Low hanging fruit and other newbie questions.

[NewV]

joecar - Thanks for the explanation on the AutoVE. Glad to hear its not too far off from what I thought it did.

jkg - I am considering the 160 thermostat as well. On another forum I posted a question about it and one response was a little worrisome: "Another thing to consider is that the oil should normally operate around 212F or so. If the oil is kept well below 200F due to low coolant temps, moisture in the oil won't boil off as fast and that could lead to condensation and potential rust in the motor." May want to watch the oil temperature.

[jkg]

The car seems to want to run at water temps in the 180s while crusing, higher when standing with the 160 thermostat. The oil temp gauge is notoriously unreliable on these cars, since it often runs many degrees higher than water temp, and was the subject of a TSB early on -- GM responded to concerns of unreliable oil temp readings by recalibrating the gauge, so that it reads closer to the water temp. This quieted the complaints, but makes the temp readings no more accurate.

Regarding the concern for water in the oil, running the car on the highway a bit should take care of any condensation. And the oil temp varies depending on where it is measured. It is probably much hotter around the main bearings, cooler in the pan. And I think it is better to run 180-190 on engine temp than 210-230. Other than just feeling cooler in and around the car, it is a first step toward making more power. The cooler the air intake, the denser the air (supercharger effect). The LS6 engine is particularly sensitive to air intake temp - on a cool day, even I can feel the difference in power.

Next step - Auto VE tune I guess.

[TAQuickness]

Every motor will run better when it's cooler outside. BUT - you still need to run the motor at it's normal operating temp.

[eboggs_jkvl]

joecar - Thanks for the explanation on the AutoVE. Glad to hear its not too far off from what I thought it did.

jkg - I am considering the 160 thermostat as well. On another forum I posted a question about it and one response was a little worrisome: "Another thing to consider is that the oil should normally operate around 212F or so. If the oil is kept well below 200F due to low coolant temps, moisture in the oil won't boil off as fast and that could lead to condensation and potential rust in the motor." May want to watch the oil temperature.

That would be correct information. THe car runs best on cold air not cold engine. Stick with the stock t-stat temperature.

Elmer

[dfe1]

I don't think running too cool is ever an issue unless you live in the frozen north. I don't know of any LS-powered vehicles that run at thermostat temp. I have 160-degree stats in several vehicles, and all run at least 175 even at 40-degrees ambient. Running on the interstate at 60+ ambient, coolant temps are always 180-185. Oil temp is more a function of engine load than coolant temp. As soon as you start driving, oil temps climb.

[joecar]

Yes, oil temp outpaces coolant temp.

[SSpdDmon]

The one thing about the t-stat debate I don't get is this...

The main arguement against running a cooler t-stat is that engines run at higher temps to cut down moisture in the block/oil/etc., right? In other words, if an engine runs at 212*F (100*C) it will 'boil' off any water in the system. So, we're basically talking about accelerating the evaporation process.

I don't know about you guys, but I don't live in the rainforest. Therefore, I would assume the amount of moisture that can collect in the engine is somewhat minimal to begin with. This little bit of moisture will still evaporate at slightly cooler temp. **A quick test...stick a pot on the stove with a teaspoon of water and heat it up (don't let it boil). It will evaporate rather quickly - faster than if left at room temps.** In the engine, the moisture may burn off slightly faster at 212*F compared to 180*F. But, it will still burn off.

Personally, I'd rather run a cooler motor, change the oil every 3K (just to be safe), and make a little more power with less risk of detonation. Until someone shows some solid proof of it causing problems, I don't plan on changing my ways...

[TAQuickness]

SSpdDmon - good perspective.

For the sake of splitting hairs: Teaspoons are much cheaper to replace than engines But seriously, There is less potential for water to damage the engine the faster it evaporates out.

At some point on Google I had found a very good explaination of the effects of running the engine cooler than designed. I'll post it if I can find it again. In short, the cooler engine made more power (5 or 10 hp), but lived a much shorter life.

