Thermostat poll, 160 vs 180

[Redbob]

I've been running 160 thermostats in my '89 since '93, something like 80,000 miles, and the only thing I notice it that it takes a little longer to overheat in summer traffic, since it's starting from a lower temperature. Runs fine.

And that "thermoshock" thing sounds like a bunch of hooey.

 

[Redbob]

Oh, yeah; and I do live in Texas, where a mild summer day is anything under 100, and 105 at quitting time is very common.

 

[Rogier]

So, back from skiing in Austria.

Thermoshock is ofcourse a technical term that exsists. But I am refering to thermoshock in an corvette engine. (And then I don't mean a nitrous 500 bhp+ engine! ) In an standard or almost standard engine thermoshock will not occur.

For the rest I am amazed how many of you drive around in a corvette that overheats. It's basically very strange. Because of the following:
either a 160 or a 180 degree thermostat opens whenever the engine reaches these temperatures. When it's open the full cooling of the engine is working. If the engine then still overheats it doesn't really matter which one you mount. The engine will overheat anyway. It's only somewhat later.

If you have trouble with your engine overheating because of high ambient temperature's why don't you just fit an aftermarket bigger radiator? It's an easy job and doesn't have to cost very much. Chipping your fans or changing your thermostat won't help you really. It's only an easy way to mask the real problem.

 

[Redbob]

One more thing about "thermoshock:"
Once your engine is up to operating temp, the thermostat doesn't open and close, but stays in pretty much the same position constantly except as load conditions change, and then it slowly opens or closes to compensate, until it's all the way open with the engine fully warmed up.
Once it's there, it matters not one little bit whether it's a 160 or a 190; anyone running his car hard enough for "thermoshock" to be an issue, before the engine is fully warmed up, deserves whatever ill befalls him.
---------------------------
As for turning on the cooling fans "masking the real problem:" if I can turn on the fans and the car then does not overheat - what's the problem?
Larger radiators are just more weight, and if I wanted an overweight pig, why, I'd just have bought a Mustang!

 

[douglas foster]

just replaced with 180 , but i really feel that cleaning out the front of your radiator makes the real difference. also added a front inlet grill, from Ecklers.

thank you

ps. returned the grill to Ecklers was not what i expected, you have to remove part of front inlet to make it work. I want to keep my vette all ori. Also the 180 does not keep my vette cooler in stop and go traffic, just on normal driving speeds. Instead of 195-200, it stays at 185-190 now. It does not perform better, but my mind stays cooler.

 

[Mart]

Hey Redbob,

You got me a little confused by this

and then it slowly opens or closes to compensate, until it's all the way open with the engine fully warmed up.

Going by this quote, as soon as the engine is warmed up the thermo is open and you are at full coolant flow capacity. Now explain exactly what warmed up is ???????

Mart

 

[Rogier]

slowly opens and closes? -> no way.

As the temperature rises.. (and it will, either driving hard, driving not at all whatever) there comes a point (160, 180 etc. etc.) on which the thermostat will open. There's a small bi-metall spring inside that reacts to temperature. Once it's openening (this goes not really fast) the coolant starts using the large circuit. (via the radiator). The radiator will then cool the coolant when driving with ridewind. When standing still the fans will do that job.

If the fans / ridewind are not capable of cooling the coolant down you should check your radiator and not the computer setting the fan temperature. The fan should ALWAYS be able to get your temperature down! It doesn't matter from how high.

In math: The engine produces energy... this causes heat. The cooling system of the engine is designed with an overcapacity. This means it will always "win" from the produced heat. Resulting in a dropping temperature. To prevent the engine from cooling down to much they installed an thermostat. Fans are only there to simulate ridewind. If they cannot do the job, reprogramming them will only delay the problem.

Best regards,

 

[vettered91]

So, back from skiing in Austria.

Thermoshock is ofcourse a technical term that exsists. But I am refering to thermoshock in an corvette engine. (And then I don't mean a nitrous 500 bhp+ engine! ) In an standard or almost standard engine thermoshock will not occur.

For the rest I am amazed how many of you drive around in a corvette that overheats. It's basically very strange. Because of the following:
either a 160 or a 180 degree thermostat opens whenever the engine reaches these temperatures. When it's open the full cooling of the engine is working. If the engine then still overheats it doesn't really matter which one you mount. The engine will overheat anyway. It's only somewhat later.

If you have trouble with your engine overheating because of high ambient temperature's why don't you just fit an aftermarket bigger radiator? It's an easy job and doesn't have to cost very much. Chipping your fans or changing your thermostat won't help you really. It's only an easy way to mask the real problem.

