I never said there was anything wrong with a 160 stat under the right circumstances, I offer this all the time to people as a help with keeping their car in "the sweet spot"
Here is a typical response to the tread I made a few days ago. Many people here who argue with me over this point have seen me post this hundreds of times over the last five years. I dont make this stuff up, I made my career on it. All the administration here know exactly who I am and my credentials..

http://forums.corvetteforum.com/show....php?t=1364594

Two issues with this very specially designed engine.
One is running the car cool enough to get the optimum hp.
But at what cost?
While running at 160 or 170 may give you a few more hp, it will definitely cause premature engine wear... the LS/X engine was tested over hundreds of thousands of hours in the engine test lab.
The C5 has a definite sweet spot: for power and engine life..... keeping it there is the trick..
the sweet spot is between 180 and 200 coolant\and 200 to 210 for oil...
Anything lower than that for a sustained amount of time will be internally destructive.
This amazing engine is an aluminum alloy that was designed to see 200,000 miles...
Many of these 60's thinking people think this is a cast iron engine that back in the 60's was lucky to see 60,000 /80,000miles.

Some people here think their liberal art degree qualifies them to speak about this engine and its design..

What I tell most people in this forum is to be careful who you listen too...when people bring up their hot rods and engine build from the 60's and seventies... throw up a red flag because that technology went out went we got flush toilet.

So many wannabe's here, so many hero's of technology that dont know
internal stress from structural deformation under load.

Every one has an answer, but few have a clue.
BTW I run a 160 stat in my car from may until October to maintain the sweet spot. I adjust the fans to come on sooner, and I clean both the condenser and the radiator every spring..I put the stocker back in in Nov and run stock fan settings.Many people think that when they look up under the front air diffuser and talk about all the leaves that get caught up there... they think they are looking at the radiator, which they are not, the radiator sits two inches behind the condenser and is hidden from view.,. it requires alot of maintenance to keep it like knew...I get a half a cup of sand dirt fuzzies and grass from the cleaning of my radiator , this doesn't include the leaves and cigarette buts and other stuff caught in the condensor...
the combination of the two heat transfer cores are the reason you get little air flow after the fans shut off.

Be careful who you listen too, and who has the right credentials to discuss this car.l.. BTW there are some very intelligent, tuners, engineers, and mechanics here.. I can think of a dozen or so of all the people who claim to have some knowledge.
Bill aka ET

Two issues
1) optimum hp output without costing engine life.
2) internal integrity using the right oil flow rate, viscosity, expansion factor, particle suspension.
keeping the LS/X engine in the sweet spot will insure the longest amount of engine life with the best hp output.

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The point to all of this is: if you live in a cold winter climate where temps get below freezing, you do not want to run your car @ 160 F coolant, this will keep your oil temp at 170 which will cause severe damage over time.. The car was designed to get 200,000 miles you will never see that if you run for hours @ 160 F. Some Tuners fail to tell people all the time that they can not run their car at these temps in the winter... Keep it in the sweet spot..

 

Evil Twin, you confirm that their is a sweet spot, so I am not nuts.
I also go along with what you are saying. I have a question in all the testing with the ls/x motors did you see any extra ware
during warm-up with a lower t-stat. I notice, it will take longer for the engine temp to get hot (187) then with the stock t-stat, but I figure good oil flow and the moble-1 take care of any extra ware. Can you shad some light on this.

 

If you want too run your car at optimum efficiency focus on the sweet spot, and do whatever it takes to keep it there...
I change my stat twice a year, every year, it takes five minutes to do it, and I loose less than a pint of coolant in the exchange...I have posted this hundreds of times also..

LV Vette keep that 160, for the hot months, learn to swap it out... it will make your car run better if you keep it in the sweet spot.
do a search for my posts on this.... make sure you use anitseize on the housing and make sure you use the proper torque.

 

Well at least you are stating some of the issues, that's good. But I see some contradictions. YOU run a 160 part time, which as everyone here who runs one knows, will keep your coolant at/about 170 at highway speeds, even when it's hot outside, but tell others to run the stock one, AND say there major problems to run below 180?????

Is it "premature engine wear", or "structural deformation under load", or what? Some of us aren't lib art majors (No offense to you who are), and have studied/tested/worked issues like these, and could, maybe, understand what information you have to share.

If the issue is wear caused by oil contamination from lowered oil temps, then following the oil life algorythm for earlier changes (along with the proper oil) should eliminate this concern.

If the issue is wear/structural deformation caused by the alloy engine not being at correct operating temp then why does the PCM allow full throttle/high rpm/high load operation at MUCH lower temps than 170?

