Oil's affect on motorcycle gear shift feel?

[bmwpowere36m3]

Originally Posted By: ZeeOSix
Originally Posted By: Shannow

I told you, squirter oil flow is based on pressure applied to it, not RPM...asking for an answer to a nonsensical question ?


Well, actually more engine RPM means more volume being forced through the squirter (or any other flow element), and the resulting pressure is seen. So yes, in the case of an engine with a PD oil pump the flow through it (and everything else) IS a product of RPM which produced the oil pump volume.

Originally Posted By: Shannow
Again, asking a nonsensical question (% change in squirter flow versus RPM) in and of itself clearly identifies that you really haven't had the opportunity to grasp fluid dynamics.


I don't think you're really grasping my question. I'll try again. You say that as engine RPM increases the tight crank, rod and cam bearings will flow less oil (non-linear flow curve with increased oil volume supplied) and the result is that the oil squirters will then flow more oil as a result (ie, the flow slit percentage to the squirters will increase). Isn't that what you are saying?

So let's say the oil squirters at idle flow 10% of the total flow volume from the pump. As you increase engine RPM the flow volume (and resulting oil pressure) will increase. At 2000 RPM are the oil squirters now drawing 11%, 15%, 20% of the total volume? At 5000 RPM they would be drawing an even higher percentage ... by how much? Does it change enough to even be measurable? I doubt it changes enough to even matter as engines can run for hours on end at near redline in race conditions and never fail.

I just want to know what oil will make my XSR shift less notchy while down shifting.

Thousands of miles... shifting improved greatly in the first 1k on my FZ-07, but its still not as silky as my old Kawasaki 454. Run Yamalube, Rotetlla TTT, M1 T&S and M1 15W-50.

 

[ZeeOSix]

Originally Posted By: turtlevette
Originally Posted By: ZeeOSix

Go back and do some re-reading. You thought that I said the flow split was the same percentage between engine components. I said the flow spit percentage of each component (whatever that may be) basically stayed the same through the oiling system's flow range, not that they all had the same exact same flow split percentage.


Let's settle it this way. Neither of your statements are true.

You have a fluids background? Doing what?


Exactly what two statements are you talking about? My quote you used above was just a clarification for Shannow since he seemed to not be following what I was saying.

 

[turtlevette]

Originally Posted By: ZeeOSix
Originally Posted By: turtlevette
Originally Posted By: ZeeOSix

Go back and do some re-reading. You thought that I said the flow split was the same percentage between engine components. I said the flow spit percentage of each component (whatever that may be) basically stayed the same through the oiling system's flow range, not that they all had the same exact same flow split percentage.


Let's settle it this way. Neither of your statements are true.

You have a fluids background? Doing what?


Exactly what two statements are you talking about? My quote you used above was just a clarification for Shannow since he seemed to not be following what I was saying.


You've got to be kidding.

1. There is no equal percentage split.
2. The percentage flow does not remain the same regardless of pressure.

 

[ZeeOSix]

Originally Posted By: turtlevette
Originally Posted By: ZeeOSix
Originally Posted By: turtlevette
Originally Posted By: ZeeOSix

Go back and do some re-reading. You thought that I said the flow split was the same percentage between engine components. I said the flow spit percentage of each component (whatever that may be) basically stayed the same through the oiling system's flow range, not that they all had the same exact same flow split percentage.


Let's settle it this way. Neither of your statements are true.

You have a fluids background? Doing what?


Exactly what two statements are you talking about? My quote you used above was just a clarification for Shannow since he seemed to not be following what I was saying.


You've got to be kidding.

1. There is no equal percentage split.
2. The percentage flow does not remain the same regardless of pressure.


For starters, go back and re-read. I never said the split was equal between all the engine flow components. I said the flow percentage split basically remains constant between the flow components. There is a huge difference in those statements.

And I never said the "percentage flow" stays the same regardless of pressure. I don't think you're really following what's being said here. I said the percentage of flow split basically stays the same throughout the engine's RPM range - meaning for example that a main bearings aren't going to get their flow cut in half while and oil squinters double their flow.

Shannow says that journal bearings change their flow resistance as RPMs change (and hence their flow rate as oil pump volume increases), so my question was by how much? Is it 1%, 10%, 50% ... ?

Remember that if the oil pump is not in pressure relief that all the oil volume leaving the pump must go through the oiling system. Unless someone can actually prove the flow split percentage breakdown within the engine of that 100% volume leaving the pump changes dramatically as engine RPM goes from idle to redline, I'll maintain my thoughts on the subject.

I'd like to see a flow percentage split breakdown of the oil flow volume something like this. Each line must add up to 100%.

