Honda Paper (2009) on F1 engine development

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Good thing that engine has pressure fed journal bearings ...
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Originally Posted By: ZeeOSix
Good thing that engine has pressure fed journal bearings ...
grin.gif



From the paper...

Quote:
The set oil supply pressure in Honda’s initial FormulaOne engine specifications was 700 kPa, but this figure increased to 900 kPa in response to annual increases in engine speed. There were two main reasons for this. The first of these was to increase the volume of oil that might contact to the piston ceiling close to top dead center by increasing the injection speed of the piston cooling oil jet. The second was that the supply of oil to the crankpins using the center supply method against centrifugal force necessitated higher oil pressures in order to achieve a stable oil supply at high engine speeds.


Again, they increased the pressure...just to get it in adequate volumes to the big end, the drilling of which is often operating in partial vacuum.

The big end is the worst of the bearings, and isn't force fed cooling oil as per your erroneous assertion in the other thread...the pressure is simply to get an adequate supply of oil into it to replace side leakage, not to force flow through it.

If you can get the big end to survive, then you would NEVER have to push oil through the mains to provide additional cooling, they are a cakewalk compared to the big end.

http://www.vandervell.co.uk/images/slide...ngPerforman.pdf

Note the intermittent nature of the big end oiling versus your pressure fed for cooling position, and the statement that going to 360 degree main grooving can direct too much oil to the big end....again, the pressure is to get the oil there, not jam it through the bearings.
 
900 KPa = 130 PSI. If 130 PSI is put on the inlet hole to a journal bearing you're going to get lots of oil volume flowing through that bearing ... regardless if it's rotating or not. It's a pressure fed bearing; it doesn't "suck" what it needs from the gallery ... it gets force fed by oil pressure. Honda increased the oil pressure to ensure that bearing got increased oil flow volume in order to survive under race conditions. No place inside a journal bearing operated at "partial vacuum" when it's being pressure fed at 130 PSI. If it was fed at atmospheric pressure, then yeah it could have a partial vacuum in the bearing.

I know you can't grasp the technical information I supplied in the other thread, but it's pretty simple to see, and shown by a flow equation (same equation from more than on source) that the more oil supply pressure you provide to the bearing the more oil volume it flows. Pressure fed bearings certainly do get oil jammed through it.

Put a motor on a stand and take the oil pan and valve cover off of it, then pressurize the whole oiling system. What you see is every journal bearing flowing oil like mad because they are all being force fed oil through the bearing's clearance. Based on your belief, there would be no flow seen in that scenario because the bearings because the engine wasn't rotating. There's a big disconnect there and erroneous thinking.

https://www.youtube.com/watch?v=iy_OmYl21hA

The link you provided is simply talking about the groove design in the journal bearing and how it changes the oil film pressure during hydrodynamic lubrication. It has nothing to say or do about how much oil flows through a bearing when it's pressure fed vs when it's not. All that info was clearly given in the other thread.
 
Originally Posted By: ZeeOSix
Put a motor on a stand and take the oil pan and valve cover off of it, then pressurize the whole oiling system. What you see is every journal bearing flowing oil like mad because they are all being force fed oil through the bearing's clearance. Based on your belief, there would be no flow seen in that scenario because the bearings because the engine wasn't rotating. There's a big disconnect there and erroneous thinking.


What ???

Where have I ever said that applying pressure to the galleries of a stationary engine doesn't create flow ?

Of course it does...

Your static crank, electric oil pump has SFA to do with what's happening in a spinning engine...that fact that you think it's demonstrative is quite telling really.

But the things that happen inside operating engines are dynamic ... that's why Honda said that when they increase the RPM, they increased the pressure to overcome the centrifugal action from the big end throws...need enough pressure to overcome the dynamics within the crank drillings.

Big end throws

http://www.tytlabs.com/english/review/rev383epdf/e383_044suzuki.pdf
clearly not "pressure fed", as for significant parts of the rotation, there isn't any pressure at all.
 
Originally Posted By: Shannow
Originally Posted By: ZeeOSix
Put a motor on a stand and take the oil pan and valve cover off of it, then pressurize the whole oiling system. What you see is every journal bearing flowing oil like mad because they are all being force fed oil through the bearing's clearance. Based on your belief, there would be no flow seen in that scenario because the bearings because the engine wasn't rotating. There's a big disconnect there and erroneous thinking.


What ???

Where have I ever said that applying pressure to the galleries of a stationary engine doesn't create flow ?

Of course it does...


In the other thread you said:
Originally Posted By: 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.

