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[feeutfo]

Whats the ideal engine running temp for any engine generally speaking?

Reason I ask is my experience is mostly with bikes, and the thinking there is 70 degrees is ideal, any hotter and you start to loose power. Now this is for higher tuned stuff like 180 190 hp 1000 cc four pots or twins. Higher stressed stuff, much more so than the omega.

But if 70 degrees is a theoretical limit, is there anything to be gained by cooling the omega v engines further? Hopefuly more power from less fuel? Can't help but wonder if removing the oil Cooler from coolant flow would help, at risk of upsetting the die hards on here I know.

Discuss, maybe....?

[Kevin Wood]

Some more modern cars have a certain amount of control of the thermostat via the ECU so it can reduce coolant temperature when "caning it", and increase it during other conditions.

It's also a compromise between engine operating conditions and external factors like effectiveness of the heater, emissions and fuel consumption.

Many modern cars run the coolant in the high 90's to over 100 degrees C as a matter of course. If you do this and the car is used for short trips, the engine is generally warmer when restarted so emissions and wear are reduced and the heater is more effective.

I think I'm right in saying that for emissions and fuel consumption generally the hotter the better whereas for maximum power a cooler running engine is better.

I doubt the oil cooler will make much odds. It does dump heat to the cooling system under some conditions but also acts in reverse and pre-heats the oil when the engine is warming up, which is beneficial.

Remember it's the thermostat alone that controls the temperature of the coolant. It doesn't matter how much heat the oil cooler is dumping in, as long as the rad is effective enough to lose the heat, the engine temperature will be the same.

Kevin

[Kevin Wood]

You also have to consider that engine heat is the main mechanism by which moisture and combustion products are "boiled off" from the oil and exit the crankcase via the breathers.

It's fine to run a racing engine at 70 degrees C where the fluids are changed every few hours of use but it would lead to a road car engine getting sludged up pretty quickly.

Kevin

[Seth]

Some more modern cars have a certain amount of control of the thermostat via the ECU so it can reduce coolant temperature when "caning it", and increase it during other conditions.

It's also a compromise between engine operating conditions and external factors like effectiveness of the heater, emissions and fuel consumption.

Many modern cars run the coolant in the high 90's to over 100 degrees C as a matter of course. If you do this and the car is used for short trips, the engine is generally warmer when restarted so emissions and wear are reduced and the heater is more effective.

I think I'm right in saying that for emissions and fuel consumption generally the hotter the better whereas for maximum power a cooler running engine is better.

I doubt the oil cooler will make much odds. It does dump heat to the cooling system under some conditions but also acts in reverse and pre-heats the oil when the engine is warming up, which is beneficial.

Remember it's the thermostat alone that controls the temperature of the coolant. It doesn't matter how much heat the oil cooler is dumping in, as long as the rad is effective enough to lose the heat, the engine temperature will be the same.

Kevin

In other words - 'thermal efficiency' Kev!

[feeutfo]

No heater on a bike of course, and more performance orientated with emissions even more frowned upon. Heater on omega certainly heats up quick IMO. Which adds to my pondering, chin stroking.

But need to remember it is primarily it's a family car 

No problem with mayo on mine, not seen it since first week of ownership. And breather box small pipe now unblocked from previous lady owners bimblings, by the way.

Pop the bonnet after the commute home and the latent heat in surrounding parts is impressive, wings and front cross member are almost too hot touch...

[Marks DTM Calib]

A few things to consider

1) the temp gauge is not an exact match to the temp of key components

2) all engines are different

Hence. There is no correct answer

[Lizzie_Zoom]

A few things to consider

1) the temp gauge is not an exact match to the temp of key components

2) all engines are different

Hence. There is no correct answer

Indeed Mark!  The Rolls Royce Turbofan engines have a running temperature of between 850 - 920 degrees C. during take off and average in-flight operation!!  Whereas a steam main line engines firebox temperature can reach 3,000 degrees F./ 1649 C.  !!:D

[Mr Skrunts]

A few things to consider

1) the temp gauge is not an exact match to the temp of key components

2) all engines are different

Hence. There is no correct answer

Indeed Mark!  The Rolls Royce Turbofan engines have a running temperature of between 850 - 920 degrees C. during take off and average in-flight operation!!  Whereas a steam main line engines firebox temperature can reach 3,000 degrees F./ 1649 C.  !!:D

Lizzie, trust you...... 

