For the thermostat temp what is stock?
I have a 195 in my car currently.
I went to the autoparts store, they sell anything from 160 to 200.
Any advantage for a lower or higher temp?
The engine has been modified slightly, it is a 350, auto tran, 1979 year car

Thanks
Chris

 

 

there is some debate on the topic but I run a 160. A lot of people will tell you thats too cold and you should run a 180. So your choice!

 

You might want to give us a clue as to what year car and which engine and transmission you've got.

 

I also run 160.

 

Thermostats don't determine your engine's operating temperature, your radiator and fan do. Higher ambient temperatures will add to the equation. The thermostat opens at a supposed specified temperature to allow coolant to flow. Up until that point, your engine is building heat...just what you want it to do. Cold engines are not very efficient. You can open at 160 if you like, but the engine still may reach 180, 195, 200 or whatever. Most thermostats are not all that accurate. I would go with what your car is supposed to have.

 

In my car while on the freeway it seems to me the thermostat is determining the temp. The temp goes up to 205 then drops to 180 and cycles like this. I was guessing the thermostat was opening at 205 the radiator was cooling the water to 180 before the thermostat closed again.

I am having over heating problems in around town driving, it got up to 220 at a long light. I am replacing the radiator(it leaked), a radiator hose (that looked kinked and too long) and the fan clutch as I don’t think it was working correctly.

I am having truble figuering out what was stock for my car.
I have a 1979 350 with auto and a/c but the a/c has no compressor currentaly.

 

The chevy V8 was designed to run at 180F. After the EPA got involved, the stat temps went to 195 so that the hotter engine would burn off more hydrocarbon emissions. But, that isn't by the choice of the GM Engineering department. With the advent of the computer control systems (1981 for Corvettes), the computers need to see higher than 180F to 'know' that the engine is at operating temp. Putting a lower temp stat in a computer controlled vehicle (which is intended to work) would be defeating the purpose.

160F or 180F is your choice. There may be minor differences in fuel mileage, durability, performance between those temps....but it won't be much.

As stated above, the stat does not determine the operating temp of the engine/cooling system. It MAY be able to regulate at the stat temp, and it may NOT be able to. That depends on whether the cooling system has the capability of keeping the engine cooler than the stat temp. If it can...and if the stat is functioning properly...then the stat will regulate at [or close to] its rated temperature.

 

Stock thermostat for your car was a 195.

 

I ran a 160 in my BB and it ran too cold - Put in a 180 = PERFECTO!

 

Read the timing "sticky", your timing may be a bit off. Also, what condition is your radiator?

As for the the thermostat, I run a 185, "Fail Open" and drilled a small hole in the base.

 

Agreed. I drove a stock 1979 L-82 with TH350 for many years. As an experiment some time ago I tried 160, 180, along with the 195. It was obvious that the engine (remember stock with all emissions equipment intact) "liked" the 195. This hardly surprising as GM engineers designed the car to run at that base temperature in order to maximize the efficiencies of the emissions devices. It ran consistently at ~200, rising perhaps to 210 at highway speeds on a hot July day. I considered that normal operation. After all, water boils at 212 and with a good anti-freeze mix and a pressurized system the boiling point is much higher. To illustrate, there was an optional auxiliary electrical fan in 1979 and the temp sensor for it kicked in at 238.

With my stock 1974 L-48 (both cars shown in pic) I use a 180 as that was standard. But it does not have a catalytic convertor and other emissions devices are tuned for that base temp.

I tend not to second-guess GM engineers when dealing with a stock setup. With mods I guess anything goes.

 

The thermostat is to get the engine up to temp. as soon as possible & regulates the min. temp. The rating is the opening temp. so a 160 or 180 may only run that in very cold weather.

 

I had a 160* thermostat on my Z28 and didn't like the way it ran and went with a 180* thermostat. The 180 made a big difference for my Z28 and runs much better.

 

Contrary to some of the logic I have seen on the above posts, my BB car runs pretty well with a 160.. if I put a 180 ( currrently) in it and drive it around town, when I shut it off, it spits about 5 oz. of fluid out the overflow tank tube. I figure I am just overfilled and it will settle into the proper level after a few more drives.. I currently have a 180, but if this keeps up, I will drop back to a 160. screw the gremlins and go with what works...

 

Joewill
A BB generates a lot of heat & can easily run a 160 which is the opening temp. & fully open about 180-185.

 

Joewill
Ya know, the same thing has been happening with my '69 BB. I ran for years with a 160 stat and maintained the surge tank at half full (recommended) when cold. No problems, never puked out the overflow tube. Now that I had the engine rebuilt and replaced the radiator with a Dewitts aluminum Direct Fit, I am running the recommended 180 stat. The engine runs cooler now, due to the radiator, but if I try to keep the surge tank at half full cold...it pukes out about 1/4 tank after I shut it off. I'm going to leave mine where it is...1/4 full. I realize these are large capacity systems (22 quarts) and heat soak after shutoff can cause considerable expansion of that much liquid. I just haven't quite figured out why the stat should affect the amount of expansion. You probably have a surge tank built into the radiator and an overflow tank, correct?

 

Some of the above needs clarification,..to say the least.

The engineers set the coolant operating temps at a level that would keep the oil's temp at 212+ F, the boiling point water. Water is a byproduct of combustion and blowby (all engines have some blowby), and this water will foul the oil which will reduce engine life. It's why engines, that always run short trips and never reach operating temp, don't last long.

At 212 F, liquid water is vaporized from the oil then this vapor (and other harmful blowby gases) are removed via the PCV system. Typically, a coolant temp of 180-190F equates to an oil temp of 210-220F.

In other words, a 160 degree thermostat, or no thermostat, will never heat the oil to the needed 212 F. Plus, it's no secret that hotter oil is a better lubricant than colder.

If your cooling system is up to the task, yes, it should run at the thermostat's rating. If you have a 180 degree thermostat and your coolant's temp bounces around 200F or more, your cooling system is overpowered by engine heat. The system is either not functioning properly or you could be running a stock pump and radiator on a modified and/or bigger engine (HP = heat). Happens often,..time for upgrades.

More here on the relationship of coolant temp and engine longevity.

http://www.carnut.com/ramblin/cool3.html

 

yes I have the expansion overflow tank ( stock ) but it was basically full and never puked until I put in a 180 ( trying to get my gauge to move off of cold).. I put in a 180, and now it moves to mid warm ( another issue), but i tested both thermostas with a stove and a pot of water and a thermometer and they both work correctly.. but with my 180, it pukes only immediately after engine shut off... no puking at all with my 160 installed...

 

195° is stock for 1980 L-82 ,,, also with todays fuel, 195°-200° is fine for burn off...back in the 80s there was different gas, todays i keep atock 195°