Viscosity Choice based on Oil temp
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Originally Posted By: Shannow
Originally Posted By: ZeeOSix
Originally Posted By: userfriendly
When the oil heats up due to high rpm it will become thinner, oil pressure will drop if the pump output is inadequate.
In this case would the solution be install a larger oil pump, or use a thicker oil?
Per Shannow, you don't need any oil pressure for bearings to survive.
Again, you are making up a position and stating that I am stating it...nice work...you must be an absolute pleasure to be around as a person
I have never once said that you don't need oil pressure...and I'd appreciate that you stop attributing it to me, as it's a lie that you keep perpetuating.
I have stated, time and time again, that you only need sufficient pressure to get the required volume to the bearings.
You have commented many times in all of these discussions (other 2 big threads) that you believe journal bearings don't need any oil pressure above ATM to survive, as long as oil is naturally ingested by the rotating bearing. You even said is again on page 2 of this thread.
Originally Posted By: Shannow
The oil pump is only supplying oil to make up for the bearing's inherent side leakage, which is influenced by viscosity, RPM, speed, diameter, length, load, and diametrical clearance...it's not "flowing" oil through the bearings.
So, yes you are really saying journal bearings don't need any oil pressure above ATM to survive, and that is true for some journal bearings used in low power small engines, etc.
Originally Posted By: ZeeOSix
Originally Posted By: userfriendly
When the oil heats up due to high rpm it will become thinner, oil pressure will drop if the pump output is inadequate.
In this case would the solution be install a larger oil pump, or use a thicker oil?
Per Shannow, you don't need any oil pressure for bearings to survive.
Again, you are making up a position and stating that I am stating it...nice work...you must be an absolute pleasure to be around as a person
I have never once said that you don't need oil pressure...and I'd appreciate that you stop attributing it to me, as it's a lie that you keep perpetuating.
I have stated, time and time again, that you only need sufficient pressure to get the required volume to the bearings.
You have commented many times in all of these discussions (other 2 big threads) that you believe journal bearings don't need any oil pressure above ATM to survive, as long as oil is naturally ingested by the rotating bearing. You even said is again on page 2 of this thread.
Originally Posted By: Shannow
The oil pump is only supplying oil to make up for the bearing's inherent side leakage, which is influenced by viscosity, RPM, speed, diameter, length, load, and diametrical clearance...it's not "flowing" oil through the bearings.
So, yes you are really saying journal bearings don't need any oil pressure above ATM to survive, and that is true for some journal bearings used in low power small engines, etc.
Originally Posted By: ZeeOSix
You have commented many times in all of these discussions (other 2 big threads) that you believe journal bearings don't need any oil pressure above ATM to survive
where ?
making stuff up again ?
There ALWAYS has to be sufficient pressure to get the oil to where it needs to be...pressure isn't there to FORCE oil THROUGH the bearings, which is your premise.
You have commented many times in all of these discussions (other 2 big threads) that you believe journal bearings don't need any oil pressure above ATM to survive
where ?
making stuff up again ?
There ALWAYS has to be sufficient pressure to get the oil to where it needs to be...pressure isn't there to FORCE oil THROUGH the bearings, which is your premise.
Originally Posted By: Shannow
OK, again...find me something in a paper/journal that states that current design practice in production engines is to overfeed the bearings to control temperatures.
Not a "magazine" article on race engine...a proper paper, SAE, Ricardo or the like.
OEMs are REDUCING oil pump volumes currently...which is diametrically opposite to your premise.
Here ya go ... interesting stuff.
RESEARCH PAPER RP1295
Part of Journal of Research of the National Bureau of Standards, Volume 24,
May 1940
Even back in 1940 they knew that pressure feeding journal bearings to remove heat was very beneficial. Force feeding flow removes heat which keeps the oil film stronger and able to take more load. Link: http://nvlpubs.nist.gov/nistpubs/jres/24/jresv24n5p491_A1b.pdf
Look at Section VIII on page 504. Curve B is same bearing and conditions except with 85 PSI of force fed oil pressure.
OK, again...find me something in a paper/journal that states that current design practice in production engines is to overfeed the bearings to control temperatures.
Not a "magazine" article on race engine...a proper paper, SAE, Ricardo or the like.
