First of all, zero difference from fbody and C5 LS1. Second, my UOA's have no differences from stock to 160. so obviously the 10-15 degrees isn't producing more wear. Even stock my oil temps wouldn't go above 200 on a cool day, and I'm still getting factory oil temps with the 160 tstat. Also, I have no idea why the correlation between coolant temps and oil temps keeps coming up they are completely different. You say "we at GM" but you live in PA.. how's that?

 

Bill, you bring up a question that has puzzled me for quite some time. Yes, I know that in a previous post I said that I installed a lower temperature rated t'stat. However, even with the OE t'stat in place, I'd have to drive my car 20-30 miles, sometimes more, just to see the oil temp get to 200*, according to my DIC. Is this a normal condition?

I fully understand the need to get the oil hot enough to cook off condensation. Before I retired, and I was working full time, my route to work was 24 miles (each way) of mostly expressway driving. That usually did the trick. I retired several years ago, and now work part time. My job is only 3 miles from my home. Obviously, that won't get the car fully warmed up, so I do take the "scenic route" to work, but it's not practical to add 20 miles of "cruising" to get to work, and doing it on the way home isn't going to happen.

Any thoughts?

 

What is your opinion regarding a 160 thermostat for a Supercharged LS1 with 8 psi of boost at WOT and a moderately heavy footed driver
I don't think it would last 200k miles.
I'm running a 160 now but may consider a 180.

 

I don't have any test data to support an answer. AS you know everything we do as design engineers comes with test data. Sorry I cant comment. The idea is to keep the oil in the sweet spot so the top end can get oil under any circumstances.
As far as the Genius who says the LS1 in a Y body is the same as the in a F body, again he shows his cluelessness.

While the engines are almost the same, the application is different. The LS1 in the F body does not require the C5 oil spec for heat saturation because the F body is not a bottom feeder like the C5, has a different cooling system, and breaths air through the grill which is 28 inches about the surface of the road and draws ambient air temps, not road surface air temps that can reach 140F in a bottom feeding Y body. So again for the genius, you are showing your ignorance.

 

One WOT pull = 200+ degree oil temp regardless of thermostat.

 

As long as I have been here, I've tried to explain things in simple terms , so anyone could understand.
this moisture issue seems to be the main focus of many people.

Consider this; an LS1 through the -90 degree crank angle will see about 500 F combustion temperature @ 2000 rpm through + - 0 crank angle. and at a + 20 degree crank angle will see 2500 F combustion temperature at 2000 rpm through a + 90 degree angle where combustion temps bleed off.. There is little concern for moisture in the oil. There is some concern, but not all the focus that people seem to gravitate too. The combustion chamber acts like a moisture filter to instantly vaporize any moisture. Moisture bleeds off via surface tension not the boiling point.

That's exactly why the OLM works so well.. you get cold starts and short runs, and your own driving style.. some people never get out of fourth gear running around town. We developed the OLM to address these driving conditions.. so the OLM would recognize conditions that would break the oil down quicker and reduce the amount of time the oil could safely be used. This I change the oil every 3000 miles or 5,000 miles or I had a guy argue with me that he use 15,000 mile extended life oil and he doesn't change it until it has 15,000 miles on it. Even if it takes two years. That's why there are really some bad choices in buying a used C5. AS I've said from Day 1 Use the OLM it works and is a contributing factor in the life of your engine. It works so well that we boosted the base line from 10,000 miles to 15000 miles in 2000. That doesn't mean you can run your oil for 15000 miles. That's the starting point for the OLM to calculate the oil life remaining.
Bill aka ET

 

Ok then.
My car only has 25,000 miles on it since I got it last July with 20k on the clock and I may put 5-10,000 miles on it per driving season from now on.
I have the intercooler in front of the rad and AC as well.
Plus I rarely drive the car for longer than 20 minutes at a time.
It was getting up to 210 without the supercharger in August.
The engine is stock with shortie headers but the car now has 540 rwhp and 500 ft/lb of torque.
When I bring the car back out in March or April I will pay close attention to the temperature reading and make my own judgment
as to which thermostat to run and when based on my driving.
I'll leave the fan turn on temps as they are with my dynotune.

 

fbodies aren't bottom feeders?? could have fooled me!


yes, both the LS1 C5 and LS1 fbodies are identical even 02 fbodies have LS6 intake. the application is irrelevant. I have UOA's to prove the oil in my Z is fine. you on the other hand have zero proof.

 

