Oil's affect on motorcycle gear shift feel?

[ZeeOSix]

Sorry, can't divulge that info ... so stop asking. It doesn't matter anyway because the words that are typed in this discussion is all that does matter. My education and experience isn't going to make you suddenly believe me anyway ... so your digging for [censored] that doesn't matter. You're deflecting.

Go bone up on engine oiling systems, and particularly PD oil pumps. And do you know (maybe not) that hydrodynamic lubrication still happens even though the PD oil pump is force feeding the bearing. If the PD oil pump didn't force feed journal bearings in an IC engine, those bearings may not have adequate oiling - especially in a very high performance/high HP engine which extremely loads the crank and rod bearings.

Why do you think high performance engines have PD pumps that will put out 12~14 or more GPM? Can you even visualize how much oil volume is going through bearings when the oil pump is forcing 12~14 GPM through the oiling system? It's the PD oil pump force feeding all those bearings ... it's not the bearings feeding themselves by "sucking" oil from the galleries like some kid with a straw in glass of soda.

 

[HerrStig]

Originally Posted By: ZeeOSix
Sorry, can't divulge that info ... so stop asking. It doesn't matter anyway because the words that are typed in this discussion is all that does matter. My education and experience isn't going to make you suddenly believe me anyway ... so your digging for [censored] that doesn't matter. You're deflecting.

Go bone up on engine oiling systems, and particularly PD oil pumps. And do you know (maybe not) that hydrodynamic lubrication still happens even though the PD oil pump is force feeding the bearing. If the PD oil pump didn't force feed journal bearings in an IC engine, those bearings may not have adequate oiling - especially in a very high performance/high HP engine which extremely loads the crank and rod bearings.

Why do you think high performance engines have PD pumps that will put out 12~14 or more GPM? Can you even visualize how much oil volume is going through bearings when the oil pump is forcing 12~14 GPM through the oiling system? It's the PD oil pump force feeding all those bearings ... it's not the bearings feeding themselves by "sucking" oil from the galleries like some kid with a straw in glass of soda.
"Can't divulge that info"? ROFL. What are you, a "secret agent"?

 

[02SE]

Originally Posted By: HerrStig
"Can't divulge that info"? ROFL. What are you, a "secret agent"?


Maybe he is. Or more likely he's like me, and has signed an NDA.

In my own case, I used to share more information on another website, than I do here. Why did I stop? because someone, and I have no idea who, tried to cause problems for me with a prior client. They were unsuccessful, but it clearly illustrated that there are vindictive cowards out there that will try to cause harm to others and their livelihoods.

 

[bmwpowere36m3]

And what does this have to do with shifting?

What more important, pressure or volume? I think pressure is a byproduct of supplying a certain volume of oil required. A side benefit, pressure tells you things are operating appropriately. Is 50 or 60 or 70 psi better at operating temps?

 

[ZeeOSix]

Shannow - I'll give you some info I had to dig up in one of my old machine design handbooks. I think your disconnect here is that you are not looking at what they call "Pressure Fed Bearings". Much of what you've discussed in this thread pertains to journal bearings that do not fall into the "Pressure Fed" category, as you will see with the following information.

Take note that it says at the bottom of page 383 that Figures 10-17 and 10-18 do NOT apply to pressure fed bearings - you had shown Figure 10-17 awhile back, but it's not relevant here.

Also note that equations (k) and (10-20) show that flow through the journal bearing is a function of the supply pressure, as well at the fluid properties and the physical dimensions of the bearing.

In "Pressure Fed" journal bearings, there is a constant flow of oil moving through them due to the forcing of volume from the PD oil pump. Just as was demonstrated in the engine pre-oiling video above, as long as there is sufficient volume & pressure feeding the bearings, there will be constant oil flow through them. The higher the pressure the higher the flow per the equations given below - basics fluid dynamics stuff. And in the case of a high performance/high HP engine the flow will be pretty significant when you have an oil pump putting out 12~14 GPM at near red line RPM.

 

[ZeeOSix]

Originally Posted By: bmwpowere36m3
And what does this have to do with shifting?


Nothing ... but I'm happy to say that the XSR900 is downshifting a little better now that it has ~500 miles on it. I'm sure it will continue to improve with some more miles.

 

[ZeeOSix]

Originally Posted By: HerrStig
"Can't divulge that info"? ROFL. What are you, a "secret agent"?


