Most of these reading unless really off the mark are good for establishing a trend. That way your instrumentation does not have to be that accurately calibrated or dead accurate, just repeatable. Start when new or an engine is good shape and call your reading normal and go from there. If you're starting from scratch with a problem then you need more information than just temps and pressures. Small variations in oil temperature can't tell you much but you can read into them a lot of unnecessary responses that won't solve anything. The kind of information that would be useful is an upward or downward trend that continues over time. If you're into analysis the acceleration of the curve is what you want to watch so you can get things fixed before damage occurs.
Oil temperature?
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OVERKILL
$100 Site Donor 2021
Originally Posted By: kjbock
Originally Posted By: 901Memphis
Is this a real scenario or mock? Are both oils the same viscosity grade? Usually the thinner oil will cool better so the cooler one might be formulated on the lower end of the viscosity range.
It was a mock scenario. But as a real example, on another BMW forum, a member claimed a 20F drop switching from Mobil 1 0W-40 to a Castrol 0W-40.
That's highly suspect. The thing with the biggest impact on my M5's oil temperature: winter
A close second would be driving it incredibly hard. The effect of oil choice is absolutely nothing.
Originally Posted By: 901Memphis
Is this a real scenario or mock? Are both oils the same viscosity grade? Usually the thinner oil will cool better so the cooler one might be formulated on the lower end of the viscosity range.
It was a mock scenario. But as a real example, on another BMW forum, a member claimed a 20F drop switching from Mobil 1 0W-40 to a Castrol 0W-40.
That's highly suspect. The thing with the biggest impact on my M5's oil temperature: winter
A close second would be driving it incredibly hard. The effect of oil choice is absolutely nothing.
Originally Posted By: OVERKILL
Originally Posted By: kjbock
Originally Posted By: 901Memphis
Is this a real scenario or mock? Are both oils the same viscosity grade? Usually the thinner oil will cool better so the cooler one might be formulated on the lower end of the viscosity range.
It was a mock scenario. But as a real example, on another BMW forum, a member claimed a 20F drop switching from Mobil 1 0W-40 to a Castrol 0W-40.
That's highly suspect. The thing with the biggest impact on my M5's oil temperature: winter
A close second would be driving it incredibly hard. The effect of oil choice is absolutely nothing.
I've noticed different stabilized oil temps when going from a 20 grade to a 40 grade in my charger.
On the highway at 70mph with cruise set oil temps with a 20 grade stabilized at 213f.
When I went to a 40 grade and driving under the same conditions oil temps stabilized at 195f.
So because I've seen it with my own eyes I can believe changing grades can affect oil temps however I went 2 grades thicker.
I've now used liqui-moly 0w-40,Castrol euro 0w-40 and m1 0w-40 in my charger. And all of them sit oil temps around 195f on the highway at 70mph with cruise set.
Ambient temps in that car only affect how long it takes for oil temps to stabilize,not what temp they stabilize at.
So in my experience using the 2 oils mentioned I saw similar stabilized oil temps.
So I gotta agree with overkill
Originally Posted By: kjbock
Originally Posted By: 901Memphis
Is this a real scenario or mock? Are both oils the same viscosity grade? Usually the thinner oil will cool better so the cooler one might be formulated on the lower end of the viscosity range.
It was a mock scenario. But as a real example, on another BMW forum, a member claimed a 20F drop switching from Mobil 1 0W-40 to a Castrol 0W-40.
That's highly suspect. The thing with the biggest impact on my M5's oil temperature: winter
A close second would be driving it incredibly hard. The effect of oil choice is absolutely nothing.
I've noticed different stabilized oil temps when going from a 20 grade to a 40 grade in my charger.
On the highway at 70mph with cruise set oil temps with a 20 grade stabilized at 213f.
When I went to a 40 grade and driving under the same conditions oil temps stabilized at 195f.
So because I've seen it with my own eyes I can believe changing grades can affect oil temps however I went 2 grades thicker.
I've now used liqui-moly 0w-40,Castrol euro 0w-40 and m1 0w-40 in my charger. And all of them sit oil temps around 195f on the highway at 70mph with cruise set.