OEMs are REDUCING oil pump volumes currently...which is diametrically opposite to your premise.
Here ya go ... interesting stuff.
RESEARCH PAPER RP1295
Part of Journal of Research of the National Bureau of Standards, Volume 24,
May 1940
Even back in 1940 they knew that pressure feeding journal bearings to remove heat was very beneficial. Force feeding flow removes heat which keeps the oil film stronger and able to take more load. Link: http://nvlpubs.nist.gov/nistpubs/jres/24/jresv24n5p491_A1b.pdf
Look at Section VIII on page 504. Curve B is same bearing and conditions except with 85 PSI of force fed oil pressure.
Originally Posted By: Shannow
Originally Posted By: ZeeOSix
You have commented many times in all of these discussions (other 2 big threads) that you believe journal bearings don't need any oil pressure above ATM to survive
where ?
making stuff up again ?
There ALWAYS has to be sufficient pressure to get the oil to where it needs to be...pressure isn't there to FORCE oil THROUGH the bearings, which is your premise.
See, you just said it again. You say the oil pressure is to just get the oil to the bearing, but why would you need 80~100 PSI to do that? The galleries could easily be kept full of oil with only 5~10 PSI. So why don't engine makers use low pressure oiling systems then?
And under the same premise, the bearing should run just the same if the oil was supplied at ATM pressure ... just like you've always claimed ... which means you are saying they really don't need any more pressure than ATM to survive.
But again you are mistaken, because the oil pressure surely IS there to FORCE more oil volume through the bearing.
Originally Posted By: ZeeOSix
You have commented many times in all of these discussions (other 2 big threads) that you believe journal bearings don't need any oil pressure above ATM to survive
where ?
making stuff up again ?
There ALWAYS has to be sufficient pressure to get the oil to where it needs to be...pressure isn't there to FORCE oil THROUGH the bearings, which is your premise.
See, you just said it again. You say the oil pressure is to just get the oil to the bearing, but why would you need 80~100 PSI to do that? The galleries could easily be kept full of oil with only 5~10 PSI. So why don't engine makers use low pressure oiling systems then?
And under the same premise, the bearing should run just the same if the oil was supplied at ATM pressure ... just like you've always claimed ... which means you are saying they really don't need any more pressure than ATM to survive.
But again you are mistaken, because the oil pressure surely IS there to FORCE more oil volume through the bearing.
Firstly...
engine bearings are pertinent to the topic...seriously, I've never come across an engine with oil ring bearing feed...have you ???
and what's it's relevence here ?
(more to the point do you know what oil ring feeding is ???)
They certainly aren't furnished with full flow, which seriously DOES degrade their load carrying capabilities.
Secondly,
you've also stated that my position is that you could remove the oil pump and the bearings would draw the oil from the pan sans sump, so your use of my words is clearly coming from a position of misrepresentation (where standing up to your neck in water ISN'T swimming for example)
engine bearings are pertinent to the topic...seriously, I've never come across an engine with oil ring bearing feed...have you ???
and what's it's relevence here ?
(more to the point do you know what oil ring feeding is ???)
They certainly aren't furnished with full flow, which seriously DOES degrade their load carrying capabilities.
Secondly,
you've also stated that my position is that you could remove the oil pump and the bearings would draw the oil from the pan sans sump, so your use of my words is clearly coming from a position of misrepresentation (where standing up to your neck in water ISN'T swimming for example)
Originally Posted By: Shannow
Firstly...
engine bearings are pertinent to the topic...seriously, I've never come across an engine with oil ring bearing feed...have you ???
and what's it's relevence here ?
(more to the point do you know what oil ring feeding is ???)
They certainly aren't furnished with full flow, which seriously DOES degrade their load carrying capabilities.
You just don't get it and make excuses to discount everything. The test clearly shows that keeping the oil and bearing cool with forced oil flow increases the load capability of the bearing, which in turn will ensure it survives a very long time.
Originally Posted By: Shannow
Secondly,
you've also stated that my position is that you could remove the oil pump and the bearings would draw the oil from the pan sans sump, so your use of my words is clearly coming from a position of misrepresentation (where standing up to your neck in water ISN'T swimming for example)
You obviously don't get sarcasm, and I explained that last time - you're being naive. And dude, swimming and wading are not the same thing - like you think they are from that Disneyland Gator thread. There you go again deflecting and making up your own definition for words.