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


That clearly tells me (as well as many other of your posts) that you don't believe a pressure fed bearing gets increased oil flow through it from a higher supply pressure. Your premise is that the bearing "sucks" the volume it needs from the supply gallery based on it's side leakage, and the flow through it isn't influenced by the supply pressure, no matter how high the supply pressure is. But if that was really true (which it's not), then in the scenario shown in the YouTube video there would be zero flow through the bearing because all the bearings were stationary and unable to suck oil in like they normally would from their rotation action. Isn't that your whole position in these discussions.

I've shown that if the supply pressure is increased, then so is the flow through the bearing. Equation shown here - same equation (10-20) shown in the other thread: http://www.mathworks.com/help/physmod/hy...w.mathworks.com
Increase the supply pressure p, and flow q has to increase. Simple case that a pressure difference causes fluid to flow. Still holds true when the engine is running.

Even in a pressure fed bearing, it's rotation still does help "suck in" oil from the gallery, but it's very insignificant compared to the high supply oil pressure forcing the flow through the bearing. If the oil gallery was only at atmospheric pressure (ie, gauge pressure = 0), then the rotation of the bearing and he partial internal vacuum it produces would be the only driving force to draw ("suck") oil into the bearing. That's why Figures 10-16, 10-17 and 10-18 discussed in the other thread are not valid for pressure fed bearings, but are derived to only be valid for atmospheric supplied bearings. The equation shown in the link about (same as equation 10-20 in the other thread) is what defines bearing oil volume flow as soon as positive supply pressure is involved. It's clearly discussed in the machine design handbook I referenced.

Originally Posted By: Shannow
Your static crank, electric oil pump has SFA to do with what's happening in a spinning engine...that fact that you think it's demonstrative is quite telling really.


What you're failing to see is that a positive supply pressure causes more oil volume to flow through the bearing ... and that's also true when the engine is running. The hydrodynamic action inside the bearing is still going on when it's rotating even in a pressure fed situation. The bearing doesn't care much about the supply pressure in terms of lubrication unless of course the supply oil volume is way too low (due to low pressure), which could cause lack of lubrication and/or over heating of the bearing.

Originally Posted By: Shannow
But the things that happen inside operating engines are dynamic ... that's why Honda said that when they increase the RPM, they increased the pressure to overcome the centrifugal action from the big end throws...need enough pressure to overcome the dynamics within the crank drillings.

Big end throws

http://www.tytlabs.com/english/review/rev383epdf/e383_044suzuki.pdf
clearly not "pressure fed", as for significant parts of the rotation, there isn't any pressure at all.


Yes, Honda increased the oil pressure to the bearings to overcome the decrease in supply pressure right at the bearings due to increased centrifugal force from the increased RPM, and most likely to ensure the oil volume was still high enough for adequate cooling. If they didn't increase the supply pressure then the oil volume being forced through the bearing would be too low during high RPM and load for the bearing to survive as they wanted. Now if the bearings only "sucked in" what they wanted from the galleries due to their small internal vacuum, do you really think they would survive in an engine like that Honda F1 engine? I don't think they would last one 30 second blast to red line. That's why Honda is force feeding those bearings with 130 PSI.
 
Originally Posted By: ZeeOSix
That clearly tells me (as well as many other of your posts) that you don't believe a pressure fed bearing gets increased oil flow through it from a higher supply pressure. Your premise is that the bearing "sucks" the volume it needs from the supply gallery based on it's side leakage, and the flow through it isn't influenced by the supply pressure, no matter how high the supply pressure is. But if that was really true (which it's not), then in the scenario shown in the YouTube video there would be zero flow through the bearing because all the bearings were stationary and unable to suck oil in like they normally would from their rotation action. Isn't that your whole position in these discussions.


Do you have one of these on your desk ?

i_make_stuff_up_coffee_mug_coffee_mug-r71b24da651be44b09adbd6b49dad5244_x7jg5_8byvr_512.jpg


Because your version of what I'm "clearly" telling you smacks of it.
 
So then just what exactly is your position? At this point I actually do believe you "make stuff up".

I think you're back peddling now. You've made numerous posts indicating you believe the bearing only sucks volume off the galleries based on what it "needs" based on the slight internal vacuum it produces while rotating.

I say the bearings are force fed oil with the supply pressure in the gallery, and as a result they will have a much higher flow volume then they could ever "suck" from a gallery on their own.

Do you believe pressure fed journal bearings flow more oil volume as the gallery supply pressure is increased, regardless of how fast the bearing is rotating? Yes or No?

Do you believe the PD oil pump forces oil volume through a journal bearing, and the total flow through the bearing is dependent on the oil pressure on the bearing inlet? Yes or No?
 
OK, the function of the oil pump is to ensure that there is sufficient volume to meet a bearing's needs at the point of operation.

On a multi path system, it needs to take into account the worst location, under the worst conditions.

