VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 pros/cons of thermostats

Chevnut I sent you a PM.

thanks

My thioughts for using a thermostat;
I run or have run 160 degree thermostats in all of my cars ranging froma 1934 through a 1957.
The thermostat makes the coolant come up to a reasonable operating temperature quicker. I belive that 160 degrees is sufficent for summer dirving. Under some conditions the temperature will exceed 160 and then I know it is time to watch the gauge closer.
With some cars that can run a pressure cap a 180 can be used, In 1968 when the cars came with a 195 Deg. they used a 15 pound radiator cap and an overflow tank. A 50/50 mix of ant-freeze was required to further raise the boiling point.
I do not believe a thermostat will cause an engine to run hotter or cooler.I do not believe it witll make the enginemore efficent and in the summer the oil gets hot enough to boil off any moisture.

I agree with Gene, I also run 160 degree thermostats in all of my old Chevys and have for years. They work fine and although They sometimes run 180 or more in a parade on a hot day, I have never had one boil over. I watch the temp and if they are getting too warm I just speed up the idle and that seems to do the trick.

I am a strong believer in the use of thermostats in the early vehicle engines especially those driven during the winter months in the northern climates. My preference is 160 degrees with or without pressure caps. The thermostat insures that the engine is operating at a temperature high enough for good combustion during cold weather conditions.

Fred

Good guidance provided.

The factory specs (extracted from the '49-'54 Chevy shop manual and GM Heritage documentation) go like this:

'49-'51: OE T-stat stamped "143" starts opening at 140-147 deg, fully open at 170 deg, and the cooling system is not pressurized (the radiator cap is not a pressure cap);
'52-'53: OE T-stat stamped "151" starts opening at 148-156 deg, fully open at 176 deg, 4 psi radiator cap;
'54: OE T-stat is either the lower temp "143" or stamped "181", which starts opening at 175-184 deg, fully open at 204 deg, specified if "permanent anti-freeze is installed." 7 psi radiator cap is used with either T-stat.

Modern T-stats are rated (according to Stant info) by opening temperature, and the fully open temp is 15-20 degrees higher.

Long story short, either the modern 160 or 180 deg T-stat should work fine in the later vehicles in this range. The engine temperature will stabilize based on engine load and cooling capacity of the radiator/system, not the T-stat opening temperature (as Chev Nut points out). Even though I'm in TX, I use a 180 deg in my '53, and the engine temp runs a bit below half-gauge, consistently.

The 160 deg T-stat makes sense for the non-pressurized systems.

In this cold winter part of the country a 180 Deg. thermostat came with the heater (heaters were dealer installed) and it was common practice to install the 180 in the winter and the stock 151 in the summmer. Some owners left the 180 inn all year,
A 4 pound pressue cap was used in 1948, 1950-1953 Power Glides. and late 1951 and all 1952-1953 sticks.
In 1954 and up the cars came with a 170 Deg. (no long available) and a 7 pound cap.
In the '40's the factory installed a 143 Deg. thermostat....also no longer available.

Great info! Thanks to all and especially Chev Nut for going public on this. This question comes up a lot in most forums, and it puts to rest the myth that a car runs cooler without a T-stat. Guess it's better to run a little hot than too cold or below normal op temps.

Just a little add to this.I raced cars for many years and read books. I once read that all internal combustion engines run best at 180 deg. This includes your lawn mower.

A mild correction on what chevy1937 read. Internal combustion engines are more efficient the hotter they are. That is why 193 deg. thermostats and recommended 50-50 coolant mixtures are specified in modern vehicles. However there are severe problems when they get too hot. So it is a compromise between efficiency and destruction.

Just remember that the car's engine is not flesh and blood. It will run best at a reasonable temperature. Even "Sweetie" Tiny.

I run a 180 in all my old cars. That seems a good temperature for heating up the engine on a cold day, getting the oil to its most efficient operating level, and not causing the coolant to expand beyond escape level.

A 160 degree thermostat seems to work just fine for most of you but in the winter/cold conditions, that may be insufficient. Your call.

As long as there is water circulating in the engine. you're not likely to damage it none, When it boils over and looses coolant then is when trouble arrives. Lower quantity of coolant. especially below the water pumps ability to circulate it will likely cause damage.

Best I recall, steam will not register on the heat probe so watch out for that condition. You may crack the block or head.

Relatively speaking you can run an engine at a temperature way below what is efficient for it. I recommend a thermostat. Whatever the temp you choose.

Your engine will thank you for running it at 180-190 degrees.

I agree with Chipper on this issue. After fully open the thermostat is on little help in establishing the running temperature of the engine.

Best and my two cents worth.

Charlie

Usually you want to add coolant while the engine is idling, especially when it is overheated.. Best is to wait until it has cooled way down. Pressure caps were a great help to automobile engines.

Water boils at 212 F at sea level. Some of you live way above that so keep it in mind.

Well Charlie, my old cars have hopefully done all of the cold winter driving they have to do. When winter comes they settle into my nice cozy shop and hibernate, no more plowing snow at -20 degrees for them. I have driven my '37 in those conditions many times and I am sure my other 2 cars have experienced that also. Like me, they are old and don't have to work anymore. All we have to do is play when the weather is nice! 160* thermostat is good enough for me. LOL Just kidding but I think our Iowa winters may be a little colder and snowier than yours!

Uncle Ed,

A good thermostat will bring the temperature of the coolant up to its rating and keep it there unless the engine's operating temperature is above the thermostat's rating. Coolant that is raised above ” he thermostat's rating will cause the thermostat to be as open as it gets and thus has no function unless the coolants goes below the fully opening of the thermostat.

Oh, the heck with it, Just put the missus on. I think she will understand all this and ” hen explain it to you.

160 is too cool for your engine. Just because it seems to do okay with the shivers is no indication thath tt's not freezing to death. Again, just put the missus on. You know.

Best,

Charlie

OK Charlie, I will ask her if she ever gets off the phone! BTW, have you researched what thermostat was recommended back when these cars were new?