Cooler thermostat = better power and efficiency?

[VR38]

I doubt anyone here is disputing running an engine too hot burns the oil and contributes to sludge but as pointed out, I think every make of vehicle hand book outlines that cooler running, whether it be stop start driving short trips or in this case, self inflicted, requires shorter service intervals to help prevent oil contamination leading to sludge build up.

 

[wraith]

Understood, lawl. What's the use of spacers and stuff then? Don't they just keep the engine cooler too?

Plenum spacers help to increase the amount of air available in the plenum. Manifold spacers provide extra runner length and also have the added benefit of decreasing the manifold temperature which in turn means the air provided is cooler.

 

[Brett_jjj]

Understood, lawl. What's the use of spacers and stuff then? Don't they just keep the engine cooler too?

Intake air temps are a different matter again. Manifold insulator spacers can help keep the incoming fuel/air mix cooler, which will help give you a bigger better bang. They wont really have much of an effect on the the actual running temps of the engine coolant or oil etc.They also change the runner length in the manifold.

 

[frogsta]

Ahh okay cheers guys, cooler air = more dense so bigger bang, all makes sense. At first I thought anything cooler would help the engine hah, only new to cars D:
Chemistry knowledge helps though.

 

[MACE]

I'm curious if anyone can find an article or recommendation that petrol in oil can directly cause sludge build up. I've think I've read of something like this before however if anything petrol acts more like a solvent dissolving sludge.

If people were concerned that petrol in oil was diluting it, altering it material properties (viscosity) then that's a different problem, which is likely to happen during very short trips (something I've directly experienced on a old carb 3 cylinder). It's one of the main reason oil is recommended to be changed more frequently under these conditions.

 

[Immortality]

As far as i'm aware the primary reason for the factory running such high engine temps is for pollution reasons. I think it has been well proven that for economy you run engines at a higher temp. For power you run the engine at a slightly cooler temp. Having said that, I've noticed no reduction in economy from running the engine with the cooler 82 degree thermostat

If you care to look, download Tunerpro and have a look at the tunes for these engines. You'll see that 82 degrees is within what is considered to be the normal operating range, check the fuel Vs temp correction tables. maybe someone can remind me at which temp the PCM starts add extra fuel to help keep the combustion temps down to stop pinging..... (If extra fuel is being injected it means that you not producing as much power )

Engine oil tends to get contaminated easily if the oil isn't bought up to it's proper operating temp. This would be a problem if you do a lot of short trips. If this is the case, make sure you take the vehicle on a decent drive every couple of weeks to ensure the engine oil gets up to the proper operating temp.

I've run a oil temp gauge for a fair few years now and from what I have seen, it takes the oil a lot longer to heat up then it does for the engine coolant. Just jumping on the motorway isn't the best way to heat up the oil as the engine is under a relatively light load (so producing relatively little heat) and you have a lot of airflow through the engine bay which is actually cooling the engine block/sump (the alloy sump on the ecotec conducts heat very well).

On the subject of heat. It is a lot easier to heat something up then it is to cool it down. Although the cooling system may be pulling the coolant temps down relatively quickly, that is only the coolant that is flowing through the engine, heat soak through the rest of the engine takes a lot longer to dissipate so in my opinion of you can prevent that extra heat soak then it's a good thing.

 

[Krisp]

Im surprised no one has mentioned about the coolant. Antifreeze prevents the cooling system to freeze up, not many places in australia with a european winter. There has been quite a few posts online about buggering off the antifreeze in the coolant and having just anticorrosion mixed with water. They are saying the car will run alot cooler due to antifreeze keeping the coolant higher temp . Concur?

 

[savage1987]

I concur... straight water is actually much better for cooling.... just the corrosion bit that we need to worry about in engines

No antifreeze necessary.

Also yes antifreeze raises your boiling point but really your water jacket is under pressure if your system is operating properly so that raises the boiling point also, doesn't it? I can't remember much chemistry

Either way I have run plain water through a few cars for a week or two here and there between engines etc... don't recall ever having a problem

 

[Brett_jjj]

I have ran plain water in my cars at times just to get out of trouble when Ive had a burst radiator hose or cap or whatever,and they always ran at about the same temperature as they did with coolant in them. Id say that coolant would only start to make a difference once the coolant temp gets up around 120 degrees C or more. The pressure in the cooling system does raise the boiling point of the water or coolant,thats why they are pressurised in the first place. I was looking at some nascar stuff somewhere and apparently they pressurise the cooling systems on some cars with compressed air.Up to 40 -50 PSI the pressures kept at so they said. Ive certainly never heard of it before.

 

[Immortality]

Hmmmm, you don't want air in the cooling system. Air pockets inside the engine will cause hot spots which will cause more problems.......