TommyV

This is a statement by a tuner on another site. Just wondering what the 160 Stat gurus think about it.

Statement: The myth about 160* thermostats

The graph below illustrates the importance of how critical optimum coolant temperature is to the longevity and performance of an internal combustion engine. Cool water makes good horsepower, to a point. Warm water minimizes engine cylinder wear, to a point also.
However, there is a "middle ground" where both optimum performance as well as minimal wear share similar characteristics. That "magic" number lies in the 175-180 degree range, which requires a 180 degree thermostat..

The all too commonly used 160 degree thermostat is way too low to be considered for performance or engine longevity. As the chart illustrates, engine wear increased by double at 160, than at 185 degrees. So then, why do the 160's exist in the first place? The 160's were commonly used in older, open loop cooling systems where only 6 pound radiator caps were used, and low 212 degree boiling points were experienced. In contrast, modern cooling systems can see up wards of 260 degrees in coolant temperature with radiator pressures exceeding 45 pounds. Many early hot rodders found the 160's to be better performing than the 190's, however, the in between "180" appears to satisfy both ends of the spectrum. The correct water temperature is required for the cylinders to achieve a minimum specific temperature in order to allow a fully homogenized Air/Fuel mixture to combust efficiently. Guess what the minimum number is… right! 180 degrees. Even so, you might see some still recommending the lower 160's, for no other reason than to possibly get that last drop of horsepower out, at the high price of dramatically reducing the life of the engine and it's internal components.



Reply: I see 181-185* with my 160* tstat. Tried it in a bucket of water before installing and it started opening between 160-165 or so.

A: You see 181-185 on the DIC and at the back of the motor. You're water temps at the thermostat are still 160. I think you're running too cool the water coming out of the radiator and running through the cooling jackets in the block is too cold. Your motor never gets a chance to get to optimal operating temps before it gets and jolt of cold water, especially that first batch when the thermo opens for the first time, it would be better if the block was a little warmer even if it is 25 degrees.

Reply: I thought it had something to do with the location of the sensor or thermocouple. Probably better then to keep my factory tstat and set the fan to come on sooner. In traffic with the factory tstat I would see 215-217* at idle. Did not like that high. About 199-200 at freeway speed.

A: I run 203 on the highway all the time, I've seen 225 twice in stop and go. That is 188 on the highway at the thermo and 210 in traffic. That is right in these motors ball park of where you want to be. I'd go with the stock thermo if I were you. More damage can and will be done by running that cool and nothing is gained. It's really not hot and I wouldn't worry until you see the temp rise above 230. I never run my fans 100% it's 90% max and that doesn't come on till 205. Stock fan settings are fine as well.

Corvette.C6-R

I almost bought one and was about to adjust the stock fan settings while I was at it. I want to keep my car at least till the C7 comes out so I'll pass on a new thermostat for now.

davekp78

Is this statement based on a conventional engine (iron block, thermostat located at the engine water outlet) or a LS series (aluminum block, stat at inlet)?

6Speeder

A: You see 181-185 on the DIC and at the back of the motor. You're water temps at the thermostat are still 160. I think you're running too cool the water coming out of the radiator and running through the cooling jackets in the block is too cold. Your motor never gets a chance to get to optimal operating temps before it gets and jolt of cold water, especially that first batch when the thermo opens for the first time, it would be better if the block was a little warmer even if it is 25 degrees.

He's wrong. He's thinking of the thermostat as a switch. It doesn't go full open at 160 and provide a "jolt" of cold water, only a trickle at best at that temp. The motor gets plenty hot before the stat opens enough to provide much flow and cooling. That's why you are seeing 180's, not 160.

AORoads

I don't know if his entire statement/thesis is wrong. I do know that if the system temp is at 180, 200 or more, the temp at the thermostat is NOT 160 simply because it's a 160 stat. It opens at 160. The water passing through it thereafter may or may not be 160 and probably never is, unless the outside temp is cold, the car is running at speed, or it's idling in cold ambient temps and engne fan is on.

On a summer day, with both fans set to go on and a 160 stat, I doubt if many will report a temp at the stat of 160, if they could even accurately measure it there.

plasticspider

I would like for someone who really knows about this stuff to answer the question on what makes a 160 thermostat better than a 180. I see some people list a 160 thermostat in their signatures like it is some awesome performance modification and would like to understand it better.

1. Other than the opening temperature are 160 and 180 stats the same? i.e.: same size opening and flow characteristics? What is the fully open temp of a 160 vs a 180?

2. If they are the same other than just opening up at a different temperature what is the benefit? If the engine runs at 200 on the hwy with the thermostat open then doesnt it mean it will run at 200 with a 160 or a 180 thermostat with the only difference being that the engine would warm up slower between 160 and 180?

3. From some of the posts I have read it seems that some people feel the 160 will cause their engine to run cooler at normal operating temperature but if they both open at a temperature lower than normal operating temperature it would mean they both are fully open at normal operating temperature. I have seen a few posts where people have questioned why their car still ran at the same temperature after changing to a 160.

