Oil's part in cooling engine
- Thread starter avi1777
- Start date
- Status
Nope...most of the heat in the engine oil is created by the shearing of the engine oil between moving surfaces.
Yes, there's some contribution in piston undercrown, however the piston skirt to cylinder bore friction typically ends up as coolant load.
Yes, there's some contribution in piston undercrown, however the piston skirt to cylinder bore friction typically ends up as coolant load.
Here's how I understand the oils cooling in an engine.
Not that the oil in and of itself actually does or has any cooling properties(although it may). It's that the oil carries away heat through circulation. And again, oil in and of itself, can handle a great amount of heat.(I din't want to leave that out).
Kind'a like cooking on a grill or stovetop. Keep the food moving and it won't burn. Let is sit and you'll be eating charcoal...IDK, did I say that right?
Not that the oil in and of itself actually does or has any cooling properties(although it may). It's that the oil carries away heat through circulation. And again, oil in and of itself, can handle a great amount of heat.(I din't want to leave that out).
Kind'a like cooking on a grill or stovetop. Keep the food moving and it won't burn. Let is sit and you'll be eating charcoal...IDK, did I say that right?
Last edited:
I think thicker oil will carry more heat but also produces more heat so overall if you don't need a thicker oil and can get by with a thinner oil, you will have less heat with thinner oil.
But if you need thicker or higher hths oil, better not use a thin oil for sake of less heat. Because at some point you will produce more heat using thin oil by destroying your engine.
Edit:
I'm sure experts can explain that more elegantly!
But if you need thicker or higher hths oil, better not use a thin oil for sake of less heat. Because at some point you will produce more heat using thin oil by destroying your engine.
Edit:
I'm sure experts can explain that more elegantly!
Last edited:
Originally Posted by avi1777
is there a %of how much the oil cools an engine bedsides the radiator?
for example the oil is cooling 15% and the radiator85%
can such a thing be determent and if so does syn oil cools more than blends or conventionals?
tnx
Are you racing/dragging your vehicle at the track?
is there a %of how much the oil cools an engine bedsides the radiator?
for example the oil is cooling 15% and the radiator85%
can such a thing be determent and if so does syn oil cools more than blends or conventionals?
tnx
Are you racing/dragging your vehicle at the track?
Originally Posted by ChrisD46
Will a thinner grade oil (20W) carry away heat more rapidly than a thicker grade oil (30W) ?
Referencing Shannow's post above, a thinner oil will heat up less than a thicker one in an identical application because the shearing losses are lower.
I noticed this when I ran high HTHS M1 5W30 ESP in my car and saw higher sump oil temps than I did with regular M1 5W30 (I keep that temp up on my MFD all the time).
He also mentioned that the higher grade of oil will never heat up so much more that it will actually have a lower viscosity than a lower grade at a given operating point...makes intuitive sense to me, but Shannow works in that field and I'd guess he's actually run the numbers to prove it.
Will a thinner grade oil (20W) carry away heat more rapidly than a thicker grade oil (30W) ?
Referencing Shannow's post above, a thinner oil will heat up less than a thicker one in an identical application because the shearing losses are lower.
I noticed this when I ran high HTHS M1 5W30 ESP in my car and saw higher sump oil temps than I did with regular M1 5W30 (I keep that temp up on my MFD all the time).
He also mentioned that the higher grade of oil will never heat up so much more that it will actually have a lower viscosity than a lower grade at a given operating point...makes intuitive sense to me, but Shannow works in that field and I'd guess he's actually run the numbers to prove it.
And what about those engines with oil squirters which shot oil to the pistons' undersides?
Also, compare oil's heat transferring capability in air cooled engines to that of water cooled engines.
Hmmmm...are external oil coolers helpful...or even necessary?
Also, compare oil's heat transferring capability in air cooled engines to that of water cooled engines.
Hmmmm...are external oil coolers helpful...or even necessary?
Some cars have engine oil cooler. Not sure what % of heat is transferred by that!
They must be effective. My truck has one. Trucks with no tow package didn't come with the engine oil cooler.
Also some engine oil heat is transferred by the block.
They must be effective. My truck has one. Trucks with no tow package didn't come with the engine oil cooler.
Also some engine oil heat is transferred by the block.
Last edited:
Originally Posted by Kira
And what about those engines with oil squirters which shot oil to the pistons' undersides?
Also, compare oil's heat transferring capability in air cooled engines to that of water cooled engines.
Hmmmm...are external oil coolers helpful...or even necessary?
It was actually pointed out to me recently on this very site that my car has an oil cooler right under the fill port...never noticed the coolant line running to it.
