F-Body Europe

What's with the craze on low temp t-stats. I can understand going down to 180' vs. 195' stock, but LG is recomending that I use a 160' t-stat with the head/cam package I'm putting in (FINALLY). In my mind at least, an open t-stat is an open t-stat, so once it's open, it's up to the radiator to keep things cool. Even with a 160' t-stat and reprogramed fans that come on at lower temps, most people say their car still runs in the mid-high 180, it just takes a little longer to get up to temp, so why not just run a 180' t-stat and let the car get up to temp faster then program the fans to turn on at around 190??

With the aluminum block our engines heat up quickly and if you have a bad cooling system, you can overheat faster. Having the radiator start working at 160 helps to get ahead of the problem.

If there's an issue with cooling, wouldn't you only be delaying the problem 10 min or so, if that

The main reason for the160 is for the drag racers. With the cooler thermostat and the fans reprogrammed, the fans will keep running to get it cooled down more between rounds. Since the fans kick in earlier, it also won't heat up quite as fast.

that makes sense to me, but also brings up question 2. What's the ideal operating temp for an LS1 engine?

I couldn't tell you but try LS1tech.com, there are some smart dudes over there.

Once again, it depends on what you want. 180 used to be the normal thermostat. They increased the temps to improve emissions and fuel mileage a little bit when the restrictions got so ridiculous. Cooler is better for power normally. Heat breaks down lubricants, but it is not a problem that hits at a certain point, it is gradual. That is one of the advantages of synthetic lubricants that they can handle higher temps better. If you run the engine real cool, it takes longer to get the moisture out of the oil so short trips causes water from condensation to build up in the oil. I think it would be hard to say that there is an ideal temp without defining what you consider to be ideal.

A cooler engine also means less likely to knock, denser air charge and therefore more power and more optimal timing.
It probably wears a little more though.

i think an all aluminium engine would need less radiator size to keep it cool, due to the fact that aluminum radiates/ dissapates heat much better then a cast iron blok

Maybe the trick is to have it run as cool as possible without getting the engine oil out of it's best operating temperature range 85-90deg c

Hey guys. I'd like to add my .02
Theres several things to consider when talking about heat in an engine, and why you would want to run at dif temps than the cars was engineered for.
First, the Automotive Engineers didnt engineer your car to make max power. They engineered it with emissions, mileage, and durability in mind. For all of these things, the hotter you can make an engine run, (and I mean right on the verge of overheating), the better.
As for power, ideally you would want the engine to run somewhere between 185 and 200 coolant temp, with the oil temp the same. Along with that, you want the exhaust to funnel the exhaust heat away from the engine, and engine compartment, instead of through the walls of the exhaust, which adds to under hood temps, and at the same time, you want to funnel cool air to the intake tract.
The idea is to get the engine itself to run hot, while keeping the intake cool. Its hard to do, and the hotter you run the engine, the harder it is to do.
So all that being said, if you walk the fine line of cool coolant temps, warm oil temps, and cool intake charge, you end up being able to run more timing, or at least not having the PCM pull timing because of heat induced knock.
and BTW, it seems most of the LS motors make the most power about 190/195 degrees.
BTW, Lancer, I'm in Chesapeake if you're in need of any assistance. I'm very active on the corvetteforum. You can catch me over there in the SE section.

Hey Lancer33,

Great question. As you can see, the main reason we have our temps set where they are is because of emmisions, mostly in closed loop operation. When in open loop mode, the computer will adjust timing for performance but the thermostat will not change, but the fans on board, they have two different on and off temps and will come on and off at the preset factory settings. You can edit them with EFI live or LS1 edit to change the on and off temps for the fans to cool off the car. Heat is any enemy of all cars, so dropping the intake charge temp will aid in keeping your car to run cooler until you reach that point of diminishing returns with high HP and the heat associated with it. Then you need to look at lowering temps in places where it makes a difference, not just the thermostat. For example, when I had my Katech head and cam package, the approximate 525HP (verified by a Swiss tuner) I had then raised the inherent heat and thus the threshold of underhood temps tremendously. I attacked the cooling with a larger radiator, A Doug Rippie racing aluminum with integrated oil cooler unit. This lowered colling temps by about 15 degrees. I expect something like this will be needed when you have exceedingly higher horsepower. When we install the Callaway blower, I will flush the system clean and install the 180 thermostat, for the added benefit of the overall gain in lowered intake charge temperature equating to reduced risk of detonation either with blowers or heads and cams. I would explore any and all avenues of cooling depending on how much HP you plan on making. Believe me, I have experienced the unintended outcome of having a lot of HP on a stock cooling system. That's my 02 cents at least.

I have never been a fan of ultra low temp thermostats either. I do have a 180 that came with my blower and the new programmer, so I will install that. FYI, at the track last Sunday, my coolant stayed constant at 210 or so on a brisk 40-45 F day at Hockenheim racing speeds mostly at redline and the oil temps only reached 260.

Ciao,
Nick

edcmat-l1 - we'll talk soon. Got 50 things on my plate right now, but i'm looking for a tuner in the area to do some work for me this year.

the goal for me is a 450-500rwhp head/cam engine by the end of the year (G5X3/AFR205/Fast 90mm/LS2 Throttle body + all the goodies that go with it.). An aftermarket radiator/oil cooler will be part of that package along with trans/diff coolers. For now, I'm just replacing the t-stat and hoses & gaskets because it needs to be done (I'm tired of dex-cool messing up my garage floor )

If you're not busy this Saturday, we're having a small group of Vettes at the shop. We'll be doing some updates on a pretty high profile C5 403 L92/L76.
Some of the guys that'll be there include a 650 hp blown (KB) C5 and a 500 hp 383 road racer, both tuned by me. And a few others, just hangin out. You're welcome to come hang out.

Thanks for the invite, I'll be there

If you need directions please call me. 757-424-1740
If you're going to use a nav system, MAKE SURE YOU PUT IN CHESAPEAKE or you will end up about 15 miles away on the other end of Indian River Rd in Va Beach.
Our web directions, mapquest, will lead you to the corner of Indian River Rd and Hazel Ct. When you get there, take a right on Hazel Ct and we are the first building on the left.