HD engine, economy and wear 5W30 vs 0W20
- Thread starter Shannow
- Start date
- Status
Originally Posted By: Shannow
Originally Posted By: Jetronic
HTHS viscosity seems to be the first line of defense against wear.
Jetronic, yes, the initial fundimental of lubrication is to keep the parts separated, the ideal "zero wear" condition.
It's not a condition that exists in areas like the cam, lifters, and piston rings at the top and bottom reversal points, where the additives are in play.
As we move to a lower viscosity future, the additives come into play more frequently, and in more areas.
Originally Posted By: Jetronic
Note that the article only mentions bearing wear, and says nothing about ring wear which is more likely to send a car to the scrapyard
Rings are a bit more tricky, being hydrodynamic in the mid stroke (to the point that thermal barrier coatings are being applied to drop the mid stroke viscosity majorly), and heavily additive dependent at the ends of the stroke.
The dwell time a TDC and BDC is mind boggling. Like a helicopters main rotors advancing and retreating lift difference when flying.
Originally Posted By: Jetronic
HTHS viscosity seems to be the first line of defense against wear.
Jetronic, yes, the initial fundimental of lubrication is to keep the parts separated, the ideal "zero wear" condition.
It's not a condition that exists in areas like the cam, lifters, and piston rings at the top and bottom reversal points, where the additives are in play.
As we move to a lower viscosity future, the additives come into play more frequently, and in more areas.
Originally Posted By: Jetronic
Note that the article only mentions bearing wear, and says nothing about ring wear which is more likely to send a car to the scrapyard
Rings are a bit more tricky, being hydrodynamic in the mid stroke (to the point that thermal barrier coatings are being applied to drop the mid stroke viscosity majorly), and heavily additive dependent at the ends of the stroke.
The dwell time a TDC and BDC is mind boggling. Like a helicopters main rotors advancing and retreating lift difference when flying.
The highest liner/cylinder wear is at the top
ring reversal point.
A worn out engine will have a taper from that
point downward, and sometimes the cross-hatch
is still visible near the bottom of the cylinder.
The TDC and BDC of a 440 Chrysler and 454 Chev
are quite very different for engines of the
same basic size.
The 454 (with it's longer stroke
and shorter connecting rod)
piston moves away from TDC quicker
per degree of crankshaft rotation than
the 440's piston.
Would I be correct in saying...
Because of that, the 454 can tolerate
a larger intake port than the 440?
ring reversal point.
A worn out engine will have a taper from that
point downward, and sometimes the cross-hatch
is still visible near the bottom of the cylinder.
The TDC and BDC of a 440 Chrysler and 454 Chev
are quite very different for engines of the
same basic size.
The 454 (with it's longer stroke
and shorter connecting rod)
piston moves away from TDC quicker
per degree of crankshaft rotation than
the 440's piston.
Would I be correct in saying...
Because of that, the 454 can tolerate
a larger intake port than the 440?
Would I be correct in saying...
Because of that, the 454 can tolerate
a larger intake port than the 440?
Correct!
Short rods (lower R/S ratio) require larger ports and vice versa.
Shorter ,sharper intake pulses with the 454.
Because of that, the 454 can tolerate
a larger intake port than the 440?
Correct!
Short rods (lower R/S ratio) require larger ports and vice versa.
Shorter ,sharper intake pulses with the 454.
i have a question. in that test they allowed the oil supply temp to vary as the engine heated or cooled it on its own. their chart (figure 1) on page 144 shows the supply oil temperature varied from 87c-121c (188-250f).
then on page 147 they say this:
"Compared to main bearings the big end bearings work under higher loads while being lubricated
with less oil flow. This results in higher bearing shell temperatures which is also taken into account.
Experimental results in an engine [20] show a rise in big end bearing shell temperature of about 3–5
◦ C
for a wide range of load and speed conditions compared to the main bearing temperature. Newer results
measured on two journal bearing test-rigs [4,6] show a little higher values for the much higher bearing
loads that are typical today in Diesel-engines. Consequently, the temperatures of the big end bearings
are approximated to be about 7
◦ C constantly higher than the main bearings. While it is plausible to
adjust the temperature difference depending on the actual load, it is worthwhile to note that already this
7
◦ C difference has only a very small impact on the results. So while minor deviations of a few single
degrees Celsius are not critical, it is however crucial to use measured bearing shell temperatures as these
deviate by as much as 30
◦ C from the oil supply temperature. Figure 3 shows the so obtained equivalent
temperatures that are used in the following as input data for the calculations. As can be seen from the
shown temperatures there is a strong dependence on engine speed and load present that counteracts the
increase in the friction power losses at high engine speeds and loads."
so, are they saying that oil temps at the bearing were as high as 300f or that just the shell of the bearing got that hot and the oil heated up to something in between as it didnt take on all the heat because its going through there too fast?
just want to know if i let my bulk oil temp reach 240f if my oil is actually reaching 295f at the bearings under full load/high rpm. if thats the case i may be more wary of letting it get that hot
then on page 147 they say this:
"Compared to main bearings the big end bearings work under higher loads while being lubricated
with less oil flow. This results in higher bearing shell temperatures which is also taken into account.