I'll pull a Shannow here to deflect ... you misspelled 'relevence'.
Firstly...
engine bearings are pertinent to the topic...seriously, I've never come across an engine with oil ring bearing feed...have you ???
and what's it's relevence here ?
(more to the point do you know what oil ring feeding is ???)
They certainly aren't furnished with full flow, which seriously DOES degrade their load carrying capabilities.
You just don't get it and make excuses to discount everything. The test clearly shows that keeping the oil and bearing cool with forced oil flow increases the load capability of the bearing, which in turn will ensure it survives a very long time.
Originally Posted By: Shannow
Secondly,
you've also stated that my position is that you could remove the oil pump and the bearings would draw the oil from the pan sans sump, so your use of my words is clearly coming from a position of misrepresentation (where standing up to your neck in water ISN'T swimming for example)
You obviously don't get sarcasm, and I explained that last time - you're being naive. And dude, swimming and wading are not the same thing - like you think they are from that Disneyland Gator thread. There you go again deflecting and making up your own definition for words.
I'll pull a Shannow here to deflect ... you misspelled 'relevence'.
Originally Posted By: Shannow
http://www.tytlabs.com/english/review/rev383epdf/e383_044suzuki.pdf
And ... what?
You did see the graph where increased oil pressure gave increased flow through the crank pin bearings in both types. Wow, amazing.
http://www.tytlabs.com/english/review/rev383epdf/e383_044suzuki.pdf
And ... what?
You did see the graph where increased oil pressure gave increased flow through the crank pin bearings in both types. Wow, amazing.
Originally Posted By: ZeeOSix
Originally Posted By: Shannow
http://www.tytlabs.com/english/review/rev383epdf/e383_044suzuki.pdf
And ... what?
Opening paragraph...clearly, you only deal with pictures...
Quote:
Minimizing the oil pump capacity of an engine while maintaining reliability is one of the mosteffective ways of reducing mechanical loss of an engine. Care is required to assure reliability,because an excessively low oil flow may result in poor lubrication that can cause engine components to seize. The oil flow was observed by visualization and the pressure was measured in two types of oil passage that link main bearings and con-rod bearings, namely, "V type" which has an oil passage in the main journal, and "I type" whichdoes not have this passage. The oil flow in the passage was observed using a CCD camera and a crankshaft made of acrylic resin. The oil flowrate was measured at the same time as the flow was observed. The pressure at which the oil supply failed due to the occurrence of aeration differed with the oil passage types
Originally Posted By: Shannow
http://www.tytlabs.com/english/review/rev383epdf/e383_044suzuki.pdf
And ... what?
Opening paragraph...clearly, you only deal with pictures...
Quote:
Minimizing the oil pump capacity of an engine while maintaining reliability is one of the mosteffective ways of reducing mechanical loss of an engine. Care is required to assure reliability,because an excessively low oil flow may result in poor lubrication that can cause engine components to seize. The oil flow was observed by visualization and the pressure was measured in two types of oil passage that link main bearings and con-rod bearings, namely, "V type" which has an oil passage in the main journal, and "I type" whichdoes not have this passage. The oil flow in the passage was observed using a CCD camera and a crankshaft made of acrylic resin. The oil flowrate was measured at the same time as the flow was observed. The pressure at which the oil supply failed due to the occurrence of aeration differed with the oil passage types
Originally Posted By: ZeeOSix
You just don't get it and make excuses to discount everything. The test clearly shows that keeping the oil and bearing cool with forced oil flow increases the load capability of the bearing, which in turn will ensure it survives a very long time.
Your posit is that engines are designed with overpressurisation to "ensure" running temperatures. You have yet to provide any evidence of same, but wheel out a 1940s paper that compares the load carrying capabilities of an oil ring fed bearing with a bearing with full flow feed.
Again, papers please...something automotive (aka NOT oil rings) might help your cause...
(BTW you missed the part where you explained that you even understood what that meant)
You just don't get it and make excuses to discount everything. The test clearly shows that keeping the oil and bearing cool with forced oil flow increases the load capability of the bearing, which in turn will ensure it survives a very long time.