Ambient temps in that car only affect how long it takes for oil temps to stabilize,not what temp they stabilize at.
So in my experience using the 2 oils mentioned I saw similar stabilized oil temps.
So I gotta agree with overkill
Originally Posted By: kjbock
So a higher grade will most likely lower the operating temp?
Actually, a higher grade might increase operating temp due to additional internal friction (resistance to flow) that a thicker oil causes.
So a higher grade will most likely lower the operating temp?
Actually, a higher grade might increase operating temp due to additional internal friction (resistance to flow) that a thicker oil causes.
Pete, it's resistance to shear, not flow technically.
People keep thinking that oil pumps are the friction robber...they aren't, pumps use power proportional to pressure*volume*density, so for a given oil pressure, positive displacement pump, pretty much the same power...20 psi difference is 50 watts or so oil pump drive...thinner oils have more slippage, and reduce pump volumetric efficiency for a given discharge pressure.
It's the oil between the journal and the shell of the bearing that makes the heat, by the crank shearing the oil (silly analogy is a chinese burn)...increased viscosity will increase the power loss here, and increase the temps (see my Briggs example quoted, no oil pump, no pumping, just friction between moving parts and their oil film...10C higher oil temperatures, which is rational and to be expected).
People keep thinking that oil pumps are the friction robber...they aren't, pumps use power proportional to pressure*volume*density, so for a given oil pressure, positive displacement pump, pretty much the same power...20 psi difference is 50 watts or so oil pump drive...thinner oils have more slippage, and reduce pump volumetric efficiency for a given discharge pressure.
It's the oil between the journal and the shell of the bearing that makes the heat, by the crank shearing the oil (silly analogy is a chinese burn)...increased viscosity will increase the power loss here, and increase the temps (see my Briggs example quoted, no oil pump, no pumping, just friction between moving parts and their oil film...10C higher oil temperatures, which is rational and to be expected).
I have read where oil temp needs to be at least 210-220*F for an extended amount of time to cook off any carbons or moisture that has developed in the oil.
Is there any truth to this?
My New Ram averages 222*F @ 69-70mph on the interstate-{Outside Temp 99*F}. 5Qts M1 AFE 0W-20 & 2Qts M1 0W-40.
Is there any truth to this?
My New Ram averages 222*F @ 69-70mph on the interstate-{Outside Temp 99*F}. 5Qts M1 AFE 0W-20 & 2Qts M1 0W-40.
Originally Posted By: Quattro Pete
Originally Posted By: kjbock
So a higher grade will most likely lower the operating temp?
Actually, a higher grade might increase operating temp due to additional internal friction (resistance to flow) that a thicker oil causes.
That's what I thought too,however my charger displays actual oil temp and going from a 20 grade to a 40 grade lowered oil temps,at least its lower at the point where my car measures oil temps anyway.
I keep on reading here that thicker oil should increase oil temps based on more resistance and therefore the engine having to work harder pumping thicker oil however I haven't seen that in my particular applications.
Not saying its not true,just that I haven't seen it in practice in my hemi.
Originally Posted By: kjbock
So a higher grade will most likely lower the operating temp?
Actually, a higher grade might increase operating temp due to additional internal friction (resistance to flow) that a thicker oil causes.
That's what I thought too,however my charger displays actual oil temp and going from a 20 grade to a 40 grade lowered oil temps,at least its lower at the point where my car measures oil temps anyway.
I keep on reading here that thicker oil should increase oil temps based on more resistance and therefore the engine having to work harder pumping thicker oil however I haven't seen that in my particular applications.
Not saying its not true,just that I haven't seen it in practice in my hemi.
Originally Posted By: Clevy
Originally Posted By: Quattro Pete
Originally Posted By: kjbock
So a higher grade will most likely lower the operating temp?
Actually, a higher grade might increase operating temp due to additional internal friction (resistance to flow) that a thicker oil causes.
That's what I thought too,however my charger displays actual oil temp and going from a 20 grade to a 40 grade lowered oil temps,at least its lower at the point where my car measures oil temps anyway.
I keep on reading here that thicker oil should increase oil temps based on more resistance and therefore the engine having to work harder pumping thicker oil however I haven't seen that in my particular applications.