Experimental results in an engine [20] show a rise in big end bearing shell temperature of about 3–5
◦ C
for a wide range of load and speed conditions compared to the main bearing temperature. Newer results
measured on two journal bearing test-rigs [4,6] show a little higher values for the much higher bearing
loads that are typical today in Diesel-engines. Consequently, the temperatures of the big end bearings
are approximated to be about 7
◦ C constantly higher than the main bearings. While it is plausible to
adjust the temperature difference depending on the actual load, it is worthwhile to note that already this
7
◦ C difference has only a very small impact on the results. So while minor deviations of a few single
degrees Celsius are not critical, it is however crucial to use measured bearing shell temperatures as these
deviate by as much as 30
◦ C from the oil supply temperature. Figure 3 shows the so obtained equivalent
temperatures that are used in the following as input data for the calculations. As can be seen from the
shown temperatures there is a strong dependence on engine speed and load present that counteracts the
increase in the friction power losses at high engine speeds and loads."
so, are they saying that oil temps at the bearing were as high as 300f or that just the shell of the bearing got that hot and the oil heated up to something in between as it didnt take on all the heat because its going through there too fast?
just want to know if i let my bulk oil temp reach 240f if my oil is actually reaching 295f at the bearings under full load/high rpm. if thats the case i may be more wary of letting it get that hot
Originally Posted By: Festiva_Man
so, are they saying that oil temps at the bearing were as high as 300f or that just the shell of the bearing got that hot and the oil heated up to something in between as it didnt take on all the heat because its going through there too fast?
just want to know if i let my bulk oil temp reach 240f if my oil is actually reaching 295f at the bearings under full load/high rpm. if thats the case i may be more wary of letting it get that hot
I've posted on BITOG a number of times (met with criticism, but it's a fact), that most of the heat that the oil is dealing with in the bearings is self generated, but the lubricant within the bearings shearing, being worked on by the engine.
Each bearing is creating a couple hundred watts of heat, and that heat is related to an exponential function of engine speed, not engine load, or fuel burned per se.
The big end oil temperature will be 20-30C more than the bulk oil temperature.
It's not what 101 has about flow carrying away temperature, it's thermodynamics of oil under shear.
I'll give an example, on my 3.8 supercharged Holden.
I can place a type K thermocouple down the dipstick hole, and get the oil temperature of what's raining off the crank (immediately after shut-off.
On a typicla 15 mile highway commute, it's 105-110C (230)...heat gun on the sump is around 90C (195F).
However, if I hold the tranny in "2", and do the same trip at 4,000RPM (not 1750 like in drive), I've got oil temperatures of 135C in the drain down areas...275F...and that's still a mix of the bearings and the coolant temperature oil that has drained down the valley.
So yes, the oil in your bearings could easily be 300F, the exit temperature of the oil is the average of the supply temperature and the shell temperature.
As an aside, it's my view that this hot atomised spray of oil, into an environment of highly reactive blowby gasses is where the process of varnish formation takes place.
so, are they saying that oil temps at the bearing were as high as 300f or that just the shell of the bearing got that hot and the oil heated up to something in between as it didnt take on all the heat because its going through there too fast?
just want to know if i let my bulk oil temp reach 240f if my oil is actually reaching 295f at the bearings under full load/high rpm. if thats the case i may be more wary of letting it get that hot
I've posted on BITOG a number of times (met with criticism, but it's a fact), that most of the heat that the oil is dealing with in the bearings is self generated, but the lubricant within the bearings shearing, being worked on by the engine.
Each bearing is creating a couple hundred watts of heat, and that heat is related to an exponential function of engine speed, not engine load, or fuel burned per se.
The big end oil temperature will be 20-30C more than the bulk oil temperature.
It's not what 101 has about flow carrying away temperature, it's thermodynamics of oil under shear.
I'll give an example, on my 3.8 supercharged Holden.
I can place a type K thermocouple down the dipstick hole, and get the oil temperature of what's raining off the crank (immediately after shut-off.
On a typicla 15 mile highway commute, it's 105-110C (230)...heat gun on the sump is around 90C (195F).
However, if I hold the tranny in "2", and do the same trip at 4,000RPM (not 1750 like in drive), I've got oil temperatures of 135C in the drain down areas...275F...and that's still a mix of the bearings and the coolant temperature oil that has drained down the valley.
So yes, the oil in your bearings could easily be 300F, the exit temperature of the oil is the average of the supply temperature and the shell temperature.