Your posit is that engines are designed with overpressurisation to "ensure" running temperatures. You have yet to provide any evidence of same, but wheel out a 1940s paper that compares the load carrying capabilities of an oil ring fed bearing with a bearing with full flow feed.
Again, papers please...something automotive (aka NOT oil rings) might help your cause...
(BTW you missed the part where you explained that you even understood what that meant)
Originally Posted By: Shannow
Originally Posted By: ZeeOSix
Originally Posted By: Shannow
http://www.tytlabs.com/english/review/rev383epdf/e383_044suzuki.pdf
And ... what?
Opening paragraph...clearly, you only deal with pictures...
Quote:
Minimizing the oil pump capacity of an engine while maintaining reliability is one of the most effective ways of reducing mechanical loss of an engine. Care is required to assure reliability, because an excessively low oil flow may result in poor lubrication that can cause engine components to seize. The oil flow was observed by visualization and the pressure was measured in two types of oil passage that link main bearings and con-rod bearings, namely, "V type" which has an oil passage in the main journal, and "I type" which does not have this passage. The oil flow in the passage was observed using a CCD camera and a crankshaft made of acrylic resin. The oil flow rate was measured at the same time as the flow was observed. The pressure at which the oil supply failed due to the occurrence of aeration differed with the oil passage types
And you can't seem to comprehend written words. See the text in red from the article quote you posted.
The graph I posted from the paper clearly shows there is increased and constant oil flow to the bearing as RPM increases. Now why do you think it's designed that way? Do you think those bearings would survive just as well if the oil flow was cut in half or by three quarters? These engine designers can try to save a fraction of 1 HP by cutting back on supplied oil volume but with the risk of causing lack of lubrication and engine reliability.
Originally Posted By: ZeeOSix
Originally Posted By: Shannow
http://www.tytlabs.com/english/review/rev383epdf/e383_044suzuki.pdf
And ... what?
Opening paragraph...clearly, you only deal with pictures...
Quote:
Minimizing the oil pump capacity of an engine while maintaining reliability is one of the most effective ways of reducing mechanical loss of an engine. Care is required to assure reliability, because an excessively low oil flow may result in poor lubrication that can cause engine components to seize. The oil flow was observed by visualization and the pressure was measured in two types of oil passage that link main bearings and con-rod bearings, namely, "V type" which has an oil passage in the main journal, and "I type" which does not have this passage. The oil flow in the passage was observed using a CCD camera and a crankshaft made of acrylic resin. The oil flow rate was measured at the same time as the flow was observed. The pressure at which the oil supply failed due to the occurrence of aeration differed with the oil passage types
And you can't seem to comprehend written words. See the text in red from the article quote you posted.
The graph I posted from the paper clearly shows there is increased and constant oil flow to the bearing as RPM increases. Now why do you think it's designed that way? Do you think those bearings would survive just as well if the oil flow was cut in half or by three quarters? These engine designers can try to save a fraction of 1 HP by cutting back on supplied oil volume but with the risk of causing lack of lubrication and engine reliability.
Originally Posted By: Shannow
Originally Posted By: ZeeOSix
You just don't get it and make excuses to discount everything. The test clearly shows that keeping the oil and bearing cool with forced oil flow increases the load capability of the bearing, which in turn will ensure it survives a very long time.
Your posit is that engines are designed with overpressurisation to "ensure" running temperatures. You have yet to provide any evidence of same, but wheel out a 1940s paper that compares the load carrying capabilities of an oil ring fed bearing with a bearing with full flow feed.
Read that paper again ... it was a test on the same bearing. The test still shows that pressurizing the bearing to increase flow dropped the oil film & bearing temperature and increased the load capability.
Originally Posted By: Shannow
Again, papers please...something automotive (aka NOT oil rings) might help your cause...
Show me a paper that says increased oil flow in pressure fed bearings doesn't do anything or that the oil film temperature remains the same regardless.
Originally Posted By: ZeeOSix
You just don't get it and make excuses to discount everything. The test clearly shows that keeping the oil and bearing cool with forced oil flow increases the load capability of the bearing, which in turn will ensure it survives a very long time.