Not saying its not true,just that I haven't seen it in practice in my hemi.
I can confirm this with Cayenne ... M1 0w40 to RL 0w40 more like 0w50
No temp change in oil or coolant
Pressure pretty much the same too
Originally Posted By: Quattro Pete
Originally Posted By: kjbock
So a higher grade will most likely lower the operating temp?
Actually, a higher grade might increase operating temp due to additional internal friction (resistance to flow) that a thicker oil causes.
That's what I thought too,however my charger displays actual oil temp and going from a 20 grade to a 40 grade lowered oil temps,at least its lower at the point where my car measures oil temps anyway.
I keep on reading here that thicker oil should increase oil temps based on more resistance and therefore the engine having to work harder pumping thicker oil however I haven't seen that in my particular applications.
Not saying its not true,just that I haven't seen it in practice in my hemi.
I can confirm this with Cayenne ... M1 0w40 to RL 0w40 more like 0w50
No temp change in oil or coolant
Pressure pretty much the same too
Originally Posted By: Clevy
Originally Posted By: Quattro Pete
Originally Posted By: kjbock
So a higher grade will most likely lower the operating temp?
Actually, a higher grade might increase operating temp due to additional internal friction (resistance to flow) that a thicker oil causes.
That's what I thought too,however my charger displays actual oil temp and going from a 20 grade to a 40 grade lowered oil temps,at least its lower at the point where my car measures oil temps anyway.
I keep on reading here that thicker oil should increase oil temps based on more resistance and therefore the engine having to work harder pumping thicker oil however I haven't seen that in my particular applications.
Not saying its not true,just that I haven't seen it in practice in my hemi.
Didn't you use Ceratec with the 40s?
Originally Posted By: Quattro Pete
Originally Posted By: kjbock
So a higher grade will most likely lower the operating temp?
Actually, a higher grade might increase operating temp due to additional internal friction (resistance to flow) that a thicker oil causes.
That's what I thought too,however my charger displays actual oil temp and going from a 20 grade to a 40 grade lowered oil temps,at least its lower at the point where my car measures oil temps anyway.
I keep on reading here that thicker oil should increase oil temps based on more resistance and therefore the engine having to work harder pumping thicker oil however I haven't seen that in my particular applications.
Not saying its not true,just that I haven't seen it in practice in my hemi.
Didn't you use Ceratec with the 40s?
I used ceratec in the winter with the 20 grade and again with the 40 grade.
I'm a sucker for trying to only change 1 variable at a time.
I haven't added anything in the charger,just oil,because I wanted to see if I lost any mpg.
I'm a sucker for trying to only change 1 variable at a time.
I haven't added anything in the charger,just oil,because I wanted to see if I lost any mpg.
That's interesting information, thank you for posting. A couple hundred watts per main bearing? Wow, I would never think it was that high. I don't know how many bearings that engine has, but if there are five that could be over a thousand watts.
I'd love to be able to fully instrument an engine and run it in some kind of environmental chamber to experiment.
Originally Posted By: Shannow
Originally Posted By: kschachn
I'll play my hand here and say that no one, ever, is going to convince me that you could see the difference. The heat transfer between the coolant and the block/head is where the vast majority of the cooling takes place. Besides, any cooling the oil performs has to be rejected at the pan, right? Or on some cooler interior surface (but where do you find that?)
I sort of agreed until recently, but my experiments prove otherwise.
Logically, the hottest oil in the engine is that coming out the big end bearings, second hottest the mains...these are the locations where the engine is actively working against the oil, shearing it, a couple of hundreds of watts per bearing at 3-4k RPM.
That oil drops back into the sump, having made no contact with cooled surfaces...that which does little to no work anyway, is, as you say cooled/warmed by running down water cooled/heated surfaces.
Dropping a type K thermocouple down my disptick, directly between the high/low mark, my Caprice regularly reads 105-110C,and if I run 5 minutes at 4K revs, will read 120-125c...in ambients of -2 to 5C, well above coolant temperature.
