What are yall's coolant temps with the 160* thermostat? I watched mine this weekend while driving around town. It would run 170-175 on the interstate. In stop and go traffic with ambient temps above 95 Deg, mine would start to creep up to around 200 Deg. I think it got as high as 205 at one point.

I tried blowing the radiator out and washing it out with the water hose this weekend, but not sure how effective it was if I am still seeing 200* idling in stop-and-go traffic.

I am running in a HPDE this weekend in Cresson. I am worried that I need to pull the radiator and clean it right prior to going out there.

 

Those temps are fine on the stock rad.
The engine is designed to run at 210-225.
If you do not have your fans programmed to turn on at a lower temp you may consider doing that or a simple switch to turn the fans on whenever you want.

 

Copied from a 2005 Evil Twin post

IT is a tight clearanced aluminum alloy engine. it has a sweet spot. Every tuner knows this... keeping it in the sweet spot is what everyone strived for... the sweet spot is 190/200 coolant and 200/210 oil temp.

I was fully involved in the prototype design and subsequent launch and post launch debugging of this car, I have 35 years of automotive engineering under my belt I am an SAE Sr Engineer. This motor is almost bullet proof with the right configuration, that is, the right oil, and the motor running at the right temperatures, both oil and coolant. This allows proper lubrication , suspension of contaminants in the oil, and reduction of thermal breakdown... The sweet spot was established buy thousands of hours of run time while developing this LS1 design... simultaneous test were done to develop the algorithms for the oil life monitor, under all types of loads and driving conditions.. unfortunately WE build cars that run in Minnesota in the winter @ -30F, and the same car has to run in the Arizona desert @ +130F. The hp vs. cu. in of the LS1/6 was developed through tight clearances and a lubrication system that needs the right combination. Running an LS1/6 at 160 F will cause premature carbon build up...increase compression ratio, cause automatic Knock retard sensors to retard the timing, thus causing a loss in performance.. WE ( GM engineering ) have seen this scenario so many time we have developed the famous GM De carbonization process... these cars run anywhere from 190F to 235 F. and that is normal in the general design.. the PCM helps to compensate for this variance with appropriate fan settings.. but the car runs best at one temperature..both coolant and oil.. but it will function and various temperatures.. the sweet spot is insider information..keeping it in that sweet spot is what a well tuned engine wants to see.. and where optimal performance is gained...without loss of internal integrity
This is similar to the tire pressure sticker 30 pounds cold on the door... it is just a generic tire pressure sticker setting.. so customers wont use the max pressure settings on the tires,..,, but that 30 psi sticker is just a general statement.. the tires perform best at 30 psi.. but if you set them cold at 30 psi and get out on a Hot black top on a summer 90+ day road where temps can reach 160F, those tires will increase to 36 psi... that is not where they should run... I never allow my tires to get over 30/31 psi "Hot" that's where they perform,, they do not perform cold...so why set the temperature there. Tire pressure is so critical... Nascar pit crews monitor track temperatures all day long and adjust tire pressure accordingly. Two psi can give you better mileage and more tire life... these are critical in Nascar. A few extra laps on the tires and better fuel economy are all part of a well tuned Nascar. Not as critical to a daily driver, but the concept is the same... I consistently get 33 mpg on the highway with my car.. and I can get 45,000 miles out of a set of tires.. because I know what I am doing.. my car is tuned for me and where I live and how I drive... I have been trying to teach this concept to people here... many have adopted this, and other do not..
Running too hot will also cause pre-ignition, and the knock sensors will cause timing retard, loss of performance, and poor gas mileage...esspecially for those that can only get 91 octane gas.
keeping the car in the sweet spot is a function of a custom cooling system adjustment. I use a 160 stat and adjusted fan settings in my car from late April through September, thi9s keeps my car in the sweet spot through the summer. I use a stock stat and fan seeting through the fall and winter..
It takes five minutes to swap stats, with very little ( less than a pint of coolant loss).
This sweet spot concept is used by all tuners, that why they put a 160 stat and adjust fans settings in cars with mods. Summer driving conditions and a 160 stat will never allow your car to see actual 160 F coolant temps. Ambient air will not transfer heat when its 80 to 90 F.
a 90+ day on a black top road can yeild 140/160 F surface temps. So there is very little cooling from a bottom feeder air flow system. Your cooling system needs alittle help to gain optimum performance... Running Too Hot, is a definite NO NO........
Bottom line here..

 

Fans have been tuned to come at lower temps.

 

I think you're fine but you could get these 2 air/water wands if you want to thoroughly clean your rad.

http://www.ebay.com/itm/Tractor-Radiator-Genie-New-/400540264007?pt=LH_DefaultDomain_0&hash=item5d420f6647

 

I agree with what you are saying. I am concerned with the lack of keeping it below 200 Deg in stop and go traffic that once i hit the track, temps will creep up beyond that. I would rather not be sidelined at a HPDE because my temps are 250+.

