I recently purchased, but have not installed, a 160 degree thermostat. I also plan to get my car tuned and set the fans to turn on about 180 and 195. My question is that will these lower operating temperatures cause too much carbon buildup in my engine. After researching this mater I am thinking that I might just go to the 180 degree therm with the same fan settings. Anybody have any knowledge about carbon buildup? Also, doesnt the engine run best around 180?

 

Don't know but if you decide to sell the 160 thermo let me know I need one......

 

With a PCM controlled ALUMINUM engine, I'd keep the stock thermostat - there have been many threads on this over the years, and the consensus seems to be that the LS1 works best at a stock temperature, but with the fans set to come on a bit earlier, when in typical everyday use. Now racing and other modified applications are a different matter, but them you prob aren't using Dexcool, and stock PCM programming, nor are you worried about longevity of the engine!

Do some searches on the various boards found in the "links" of my website in my sig.

 

I have a 160 thermostat on the way as well and you have my attention...

 

11k Miles (2 Yrs) Of Weekend Use So Far All Is Good 4 Me

 

i think it will work fine, i dont think it will crabon up,if not help prevent carbon
running rich will cause carbon, running a cooler engine will premote a cooler air charge and lower detnation,just put in good plugs to produce a strong spark to ignite the extra CR. and cooler air charge.the reason cars run at 210* is for emisions
i know that most (UL.gasoline) engine will run better, and last longer
when it runs cooler,be sure not to run to cold or you could do more damage
160 - 175 is a real good temp.
if needed i can type up the full facts to help understand what, and why
it helps,very intresting, and educating to read.
hope that helps

 

You have mail.

 

I read so much on this....

Some say that the colder (160) stats will cause cylinder wash, heavy fuel comsumption, premature wear on rings, etc. Some say that the 172-185 temps that most LS1s cars will run at with a 160 stat is not low enough to cause this condition. They also state that the 160 stats have ended their pinging issues.

I really don't know what to beleive anymore. I've read tons on this lately because I have both a 160 and 180 stat that I can use, and I'm not sure which one I want to stick with. There are good arguements for both sides, and pros & cons to each.

Here is what I have found:

180 stat is not capable of running the motor much cooler than 192* even in cold air at speed, or around 194-196 idling in cool weather with fans on full speed.

160 stat is not capable of running the motor much cooler than 172* even in cold air at speed, or around 174-176 idling in cool weather with fans on full speed.

Obviously, either stat can be made to run hotter at low speeds with higher fan settings. Question is, which stat is really better? Many people run 160s without issues, but are they really gaining anything from it? Probably not, unless they are running enough timing or compression to really need the cooler temps.

What is the ideal temp if KR is not an issue in your setup? That's the question we all need answered.

I am thinking at this point that I will use my 180 stat and try some new fan settings to keep me in the 195-206* range (stage 1 fan on/off at 200/195 stage 2 fan on/off at 206/201). Any thoughts on that?

Or maybe use the 160 and try a 190-201* range (stage 1 fan on/off at 195/190 stage 2 fan on/off 201/196). Which might be better?

Lets get more opinions......

 

Another concern is that aluminum expands much faster than iron. Meaning any temperature changes in our engines have a more dramatic affect on it- expansion wise.

Just something else for this converstion to consider- whether that's good/bad...I don't know.

 

Cooler by 20 degrees in a modern, well maintained and not abused EFI engine is NOT going to have ANY relationship to the amount of carbon in the CC!

Yes, CC temps are hotter that optimal for emission related issues, but only by a few degrees, and the performance loss is negligable (remember 1 HP in a LS1 is only 0.3%!). I'd pull the fans to come on sooner before I'd lower the thermostat - but again its your mods, budget, and knowlege of metallurgy, combustion dynamics, and thermodynamics that should be used in deciding on "outsmarting" the engineers at GM... (IMHO)

I recalled these threads as interesting comments on this topic:

http://www.ls1.com/forums/showthread...S1+temperature

http://www.ls1.com/forums/showthread...S1+temperature

 

Thanks emarkay,

Very good threads on ideal engine temps.

 

i think the only advantage to look at will be the lesser detonation with cooler engine temps. like if you got a blower, N2O, high compression, ect, anything that causes more detonation i would defenetly use a 160. GM did not intend these engines to run like this so i think it to should be modded if you got one of these engines. if you are not haveing any problems with it just run the stock one and it will be fine without any HP lost.