@Idle: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%
@2000 RPM: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%
@4000 RPM: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%
@6000 RPM: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%
@8000 RPM: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%
@10000 RPM: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%

 

[Shannow]

Originally Posted By: ZeeOSix
I'd like to see a flow percentage split breakdown of the oil flow volume something like this. Each line must add up to 100%.

@Idle: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%
@2000 RPM: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%
@4000 RPM: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%
@6000 RPM: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%
@8000 RPM: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%
@10000 RPM: Mains = xx%, Rods = xx%, Camshafts = xx%, Oil Squirters = xx%


OK, that's pretty engine specific...now, so as we know WHAT you actually mean by splits and percentages, how about you fill in your perception of what happens at the different points and revs.

it might be able to convey what you are having difficulty using words to do...where's the pump relief in all of this ?

So fill in your numbers, and we'll critique them based on logic and any information that I can find.

 

[ZeeOSix]

Originally Posted By: Shannow
it might be able to convey what you are having difficulty using words to do...where's the pump relief in all of this ?


I've used words pretty well if you read my posts carefully.

In this example, it really doesn't matter if the oil pump's pressure relief is active or not. Because at any given moment in time, there is X volume of oil being fed to the engine, which is defined as the "100% of oil supply" (my term) at that instant in time. As this 100% supply volume gets pushed through the engine, it splits up and feeds the different engine components (crank, rods, cams, squirters, oil cooler, turbo, transmission gears, whatever else, etc).

If a component(s) decrease in flow as a function of RPM, then a different component(s) must increase its flow to maintain that split summation of the "100% of oil supply".

I would be taking a stab in the dark trying to come up with some way of determining what the flow % split would be, but obviously I would say the crank shaft bearings followed by the rod bearings would comprise the majority of the flow split. The cam bearings, and then probably the piston squirters. Also, in most motorcycles, the transmission shafts & gears and clutch get some dedicated oil feeding them, so that's another "flow circuit" in the oiling system. If the engine had a turbo, then that component would probably get a pretty good split of the supply volume. It's obviously something that is quite complicated when you start looking at it closely.

 

[Shannow]

So you are saying that if it's
w%, x%, y%, z% at 2,000
Then it's
w%, x%, y%, z% at 4,000

Because that's what you said, both in the way that you said it, and the way that you state that you didn't say it.

If that's what you are saying...then you are wrong.

 

[ZeeOSix]

Originally Posted By: Shannow
So you are saying that if it's
w%, x%, y%, z% at 2,000
Then it's
w%, x%, y%, z% at 4,000

Because that's what you said, both in the way that you said it, and the way that you state that you didn't say it.

If that's what you are saying...then you are wrong.


Not saying that exactly. It might be something generally like this:

w%*0.99, x%*0.99, y%*1.01, z%*1.01 at 2,000

Then it's,

w%*0.98, x%*0.98, y%*1.02, z%*1.02 at 4,000

Do you have real numbers, or what do you think it would be? You can "calculate" all day long, and it's probably not going to reflect what's really going on.

If you go back and read a bit I said I do believe you that journal bearing may change their flow resistance some as RPM changes, but I don't think it's by very much ... not enough to matter, as I mentioned that bike engines live near redline for hours at a time and don't have any detrimental consequences.

 

[Shannow]

Originally Posted By: ZeeOSix
I do believe you that journal bearing may change their flow resistance some as RPM changes, but I don't think it's by very much ... not enough to matter, as I mentioned that bike engines live near redline for hours at a time and don't have any detrimental consequences.


Ahhh...there's your misunderstanding...they are not "resistive" at all...they replace oil that leaks out of them in service with oil from the galleries, if they need less than the pump delivers, then oil pressure goes up.

You do not pump oil through a bearing at all...

A big journal bearing can actually SUCK oil into itself up quite a few inches of head, so clearly, they are not being pumped into.

 

[ZeeOSix]

Originally Posted By: Shannow
Originally Posted By: ZeeOSix
I do believe you that journal bearing may change their flow resistance some as RPM changes, but I don't think it's by very much ... not enough to matter, as I mentioned that bike engines live near redline for hours at a time and don't have any detrimental consequences.


Ahhh...there's your misunderstanding...they are not "resistive" at all...they replace oil that leaks out of them in service with oil from the galleries, if they need less than the pump delivers, then oil pressure goes up.

You do not pump oil through a bearing at all...

A big journal bearing can actually SUCK oil into itself up quite a few inches of head, so clearly, they are not being pumped into.


The bearing is being "force fed" oil by the positive displacement oil pump ... regardless of how you view it happening.