Here is my point. If you drive your C5 with a 160 stat in it and the outside temp is 20F. and you are driving on a highway doing 60/70/80. your coolant will get down to 160. That is with a real 160 stat. running at 60/70/80 with coolant @! 160 . the chances for shear are very high, and an hour at this shear rate will destroy the engines ability to lubricate the motor properly. Tring to keep the coolant around 190/200 F and the oil at 200/220 is ideal. how you get it there is adjustable. This trade off is like that Old frame commercial.. pay me now or pay me later. You can get more HP with a colder engine but you will pay for it later. but then if you don't care about later then you can dump ( sell ) your C5 in the hands of someone who will pay for it later. It doesn't take a genius to recognize that pushing the car beyond its design capabilities takes away some of the designed in longevity. I have dozen of guys PM with stock or close to stock engines that are getting 300,000 and 400,000 miles. That doesn't mean that I am against modifications.. it just means that those who heavily mod their engine will not see the same longevity as those who don't. The real professionals here who track their car know up front that things break , and they break much quicker when you push them over their design. The thing that pisses me off is that some people think they can heavily modify their car and think nothing can go wrong and do not have the ability to grasp the concept that it will. The dangerous ones are those who talk about heavy mods with no complications or consequences. That's why I say be careful who you listen too here.
Anyone can buy a cam, heads or a supercharger, and there are many tuners and builders who will gladly take your money. That's what they are in business to do. I have nothing against these vendors, builders and tuners. My only advice is not to go into this blindly. You want the biggest , baddest, fastest car, or for many, bragging rights to say they spent the most money, go for it. but don't think that there wont be any consequences. About 5 % of the 30,000 people who have pm'd me tell me they wish they never modified their car. About 20 % have told me the C5 is a great platform to modify. Many have not paid the price " Yet " for their desire to make it better than we did. AS far as aesthetics like the radio and the leather etc... we didn't invest much in the way of the budget to make them better than average. Dave wanted most of the money in the drive train, and the body design. Just some educated insider stuff.

 

You really want to joust with me? An F body uses a mechanical Throttle body and a vertical radiator that was not restricted by body design. Identical indeed.
I have seven proprietary designs in every C5 on the planet, including yours.
IN 2001 the f body added a new intake for a whopping 5 hp bring it up to 310 HP or 325 in the WS6. Identical indeed .

 

what does that have to do with anything?? I'm talking about LS1 longblock which is identical. I'm not talking throttle by wire and any other schemes of over-engineering which were after the fbody was shutdown. Early C5s had mechanical.. then again I have no idea wtf this has to do with anything.

yes, coolant temps can get down to 165 while cruising on a VERY cold day but oil temps will still be 190+ all day, and 200+ after a WOT run. So where does the correlation between coolant temps and oil temps begin?

 

Thermostat has nothing to do with "heat soak". And as for my facts, just ask anyone that tunes on a dyno.

 

I did and they all recommend a 160 which THEY tune for.. And I can literally feel a difference in power when the motor is running cooler.

 

I thank you for your advice.
I'll keep an eye on the coolant temp and if it runs too cold I'll switch to a 180.
If that gets too high for the recommended spec I'll drill a 1/4 hole in it to keep the temp at 200.
Money is not an issue and I can afford these things or another engine but I don't want to wear it out too soon.
I don't drive the car too hard like some here would or race it so I think I'll be ok for the next 5+ years.
After the 200+ hrs I've put into the car personally plus the $15k on top of the 25 I paid for it I want to keep it for a while.

 

Ok up date. I had the car tuned. It has air filter and cat back is all. I drove the car 180 miles temp stay 190 rang oil 190 to 200. Had car tuned oil and water stay about the same on way back. Temps out side was 40 to 60 most the trip. Now my deal was if you was in slow traffic it would heat up. Doc said leave 190 in and drop the fan cut on to lower setting. Think he drop to around 200 to 205.

 

Bill, thank you for the insider information and your comments based on the development of these amazing engines. Not through any fault of yours or the others on this forum, but I'm about as confused as I was before I read this. The only difference is that now I'm confused at a higher and a more informed level. I've been considering changing out the thermostat for some time, but now I think I'll just leave it alone. My LS6 runs sweet now and won't normally get over 210 degrees in stop and go traffic. If I get passed by a car that has lots of mods or one that has been dyno tuned, well I'll just try to enjoy the drive anyway. Happy New Year and I wish all of you Z best. Mississippi Mike

 

Ya, I'm confused too. The info is saying the oil has to be in the 200*F to 220*F range to achieve 200,000 miles on the engine. So, how could the engine go anywhere close to 200,000 miles if used for short drives to work, say 15-25 minutes each way?

For me, on my 20 minute drive to work I would be lucky if the oil reaches 200*F for 5 minutes of that drive. Some days, it wouldn't reach 200*F at all. I still have the stock thermostat and I'm talking 15*C to 25*C days here.

 

I really find it hard to believe so many so called car people are willing to argue, dispute, play the doubting Thomas. After twelve years of fighting off this apparent compulsion I feel this forum would be better sever with all these geniuses to figure it out all by yourself. I've answered these questions hundreds of times here..( we do have a search feature ) the only confusion I see is the lack of automotive basic intelligence.
One more time.. The OLM counts the number of cold starts.When a car is started, the computer is in open loop until it counts the number of open loop operations against the number of miles. The OLM tells you to dump the oil much quicker in a high cold start ratio. People with lots of cold starts do not get their oil into the sweet spot for a long time. People with a good driving profile can get 10,000 miles out of a year's use of a single oil change, while others get 2500 to 3000 miles.
This is really getting old. Confused indeed. The best advice I can give is do whatever you think is right. Get advice from construction workers, bankers, fast food clerks, data entry people, they have the right answers. I've spent more than a decade here trying to educate people but the more I try to help , the more stupid some people become. IM back to PM help only.......
Bill aka ET

 

I feel your pain. I'll never claim to be an expert, but I too shake my head from time to time when I'm only trying to help. I understand what you're saying and it's cleared some misconceptions in my head. So thank you for taking the time to reply in this thread.

 

Yes there seem to be a lot of clowns and trolls here who get off on making fun of other people's accomplishments

After reading all this I conclude that if you run a 160 thermostat and/or have a lot of cold starts and power mods then change the oil every 2500-3000 miles