, and was forced to replace... and throw the old one away, dammit. But I wasn't caught this time.

 

??? huh, grease isn't nearly as bad for you as the bacteria you'll find on raw meat....

 

For thermometer calibration, the temperature of ice water and boiling water is well known. If it's accurate at those temperatures, it will most likely be accurate in between too. On the other hand, if it's off by about the same amount at both temperatures, it's likely off by the same amount at all temperatures.

 

I'd for sure go along with the concept that not all thermostats are created equal. I've seen that on a couple of my late model rigs. On my current daily it is a serous case of pay the money and get the good one or you will be paying twice.

 

Make sure you include al***ude in your testing if you want to be accurate. In Denver, water boils at 202 degrees.

 

Have been studying thermostats a little closer. Last year as part of a coolant flush replaced thermostat with a new 180°F, and then proceeded to freeze my *** off on a springtime road trip. It was windy and in the teens. Normally the heater works great, it will "run you out". The previous thermostat installed was a 195°, makes a big difference from 180° if heater output is a factor.

So then I wondered, what is the "correct" thermostat? Well the manual allowed there were different thermostats available depending on the coolant used.
160° thermostats were a legacy of alcohol based antifreeze as near as I can tell, can't think of any reason to use one today? The specification in 1964 for all Ford truck engines for example was open at 185-192, fully open 210-212 deg. So while "180" might be considered stock in some parts books, it sure looks like 195 is closer to spec. I thought the 195 was an emission era development?

One thing to keep in mind the thermostat temperature sets the floor temperature, not the ceiling. The temp that it starts to open is also the tempit starts to close. But, if overheating is a problem a lower temperature thermostat isn't going to help anyway! The notion that an engine should be run "cool" is not really true either. I believe there are a lot of poor quality thermostats out there these days too or have a lot of variation in tolerance as well.

 

OK, I'll chime in, so many folks have said "that you get what you pay for in a thermostat", that makes sense, so, what is the best/highest quality thermostat to use? Any input greatly appreciated.

 

Part of the problem is what was good 20 years ago, 30 years ago, has been offshored. Brand names don't mean **** anymore. Even then the quality may be fine.. In the first batch. Q.C. is a ****shoot when wholesalers buy stuff by the pound, or conex shipping container. For a lot of parts, it's tough to go wrong with NOS or NORS, they fit better and work better, they were designed for use in what we are installing them in. Body panels and grills and brightwork gets pretty spendy but contact points, thermostats, electrical and ignition parts, switches etc and other everyday replacement parts don't really cost anymore and are often just better quality. I'd think a thermostat would qualify.