Your posit is that engines are designed with overpressurisation to "ensure" running temperatures. You have yet to provide any evidence of same, but wheel out a 1940s paper that compares the load carrying capabilities of an oil ring fed bearing with a bearing with full flow feed.
Read that paper again ... it was a test on the same bearing. The test still shows that pressurizing the bearing to increase flow dropped the oil film & bearing temperature and increased the load capability.
Originally Posted By: Shannow
Again, papers please...something automotive (aka NOT oil rings) might help your cause...
Show me a paper that says increased oil flow in pressure fed bearings doesn't do anything or that the oil film temperature remains the same regardless.
Zee0; I'll buy into the fact (I don't know its a fact, I just know its true), that higher oil pressure as well as increased rpm will flow more oil through a bearing over time. The time factor per revolution is eroded as rpm increases. Leave pressure alone and change the rpm, or hold the rpm at one speed and change the pressure.
The graph shows that oil flow increases with pressure when engine speed is held at a given rpm, or the engine is stopped altogether.
Did you state that bearings will run cooler with increased oil flow resulting from an increase in pressure, and as a bonus, bearings can carry a higher load load, especially at high rpm, or am I jumping to a conclusion?
The graph shows that oil flow increases with pressure when engine speed is held at a given rpm, or the engine is stopped altogether.
Did you state that bearings will run cooler with increased oil flow resulting from an increase in pressure, and as a bonus, bearings can carry a higher load load, especially at high rpm, or am I jumping to a conclusion?
Last edited:
See page 12 of 15 - "Pressure Fed Bearings".
https://eis.hu.edu.jo/ACUploads/10526/CH 12.pdf
I'm sure you'll deflect and discount the information even though the information is from Shigley’s Mechanical Engineering Design handbook. It's obvious in these discussions that you have near zero knowledge of the thermodynamic aspect of the discussions.
"The load carrying capacity of self - contained bearings is limited because of the limited heat - dissipating capability. To increase the heat - dissipation, an external pump is used to increase the lubricant flow through the bearing. The pump supplies the bearing with lubricant of high pressure therefore increasing the lubricant flow and heat dissipation."
All you have to do is run an example for temperature rise of an ATM fed journal bearing, then the same bearing with a few different force fed supply pressures to see how the temperature rise decreases with increased flow rate.
From another source, they say:
"In practice, the supply flow rate is often larger than this minimum requirement to maintain the temperature rise between the oil supply and drain within recommended limits (typically between 40 to 60°F)."
https://eis.hu.edu.jo/ACUploads/10526/CH 12.pdf
I'm sure you'll deflect and discount the information even though the information is from Shigley’s Mechanical Engineering Design handbook. It's obvious in these discussions that you have near zero knowledge of the thermodynamic aspect of the discussions.
"The load carrying capacity of self - contained bearings is limited because of the limited heat - dissipating capability. To increase the heat - dissipation, an external pump is used to increase the lubricant flow through the bearing. The pump supplies the bearing with lubricant of high pressure therefore increasing the lubricant flow and heat dissipation."
All you have to do is run an example for temperature rise of an ATM fed journal bearing, then the same bearing with a few different force fed supply pressures to see how the temperature rise decreases with increased flow rate.
From another source, they say:
"In practice, the supply flow rate is often larger than this minimum requirement to maintain the temperature rise between the oil supply and drain within recommended limits (typically between 40 to 60°F)."
We've been through Shigley in the other threads, and I introduced Orlov...
Anyway, YOU have to demonstrate that engine bearings are designed such that they REQUIRE sufficient pressure to FORCE oil through them for cooling...
...because it is your posit/premise.
and simply that.
Start at the big end, which as I've amply demonstrated is intermittently oiled, and the oil supply pressure is clearly to ensure that sufficient pressure is available to get the oil to the bearing...not force it through.
It's easy, just one paper that states that oil is forced through the bearing to provide cooling...just one is a start.
You've sidetracked three threads now and not demonstrated your posit once.
Anyway, YOU have to demonstrate that engine bearings are designed such that they REQUIRE sufficient pressure to FORCE oil through them for cooling...
...because it is your posit/premise.
and simply that.