As an aside, it's my view that this hot atomised spray of oil, into an environment of highly reactive blowby gasses is where the process of varnish formation takes place.
Originally Posted By: Shannow
Originally Posted By: Festiva_Man
so, are they saying that oil temps at the bearing were as high as 300f or that just the shell of the bearing got that hot and the oil heated up to something in between as it didnt take on all the heat because its going through there too fast?
just want to know if i let my bulk oil temp reach 240f if my oil is actually reaching 295f at the bearings under full load/high rpm. if thats the case i may be more wary of letting it get that hot
I've posted on BITOG a number of times (met with criticism, but it's a fact), that most of the heat that the oil is dealing with in the bearings is self generated, but the lubricant within the bearings shearing, being worked on by the engine.
Each bearing is creating a couple hundred watts of heat, and that heat is related to an exponential function of engine speed, not engine load, or fuel burned per se.
The big end oil temperature will be 20-30C more than the bulk oil temperature.
It's not what 101 has about flow carrying away temperature, it's thermodynamics of oil under shear.
I'll give an example, on my 3.8 supercharged Holden.
I can place a type K thermocouple down the dipstick hole, and get the oil temperature of what's raining off the crank (immediately after shut-off.
On a typicla 15 mile highway commute, it's 105-110C (230)...heat gun on the sump is around 90C (195F).
However, if I hold the tranny in "2", and do the same trip at 4,000RPM (not 1750 like in drive), I've got oil temperatures of 135C in the drain down areas...275F...and that's still a mix of the bearings and the coolant temperature oil that has drained down the valley.
So yes, the oil in your bearings could easily be 300F, the exit temperature of the oil is the average of the supply temperature and the shell temperature.
As an aside, it's my view that this hot atomised spray of oil, into an environment of highly reactive blowby gasses is where the process of varnish formation takes place.
ok, do you mean " that most of the heat that the oil is dealing with in the bearings is self generated, by (or but?) the lubricant within the bearings shearing"? why would anyone argue that? its common sense. rub your hands togeather and call them molecules and you proved it. i believe thats how a microwave works, it excites water molecules which heats them up...
"It's not what 101 has about flow carrying away temperature, it's thermodynamics of oil under shear." sorry, what?
i have a oil temperature guage connected at the oil filter sandwich adapter. i can confirm that. at 100km/hr (2550rpm) on my civic on a long drive the oil will stabilize at say 210f. speed up to 110km/hr (2800rpm) and it will stabilize at 215f. speed up to 220-230km/hr (3000-3300ish rpm) and it will run 220-230f. all on the same drive, same terrain, same outside temps, and same load on the car.
if after an hour drive i stop and measure and record my oil pressure readings at different rpms, so stop, put it in first and write down what pressure is at 1k, 2k, 3k... by the time i get to 6k rpm the oil has gone from say 212f to 220f. i thought that had more to do with the oil around the piston rings being heated faster at higher rpms but it makes sense that it would come from all the components as they all turn faster.
prior to now i assumed that while oil can take away a large amount of heat that it did not heat up quickly like coolant does. i thought that because coolant might take 2 minutes of driving to reach 180f (op temp) and oil takes 18-20 min to reach 180f and 25-30 min to reach 212f (op temp) on the same drive all while being closer in contact with heat sources that meant it heated up slower. so i thought for example that oil at 212f passing very quickly through a bearing at 280f would only heat up to maybe 230f, fall back to the pan and cool off to 212 before being sucked back up to my temp guage. and i thought just the large volume of oil passing through the bearing-each particle not heating up much- kept the bearing cool enough.
from what your saying i take it that that assumption is wrong and the oil picks up and looses heat very, very fast. if thats the case can you please tell me why it takes so long for oil to heat up compared to coolant when it would seem that the oil comes in contact with a lot more heat? i have heard tell that the valves get up to 900f... if thats true wouldn't the oil boil as it got near there if it heated up that fast? or is it different when it shears compared to just flowing around the valves? i presume the area the oil sees near the rings is very hot as well.
thanks!
and interesting idea, but that spray is all in the pan and most varnish happens in the valve cover right? or does just as much occur in the pan and i have just taken off more valve covers than pans?
Originally Posted By: Festiva_Man
so, are they saying that oil temps at the bearing were as high as 300f or that just the shell of the bearing got that hot and the oil heated up to something in between as it didnt take on all the heat because its going through there too fast?
just want to know if i let my bulk oil temp reach 240f if my oil is actually reaching 295f at the bearings under full load/high rpm. if thats the case i may be more wary of letting it get that hot
I've posted on BITOG a number of times (met with criticism, but it's a fact), that most of the heat that the oil is dealing with in the bearings is self generated, but the lubricant within the bearings shearing, being worked on by the engine.