I don't think a bigger radiator will fix nothing if you don't put enough air through it. There can be two different problems here; if the engine gets hot in stop and go traffic, a 160° stat and both fans on at somewhere around 170°-175° can be the solution.... (if it's not get the bigger radiator WITH THE 160° AND THE FANS ON). But if the overheat goes on at highway speed then there's radiator time!

 

[elints]

If you have electric fans, they should be set to come on just above the thermo setting. The should turn off 10 to 20 degrees below the thermo setting. A 180 degree F thermostat is fine if the cooling system is sufficient to maintain that temp. The fans sensors should be measuring the radiator intake temp and not mounted on the engine.

Let the fans control the radiator temp and the thermostat control the engine temp. In order to cool the engine the radiator needs to be cooler than the thermostat setpoint. Without doing this you are letting the ambient air temp control your engine temp when the ambient temp is high and the engine temp will rise high enough for the thermo to open fully. This greatly decreases transient times of the coolant through the radiator making the cooling efficiency of the radiator even worse. If the cooling system is properly controlled and has the capacity you should see the engine temp close to the thermostat setting.

 

[dwsjr50]

180 degree T-stat

I have had my vette for 2 weeks. I changed it out there was a 180 which what I installed. The electric fan comes on at 230 + or -.

 

[warp8]

Well I have seen a lot of threads on this but no definite answers, so maybe a poll will help, mainly because I am in my garage with a 160 in one hand and a 180 in the other.

lets see what you guys think.

Mart

No thermostat!

Florida

 

[Louis Bartay]

No thermostat!

Florida

Did that to a older car once and it ran hot as the water went thru TOO fast. 180 winter,160 summer.Too Hot in the Summer here in Texas.

 

[grapeknutz]

I know Im late on this post but;
Originally Posted by JohnZ
A 160 'stat will have absolutely no effect whatsoever on your summer engine operating temperature, as it's full open all the time anyway; the 'stat only controls MINIMUM operating temperature, like in the winter, when low ambient outside air temperature allows your radiator to cool the engine down to or below the 'stat rating. 160 degrees doesn't do you much good in cold weather when you need the heater to operate, and it also won't let the oil get hot enough to boil off condensation and blow-by contaminants which then stay in the engine, get acidic, and form sludge.

160 'stats were used in the old days (40+ years ago) when cheap alcohol-based anti-freezes were used, so the alcohol base wouldn't boil off; they have no place in a modern cooling system, and have no benefits at all (except to the people who sell them and tell people they will solve overheating problems - they won't).


Thats wrong! If the radiator is running good and not clogged the theromstat will cycle NOT STAY ON ALL THE TIME!!! if it stays on all the time it will either be too cold as the radiator will over cool or if the radiator is clogged and the stat is open all the time, it's is on the verge of over heating!
Stay with the 180 in the standard engine or with the reverse colling system (LTs) use the factory stat as it will work best!

 

[Louis Bartay]

I know Im late on this post but;
Originally Posted by JohnZ
A 160 'stat will have absolutely no effect whatsoever on your summer engine operating temperature, as it's full open all the time anyway; the 'stat only controls MINIMUM operating temperature, like in the winter, when low ambient outside air temperature allows your radiator to cool the engine down to or below the 'stat rating. 160 degrees doesn't do you much good in cold weather when you need the heater to operate, and it also won't let the oil get hot enough to boil off condensation and blow-by contaminants which then stay in the engine, get acidic, and form sludge.

160 'stats were used in the old days (40+ years ago) when cheap alcohol-based anti-freezes were used, so the alcohol base wouldn't boil off; they have no place in a modern cooling system, and have no benefits at all (except to the people who sell them and tell people they will solve overheating problems - they won't).


Thats wrong! If the radiator is running good and not clogged the theromstat will cycle NOT STAY ON ALL THE TIME!!! if it stays on all the time it will either be too cold as the radiator will over cool or if the radiator is clogged and the stat is open all the time, it's is on the verge of over heating!
Stay with the 180 in the standard engine or with the reverse colling system (LTs) use the factory stat as it will work best!

If you have your fans on sooner and 160 stat it will run cooler, as we have months at a time of over 100 degree temp here in Texas. Tried it both ways (stop and go traffic for an hour in 100 degree summer)in the summer and a 160 opens sooner so it takes longer for the engine to get hotter. Notice in my other post I go back to 180 in the winter and have to fans back to the stock settings.