My mental picture of an oil cooler was a contraption maybe the size of a microwave oven with several pounds of copper in it and lines running everywhere...I would guess the turbo is the reason for the cooler being added to the design, even though that also has coolant running to it.
And what about those engines with oil squirters which shot oil to the pistons' undersides?
Also, compare oil's heat transferring capability in air cooled engines to that of water cooled engines.
Hmmmm...are external oil coolers helpful...or even necessary?
It was actually pointed out to me recently on this very site that my car has an oil cooler right under the fill port...never noticed the coolant line running to it.
My mental picture of an oil cooler was a contraption maybe the size of a microwave oven with several pounds of copper in it and lines running everywhere...I would guess the turbo is the reason for the cooler being added to the design, even though that also has coolant running to it.
The amount of hear put into the oil varies depending on on a lot of engine design parameters. Piston cooling jets, oil volume pumped to head, location of oil gallys in block, airflow over oil pan, exhaust pipe under oil pan, turbo.
Last edited:
I read on the internet, so it must be true, of all the heat generated in an engine, 1/3 goes out the exhaust, 1/3 is radiated by the surface of the engine and 1/3 is removed via the radiator.
Originally Posted by Virtus_Probi
Originally Posted by Kira
And what about those engines with oil squirters which shot oil to the pistons' undersides?
Also, compare oil's heat transferring capability in air cooled engines to that of water cooled engines.
Hmmmm...are external oil coolers helpful...or even necessary?
It was actually pointed out to me recently on this very site that my car has an oil cooler right under the fill port...never noticed the coolant line running to it.
My mental picture of an oil cooler was a contraption maybe the size of a microwave oven with several pounds of copper in it and lines running everywhere...I would guess the turbo is the reason for the cooler being added to the design, even though that also has coolant running to it.
Most OEM oil coolers should be an oil to coolant heat exchanger. Most often right where the oil filter mounts. I've heard of some aftermarket kits that are more like an oil filter base extension if there's enough room. Then there needs to be a coolant line and I'm not sure about how to tap into it.
Both cars I've owned had oil coolers where the oil filter mounted right on the cooler. I could always see the coolant hoses running into the heat exchanger. First was a 1995 Acura Integra GS-R. I don't believe the non-VTEC Integra had one. Then my 2004 WRX.
There are some odd aftermarket oil coolers that are like little radiators. Not sure how one is supposed to plumb an oil line though.
Originally Posted by Kira
And what about those engines with oil squirters which shot oil to the pistons' undersides?
Also, compare oil's heat transferring capability in air cooled engines to that of water cooled engines.
Hmmmm...are external oil coolers helpful...or even necessary?
It was actually pointed out to me recently on this very site that my car has an oil cooler right under the fill port...never noticed the coolant line running to it.
My mental picture of an oil cooler was a contraption maybe the size of a microwave oven with several pounds of copper in it and lines running everywhere...I would guess the turbo is the reason for the cooler being added to the design, even though that also has coolant running to it.
Most OEM oil coolers should be an oil to coolant heat exchanger. Most often right where the oil filter mounts. I've heard of some aftermarket kits that are more like an oil filter base extension if there's enough room. Then there needs to be a coolant line and I'm not sure about how to tap into it.
Both cars I've owned had oil coolers where the oil filter mounted right on the cooler. I could always see the coolant hoses running into the heat exchanger. First was a 1995 Acura Integra GS-R. I don't believe the non-VTEC Integra had one. Then my 2004 WRX.
There are some odd aftermarket oil coolers that are like little radiators. Not sure how one is supposed to plumb an oil line though.
Look at air cooled engines. The oil's part is to move the heat to the surfaces (fins) that can shed it. Oil does not cool unless you have an oil cooler. There are engines (mostly industrial and marine) with massive oil coolers where the oil going into the system is well below sump temp. Some of these engines have spray jets to cool specific parts. And oil does carry excess heat from most turbos. So oil's job is heat transfer more than cooling.
Last edited:
Originally Posted by BrocLuno
Look at air cooled engines. The oil's part is to move the heat to the surfaces (fins) that can shed it. Oil does not cool unless you have an oil cooler. There are engines (mostly industrial and marine) with massive oil coolers where the oil going into the system is well below sump temp. Some of these engines have spray jets to cool specific parts. And oil does carry excess heat from most turbos. So oil's job is heat transfer more than cooling.