LoL ... Well, I had to take out my "spy camera" to get those page photos in the machine design handbook.

I don't believe in bragging and chest pounding over education and experience, etc. Nobody is going to magically change their minds just because someone all of a sudden whips out a ton of "qualifications". What people write in these discussions should be proof enough if they know or don't know what they are talking about.

 

[Shannow]

I am so LOLing at page 369...

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4197019/Re:_Oil's_affect_on_motorcycle#Post4197019

As to your premise...if the bearings were being "pressure fed" to reduce operational temperatures, it's a nice try, and very late into the topic, but a nice try nontheless.

WERE that the case, then the oil pumps would be in oversupply 24/7, there would be no "10psi per 1,000RPM", they would be in relief from idle to max RPM...that's how "we" (fluid dynamics professionals) would do these things...there would be no "minimum 45psi at 3,500RPM"

Don't you agree Mr Bond ?

 

[ZeeOSix]

Originally Posted By: Shannow
I am so LOLing at page 369...

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4197019/Re:_Oil's_affect_on_motorcycle#Post4197019


And why is that. Figure 10-17 on page 369 is the same exact chart you posted in the link you gave above.

Originally Posted By: Shannow
As to your premise...if the bearings were being "pressure fed" to reduce operational temperatures, it's a nice try, and very late into the topic, but a nice try nontheless.


Of course pressure fed journal bearings run cooler than ones that are not if they were used in the same conditions. Lots of oil flowing through the bearing certainly does carry friction heat away. You don't believe that either?

Originally Posted By: Shannow
WERE that the case, then the oil pumps would be in oversupply 24/7, there would be no "10psi per 1,000RPM", they would be in relief from idle to max RPM...that's how "we" (fluid dynamics professionals) would do these things...there would be no "minimum 45psi at 3,500RPM"

Don't you agree Mr Bond ?


I don't agree. The reason there is "10 PSI per 1,000 RPM" (at least in most GM engines) is because the oil pump's output volume has been designed/sized for the particular total flow resistance of the engine's oiling system (mainly from crank, rod and camshaft bearing flow resistance), and with a certain hot oil viscosity in mind - many design factors went in to it all. The system also needs to be designed to ensure the proper amount of oil is being fed to each component, and that one doesn't get over fed and another starved.

As engine RPM and pump oil volume output increases, the supply pressure to the engine just so happens to rise by about 10 PSI/1000 RPM (by design of course), until the pump hits pressure relief. If you slapped on a much larger output PD oil pump, then the pressure rise per 1000 RPM would increase accordingly. Ask any racer who does a high volume oil pump installation/modification.

As long as the PD oil pump is not in pressure relief, then 100% of the pump's output goes through the engine. A well designed oiling system would give max oil volume flow through the engine with hot oil and never hit pump pressure relief, but come close at near red line RPM.

The pages I posted from the machine design handbook tell the story. If you don't believe it then I guess you don't, but it really doesn't matter to me. Just trying to show you that I believe your thinking on journal bearings in a pressure fed oiling system (key point) are a bit skewed ... at least not how I and the machine design handbook see it. And I'm sure if you started Googling around for "pressure fed journal bearing design" you'd find the same information I've shown here.

 

[gman2304]

OP, A fresh oil change normally has a positive effect on gear change feel.

 

[HerrStig]

Originally Posted By: 02SE
Originally Posted By: HerrStig
"Can't divulge that info"? ROFL. What are you, a "secret agent"?


Maybe he is. Or more likely he's like me, and has signed an NDA.

In my own case, I used to share more information on another website, than I do here. Why did I stop? because someone, and I have no idea who, tried to cause problems for me with a prior client. They were unsuccessful, but it clearly illustrated that there are vindictive cowards out there that will try to cause harm to others and their livelihoods.
He can't DISCLOSE his education and experience because of an NDA?? Did you READ the post?

 

[02SE]

Originally Posted By: HerrStig
He can't DISCLOSE his education and experience because of an NDA?? Did you READ the post?


Yes I did. I was just positing a theory of why he might choose to not disclose more..

 

[Silk]

So, anyway - apart from the Airhead, all my bikes have a full roller/ball bottom end, centrifugal oil filters, splash fed gears and oil pressure in the single digits...and oil sometimes, and sometimes doesn't have an effect on my gearchanges and clutch feel. After all these decades, I'm still feeling my way on this subject, because nothing is static - currently have SAE 30 in the Stornello, but haven't ridden it yet...I bet it feels the same as the 15W-40 and 5W-30.