Think of it this way: The oil would still flow through the bearing even if the engine was not running and the oil pump was. That's essentially what a pre-oiler system does on an engine to ensure all the bearings have good lubrication before starting up the engine. It "force feeds" the bearings basically the same way the positive displacement oil pump does when the engine is running.

The oil "leaks out of them" because it's being forced in one side and out the other. And yes, the bearing provides a resistance to the oil flow. Where do you think the oil pressure comes from? If there was no flow resistance, there would be basically zero oil pressure produced when the oil is forced through the resistance (ie, tight bearings).

 

[Shannow]

Originally Posted By: ZeeOSix
The bearing is being "force fed" oil by the positive displacement oil pump ... regardless of how you view it happening.

Think of it this way: The oil would still flow through the bearing even if the engine was not running and the oil pump was. That's essentially what a pre-oiler system does on an engine to ensure all the bearings have good lubrication before starting up the engine. It "force feeds" the bearings basically the same way the positive displacement oil pump does when the engine is running.

The oil "leaks out of them" because it's being forced in one side and out the other. And yes, the bearing provides a resistance to the oil flow. Where do you think the oil pressure comes from? If there was no flow resistance, there would be basically zero oil pressure produced when the oil is forced through the resistance (ie, tight bearings).


So what's your field of fluid dynamics and thermo again ?

Because you are clearly out of your depth with that understanding.

YES, pump oil through a stationary journal, and it flows through....but that's NOT hydrodynamic lubrication, is it ?

I have measured bearings that are pulling 5-10" water on their oil supply...look at the pressure distribution around a hydrodynamically lubricated bearing, and you'll start to "understand it the way it is" rather than "seeing it the way that you imagine"

 

[ZeeOSix]

Originally Posted By: Shannow
Originally Posted By: ZeeOSix
The bearing is being "force fed" oil by the positive displacement oil pump ... regardless of how you view it happening.

Think of it this way: The oil would still flow through the bearing even if the engine was not running and the oil pump was. That's essentially what a pre-oiler system does on an engine to ensure all the bearings have good lubrication before starting up the engine. It "force feeds" the bearings basically the same way the positive displacement oil pump does when the engine is running.

The oil "leaks out of them" because it's being forced in one side and out the other. And yes, the bearing provides a resistance to the oil flow. Where do you think the oil pressure comes from? If there was no flow resistance, there would be basically zero oil pressure produced when the oil is forced through the resistance (ie, tight bearings).


So what's your field of fluid dynamics and thermo again ?

Because you are clearly out of your depth with that understanding.

YES, pump oil through a stationary journal, and it flows through....but that's NOT hydrodynamic lubrication, is it ?

I have measured bearings that are pulling 5-10" water on their oil supply...look at the pressure distribution around a hydrodynamically lubricated bearing, and you'll start to "understand it the way it is" rather than "seeing it the way that you imagine"


Did I say it was not hydrodynamic lubrication? That's some flawed reading between the lines that you came up with. I said the oil pump FORCES oil through the bearing, and it would even IF the motor wasn't running and you had a PD pump force feeding the bearings - same basic action done by a pre-oiler (look it up).

You erroneously said "You do not pump oil through a bearing at all..." So I really have to question your "expertise" in fluid dynamics, as well as your reading comprehension skills.

Next thing you'll say is you don't need an oil pump at all because the bearings will "suck" all the oil right out of the sump - LoL. I don't care how many bearings you've played with or how much they help draw oil into them while running, the fact is you obviously have a skewed view on how they get oiled and that bearings certainly are lubricated by the oil pump forcing oil THROUGH them.

 

[Shannow]

I'll open again with the question that has yet to be answered, despite multiple requests..

Originally Posted By: Shannow
So what's your field of fluid dynamics and thermo again ?


same basic action done by a pre-oiler (look it up).[/quote]

Pre-oiler supply oil to a stationary shaft...what on earth relevence do they have here ?

They move oil that's all

You erroneously said "You do not pump oil through a bearing at all..." So I really have to question your "expertise" in fluid dynamics, as well as your reading comprehension skills.

Originally Posted By: ZeeOSix
Next thing you'll say is you don't need an oil pump at all because the bearings will "suck" all the oil right out of the sump - LoL.


By your LOL, I understand that you are out of your depth...I would NEVER say that an engine bearing would suck the oil out of the sump (nice little strawman).

What I WOULD say is that given the right geometry and feed location, you could run a bearing, once running without a pump...I would say this because I've observed it in my professional career (turbine engineer), of large (20", 3,000RPM) bearings drawing one or two psi of suction in their feed lines.

YES, they can be lubricated without "pumping oil through them"

Again, the function of the oil pump is to provide oil to the bearings, it's not to force it through them

Bearings draw off from the supply what they need, and the artifact of them needing less than the pump delivery is oil pressure.