Each bearing is creating a couple hundred watts of heat, and that heat is related to an exponential function of engine speed, not engine load, or fuel burned per se.
The big end oil temperature will be 20-30C more than the bulk oil temperature.
It's not what 101 has about flow carrying away temperature, it's thermodynamics of oil under shear.
I'll give an example, on my 3.8 supercharged Holden.
I can place a type K thermocouple down the dipstick hole, and get the oil temperature of what's raining off the crank (immediately after shut-off.
On a typicla 15 mile highway commute, it's 105-110C (230)...heat gun on the sump is around 90C (195F).
However, if I hold the tranny in "2", and do the same trip at 4,000RPM (not 1750 like in drive), I've got oil temperatures of 135C in the drain down areas...275F...and that's still a mix of the bearings and the coolant temperature oil that has drained down the valley.
So yes, the oil in your bearings could easily be 300F, the exit temperature of the oil is the average of the supply temperature and the shell temperature.
As an aside, it's my view that this hot atomised spray of oil, into an environment of highly reactive blowby gasses is where the process of varnish formation takes place.
ok, do you mean " that most of the heat that the oil is dealing with in the bearings is self generated, by (or but?) the lubricant within the bearings shearing"? why would anyone argue that? its common sense. rub your hands togeather and call them molecules and you proved it. i believe thats how a microwave works, it excites water molecules which heats them up...
"It's not what 101 has about flow carrying away temperature, it's thermodynamics of oil under shear." sorry, what?
i have a oil temperature guage connected at the oil filter sandwich adapter. i can confirm that. at 100km/hr (2550rpm) on my civic on a long drive the oil will stabilize at say 210f. speed up to 110km/hr (2800rpm) and it will stabilize at 215f. speed up to 220-230km/hr (3000-3300ish rpm) and it will run 220-230f. all on the same drive, same terrain, same outside temps, and same load on the car.
if after an hour drive i stop and measure and record my oil pressure readings at different rpms, so stop, put it in first and write down what pressure is at 1k, 2k, 3k... by the time i get to 6k rpm the oil has gone from say 212f to 220f. i thought that had more to do with the oil around the piston rings being heated faster at higher rpms but it makes sense that it would come from all the components as they all turn faster.
prior to now i assumed that while oil can take away a large amount of heat that it did not heat up quickly like coolant does. i thought that because coolant might take 2 minutes of driving to reach 180f (op temp) and oil takes 18-20 min to reach 180f and 25-30 min to reach 212f (op temp) on the same drive all while being closer in contact with heat sources that meant it heated up slower. so i thought for example that oil at 212f passing very quickly through a bearing at 280f would only heat up to maybe 230f, fall back to the pan and cool off to 212 before being sucked back up to my temp guage. and i thought just the large volume of oil passing through the bearing-each particle not heating up much- kept the bearing cool enough.
from what your saying i take it that that assumption is wrong and the oil picks up and looses heat very, very fast. if thats the case can you please tell me why it takes so long for oil to heat up compared to coolant when it would seem that the oil comes in contact with a lot more heat? i have heard tell that the valves get up to 900f... if thats true wouldn't the oil boil as it got near there if it heated up that fast? or is it different when it shears compared to just flowing around the valves? i presume the area the oil sees near the rings is very hot as well.
thanks!
and interesting idea, but that spray is all in the pan and most varnish happens in the valve cover right? or does just as much occur in the pan and i have just taken off more valve covers than pans?
Originally Posted By: Shannow
Originally Posted By: Festiva_Man
so, are they saying that oil temps at the bearing were as high as 300f or that just the shell of the bearing got that hot and the oil heated up to something in between as it didnt take on all the heat because its going through there too fast?
just want to know if i let my bulk oil temp reach 240f if my oil is actually reaching 295f at the bearings under full load/high rpm. if thats the case i may be more wary of letting it get that hot
I've posted on BITOG a number of times (met with criticism, but it's a fact), that most of the heat that the oil is dealing with in the bearings is self generated, but the lubricant within the bearings shearing, being worked on by the engine.
Each bearing is creating a couple hundred watts of heat, and that heat is related to an exponential function of engine speed, not engine load, or fuel burned per se.
The big end oil temperature will be 20-30C more than the bulk oil temperature.
It's not what 101 has about flow carrying away temperature, it's thermodynamics of oil under shear.
I'll give an example, on my 3.8 supercharged Holden.
I can place a type K thermocouple down the dipstick hole, and get the oil temperature of what's raining off the crank (immediately after shut-off.
On a typicla 15 mile highway commute, it's 105-110C (230)...heat gun on the sump is around 90C (195F).
However, if I hold the tranny in "2", and do the same trip at 4,000RPM (not 1750 like in drive), I've got oil temperatures of 135C in the drain down areas...275F...and that's still a mix of the bearings and the coolant temperature oil that has drained down the valley.