Start at the big end, which as I've amply demonstrated is intermittently oiled, and the oil supply pressure is clearly to ensure that sufficient pressure is available to get the oil to the bearing...not force it through.
It's easy, just one paper that states that oil is forced through the bearing to provide cooling...just one is a start.
You've sidetracked three threads now and not demonstrated your posit once.
Originally Posted By: userfriendly
Zee0; I'll buy into the fact (I don't know its a fact, I just know its true), that higher oil pressure as well as increased rpm will flow more oil through a bearing over time. The time factor per revolution is eroded as rpm increases. Leave pressure alone and change the rpm, or hold the rpm at one speed and change the pressure.
The graph shows that oil flow increases with pressure when engine speed is held at a given rpm, or the engine is stopped altogether.
Yes, all that was pretty well hashed over in the other threads, and what was pretty much the conclusion.
Originally Posted By: userfriendly
Did you state that bearings will run cooler with increased oil flow resulting from an increase in pressure, and as a bonus, bearings can carry a higher load load, especially at high rpm, or am I jumping to a conclusion?
That's what the info I've posted shows, and it's just a basic fact of heat transfer that increasing the oil flow will dissipate and carry away the heat with a smaller resulting temperature rise. That's why a pressure fed bearing will have lower oil film temperature, and hence better load capability because the oil doesn't thin out as much. Also less chance of failure under extreme conditions when the oil is more likely to thin out. One of the main reason race engines typically use a pretty high volume oil pump - much higher than you'd find on grandma's mini van.
Zee0; I'll buy into the fact (I don't know its a fact, I just know its true), that higher oil pressure as well as increased rpm will flow more oil through a bearing over time. The time factor per revolution is eroded as rpm increases. Leave pressure alone and change the rpm, or hold the rpm at one speed and change the pressure.
The graph shows that oil flow increases with pressure when engine speed is held at a given rpm, or the engine is stopped altogether.
Yes, all that was pretty well hashed over in the other threads, and what was pretty much the conclusion.
Originally Posted By: userfriendly
Did you state that bearings will run cooler with increased oil flow resulting from an increase in pressure, and as a bonus, bearings can carry a higher load load, especially at high rpm, or am I jumping to a conclusion?
That's what the info I've posted shows, and it's just a basic fact of heat transfer that increasing the oil flow will dissipate and carry away the heat with a smaller resulting temperature rise. That's why a pressure fed bearing will have lower oil film temperature, and hence better load capability because the oil doesn't thin out as much. Also less chance of failure under extreme conditions when the oil is more likely to thin out. One of the main reason race engines typically use a pretty high volume oil pump - much higher than you'd find on grandma's mini van.
Originally Posted By: Shannow
We've been through Shigley in the other threads, and I introduced Orlov...
Anyway, YOU have to demonstrate that engine bearings are designed such that they REQUIRE sufficient pressure to FORCE oil through them for cooling...
...because it is your posit/premise.
and simply that.
Stop deflecting with non-sense. We are talking about journal bearings which are used in modern day engines. If you don't believe the information I've shown many times supporting the fact that pressure fed bearings benefit from lower film temperature rise, etc ... then that's your problem. I could really care less what you believe anymore.
Originally Posted By: Shannow
Start at the big end, which as I've amply demonstrated is intermittently oiled, and the oil supply pressure is clearly to ensure that sufficient pressure is available to get the oil to the bearing...not force it through.
That paper you linked, and the chart I posted out of it showing the two types of big rod bearings clearly shows that they flow more oil volume with increased supply pressure. If it wasn't happening, there couldn't be a chart with a bearing flow vs supply pressure curve because it wouldn't be a function of pressure, as you seem to think.
Originally Posted By: Shannow
It's easy, just one paper that states that oil is forced through the bearing to provide cooling...just one is a start.
You've sidetracked three threads now and not demonstrated your posit once.
You really haven't proven anything except that you can deflect and go off track whenever you're not able to backup your claims.
If Shigley isn't good enough then too bad ... I'm not bowing to your continued non-sense because you can't admit you're off base on this stuff. You go dig up info on your own. I've shown plenty of information that supports the claim that pressure fed bearings are better off than not.