So is this normal for those of you that closely monitor your coolant temps in the summer? Or do I need to clean the radiator???

 

My temps are around 194 for water and 208 for the oil. I live in Florida and sent the ecm to ECS to have it programed

 

Good info. Is that with 160 Tstat?

Also, anyone who can chime in thats run a road course or HPDE.

Thanks to those who are chiming in with actual readings. Wasnt trying to turn this into a operating temperature debate.

I just want to know if my car is going to overheat or not.

 

What is the opening temp of the stock thermostat? I was thinking about a 160 myself but concerned about the "too cool" issue...

 

Great info and always reassuring to hear they put so much time and research into this motor! Thanks for the share!


Of course, it's hard to say if it will overheat or not. But your car seems to be running at normal operating temps so hopefully it will be fine. I'm a big believer in, "If it ain't broke, don't fix it". Murphy's Law says you'll go to pull the radiator and something will actually break and then you can kiss HPDE weekend goodbye.
Also, someone brought this up in another thread. Water boils at 212* so your oil temps being about 212* is actually a good thing because it removes the water that builds up leading to a longer living motor. If you find you are running too hot in your oil temps then you can always get an oil cooler for that.

It's all trial and error, especially when it comes to racing!

Have fun!

 

The thermostat controls what temperature the coolant begins circulating through the radiator, but by no means is it the temperature the car will run at. That's strictly a function of how much heat you make, and how efficiently your system can remove it.

If you are afraid that your cooling system cannot remove the heat well enough at track speed a thermostat is not what needs to be your primary concern.

Similarly, fans are not doing anything for you at track speed, the programming for them wouldn't be relevant.

You need to be looking at a more efficient coolant mix (water wetter?), more efficient ducting in and through the radiator, maybe a better radiator, maybe an oil cooler.

But you'll be well above the temperature that the thermostat opens, be it 160, 170, or 180. the point is moot. Look elsewhere.

 

I know you guys are trying to be helpful, but I'm not asking about if I should have a 160 tstat or a 195 tstat. Nor am I asking how a cooling system works.

All I am asking from those that have a 160 tstat is what temperature it normally runs. I realize it wont hold 160, the tstat doesnt go full open till 172ish (hence my temp at freeway speeds). But I want to know where it runs under HEAVY use so I can diagnose if I am getting proper cooling from my radiator or not BEFORE i take it to the track this weekend. My comment about the fans being corrected to proper temp IS relevant because I was sitting idling in traffic, so only my fans are doing the cooling. My question is am I getting adequate cooling from my radiator or is grass/dirt/debris plugging it off so that I am losing some cooling capacity. If the latter is the case, then I SHOULD be concerned this weekend at HPDE.

Thanks to those of you that have submitted your responses that are relevant to the conversation (stragelove, radical, bad455).

 

If you are running 200 in stop and go traffic and your fans are not running, I would say your radiator is doing a great job.

 

They were at full speed. A/C was running max. Thanks.

 

Then it's hard to say what's going to happen at the track. There are so many variables.

 

Which is why I was asking others what they see if they monitor coolant temps regularly. I'm just trying to figure out if what I am seeing is normal or an indication of an issue. I realize actual results may vary.

Sitting idling in traffic with A/C running max is about the most heat load on the cooling system that I can put it through prior to going to the track. And I suspect that the heat load on the cooling system will be much greater at a HPDE.

Yes, I know the fans wont be running (>35mph) at a HPDE. But if the radiator isnt getting adequate air flow, then the problem still exists.

In the amount of time I have expended coaxing CF to arrive at an understanding of what I am asking, I could have pulled the radiator and cleaned it already. LOL. Too bad im at work

 

73 - Sorry I didnt give this post some . I am a Chemical Engineering PE (not SAE engineer), so I love reading stuff like this that is engineering ****. Just didnt help with my issue.

 

I'm the original owner of my car, have had a 160^ t-stat in since about 3 months of ownership, cooling fans set to come on earlier than OEM settings, and live in N. Texas heat. I do not do HPDE's with the car, so I cannot speak to that. I also have a built motor, running twin-turbos, and have kept the stock radiator.

I realize driving style can have a lot to do with things, but I monitor my ECTs consistently...and in stop n go with AC blowing in 90-95F heat, mine will creep up to ~194^. Once moving at even a light clip, temps will drop to the 184-186^ range.

Not sure if this data point helps you much or not, but thought I'd throw it out there.

 

Excellent response. Thank you sir.

 

I have a 160 tstat and my fans are programmed to come on earlier. In summer stop and go driving I have seen as high as 212* once. Normally in the summer it runs around 190ish give or take a few degrees.