So yes, the oil in your bearings could easily be 300F, the exit temperature of the oil is the average of the supply temperature and the shell temperature.
As an aside, it's my view that this hot atomised spray of oil, into an environment of highly reactive blowby gasses is where the process of varnish formation takes place.
so your saying this varnish on the rocker on the lower right corner comes from gasses coming up the drain-to-pan hole? what about the extra varnish on the rocker 5th from the right on the bottom then? thats always puzzled me.
Originally Posted By: Festiva_Man
so, are they saying that oil temps at the bearing were as high as 300f or that just the shell of the bearing got that hot and the oil heated up to something in between as it didnt take on all the heat because its going through there too fast?
just want to know if i let my bulk oil temp reach 240f if my oil is actually reaching 295f at the bearings under full load/high rpm. if thats the case i may be more wary of letting it get that hot
I've posted on BITOG a number of times (met with criticism, but it's a fact), that most of the heat that the oil is dealing with in the bearings is self generated, but the lubricant within the bearings shearing, being worked on by the engine.
Each bearing is creating a couple hundred watts of heat, and that heat is related to an exponential function of engine speed, not engine load, or fuel burned per se.
The big end oil temperature will be 20-30C more than the bulk oil temperature.
It's not what 101 has about flow carrying away temperature, it's thermodynamics of oil under shear.
I'll give an example, on my 3.8 supercharged Holden.
I can place a type K thermocouple down the dipstick hole, and get the oil temperature of what's raining off the crank (immediately after shut-off.
On a typicla 15 mile highway commute, it's 105-110C (230)...heat gun on the sump is around 90C (195F).
However, if I hold the tranny in "2", and do the same trip at 4,000RPM (not 1750 like in drive), I've got oil temperatures of 135C in the drain down areas...275F...and that's still a mix of the bearings and the coolant temperature oil that has drained down the valley.
So yes, the oil in your bearings could easily be 300F, the exit temperature of the oil is the average of the supply temperature and the shell temperature.
As an aside, it's my view that this hot atomised spray of oil, into an environment of highly reactive blowby gasses is where the process of varnish formation takes place.
so your saying this varnish on the rocker on the lower right corner comes from gasses coming up the drain-to-pan hole? what about the extra varnish on the rocker 5th from the right on the bottom then? thats always puzzled me.
Festiva;
Could you switch from F to C for all your temperatures?
I think the rocker is not getting oil on top of it to
keep it clean like the others.
If you look at the underside of the valve cover, you should
see clean and not so clean areas, depending on if oil is
hitting those areas or not.
You also may have noticed the magic 3.6 HTHS mentioned here and there.
And in my response to your UOA post.
That number represents a comfort zone that many have used as a benchmark
or rule of thumb.
Everyone has a pucker point, whether it's 3.3 or 2.8 HTHS, or some other number.
Could you switch from F to C for all your temperatures?
I think the rocker is not getting oil on top of it to
keep it clean like the others.
If you look at the underside of the valve cover, you should
see clean and not so clean areas, depending on if oil is
hitting those areas or not.
You also may have noticed the magic 3.6 HTHS mentioned here and there.
And in my response to your UOA post.
That number represents a comfort zone that many have used as a benchmark
or rule of thumb.
Everyone has a pucker point, whether it's 3.3 or 2.8 HTHS, or some other number.
Last edited by a moderator:
well i could convert all my numbers every time i post but all my guages read in F and once you get above 50C i think in farenhight as well...
but 210f=98c, 215f=101c, 220-230f=105-110c and 280f=138c
thats probably true, then any mist would leave deposits. i should probably take the valve train apart and clean everything...
my last car had hydraulicly adjusted valve lash and kept everything so much cleaner...
yes, the HTHS number is mentioned a lot but does it have anything to do with heat transfer? im just not sure what your getting at, sorry.
this link seems to indicate to me that engine oils pick up and get rid of heat energy slower than glycol or water and that they heat up more when they pick up the same amount of energy compared to water or glycol.
heat transfer properties of engine oils
that would tell me that it has more to do with the oil pan seeing more air cooling while the engine warms up than the coolant does with the thermostat controlling it.
maybe what we need is a second 'coolant pan' around the outside of the oil pan that makes coolant flow all the way around the outside of the oil pan maybe an inch and a half thick. insulate the coolant pan very well so air doesnt cool it off too much. then the coolant would heat the oil up faster to 200f and get our oil to the proper viscosity quicker and then it would cool it once the oil tried to get hotter than 200f. probably a thermostatically controlled oil cooler would still be needed for track cars or heavy duty trucks to prevent coolant overheating.
are there flaws in this idea or why isnt this done?
but 210f=98c, 215f=101c, 220-230f=105-110c and 280f=138c
thats probably true, then any mist would leave deposits. i should probably take the valve train apart and clean everything...