Push the thermocouple lower in the pan (Caprice has a big winged alloy pan), the oil temperature drops rapidly..an oil temperature sender closer to the pan wall will give a temperature closer to the pan temperature than what's leaving the bearings...perfect indicator of bearing supply temperature, but no correlation whatsoever on the working temperature in the bearings, which is determined by specific load, and RPM, and will be 10-20(+) C higher than the bulk oil temperatures.
I'd love to be able to fully instrument an engine and run it in some kind of environmental chamber to experiment.
Originally Posted By: Shannow
Originally Posted By: kschachn
I'll play my hand here and say that no one, ever, is going to convince me that you could see the difference. The heat transfer between the coolant and the block/head is where the vast majority of the cooling takes place. Besides, any cooling the oil performs has to be rejected at the pan, right? Or on some cooler interior surface (but where do you find that?)
I sort of agreed until recently, but my experiments prove otherwise.
Logically, the hottest oil in the engine is that coming out the big end bearings, second hottest the mains...these are the locations where the engine is actively working against the oil, shearing it, a couple of hundreds of watts per bearing at 3-4k RPM.
That oil drops back into the sump, having made no contact with cooled surfaces...that which does little to no work anyway, is, as you say cooled/warmed by running down water cooled/heated surfaces.
Dropping a type K thermocouple down my disptick, directly between the high/low mark, my Caprice regularly reads 105-110C,and if I run 5 minutes at 4K revs, will read 120-125c...in ambients of -2 to 5C, well above coolant temperature.
Push the thermocouple lower in the pan (Caprice has a big winged alloy pan), the oil temperature drops rapidly..an oil temperature sender closer to the pan wall will give a temperature closer to the pan temperature than what's leaving the bearings...perfect indicator of bearing supply temperature, but no correlation whatsoever on the working temperature in the bearings, which is determined by specific load, and RPM, and will be 10-20(+) C higher than the bulk oil temperatures.
kschachn,
have a play with http://www.tribology-abc.com/calculators/c9_3.htm
with some of the parameters that you are familiar with, in the engines of your signature.
Pick a main bearing diameter, a width, and a clearance...dial in a speed and a viscosity (minimum film thickness is hard wired until you pay)...and there's a watts of power consumption of that bearing...and there's multiple bearings...it's significant.
have a play with http://www.tribology-abc.com/calculators/c9_3.htm
with some of the parameters that you are familiar with, in the engines of your signature.
Pick a main bearing diameter, a width, and a clearance...dial in a speed and a viscosity (minimum film thickness is hard wired until you pay)...and there's a watts of power consumption of that bearing...and there's multiple bearings...it's significant.
Awesome, thanks.
Originally Posted By: Shannow
kschachn,
have a play with http://www.tribology-abc.com/calculators/c9_3.htm
with some of the parameters that you are familiar with, in the engines of your signature.
Pick a main bearing diameter, a width, and a clearance...dial in a speed and a viscosity (minimum film thickness is hard wired until you pay)...and there's a watts of power consumption of that bearing...and there's multiple bearings...it's significant.
Originally Posted By: Shannow
kschachn,
have a play with http://www.tribology-abc.com/calculators/c9_3.htm
with some of the parameters that you are familiar with, in the engines of your signature.
Pick a main bearing diameter, a width, and a clearance...dial in a speed and a viscosity (minimum film thickness is hard wired until you pay)...and there's a watts of power consumption of that bearing...and there's multiple bearings...it's significant.
Originally Posted By: kschachn
That's interesting information, thank you for posting. A couple hundred watts per main bearing? Wow, I would never think it was that high. I don't know how many bearings that engine has, but if there are five that could be over a thousand watts.
I'd love to be able to fully instrument an engine and run it in some kind of environmental chamber to experiment.
Originally Posted By: Shannow
Originally Posted By: kschachn
I'll play my hand here and say that no one, ever, is going to convince me that you could see the difference. The heat transfer between the coolant and the block/head is where the vast majority of the cooling takes place. Besides, any cooling the oil performs has to be rejected at the pan, right? Or on some cooler interior surface (but where do you find that?)
I sort of agreed until recently, but my experiments prove otherwise.
Logically, the hottest oil in the engine is that coming out the big end bearings, second hottest the mains...these are the locations where the engine is actively working against the oil, shearing it, a couple of hundreds of watts per bearing at 3-4k RPM.