[Lizzie_Zoom]

A few things to consider

1) the temp gauge is not an exact match to the temp of key components

2) all engines are different

Hence. There is no correct answer

Indeed Mark!  The Rolls Royce Turbofan engines have a running temperature of between 850 - 920 degrees C. during take off and average in-flight operation!!  Whereas a steam main line engines firebox temperature can reach 3,000 degrees F./ 1649 C.  !!:D

Lizzie, trust you...... 

I know Skruntie!   Couldn't resist!

[feeutfo]

A few things to consider

1) the temp gauge is not an exact match to the temp of key components

2) all engines are different

Hence. There is no correct answer

Indeed Mark!  The Rolls Royce Turbofan engines have a running temperature of between 850 - 920 degrees C. during take off and average in-flight operation!!  Whereas a steam main line engines firebox temperature can reach 3,000 degrees F./ 1649 C.  !!:D

Lizzie, trust you...... 

I know Skruntie!   Couldn't resist!

Thanks Mizzzzoom i'll bare all that in mind. 

[Lizzie_Zoom]

A few things to consider

1) the temp gauge is not an exact match to the temp of key components

2) all engines are different

Hence. There is no correct answer

Indeed Mark!  The Rolls Royce Turbofan engines have a running temperature of between 850 - 920 degrees C. during take off and average in-flight operation!!  Whereas a steam main line engines firebox temperature can reach 3,000 degrees F./ 1649 C.  !!:D

Lizzie, trust you...... 

I know Skruntie!   Couldn't resist!

Thanks Mizzzzoom i'll bare all that in mind. 

OK Chris

[cem_devecioglu]

it depends on many factors..

but mainly initial design goals determines the working temperature of course..for a daily use engine
fuel consumption, emissions, engine weight , cost of engine are optimized .. however for special purpose engines things may differ radically..

if you use alumunium heads and components of course you are limited at lower temperatures.. but if you use tungsten or porcelain parts 4 digit temperatures may be achieved with a big price tag..

[Omegatoy]

phew what a question, ok generally the hotter an internal combustion engine runs the more effecient it becomes!! however having said that there are exceptions such as race cars/bikes etc where fuel efficiency dont come into it!!
as stATED many engines use heat nowadays to boil off contaminants and for general self cleaning and low emissions,
at a guess your not far off on your generalisation of around 70 75 degrees, but remember its compression and internal combustion temps that matter, thats why many race tuned cars and planes use EGT gauges for fuel efficiency and power output!!
did any of that make sense?? lol

[05omegav6]

you could try a colder thermostat to see if that makes any difference, and could always swap it back if it had any side effects. :-/
 my 3.2 gives off quite impressive levels of residual heat. after a 10 minute run mine is still warm after 2 hrs never seen the gauge over 90 degrees though.

[feeutfo]

Aeye, some good replies thank you, on mine and most 3.2's I gather, we're looking at 90oC summer and 80 in winter, making the gauge nicely averaged over the year. But so what, I suppose the gauge means bog all depending on where the temp is measured, or the accuracy's of the printed dial and all that, it could say what ever is wanted re numbers too.

But I fancy the engine temp runs high (for this engine ) to account for other quite legitimate reasons you all mention, so how do you see a reduction of 10 degrees affecting things, assuming that's a reasonable amount to expect of a different stat, which I've no idea if that's reasonable pr not.

Assuming the gauge is somewhere near accurate for a minute, that would give 70 in winter and 80 in summer obviously. Problems?

The rate of warm up would be the same but level off sooner presumably. Goes against gm's development? Or do they fit one stat to all countries hot or cold?