my last car had hydraulicly adjusted valve lash and kept everything so much cleaner...
yes, the HTHS number is mentioned a lot but does it have anything to do with heat transfer? im just not sure what your getting at, sorry.
this link seems to indicate to me that engine oils pick up and get rid of heat energy slower than glycol or water and that they heat up more when they pick up the same amount of energy compared to water or glycol.
heat transfer properties of engine oils
that would tell me that it has more to do with the oil pan seeing more air cooling while the engine warms up than the coolant does with the thermostat controlling it.
maybe what we need is a second 'coolant pan' around the outside of the oil pan that makes coolant flow all the way around the outside of the oil pan maybe an inch and a half thick. insulate the coolant pan very well so air doesnt cool it off too much. then the coolant would heat the oil up faster to 200f and get our oil to the proper viscosity quicker and then it would cool it once the oil tried to get hotter than 200f. probably a thermostatically controlled oil cooler would still be needed for track cars or heavy duty trucks to prevent coolant overheating.
are there flaws in this idea or why isnt this done?
All the oil specs are in C degrees, so either you have to convert F to C or we do.
How much do you want to read?
I'll move a thread up in the automotive gasoline section
called "How Bearings Work".
How much do you want to read?
I'll move a thread up in the automotive gasoline section
called "How Bearings Work".
Originally Posted By: Festiva_Man
that would tell me that it has more to do with the oil pan seeing more air cooling while the engine warms up than the coolant does with the thermostat controlling it.
maybe what we need is a second 'coolant pan' around the outside of the oil pan that makes coolant flow all the way around the outside of the oil pan maybe an inch and a half thick. insulate the coolant pan very well so air doesnt cool it off too much. then the coolant would heat the oil up faster to 200f and get our oil to the proper viscosity quicker and then it would cool it once the oil tried to get hotter than 200f. probably a thermostatically controlled oil cooler would still be needed for track cars or heavy duty trucks to prevent coolant overheating.
are there flaws in this idea or why isnt this done?
Some interesting stuff in this paper.
http://eprints.nottingham.ac.uk/13180/1/Thesis_JP.pdf
with regard to improving bulk oil warmup time.
that would tell me that it has more to do with the oil pan seeing more air cooling while the engine warms up than the coolant does with the thermostat controlling it.
maybe what we need is a second 'coolant pan' around the outside of the oil pan that makes coolant flow all the way around the outside of the oil pan maybe an inch and a half thick. insulate the coolant pan very well so air doesnt cool it off too much. then the coolant would heat the oil up faster to 200f and get our oil to the proper viscosity quicker and then it would cool it once the oil tried to get hotter than 200f. probably a thermostatically controlled oil cooler would still be needed for track cars or heavy duty trucks to prevent coolant overheating.
are there flaws in this idea or why isnt this done?
Some interesting stuff in this paper.
http://eprints.nottingham.ac.uk/13180/1/Thesis_JP.pdf
with regard to improving bulk oil warmup time.
Originally Posted By: Festiva_Man
...probably a thermostatically controlled oil cooler would still be needed for track cars or heavy duty trucks to prevent coolant overheating.
are there flaws in this idea or why isnt this done?
My little Nissan Frontier has an oil cooler supplied with engine coolant. So it is in effect an oil heater during warm-up and a cooler under load. So long as the radiator has enough capacity it's a great system. Jaguar did this with their V12 so it's nothing new.
...probably a thermostatically controlled oil cooler would still be needed for track cars or heavy duty trucks to prevent coolant overheating.
are there flaws in this idea or why isnt this done?
My little Nissan Frontier has an oil cooler supplied with engine coolant. So it is in effect an oil heater during warm-up and a cooler under load. So long as the radiator has enough capacity it's a great system. Jaguar did this with their V12 so it's nothing new.
Over 50% of cars here in Europe have such an oil cooler. I've first started seeing them 25 years ago...
Originally Posted By: used_0il
All the oil specs are in C degrees, so either you have to convert F to C or we do.
How much do you want to read?
I'll move a thread up in the automotive gasoline section
called "How Bearings Work".
oh, sorry about that! i converted all the temps in the article for myself and then forgot about that...
as long as im learning i like to read, thanks for that!
Originally Posted By: Shannow
Some interesting stuff in this paper.
http://eprints.nottingham.ac.uk/13180/1/Thesis_JP.pdf
with regard to improving bulk oil warmup time.
wow, thanks! that might take me a week to read but i have learned a fair bit so far
Originally Posted By: Joshua_Skinner
My little Nissan Frontier has an oil cooler supplied with engine coolant. So it is in effect an oil heater during warm-up and a cooler under load. So long as the radiator has enough capacity it's a great system. Jaguar did this with their V12 so it's nothing new.