Well - oil is indirectly cooled by water cooling. Also - air passing through the pan is supposed to cool it a little bit. Haven't some people tried attaching fins to oil pans? Here's an article on something (adhesive applied aluminum fins) that the manufacturer claims will help cool down oil or transmission fluid.
http://www.superstreetonline.com/how-to/aftermarket-parts/0805-turp-arc-cool-fin/
Look at air cooled engines. The oil's part is to move the heat to the surfaces (fins) that can shed it. Oil does not cool unless you have an oil cooler. There are engines (mostly industrial and marine) with massive oil coolers where the oil going into the system is well below sump temp. Some of these engines have spray jets to cool specific parts. And oil does carry excess heat from most turbos. So oil's job is heat transfer more than cooling.
Well - oil is indirectly cooled by water cooling. Also - air passing through the pan is supposed to cool it a little bit. Haven't some people tried attaching fins to oil pans? Here's an article on something (adhesive applied aluminum fins) that the manufacturer claims will help cool down oil or transmission fluid.
http://www.superstreetonline.com/how-to/aftermarket-parts/0805-turp-arc-cool-fin/
Originally Posted by Kira
And what about those engines with oil squirters which shot oil to the pistons' undersides?
Also, compare oil's heat transferring capability in air cooled engines to that of water cooled engines.
Hmmmm...are external oil coolers helpful...or even necessary?
External oil coolers (thermostatically controllled I should say) are really the best of both worlds. The system can close off during warmup and then keep oil at a very specific temp regardless of operating condition. For example, my X5 will keep oil 100-105C at all times, in all conditions. It has a very large air-to-oil heat exchanger (not the radiator integrated ones), which can remove far more heat than the internal ones, as the delta-T is much higher. Total system capacity is probably 11-12 quarts. I can remove 9 quarts with an oil change.
The cooler, coupled with piston squirters, keeps the pistons nice and cool, allowing the engine to run leaner, more spark advance, and higher compression ratio.
And what about those engines with oil squirters which shot oil to the pistons' undersides?
Also, compare oil's heat transferring capability in air cooled engines to that of water cooled engines.
Hmmmm...are external oil coolers helpful...or even necessary?
External oil coolers (thermostatically controllled I should say) are really the best of both worlds. The system can close off during warmup and then keep oil at a very specific temp regardless of operating condition. For example, my X5 will keep oil 100-105C at all times, in all conditions. It has a very large air-to-oil heat exchanger (not the radiator integrated ones), which can remove far more heat than the internal ones, as the delta-T is much higher. Total system capacity is probably 11-12 quarts. I can remove 9 quarts with an oil change.
The cooler, coupled with piston squirters, keeps the pistons nice and cool, allowing the engine to run leaner, more spark advance, and higher compression ratio.
Last edited:
Originally Posted by y_p_w
Most OEM oil coolers should be an oil to coolant heat exchanger. Most often right where the oil filter mounts. I've heard of some aftermarket kits that are more like an oil filter base extension if there's enough room. Then there needs to be a coolant line and I'm not sure about how to tap into it.
Both cars I've owned had oil coolers where the oil filter mounted right on the cooler. I could always see the coolant hoses running into the heat exchanger. First was a 1995 Acura Integra GS-R. I don't believe the non-VTEC Integra had one. Then my 2004 WRX.
There are some odd aftermarket oil coolers that are like little radiators. Not sure how one is supposed to plumb an oil line though.
You're right, the cooler is right under the filter mount...I spaced out in my earlier post. It is right NEXT to the fill port, at least!
Most OEM oil coolers should be an oil to coolant heat exchanger. Most often right where the oil filter mounts. I've heard of some aftermarket kits that are more like an oil filter base extension if there's enough room. Then there needs to be a coolant line and I'm not sure about how to tap into it.
Both cars I've owned had oil coolers where the oil filter mounted right on the cooler. I could always see the coolant hoses running into the heat exchanger. First was a 1995 Acura Integra GS-R. I don't believe the non-VTEC Integra had one. Then my 2004 WRX.
There are some odd aftermarket oil coolers that are like little radiators. Not sure how one is supposed to plumb an oil line though.
You're right, the cooler is right under the filter mount...I spaced out in my earlier post. It is right NEXT to the fill port, at least!
Originally Posted by Virtus_Probi
He also mentioned that the higher grade of oil will never heat up so much more that it will actually have a lower viscosity than a lower grade at a given operating point...
Yep, otherwise car manufacturers would not recommend thicker oil for track use where oil temperatures run much hotter.
He also mentioned that the higher grade of oil will never heat up so much more that it will actually have a lower viscosity than a lower grade at a given operating point...
Yep, otherwise car manufacturers would not recommend thicker oil for track use where oil temperatures run much hotter.
- Status
Similar threads