 

[diesel1456]

160 stat

i have an 89 and i changed mine this past summer and i love the results i also changed the chip so my fans come on early. now when i sit in traffic on a 95 degree day with the ac on she won't go over 200 i don't use the car in the winter so heat is not an issue. I also got the same gas milage as with the 180. For me you can say it's just piece of mind not seeing that temp hitting 210-220 to hot for me.
Rich

 

[Louis Bartay]

i have an 89 and i changed mine this past summer and i love the results i also changed the chip so my fans come on early. now when i sit in traffic on a 95 degree day with the ac on she won't go over 200 i don't use the car in the winter so heat is not an issue. I also got the same gas milage as with the 180. For me you can say it's just piece of mind not seeing that temp hitting 210-220 to hot for me.
Rich

I just changed back to stock for winter, and my temp gets to 230 in traffic before the fans start cooling things down, it was 60 yesterday morning going to work. And I have a new radiator and stat. The reason for summer time with the fans on sooner.

 

[code5coupe]

For me you can say it's just piece of mind not seeing that temp hitting 210-220 to hot for me.

The thing you must keep in mind is this: while 220 may be too hot for you (and your peace..not piece...of mind), it is not too hot for your engine. The Corvette engine was designed to run quite comfortably at that temperature.
In fact, 220 for your engine is analogous to 72 degrees F for you.

(Each of us think we know more than the hundreds of engineers employed by GM, don't we? I know I do..... )

Larry

 

[Louis Bartay]

The thing you must keep in mind is this: while 220 may be too hot for you (and your peace..not piece...of mind), it is not too hot for your engine. The Corvette engine was designed to run quite comfortably at that temperature.
In fact, 220 for your engine is analogous to 72 degrees F for you.

(Each of us think we know more than the hundreds of engineers employed by GM, don't we? I know I do..... )

Larry

You made me think on that post. But when it gets to 230 and the fans are just starting to try to cool it down(100 degree day) and you are in bumber to bumper traffic for 45 minutes it does not take long to see it at 250. So when I reprogram the OBDII to turn on the fans soones (Hypper-Tech Power Plus) the next day at 100 degrees outside and A/C on 230 is max. So you tell me, new radiator, hoses and water pump with no crud inbetween the radiator and Run the stock program and I see my LT4 heading for 250 or turn on the fans sooner and see 230. I am no Brain Doctor but I can see the difference and not have to turn off the A/C just to get home with out the temp going past. 250.

 

[code5coupe]

it gets to 230 and the fans are just starting to try to cool it down(100 degree day) and you are in bumber to bumper traffic for 45 minutes it does not take long to see it at 250.

If your cooling system is functioning properly, the fans will prevent the temps from reaching 250.

I see my LT4 heading for 250 or turn on the fans sooner and see 230. I am no Brain Doctor but I can see the difference and not have to turn off the A/C just to get home with out the temp going past. 250.

See comment above.

I've been stuck in stop and go traffic in 112 temps before. The coolant will reach approx 230, the fans will kick in, and the coolant temps will drop back down to about 210. Repeat cycle.
If you are seeing 250 degree coolant temperatures, then something is wrong with your car.

 

[Louis Bartay]

If your cooling system is functioning properly, the fans will prevent the temps from reaching 250.


See comment above.

I've been stuck in stop and go traffic in 112 temps before. The coolant will reach approx 230, the fans will kick in, and the coolant temps will drop back down to about 210. Repeat cycle.
If you are seeing 250 degree coolant temperatures, then something is wrong with your car.

New engine just rebuilt, Eagle Crank, Eagle Forged SIR rods, Speed Pro Hyper pistons 11 to 1 compression .020 block was squared and decked .010 and all rotating parts Balanced at the machine shop. Oh I now have the LT4 Optional Hot Cam with new S.I. SS Claimer series valves and new Comp springs, heads were decked .010. It has just over a 1000 miles on it and I have changed the oil and evey 500 miles. Used castrol GTX until 1500 miles the I will go mack to mobil 1 5/30. I am guessing the new tight engine and the new cam is making it run hotter than normal. Just spent $7,500.00 on parts and labor. New water pump,hoses and new opti-spark, plug wires etc. You can see I have had everything checked or just replaced. I have had this 96 LT4 Coupe for 8 years and I like it better than a new one, but that is just me. At the 1000 mile mark I took it back and had all the fasteners checked and the cooling system checked to make sure all is OK. As I posted I did not like seeing it get near 250.