Originally Posted By: Jetronic
Over 50% of cars here in Europe have such an oil cooler. I've first started seeing them 25 years ago...
sorry for the confusion about what i meant. i was referring to the part about 'insulating' the oil pan and heating it with coolant rather than the oil cooler part. the cooler would just be necessary if you insulated the pan.
i know of coolers that cool off the oil by bringing it up to the radiator and using the coolant and air to cool the engine oil but they were all thermostatically controlled. So untill the oil reached a certain temperature like say 230f no oil went through it.
your saying the one on your frontier is always circulating? i would think the airflow would cool it off more while its trying to heat up just like running your car without a thermostat on the coolant. or is the exchanger not located up front by the radiator?
All the oil specs are in C degrees, so either you have to convert F to C or we do.
How much do you want to read?
I'll move a thread up in the automotive gasoline section
called "How Bearings Work".
oh, sorry about that! i converted all the temps in the article for myself and then forgot about that...
as long as im learning i like to read, thanks for that!
Originally Posted By: Shannow
Some interesting stuff in this paper.
http://eprints.nottingham.ac.uk/13180/1/Thesis_JP.pdf
with regard to improving bulk oil warmup time.
wow, thanks! that might take me a week to read but i have learned a fair bit so far
Originally Posted By: Joshua_Skinner
My little Nissan Frontier has an oil cooler supplied with engine coolant. So it is in effect an oil heater during warm-up and a cooler under load. So long as the radiator has enough capacity it's a great system. Jaguar did this with their V12 so it's nothing new.
Originally Posted By: Jetronic
Over 50% of cars here in Europe have such an oil cooler. I've first started seeing them 25 years ago...
sorry for the confusion about what i meant. i was referring to the part about 'insulating' the oil pan and heating it with coolant rather than the oil cooler part. the cooler would just be necessary if you insulated the pan.
i know of coolers that cool off the oil by bringing it up to the radiator and using the coolant and air to cool the engine oil but they were all thermostatically controlled. So untill the oil reached a certain temperature like say 230f no oil went through it.
your saying the one on your frontier is always circulating? i would think the airflow would cool it off more while its trying to heat up just like running your car without a thermostat on the coolant. or is the exchanger not located up front by the radiator?
the exchanger is usually located by the oil filter. this probably helps with filtration aswell as warmer oil is less likely to trip the bypass valve in the filter.
Originally Posted By: Kuato
Originally Posted By: MolaKule
Originally Posted By: Kuato
Yeah, interesting article. 8% reduction in friction at idle with either 0w20 compared to 30 weight, but NO reduction of friction at higher power output.
Seems to me if you have a city only car with lots of idle time the 0w20 would be a benefit.
This also seems to back up the concerns that 20 weights may allow accelerated wear compared to 30 weights.
But they don't have to with proper formulation.
True, the article did suggest that additives could eliminate the metal to metal contact.
Yes, but AW additives are short lived, and base oils aren't, so thicker oils doesn't depend on the depletable.
Originally Posted By: MolaKule
Originally Posted By: Kuato
Yeah, interesting article. 8% reduction in friction at idle with either 0w20 compared to 30 weight, but NO reduction of friction at higher power output.
Seems to me if you have a city only car with lots of idle time the 0w20 would be a benefit.
This also seems to back up the concerns that 20 weights may allow accelerated wear compared to 30 weights.
But they don't have to with proper formulation.
True, the article did suggest that additives could eliminate the metal to metal contact.
Yes, but AW additives are short lived, and base oils aren't, so thicker oils doesn't depend on the depletable.
Originally Posted By: Shannow
I've posted on BITOG a number of times (met with criticism, but it's a fact), that most of the heat that the oil is dealing with in the bearings is self generated, but the lubricant within the bearings shearing, being worked on by the engine.
Each bearing is creating a couple hundred watts of heat, and that heat is related to an exponential function of engine speed, not engine load, or fuel burned per se.
The big end oil temperature will be 20-30C more than the bulk oil temperature.
It's not what 101 has about flow carrying away temperature, it's thermodynamics of oil under shear.
I'll give an example, on my 3.8 supercharged Holden.
I can place a type K thermocouple down the dipstick hole, and get the oil temperature of what's raining off the crank (immediately after shut-off.
On a typicla 15 mile highway commute, it's 105-110C (230)...heat gun on the sump is around 90C (195F).
However, if I hold the tranny in "2", and do the same trip at 4,000RPM (not 1750 like in drive), I've got oil temperatures of 135C in the drain down areas...275F...and that's still a mix of the bearings and the coolant temperature oil that has drained down the valley.
So yes, the oil in your bearings could easily be 300F, the exit temperature of the oil is the average of the supply temperature and the shell temperature.
As an aside, it's my view that this hot atomised spray of oil, into an environment of highly reactive blowby gasses is where the process of varnish formation takes place.