In the beginning (and actually you still do), you have this misconception belief that a journal bearing doesn't even flow more oil if pressure fed. In your mine, a journal bearing will flow exactly the same oil volume if it's fed at ATM pressure or at 200 PSI of pressure. With that as your baseline believe you'll never grasp what pressure fed journal bearings are about.
We've been through Shigley in the other threads, and I introduced Orlov...
Anyway, YOU have to demonstrate that engine bearings are designed such that they REQUIRE sufficient pressure to FORCE oil through them for cooling...
...because it is your posit/premise.
and simply that.
Stop deflecting with non-sense. We are talking about journal bearings which are used in modern day engines. If you don't believe the information I've shown many times supporting the fact that pressure fed bearings benefit from lower film temperature rise, etc ... then that's your problem. I could really care less what you believe anymore.
Originally Posted By: Shannow
Start at the big end, which as I've amply demonstrated is intermittently oiled, and the oil supply pressure is clearly to ensure that sufficient pressure is available to get the oil to the bearing...not force it through.
That paper you linked, and the chart I posted out of it showing the two types of big rod bearings clearly shows that they flow more oil volume with increased supply pressure. If it wasn't happening, there couldn't be a chart with a bearing flow vs supply pressure curve because it wouldn't be a function of pressure, as you seem to think.
Originally Posted By: Shannow
It's easy, just one paper that states that oil is forced through the bearing to provide cooling...just one is a start.
You've sidetracked three threads now and not demonstrated your posit once.
You really haven't proven anything except that you can deflect and go off track whenever you're not able to backup your claims.
If Shigley isn't good enough then too bad ... I'm not bowing to your continued non-sense because you can't admit you're off base on this stuff. You go dig up info on your own. I've shown plenty of information that supports the claim that pressure fed bearings are better off than not.
In the beginning (and actually you still do), you have this misconception belief that a journal bearing doesn't even flow more oil if pressure fed. In your mine, a journal bearing will flow exactly the same oil volume if it's fed at ATM pressure or at 200 PSI of pressure. With that as your baseline believe you'll never grasp what pressure fed journal bearings are about.
Originally Posted By: ZeeOSix
you have this misconception belief that a journal bearing doesn't even flow more oil if pressure fed. In your mine, a journal bearing will flow exactly the same oil volume if it's fed at ATM pressure or at 200 PSI of pressure. With that as your baseline believe you'll never grasp what pressure fed journal bearings are about.
Making stuff up again....
Originally Posted By: Shannow
Originally Posted By: ZeeOSix
With all the information I've shown in these discussions, it's pretty clear that the oil flow through a journal bearing is different when the supply is pressurized vs not pressurize. You're stuck in a world where you think bearings "suck" only the oil volume they need from the galleries, regardless of how high of a pressure those galleries are at. If the gallery was at 300 PSI do you think the bearing will flow the same (due to it's "sucking action") as if the gallery was at ATM pressure?
I agree...apply more pressure, and the flow through the unloaded side of the bearing goes up, and temperatures go down...I agree with the papers that you posted that IF you can't get a proper temperature through designing it properly for natural oil flow, you CAN increase pressure to provide increased cooling.
However, the fundamental requirement for an automotive system supplying mains and big ends is to ensure that adequate supply is there to ensure that the bearing's make-up requirements are met (and yes, that includes the pressure required to simply GET it to the conrods in adequate volume).
Your force feeding concept is NOT how automotive bearings are designed.
Now, back to YOU poviding information that engine bearings (especially the big end, which don't even GET pressure for a full revolution) are overfed oil for temperature control.
Overfeeding to control temperatures isn't the design point anywhere (except in secret agent land as it appears)...
Originally Posted By: ZeeOSix
One of the main reason race engines typically use a pretty high volume oil pump - much higher than you'd find on grandma's mini van.
Ummmmm...they open up the bearing clearances "much higher than you'd find on grandma's mini van"...changing the bearing characteristic, and requiring a higher feed rate of oil.
For the same relief valve setting, a higher volume pump doesn't "cool" the bearings more.
you have this misconception belief that a journal bearing doesn't even flow more oil if pressure fed. In your mine, a journal bearing will flow exactly the same oil volume if it's fed at ATM pressure or at 200 PSI of pressure. With that as your baseline believe you'll never grasp what pressure fed journal bearings are about.
