Komiller118

This may sound arrogant on my part, but I see in many posts about the cooling system where folks change their thermostat to a 160. My question is if GM wanted the engine to run @200 why would you change to a 160 thermostat................?

ben dover

Unless it's really cold out, I don't think it's going to run at 160 degrees.

Whaleman

I bought the 180 degree from Ecklers and it work perfect. Run at 193 all the time except stop and go. Dan

billschroeder5842

I'm kind of a "factory spec" kind of guy. I run the 195 in my L89 and the 180 in the LT5.

Why mess with perfection?

Benny42

Because the factory engineers take into account emission requirements, owners in the Arctic circle, balancing engine life against wringing the last horsepower from a combination, etc. I am not concerned about any of the above things.

C409

..... ^^^ This ! ^^^ .....

PatternDayTrader

Run the stock t-stat unless your building a max effort race engine

Kingtal0n

Heat energy is $$$ you used to buy fuel, then converted to heat.

More heat max temp means more efficiency. This is true for any kind of power plants.

In racing situations, sometimes the additional heat is unwelcome. When we race, we don't care about efficiency and economy.

kenmohr

160* thermostat doesn't keep your engine at 160*. It keeps it from going below 160*.

WW7

I have a 180 degree stat, a Dewitts radiator, and also a Dewitts high speed fan on my 383 motor , the fan is set to come on at 196 and go off at 180 degrees, the fan almost never comes on unless Im stuck in summer traffic.. My car runs at 180 degrees all day long and I don't have any problems with overheating like some of the stock cars...The reason GM made the C4 run so hot was because of emissions standards back in the 80s ,my car runs like cars before emissions came about.. I also don't have any emissions equipment on my car. Without the high temps of a stock car, all the underhood components also last much longer... WW
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FASTAZU

Stock thermostat just have the fan on/off temps adjusted.

84 4+3

I know with a 180 degree tstat my car will run at 180 if it's like 70 or lower out. It is also annoying because the overdrive on the 4+3 will kick in and out at 180 on my car... Stock everything. In the upper 90s it'll run around 190 until stop and go traffic but it comes right back down once I start moving. All a lower tstat does is allow the fluid to be cooled by the air faster. If your system is not operating correctly it'll operate at what ever temp regardless of the opening temp. If it is in good shape it'll run where it does. Maybe below 195 even. Unless you have a heavily modified engine or in my case, could only get a 180 locally when the old one stuck, just go stock.

aklim

Basically covered pretty much all the important points that GM wants. And if the customer is satisfied, why, so be it. People tend to worship the Almighty GM without realizing that GM did NOT build the vehicle specifically for them. The vehicle was designed to turn a profit within the EPA regs. The rest is gravy.

OP. Unless you are doing something for a reason, just tossing a 160 or 180 thermostat won't do squat for your power. Remember, it can make "UP TO" 20HP. What does that mean? Anything from negative 100 to 20 above achieved is within specification. Your best bet is to see what you are trying to achieve. If you live in hot areas and are always getting to overheat point, fix other stuff first.

Kingtal0n

a word of engine reliability sequence

1. Engines which drive only short distance and do not fully warm up their oil exhibit accelerated wear and tear, and do not last as long
2. Coolant warms from ambient to 180-200*F within minutes. Oil can take 30 minutes to an hour. The issue here is the OIL TEMP not the coolant temp.
3. Performance driving with cold oil facilitates excessive engine wear and tear

4. Running too low of a T-stat can have multiple consequences ranging from delayed oil temperature rise to excess engine wear. There is far more literature confirming 200*F+ Oil temperatures are good for engine longevity than there is showing that 160*F Coolant does anything for the engine.

Also don't forget that Every auto manufacturer in the world has been progressively improving their engine tech and raising the Coolant temperature in their engines, as bearing clearances get tighter and oils become thinner and higher quality.

I Will keep my "stupid" 200*F thermostat to help facilitate the warming of engine oil, where even here in Florida it takes 45 minutes to warm the 7.5 quarts in my LS engine.

arbee

Nice to see someone who understands the operation of a thermostat.

RWDsmoke

I think people that sell parts need to convince you to buy something you don't already have. I've never seen any reason to run a 160 in a street driven car. 180 was the standard for years before emissions entered the picture. Unless you change the fan settings it won't matter much what thermostat you use. Even then in the summer while running A/C it may take a bigger fan and radiator to stay under 200. I prefer my car to run 190 to 200 degrees under all conditions. I know hotter won't hurt the motor but the 30 year old under hood plastic and electrical doesn't like it.

Tom400CFI

What makes you think that GM wanted the thing to run at 200*?

Tom400CFI

^These guys "get it". GM has to care about criteria that we do not.



^These guys don't (at least, not completely). An hour to warm your oil? Come on, man. An HOUR?? No. No, it does not take an hour to warm your engine oil. Even idling, your oil is at operating temp w/in about 15-20 minutes. Know what warms the oil (under no load)? The warm coolant, as the oil flows over the heads, valley, cylinder walls, etc. That coolant that gets to ~180 w/in minutes that you talked about...that coolant heats the oil.


I ran a 160 stat in a car for years b/c I could document and repeatedly run faster at the drag track with that stat, and more timing. So there is one reason why you'd run a lower stat in a street car.

It shouldn't take any special equipment to get your car to run 200 or cooler, summer or winter, AC on or off, at speed. The stock cooling system when properly maintained is better than good enough and should be able to drive coolant temps "down against the stat" most of the time. HERE IS A POST from this past summer...
I was driving my '92 home in July. Here were the conditions:
*It was 104*F
*I was driving ~70-75 mph
*I had the AC going so there is some added heat loading to the cooling system.

*My coolant temps read (on the DIC) 184*F - 194*F. Here is where it was at when I first noticed the temp and snapped a pic....



Folks, ^this is how properly maintained C4's should run in hot weather.

Whaleman

I totally agree!!!!

kenmohr

You car isn't running that temp because of your thermostat. If it were you wolud be running at 170*. Your car is well maintained. Odds are if you ran a 196* you would run at 197*. The hotter temps burn the acids out of the engine also.