 

i would run a 160* t-stat, as said before it wont go any cooler than 170-175
(if not drilled) and that is perfect for these engines.
remember, if you put a lid,smooth bellows,ramair,intake,heads
you are rasing the CR and moving torwards detonation
if the engine ran 170-175 you can do all of that and still move away from detonation,witch inturn will gain power, and fuel milage

 

i had detonation and the 160 helped a lot. the coldest i run is when its below 30 deg out and im cruising at 60 and that is 167* in the hotter temps at about 70 or so i run 172* at the coldest temp but mostly about 174-176. my fan temps are as follows fan one 181/176 and fan two 184/179 and the fans do turn off. if your sitting in traffic my car wont barely get to 180 but with hier fan temsp in the 190's i peak neak 190* and a heat soaked engine will take longer to cool off. yes a colder tstat will make u loose a little gas mileage but its not too much and its only when its pretty cold outside. isnt the stock tstat 180*? cause i know with my stocker and my frinds on his ss we ran 186*-188* consistently in 80 deg weather. like said above if you have good spark dont worry. 10 deg wont make a ****. it will help more than anything else. i was worried about this at first and thought to go on my own reasoning. engine bay temps are way down too and thats nice. everyone has reasoning for things but most is just that, reasoning, no proof. now if every guy with a 160* tstat had the same problem and it showed consistent problems then i wouldnt get it. i knwo guys that have been running 160 or no stat in their cars for year without any problems. dont let this one bug you. i say do it...

 

I just made some changes to my Edit file for fans.

I am now using Stage 1 fan on @ 204/off @ 198, stage 2 fan on @ 210/off @ 205.

This is with a 180 stat. I did the test in my garage where it is about 44* right now, and just sitting idling, the car would reach 201-203 (atap sensor reading) and the low fan would cut on, then drop the atap reading to about 194-196, then the fan would cut off. The high speed fan never came on, even after 30+ mins of idling. My trans temps got as high as 156...

This is going to be the new settings I will run for a while and see what happens. It allows the fan to run most always on low, and even cut off when idling in cool weather. I'm guessing in the summer, it'll pretty much run at low speed all the time at idle, but that's ok because it'll keep air flowing across the trans cooler, and should shut off when moving anyway.

 

I'll through my .02 cents in. I have a 96 TA and I know switching to the 160* stat did wonders for my engine and I think most LT1 owners would agree. But the LS1 is a hole different story. The main reason my car performs better with the 160* stat is because with the engine cooler it also cools the intake and lowers the air temp reaching the cylender. I don't know about with the ls1 intake but with the ls6 intake on my friends z28 never heats up to hot (even after he has just made a run at the strip) to put my hand on it. Where as my LT1 is still hot to the touch after 45 minutes. I think that is why he can make back to back runs and it never slows down. (my LT1 loses a couple tenths if I don't let it sit for atleast 45 minutes) Because the intake never heats up as other intakes. Therefore cooling the engine would not effect it. Does this theory make sence to you guys?

 

yeah it makes a lot of sense and that was part of the engineering behind the composite ls1 intake so it would not become heat soaked. so this is one thing the 160 on an ls1 wont really do anything for, performance wise...

 

same for the ls1, maybe not as much as the lt1 because the ls1 dont have
an alluminum, but has a composite intake, but they both have alluminum
heads, and engine blocks
and with the engine coolent hot it will heat up the heads/combustion chamber
and the engine block/cylinders, and lower your C/R and, could cause detonation.
so if you run your coolent cooler than 200/210 it will raise your C/R from a cooler/denser air charge, help move away from detonation, and add power and fuel mileage.
in practice we find that for an engine on the edge of detonation (LS1 engine at 200*- 210*), every
8*-10* F. reduction in intake temp. is equivalent to adding one or more octane level to fuel.
through testing, a temp of 165*-175* helped a light - to mild modded ls1 engine produse more power (another 8.9 HP. wich =s to about 1% more HP.
for every ten degrees of temp. drop)
hope that helps

 

LS1 is aluminum block, LT1 is an iron SBC motor.

Lower running temps usually result in a loss of fuel mileage, not a gain. I have noticed this condition, as have many others using lower temp t-stats and fan temps.

An LS1 will not be on the edge of detonation at 200-210 degrees of coolant temp. Maybe with aggressive timing changes and/or raised compression, but not otherwise.


Hotter temps result in a more complete combustion, and will result in more power right up to the point that detonation begins. IMO, 165 regular running temp is unnecessarily cold unless super high compression is being used with pump gas. I have seen lots of LS1s with moderate timing increases do fine at anything under 215*.

 

I've been running a 160 deg. thermostat in my LS1 for the past 50,000 miles with no problems at all. I didn't notice any drop in my mileage either. When driving on the highway in cool weather, my coolant temp. is at 170 deg. Prior to installing it I had a problem with detonation and knock retard. The cooler thermostat helped correct this problem.