Making stuff up again....
Originally Posted By: Shannow
Originally Posted By: ZeeOSix
With all the information I've shown in these discussions, it's pretty clear that the oil flow through a journal bearing is different when the supply is pressurized vs not pressurize. You're stuck in a world where you think bearings "suck" only the oil volume they need from the galleries, regardless of how high of a pressure those galleries are at. If the gallery was at 300 PSI do you think the bearing will flow the same (due to it's "sucking action") as if the gallery was at ATM pressure?
I agree...apply more pressure, and the flow through the unloaded side of the bearing goes up, and temperatures go down...I agree with the papers that you posted that IF you can't get a proper temperature through designing it properly for natural oil flow, you CAN increase pressure to provide increased cooling.
However, the fundamental requirement for an automotive system supplying mains and big ends is to ensure that adequate supply is there to ensure that the bearing's make-up requirements are met (and yes, that includes the pressure required to simply GET it to the conrods in adequate volume).
Your force feeding concept is NOT how automotive bearings are designed.
Now, back to YOU poviding information that engine bearings (especially the big end, which don't even GET pressure for a full revolution) are overfed oil for temperature control.
Overfeeding to control temperatures isn't the design point anywhere (except in secret agent land as it appears)...
Originally Posted By: ZeeOSix
One of the main reason race engines typically use a pretty high volume oil pump - much higher than you'd find on grandma's mini van.
Ummmmm...they open up the bearing clearances "much higher than you'd find on grandma's mini van"...changing the bearing characteristic, and requiring a higher feed rate of oil.
For the same relief valve setting, a higher volume pump doesn't "cool" the bearings more.
Originally Posted By: Shannow
Originally Posted By: ZeeOSix
you have this misconception belief that a journal bearing doesn't even flow more oil if pressure fed. In your mine, a journal bearing will flow exactly the same oil volume if it's fed at ATM pressure or at 200 PSI of pressure. With that as your baseline believe you'll never grasp what pressure fed journal bearings are about.
Making stuff up again....
Nope ... that's your belief based on your comments in these discussions. So if you are now saying that is not your belief, then you must be agreeing with information I've shown on pressure fed bearings. What is it Mr. Deflector?
Originally Posted By: ZeeOSix
you have this misconception belief that a journal bearing doesn't even flow more oil if pressure fed. In your mine, a journal bearing will flow exactly the same oil volume if it's fed at ATM pressure or at 200 PSI of pressure. With that as your baseline believe you'll never grasp what pressure fed journal bearings are about.
Making stuff up again....
Nope ... that's your belief based on your comments in these discussions. So if you are now saying that is not your belief, then you must be agreeing with information I've shown on pressure fed bearings. What is it Mr. Deflector?
Zee; I get what you are saying.
Back in the day, guys racing domestic NA V8s would put as much oil pressure into the engines as they could.
Thick oils like 20w50 were also necessary to keep those engines running when they were pushed hard towing, in a boat, or hot lapping at a drag race.
The oil pans, like station wagons with 454 BBCs held 4 quarts. A 5.3L Ecotec hold 8L.
I remember guys with 351 Cleveland engines saying that if they did not shim the pump spring to 100 psi, #1 main would not last a week.
My question; Is the force feeding approach to engine lubrication applicable in a modern engineered power plant?
It seems to me that thick oil and high pressure is an obsolete band-aid approach to engine lubrication.
Is designing an engine to require 100 psi of pressure or thick oil, a good or best practice?
Back in the day, guys racing domestic NA V8s would put as much oil pressure into the engines as they could.
Thick oils like 20w50 were also necessary to keep those engines running when they were pushed hard towing, in a boat, or hot lapping at a drag race.
The oil pans, like station wagons with 454 BBCs held 4 quarts. A 5.3L Ecotec hold 8L.
I remember guys with 351 Cleveland engines saying that if they did not shim the pump spring to 100 psi, #1 main would not last a week.
My question; Is the force feeding approach to engine lubrication applicable in a modern engineered power plant?
It seems to me that thick oil and high pressure is an obsolete band-aid approach to engine lubrication.
Is designing an engine to require 100 psi of pressure or thick oil, a good or best practice?
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