4. Is a 160 truly a benefit? Is it a benefit to a stock car or is it something that really only benefits someone with certain other modifications like a cam, headers, supercharger, etc.

So anyway, I am asking because I want to know and believe there are some here that misunderstand what it is that a 160 will do for them.

95PoloGreen

I used a 160 on my last Vette. Temp readings stayed at a 190 degree range. I had 128,500 miles on that engine & it burned no oil at all. I changed oil every 3000/5000 miles. Before I did this the engine during the summer would be at or over 220 degrees. The lt/ls engines do not like to run at high temps like that.

ZPirate

I purchased a 160 degree thermostat a couple of weeks ago, but haven't installed it yet. I would like to know more about what others think too.

It seems to me that the 160 would be a benefit in warmer climates year round and in the summer almost everywhere.

retrorod

In my humble opinion, having actually built and maintained a bunch of LS powerplants, as well as everything else from a flathead Ford V-8 to exotic multi-valve, overhead cammed techie whizzer engines............the 160 degree thermostat on a stock/near stock street engine is right in there with those little gizmos that go into your air intake to "swirl" in incoming charge for high horsepower and even higher economy.......and probably magnets on you fuel lines to "align" the fuel molecules. My wife's flathead Ford roadster runs both 180 degree thermostats......my hot rod LS1 runs a stock 195 degree stat.

6Speeder

The computer pulls timing (decreasing horsepower) when the coolant gets in the high 190's. Also a hotter engine is more prone to detonation. When this happens the computer again pulls even more timing. Running your engine a little cooler via a 160 and changed fan percentages (on sooner, and faster speed) will help keep your car able to perform best.

FEAR

My Car With The Stock Stat Ran 200, With The 160 Runs Right About 180

MaxOctane

I see these 160 tstat threads pop up all of the time and there is always debate as to how they are better and what not. I'm very surprised that I have not heard any information as to how a tstat works. I see alot of people talk about them like they are a switch that opens and closes as such. I guarantee that this is not how it works.

Here, try this. Go to Autozone, and pick up a cheap tstat. Then, go home and place it in a pot of water on the stove and watch what it does as the water heats up. You see, the tstat operates by a piston which is placed in a wax. The wax has specific properties and at certain temperatures it will expand with heat and push the piston, opening the valve. You'll notice that the valve opens slowly, and will vary how much it opens depending on how hot it is. This is a very basic thermodynamics.

This means that a 160 tstat doesn't mean that your water temperature will always be 160 degrees. Your operating temperature will fully depend on what temperature the tstat starts to open and what temperature it is fully open. Many have witnessed here that with a 160 tstat that their operating temperatures were reduced from about 200+ to around 185 or so. This is reasonable and within the specifications of a well performing engine as described in the original post.

TommyV

He's referring to a LS engine.

AtlBlkZ06

I think you're right on the money there.

Shrike6

Just from my personal experience, the stock thermostat let my water temps get over 220* in traffic in the summer. Even at highway speeds, over 190*. We know the engine will have timing pulled at temps higher than 196*, I believe. After putting in a 160* stat with my other mods and tuning the fans to come on earlier, my water temps are still at or above 190* in traffic (even in cold weather), and drop to the 186-192 range on the highway. The 160* thermostat does not seem to drop the temp excessively in my engine.
GM

CodyC6

I know they are different vehicles, but both have the LS2. My Trailblazer SS suffers from heat soak and performance loss in the summer. The performance or retard-ed timing is very noticable with stock thermostat. I don't have any of those issues on my C6, with its 160 thermostat and tunes for fan control. On a hot day, I stay right around 183 degrees.

haljensen

This comes up every couple of weeks, the answers are always the same.

First; The t'stat temp is NOT the operating coolant temp. My 160° t'stat gives me 180° hiway and less than 200° heavy traffic in my South Central Texas temps.

Second; The LOWER coolant temp equals more power, the ECM pulls timing with increased coolant temp. Spend some time understanding the attached chart, notice that higher coolant temps reduce spark timing advance and that lower coolant temps allow higher timing advance. (Generally speaking, more ignition timing advance equals more power).

http://forums.corvetteforum.com/phot...a/1124/ect.jpg

Then, just to further confuse the issue look at the timing advance/retard from intake air temperatures.

http://i56.photobucket.com/albums/g1...sparktable.jpg

If you want stock power stay with a stock t'stat, if you want more power get a 160° t'stat and a CAI .

lurtonk

My experience with the t-stat is that lower opening degree t-stats will appear to keep the engine cooler during normal street driving but at the track nothing really makes any difference.

On a road course, after about 2 laps, the engine temperature will be 220+ and the t-stat becomes irrelevant. The only thing I have found that helps here is a larger capacity radiator.

c6dreamvette

I just put a 160 stat yesterday and quess what the cooling temp was all day even at the track 175-185 just because it say 160 does not mean it will keep your temp there it means it will open at 160

keyplyr

Talking with people who installed a 160° stat, they all eventually removed it and went back to stock. All said it took way too long for the engine to warm up, etc.