 

[ZeeOSix]

Like I said, education and experience isn't going to change anyone's mind here. What's being said is the prime basis of who knows what - it's pretty easy to tell who knows what. I've met plenty of people without a degree or college education who are smarter than someone else with a lot of education and "credentials".

I'll just say that I received my ME degree in 1983, and have been in many related job positions at one company for 30+ years (mainly aerospace/space hardware where the majority of fluids & thermodynamics came in) ... that's all I'll say. It's not going to make anyone believe me any more than they do or don't already. Doesn't matter to me.

 

[Shannow]

Originally Posted By: ZeeOSix
As long as the PD oil pump is not in pressure relief, then 100% of the pump's output goes through the engine. A well designed oiling system would give max oil volume flow through the engine with hot oil and never hit pump pressure relief, but come close at near red line RPM.


Never been in the design field either I take it...well designed allows redundancy for things as they wear (and journals and bearing do exactly that)...you always provide more pump.

Anyway, back to the extracts you showed, and the engineering side of things.

In the bearing side leakage chart )that was the same as the one that I posted pages ago)...where is the "P" in the bearing characteristics, if that's the parameter that's important ?

 

[ZeeOSix]

Shannow ... you're really grasping for stuff now - time to let it go as you keep getting less and less credible in this discussion. And taking little 'stabs' to try and make yourself look better is getting old. Sorry to say you don't see reality when it comes to pressure fed journal bearings or simple engine oiling systems. There is still time to learn though.

As the info I showed mentioned, that chart shows the ratio of side flow to total flow, but it's not relative to pressure fed bearings as stated on page 383, hence no P factor. The flow through a pressure fed bearing (and hence out the sides of the bearing) is given by equations (k) and (10-20) as stated earlier. Your "blood hound" is on the wrong "scent" ... do some more research.

 

[Shannow]

Note the order of your pages...

The last pages you posted are from the section on bearing design, and give the side leakage ratios based on the bearing parameters...ALL that is needed is to meet that flow requirement, and that is simply what the oil pump is doing...providing sufficient volume to make up for the bearing's inherent leakage.

The "pressure fed" aspect that is your premise is some 10 pages LATER than the bearing design parameters, and is an "IF" the natural replacement is insufficient to remove the heat generated by the dynamics within the bearing.

You have leaped PAST the design, and into the "IF" to present your argument, then presented them out of order as if the designer has automatically gone to over-supplying an overheating bearing...A tad disingenuous wouldn't you agree ?

 

[ZeeOSix]

^^^ More grasping and non-understanding. I photoed the entire Section 11-10 for "Pressure Fed Bearings" ... specifically journal bearings. It says right at the bottom of page 383 that Figure 10-17 is NOT applicable to pressure fed bearings. This book put ALL the charts in one area and may refer back to them like it did on page 383.

You're really stuck on trying to find some excuse why this information isn't accurate. Go search on the 'net for more info on PRESSURE FED BEARINGS ... or pull out your machine design handbook(s). You're so locked down in your misconception that you just can't even believe accurate information.

 

[ZeeOSix]

Here's some more info showing that the figures you are looking at only apply to journal bearings being fed at atmospheric pressure (ie, zero gauge pressure = non pressure fed).

The oil flow and film pressure in a journal bearing is totally dependent on if it's pressure fed or not. You're stuck in the atmospheric fed bearings world, and not understanding pressure fed bearings.

Figures 10-16, 10-17 and 10-18 only apply to journal bearings fed oil at atmospheric pressure. Per what was already discussed, the flow through a pressure fed journal bearing is defined by equation (10-20), and the total film pressure for a pressure fed bearing is determined by adding the supply pressure (Ps) on top of what's shown in Figure 10-18.

 

[Shannow]

You are fixated ion the concept of having to jam a pump's worth of oi through the bearings, and are using the "if there's not enough flow to stop elevated temperatures" as your justification.

You are automatically assuming, and arguing the "if the natural flow isn't enough" case simply because the engines are equipped with an oil pump...that's not a logical thought pattern, just a means to support your (flawed) argument.

Oil pumps are there to ensure that the oil is there, in the quantities that the bearings need to draw off.

Google
"oil pressure requirement automotive engine bearings", and see how many scientific hits you get...