Well, the oil falls down hotter than the bulk (in pan), because it comes from the head, the piston and cylinder walls, where is the combustion chambers are placed, therefore where the combustion happens, is the explosions that's making such heat, not from the bearings. Bearings have much less influence to temperature of the oil, than the cc.
I've posted on BITOG a number of times (met with criticism, but it's a fact), that most of the heat that the oil is dealing with in the bearings is self generated, but the lubricant within the bearings shearing, being worked on by the engine.
Each bearing is creating a couple hundred watts of heat, and that heat is related to an exponential function of engine speed, not engine load, or fuel burned per se.
The big end oil temperature will be 20-30C more than the bulk oil temperature.
It's not what 101 has about flow carrying away temperature, it's thermodynamics of oil under shear.
I'll give an example, on my 3.8 supercharged Holden.
I can place a type K thermocouple down the dipstick hole, and get the oil temperature of what's raining off the crank (immediately after shut-off.
On a typicla 15 mile highway commute, it's 105-110C (230)...heat gun on the sump is around 90C (195F).
However, if I hold the tranny in "2", and do the same trip at 4,000RPM (not 1750 like in drive), I've got oil temperatures of 135C in the drain down areas...275F...and that's still a mix of the bearings and the coolant temperature oil that has drained down the valley.
So yes, the oil in your bearings could easily be 300F, the exit temperature of the oil is the average of the supply temperature and the shell temperature.
As an aside, it's my view that this hot atomised spray of oil, into an environment of highly reactive blowby gasses is where the process of varnish formation takes place.
Well, the oil falls down hotter than the bulk (in pan), because it comes from the head, the piston and cylinder walls, where is the combustion chambers are placed, therefore where the combustion happens, is the explosions that's making such heat, not from the bearings. Bearings have much less influence to temperature of the oil, than the cc.
Originally Posted By: Pontual
Well, the oil falls down hotter than the bulk (in pan), because it comes from the head, the piston and cylinder walls, where is the combustion chambers are placed, therefore where the combustion happens, is the explosions that's making such heat, not from the bearings. Bearings have much less influence to temperature of the oil, than the cc.
Firstly, you are incorrect that bearing temperature rise is trivial.
The car was driven on the same road, at the same speed, requiring the same power to the tyres, so same nett output, the increase in heat has to come from somewhere, due to extra energy in doing something...and that something is frictional drag, and slight increase in fuel consumption (combustion) is the response to increased frictional losses.
To have discounted temperature rise across the bearings, then can you give me what the typical temperature rise across a bearing IS in a running engine ?
Can tell me how much heat is generated in a single 2" diameter bearing, 3/4" long, 0.002" radial clearance and 10cst oil viscosity at 2,000 and 4,000RPM...multiply that by the number of bearings in an engine, and it's significant.
To have discounted it as trivial, you must know the numbers right ?
Well, the oil falls down hotter than the bulk (in pan), because it comes from the head, the piston and cylinder walls, where is the combustion chambers are placed, therefore where the combustion happens, is the explosions that's making such heat, not from the bearings. Bearings have much less influence to temperature of the oil, than the cc.
Firstly, you are incorrect that bearing temperature rise is trivial.
The car was driven on the same road, at the same speed, requiring the same power to the tyres, so same nett output, the increase in heat has to come from somewhere, due to extra energy in doing something...and that something is frictional drag, and slight increase in fuel consumption (combustion) is the response to increased frictional losses.
To have discounted temperature rise across the bearings, then can you give me what the typical temperature rise across a bearing IS in a running engine ?
Can tell me how much heat is generated in a single 2" diameter bearing, 3/4" long, 0.002" radial clearance and 10cst oil viscosity at 2,000 and 4,000RPM...multiply that by the number of bearings in an engine, and it's significant.
To have discounted it as trivial, you must know the numbers right ?
Originally Posted By: Shannow
Can tell me how much heat is generated in a single 2" diameter bearing, 3/4" long, 0.002" radial clearance and 10cst oil viscosity at 2,000 and 4,000RPM...multiply that by the number of bearings in an engine, and it's significant.
To have discounted it as trivial, you must know the numbers right ?
Might try this "motoring the engine" experimental technique to see what internal friction and parasitic losses are. http://www.stle.org/assets/document/The_Friction_Behavior_of_Individual_Components_of_a.pdf
Can tell me how much heat is generated in a single 2" diameter bearing, 3/4" long, 0.002" radial clearance and 10cst oil viscosity at 2,000 and 4,000RPM...multiply that by the number of bearings in an engine, and it's significant.
To have discounted it as trivial, you must know the numbers right ?
Might try this "motoring the engine" experimental technique to see what internal friction and parasitic losses are. http://www.stle.org/assets/document/The_Friction_Behavior_of_Individual_Components_of_a.pdf
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