You talk about engine life of 200,000 miles. Will running it 20 degrees cooler cut off 50,000 miles of life? 100,000 mile? Based on what?

 

Try running your car on the highway here in Vegas in the summer. Using a 160* or non at all….YOU WILL NOT SEE 170* PERIOD.

Thanks ET, that is what I plan to do. And yes, it is easy to change out, just a little messy.

Thanks,

Clayton from Las Vegas

 

The only time it is messy is when you actually swap out one stat for the other...having the new stat ready, O ring greased and both housing bolts painted with antiseize. Pulling the cold stat housing from the motor and instantly replacing it with the other takes less than five seconds. That the only time any coolant is lost.. You can hold the new hosing against the engine block with one hand while putting in bolt #1.... once bolt # 1 in snugged up you add bolt # 2 and torque to spec... if you have your torque wrench ready and your other stat ready for the transfer you will loose less than a pint of coolant.. When you pull the radiator hose off the housing you tuck it up under the heater hose leaving the opening higher than the radiator, and no coolant will escape.

 

a couple of other things to consider are also the road temperature.. I have shot thermal imaging studies of blacktop roads and have seen temps of 140/150F in a 90+ day. You wont get much cooling from those temps...when idling... the shear rate is what lowers temps...
So even when its 50 degrees outside the road surface could still be 100 F. There is also a 30/50 degree difference in a concrete slab as oppose to blacktop.
Summer time heat greatly effects heat transfer and also tire pressure... both need to be monitored when your driving on roads that exceed 125 F.Also running too cold in a winter time environment will indeed keep the car in open loop longer thus allowing the air pump to flash off the cats... you do not want to buy a set of cats prematurely.. too cold effects many operational perameters..If you try to keep the car in the sweet spot summer and winter, you will get the most amount of HP out of your car with the least amount of engine segregation.. If you push cold temps for more timing it will cost you, keeping the car in the sweet spot in the hot summer sun will allow some latitude in timing...Tuners push for this sweet spot... meaning they want to see the car around 180, not 230... that 50 degrees is a lot with this motor.,..thats why the PCM was designed to correct operational temps between 190 and 235.

 

I guess I don't understand your post. He says don't run a 160, cause it'll damage your engine. THEN he says it'll be OK half the time. Now I'm wrong cause I say go with a 160? Do you really think it will run cooler where you are with a stock stat???? Good luck to you.

 

Keep this is mind as well....when you change stats, the way you set the fan temps in the pcm have a huge effect on final temp...it isn't enough to just change the stat ..Keep in mind, changing the stat dosen't change the fan temps....They will (without tuning) always come on at the same time.....

Chuck CoW

 

ET, what sort of engine life reduction might we expect with a 160 thermostat? 2%, 10%, 20%?

 

ET,

I tried to send you a PM or e-mail. Any way this can be done?

Clayton from Las Vegas

 

If its 30 degrees outside and your doing 60 mph on a two hour trip, your coolant with a 160 stat will be at 160/165.... oil will be close to the same... we did studies on cold flow engines that saw cam errosion and bearing wipe in 60/100,000 miles.. I had all the data 5 years ago, but I suggest you do what you want....
Im really tired of most of this stuff....

 

Well you're back at it I see. I won't rehash all the earlier mis-statements. But your last post has two statements which you try to imply one leads to the other. It doesn't. You give a scenario in which using a 160 stat could end up with oil temps in the high 160's to low 170's. Then you say that:

we did studies on cold flow engines that saw cam errosion and bearing wipe in 60/100,000 miles..

Implying that if you run a 160 stat that is what you face. Cute.

How about telling the truth, that the temps on cold flow engine studies (where there were cam and bearing issues) were significantly cooler than that?

An engine operating in the 160's and 170's is fully warmed up and not in cold flow. Cold flow testing is simulating startup conditions, before the engine is warmed up. Do you know how many miles it would take for a normal driver to accumulate 60 to 100 thousand START UP MILES? Give me a break.

If these issues were present then oil analysis would show the presence of bearing metals. Lots of folks here do oil analysis, some run 160 stats. I haven't seen one report of bearing wipe listed on this forum.

Why do you persist in these scare tactics using mis-statements and half truths? You make wild claims about these super special aluminum alloy engines not being like those in the 60's, and statements about structural deformation under load. Hey, GM was producing and fielding aluminum alloy engines in the 60's, other car makers did the same in the 50's. It ain't rocket science. Neither, by the way, is structural deformation of aluminum alloys under load or extreme temperatures. I did studies on that stuff for the Air Force Weapons Lab, back in the late 70's. It ain't rocket science either.