That oil drops back into the sump, having made no contact with cooled surfaces...that which does little to no work anyway, is, as you say cooled/warmed by running down water cooled/heated surfaces.
Dropping a type K thermocouple down my disptick, directly between the high/low mark, my Caprice regularly reads 105-110C,and if I run 5 minutes at 4K revs, will read 120-125c...in ambients of -2 to 5C, well above coolant temperature.
Push the thermocouple lower in the pan (Caprice has a big winged alloy pan), the oil temperature drops rapidly..an oil temperature sender closer to the pan wall will give a temperature closer to the pan temperature than what's leaving the bearings...perfect indicator of bearing supply temperature, but no correlation whatsoever on the working temperature in the bearings, which is determined by specific load, and RPM, and will be 10-20(+) C higher than the bulk oil temperatures.
Total heat rejection to oil in a V8 automotive engine running stabilized at max power can be in the region of 20 kilowatts. This represents about 3% of the fuel energy being supplied.
That's interesting information, thank you for posting. A couple hundred watts per main bearing? Wow, I would never think it was that high. I don't know how many bearings that engine has, but if there are five that could be over a thousand watts.
I'd love to be able to fully instrument an engine and run it in some kind of environmental chamber to experiment.
Originally Posted By: Shannow
Originally Posted By: kschachn
I'll play my hand here and say that no one, ever, is going to convince me that you could see the difference. The heat transfer between the coolant and the block/head is where the vast majority of the cooling takes place. Besides, any cooling the oil performs has to be rejected at the pan, right? Or on some cooler interior surface (but where do you find that?)
I sort of agreed until recently, but my experiments prove otherwise.
Logically, the hottest oil in the engine is that coming out the big end bearings, second hottest the mains...these are the locations where the engine is actively working against the oil, shearing it, a couple of hundreds of watts per bearing at 3-4k RPM.
That oil drops back into the sump, having made no contact with cooled surfaces...that which does little to no work anyway, is, as you say cooled/warmed by running down water cooled/heated surfaces.
Dropping a type K thermocouple down my disptick, directly between the high/low mark, my Caprice regularly reads 105-110C,and if I run 5 minutes at 4K revs, will read 120-125c...in ambients of -2 to 5C, well above coolant temperature.
Push the thermocouple lower in the pan (Caprice has a big winged alloy pan), the oil temperature drops rapidly..an oil temperature sender closer to the pan wall will give a temperature closer to the pan temperature than what's leaving the bearings...perfect indicator of bearing supply temperature, but no correlation whatsoever on the working temperature in the bearings, which is determined by specific load, and RPM, and will be 10-20(+) C higher than the bulk oil temperatures.
Total heat rejection to oil in a V8 automotive engine running stabilized at max power can be in the region of 20 kilowatts. This represents about 3% of the fuel energy being supplied.
Not all from frictional losses though, right?
Originally Posted By: A_Harman
Total heat rejection to oil in a V8 automotive engine running stabilized at max power can be in the region of 20 kilowatts. This represents about 3% of the fuel energy being supplied.
Originally Posted By: A_Harman
Total heat rejection to oil in a V8 automotive engine running stabilized at max power can be in the region of 20 kilowatts. This represents about 3% of the fuel energy being supplied.
True. Some of that heat would come from piston coolers and possibly cam phasers (if they're active a lot). But crankshaft churning of the oil in the crankcase adds a lot of heat to the oil over what it picks up when it runs through the bearings.
This forum continues to be excellent, and one of the best on the internet. This discussion started from a rather innocent question, but the collective depth of knowledge at this forum is amazing. Keep it up, gents.
OVERKILL
$100 Site Donor 2021
Originally Posted By: Hokiefyd
This forum continues to be excellent, and one of the best on the internet. This discussion started from a rather innocent question, but the collective depth of knowledge at this forum is amazing. Keep it up, gents.
Agreed
What a fantastic discussion.
This forum continues to be excellent, and one of the best on the internet. This discussion started from a rather innocent question, but the collective depth of knowledge at this forum is amazing. Keep it up, gents.
Agreed
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