I would also bet that most of us build new motors long before any negative signs of a cool engine become appearant.

[jkg]

The lower thermostat allows me to run engine temps around 20 degrees cooler. This gives the option to increase power slightly through a good tune, but also decreases the air intake temp (throttle body has coolant through it), which may increase power a little as well. Probably not enough to notice any driveability difference. In my case, I just like having the engine run cooler -- as an old V8 fan, seeing water temps at 220 or higher makes me unhappy.

On the other hand, my father found that dropping the engine temp was very helpful in his z06 corvette in keeping interior temps down - the transmission tunnel would radiate a lot of heat...

[neil]

Found this on the web. It may be of some interest.
Can't remember who produced it.

Proper Coolant Temperature and Camshaft Life!

Have you ever tried to find what proper coolant temperature is for most automotive engines? There are a lot of people who think they know, but it is difficult to find specifics, even in textbooks. We know we want the intake air to be as cold as possible (for best power) because cold air is denser (there are more oxygen atoms per cubic foot). The coolant temperature, however, is a different matter. The internal combustion engine changes chemical energy stored in gasoline into heat energy that is focused on the piston tops. If the cylinder heads and engine block are too cold, they will absorb much of the combustion heat before it can be used to push the piston down the cylinder. If the engine gets too hot, engine lubricants can break down, as well as overheating of the intake charge can lead to detonation, etc.

It turns out that coolant (usually a 50/50 mixture of coolant and water) has some fantastic properties that are ideal for use in engines. With a properly pressurized cooling system, coolant will not freeze until –30°F, and it won’t boil until +270°F (new oils don’t start to break down until well over 270°F). With these characteristics, engine designers have decided that engines should operate at approximately 210-215°F. Why, you ask? Well, it has to do with operating the engine at a high enough temperature to boil water out of the oil after the engine is cold started. If you have dew on the grass, it is certain that you have water in your oil, as the crankcase is open to atmospheric pressure! You can either remove the water by draining it out the bottom of the oil pan (remember the oil floats on water) or run the engine long enough and hot enough to boil the water out of the lubrication system. Years ago, coolants weren’t as sophisticated and engines were run at 165-180F, but the oil was changed every 1000 miles or so. That’s why many old timers think engines should run at 165-180F. Have you ever noticed that Ford doesn’t put temperature marks on their gauges? They just mark C for cold and H for hot and write “normal” through the center. If you hook up a scan tool to a GM, you will often find that the gauge reads much lower than the coolant temp sensor. That is because they know most drivers don’t understand how hot an engine should run.

So what does this have to do with camshafts? Many enthusiasts erroneously think that the colder their engine runs the better! If they are not running the engine hot enough to boil the water out of the oil, the oil becomes contaminated and the lifter/cam lobe interface is the highest load point in the engine. Engines running too cool can contribute significantly to camshaft and lifter failure. Think about it: What good does it do to use the most expensive synthetic oil and then run the engine so cold that it is contaminated by water vapor??!! Another point, piston manufacturers’ piston-to-wall clearance recommendations assume you will be running the fully warmed engine at 200°+F. Run the engine too cold, and you could see some scuffed pistons because the cylinders had not expanded enough to provide clearance.

If your engine will only run its best at the drag strip with the engine at 165°F, you probably have too cold of a spark plug heat range and you are probably jetted way too rich! If you keep the engine hot (not the intake charge), you will be using more of the heat energy in the gasoline to make power instead of just heating up your block. It does take “tuning know-how” to run an engine at 200-210°F, but you might be surprised how well and how long it runs when you do!! One final point - running a computer managed engine at 165°F compared to the factory 210°F will often cost you as much as 4 MPG. The reason for this is that the computer thinks that the engine is not off the “choke cycle” and it is still putting out a rich mixture! Check the science on this and don’t pay attention to the “old wives tales” of the past. Materials and lubricants are much better and different today than they were in the past!!

I run the fans at stock and I run the stock Thermostat.

Regards,

Neil.