No, you don't use pressure to pump the oil through, in spite of how you FEEL it works.


Originally Posted By: ZeeOSix
I don't care how many bearings you've played with or how much they help draw oil into them while running, the fact is you obviously have a skewed view on how they get oiled and that bearings certainly are lubricated by the oil pump forcing oil THROUGH them.


Go back to my first question...then hand your quals back please.

 

[Shannow]

Here's some reading that may help you understand how things actually work...

http://bobistheoilguy.com/forums/ubbthreads.php/topics/3096029/Re:_0W20_load_bearing_capabili#Post3096029

Originally Posted By: Shannow
Bearings have a pressure profile that's caused by hydrodynamics...

In places, the pressure can actually drop below ambient, and suck their own oil into the bearing (I've seen a couple of big ones that draw 1-2psi at speed)

They act as a "pump" taking oil from the high clearance area, dragging it into the low clearance area, providing "lift" and lubrication, and squeezing oil out the sides.

If you are supplying oil (say), at the point (w) in the picture above, at a rate greater than the bearing needs, it will be shifted out the side, creating excessive leakage (and really doing what a bypass would likely be doing)

If the ability of the bearing to move oil is increasing with revs (yes), and the pump can't provide the excess leakage in the area (w), then the "backpressure" will be reduced and the pressure, which in and of itself does no lubrication, will drop.

Doesn't mean that the bearings are "starved" or at risk.


and another
http://bobistheoilguy.com/forums/ubbthreads.php/topics/3686791/Bearings...how_they_work.

 

[ZeeOSix]

First of all, learn how to do quotes.

Your statement that "You do not pump oil through a bearing at all..." is false. The PD oil pump forces oil through all the bearings inside an engine. Why do you think an engine even has an oil pump ... come on man, get back to basics here.

As I already mentioned, journal bearings may change the flow rate through them as load and RPM changes, but the fact is the PD oil pump is still force feeding the bearings. And if they are indeed changing flow rate through them that means their basic flow resistance at that instant in time has changed. You do realize (I hope) the how tight or loose a journal bearing is will determine how much oil it will flow with at given source pressure.

Originally Posted By: Shannow
Again, the function of the oil pump is to provide oil to the bearings, it's not to force it through them.

Bearings draw off from the supply what they need, and the artifact of them needing less than the pump delivery is oil pressure.

No, you don't use pressure to pump the oil through, in spite of how you FEEL it works.


False ... like I said earlier oil will flow through the bearings if you simply pressurized the oiling system with the engine turned off. Explain that one - how could oil possibly flow through a non-moving bearing? . I know you didn't go Google pre-oiler systems. You might learn something if you did.

Originally Posted By: Shannow
Go back to my first question...then hand your quals back please.


LoL ... I'm really thinking you don't have any "quals" with some of the bizarre statements you make.

 

[Shannow]

I was reading SAE papers (on microfiche) back in 1989, while at University.

They prime the oil galleries...just like the oil pump on a running engine does...

What miracles do you believe that a pre-oiler does ?

 

[ZeeOSix]

Here ya go ... crank, rod and cam bearing flowing thick room temperature oil at 50 PSI when the engine is NOT running. Now how in the world could that ever happen if the bearing isn't acting like a mini-pump and "drawing in" the oil?

Yes, the journal bearing may act like a "mini-pump" to some degree while running, but the fact still remains that the the main driving force of the oil flowing through all those bearing is the force feeding of oil volume from the PD pump.

Now tell me again that the oil pump doesn't force oil through all the engine bearings when the engine is running.

 

[Shannow]

again...the pump supplies full oil galleries.

again...the bearings draw off from those galleries what they need.

again...the artifact of them needing less than the pump delivery volume is oil pressure.

As a practitioner in fluid dynamics and thermodynamics (your profile, but you still don't answer the question where and what), you would have to admit that you've NEVER seen supply pressure in the case of bearing design bar being sufficeint to get the oil to where it needs.

So...what is your role/training in these things again ?

again...a pre-oiler fills the galleries...doesn't lubricate anything, nor does pressure/volume of the oil pump.

 

[ZeeOSix]

I guess you didn't watch the video I posted above. Did you see the oil flowing out of every crank, rod and cam bearing while the engine was not running? Why was oil pouring out of every bearing if the bearings couldn't "draw off those galleries" if the engine wasn't even moving. Must be some kind of fluid magic?

Yeah, right ... the PD oil pump doesn't force/cause oil to flow through bearings inside an engine.

You just keep telling yourself that, because you'll never convince me that you know what's really going on.

 

[Shannow]

Chuckle it up...now answer the question that you haven't answered yet...tells a LOT more than your silliness.