bigbird01

iTrader: (3)

I just started night classes at a local college and the book say the hotter the engine temperature (not air temp) the faster the molecules of gas burn and the more horsepwer you make...so why would anyone want a 160 degrre tstat? I belive it makes sense because the fuel would ignite faster. I might have a lot of questions like this so please bare with me.

Bob

The best part of the class is theres no installation fees anymore!

RPM WS6

iTrader: (3)

Actually it's true. A hotter buring engine will be more effiecnt at everything (making power, fuel mileage, etc.). However, this is only true if you're running a high enough octane fuel to prevent pre-ignition of the air/fuel mixture and running a timing table that isn't too aggressive for the octane of fuel used and the engine temp. For some setups, running on race fuel all the time isn't ideal, so a cooler stat might help avoid some detonation. This might be the case with a blower/turbo setup, or a higher compression motor, or very aggressive tuning (lean mixture, aggressive timing tables).

But, the reason why some stockish motors will see more power with a lower temp t-stat is that metal/aluminum intakes are prone to heat soaking, thus making the intake air charge hotter and therefore less dense than if the intake were cooler. So to get cooler air into the motor, people will resort to a colder temp t-stat keeping the intake cooler thus allowing for a cooler air charge. This is a common mod for the LT1 motors, and it usually shows some gains even when the motor is basically stock. But in the world of stock to mildly built LS1, LS6, etc. motors with stock plastic intakes (actually made of DuPont Nylon 66 material to be exact) this heat soak condition isn't such an issue. Frankly, in general I'm not a beleiver in colder t-stats for LS1 motors, with the exception of certain aftermarket engine packages/setups. My LS1s have always run their best in the 195-210 degree range, even with full bolt-ons and a cam. The factory runs them even hotter (through higher fan cut-on temps) to make the emissions even cleaner, but IMO the stock 220-230 degree temps are a little too hot for peak performance.

Keep in mind that coolant temps are only half the story when it comes to overall engine temps. The coolant has a job, that job is to remove heat from the motor (heads, block, etc.). If you open the t-stat too often (like removing it completely) then the coolant will not spend enough time inside the motor to actually cool it properly. The idea is to keep the motor cool, not just the coolant cool.

LS1Formulation

iTrader: (13)

When I saw "Bare with me" I was thinking it was a post from a nudist camp, lol

NHRAMAN

iTrader: (1)

Where are the NUDIE PICS.?????....

Rawr256

RPM pretty much hit the nail on the head with what he said!

Engines now are built to run around the 200 degree mark, of course part of this has to do with what you are running under the hood as well. On a boosted application you want the car to be cold, I could tell a difference with my GTP in scanning by switching from a 195 tstat to the 180 and altering the fans coming on sooner than the factory setting, which was in the low 210 range. Because the car has a blower sitting on top of it with no sort of IC the extra hot air it throws in only adds to the engine already being hot and causeing more predetonation/KR (Knock Retard). I remember reading for the GTP that for every degree of KR you are running you can estimate you are loosing 10 - 15~ hp @ the crank and with every bump of timing you can about that much back, but if your getting KR the car will pull timing and try to correct for the KR.

I use to default that the coldest temp for the engine was the best, but like a person, an engine likes to be warm also! Another positive thing to haveing the engine run warmer is that it burns up any condensation/water that could have accumulated in the engine, when the car runs at a constant 160 temp it is harder for it to eliminate the water that could be coming into your intake or any other part of your engine. I remember a good read on the explanation of why it isn't the best to be running a 160 t-stat on your car on the local section of the boards, will see if I can dig it back up, basically says, if you have dew on the grass in the morning, you have water in your engine in the morning! Unfortunately water + oil =

30thanniv

iTrader: (2)

You want cool air intake because it is denser or richer in oxygen, thus you can burn more fuel and create a bigger bang in the combustion chamber.
The hotter the burn in the combustion chamber the more energy released, means even more horsepower.
Thats about as simply as I can state it.
make sense?

BLKWS.6

Most professional race engines are run at over 200*. Certain head designes work best at certain temps too. Yes, hotter is better for the most part!

'Trust'

iTrader: (24)

I guess its in my head that my car feels like a dog when the motor is running hot?! (I have a 98 so yes my gauge works!!)

RPM WS6

iTrader: (3)

Depends, these times that the car feels like a dog, are you sure it's just because the engine is hot and not because the outside temp is hot as well?

My motor feels strongest when the motor is at about 200ish and the outside temp is cold and dry.

StoleIt

iTrader: (3)

Air is more dense (IE: more oxygen per unit) when it is cold out. Moisture ruins performance so dry is optimal.


(and yes I know you already know this info, just posting it for everyone else )

RPM WS6

iTrader: (3)

jeremy341a

iTrader: (2)

An exception to the rule is a pro stock engine. They are run as cool around 100 degrees. Jason Line has even been seen putting ice chips in his radiator.

brad8266

iTrader: (23)

Hot is good until you get to the point to where the fuel starts to pre-ignite, then its not good.