The "requirement" for each of those points is determined by the bearing flow characteristic (if you recall, it was the charts that you posted some pages after I posted those charts)

Yes, overpressure will force more oil into the bearings...it's the point in your argument that fails, in that you are taking the oversupply condition as the design point...it's the "IF the bearing requires additional cooling", not "OF COURSE the bearing requires additional cooling".

And the big end...which is the worst of the worse locations is NOT a pressure fed bearing in accordance with your definition.

edit...and it's "draws", not "sucks"...
 
Last edited:
You didn't answer my two questions above:
1) Do you believe pressure fed journal bearings flow more oil volume as the gallery supply pressure is increased, regardless of how fast the bearing is rotating? Yes or No?

2) Do you believe the PD oil pump forces oil volume through a journal bearing, and the total flow through the bearing is dependent on the oil pressure on the bearing inlet? Yes or No?

I want to know if you think a journal bearing will flow more oil if the supply pressure is increased (regardless of the bearing's rotational speed to keep it simple), or do you really think the bearing will just flow "what it needs" off the gallery based on its rotational dynamics, no matter what the gallery oil pressure is at. That's the point I'm discussing.

I'm not talking about what a particular bearing design or configuration "needs" to survive (not fail), or what it will flow based on those design charts, which are only for atmospheric oil supplied bearings as pointed out before. The flow volume a pressure fed journal bearing is capable of takes on different characteristics than what those flow charts show, as stated in the design handbook.

I'm talking about the oil volume that a bearing will flow based on its physical configuration when the oil supply pressure is above atmospheric, and what effect the supply pressure has on bearing oil flow as the pressure increases. My position is that the bearing is force fed oil volume from the PD pump regardless of how much it "needs" or wants to "suck" in due to the vacuum produced during rotation, and that the flow is basically directly proportional to the supply pressure as defined in the flow volume equation given in two separate sources (equation 10-20 in the other thread).

I think you don't believe anything in the pressure fed bearing section of the design handbook I posted up in the other thread based on your many comments.
 
Originally Posted By: Shannow
edit...and it's "draws", not "sucks"...


Same thing ... semantics.
 
Originally Posted By: Shannow
Yeah, and "swim" means freestyle for a toddler, doesn't it.


You always seem to have problems grasping the real meaning of words ...
grin.gif


From the other thread:
Originally Posted By: Shannow
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.


Everything in that quote is just wrong (except for the suck part for non-pressure fed journal bearings) ... and you even used the word suck instead of "draw" - LoL.
 
Originally Posted By: Shannow
http://www.lube-media.com/documents/cont...evelopedtor.pdf


Good read, and basically reflects what I've been saying about PD pump supplied oiling systems in these discussions.

Here's a few snip-its from the article for you to ponder.

Basic lubrication systems use a positive displacement oil
pump feeding all bearings
with full flow oil filtration.


They are talking about pressure fed bearings, and hence making the bearings flow more oil than they could do by simply "sucking" oil in on their own.

"As some of the bearings will wear, the clearances between the rotating
shaft and bearing shell increase, thereby allowing more oil flow."


In a pressure fed system, if the bearing clearance increases (flow area increases), then the flow resistance decreases and the flow volume increases when supplied with the same oil gallery pressure.

However, for crankshaft bearings the flow
requirement is based on temperature rise through the
bearing
and as the engine wears the oil temperature rise is
reduced since increased clearances allow more oil flow.


One purpose of using a PD pump to force volume through the bearing is to control its temperature - as has been discussed before. As the pressure fed flow volume increases through the bearing, more heat is carried away and the bearing temperature rise is reduced. A bearing simply "sucking in what it needs" can not do this ... it needs much more volume flow than that to keep it safely cool, especially at very high RPM and load. That's why a PD pump is used in oiling systems, because the output volume increases near linearly with RPM, and therefore also force feeds all the bearings with higher and higher flow as the RPM increases to ensure they survive.

Did you see in the Honda engine development article you linked above that the engine was flowing around a maximum of 20 GPM (75 L/min) of oil. Why do you think a tiny little 2.4L V8 would need so much oil flow through the oiling system. And that was all going to lubricating the various engine components and cooling jets of course - none of it was being shunted back to the sump.

Traditionally engine designers have used oil pressure in
specific parts of the engine to gauge acceptable lubrication
with the majority of the lubrication system considered
during the engine development phase.


Modern engines with very high specific HP/liter would not survive very long without pressure fed bearings. Since you believe that the PD oil pump doesn't force oil volume through journal bearings to lubricate them, I'm wondering how you even believe half the things discussed in this article.
 
Ohhh...you completely ignored the big end, intermittent oiling part...just like I expected you to do.

"feeding all the bearings"...providing sufficient pressure to overcome system resistance, and get the oil to the worst location is NOT a pressure fed bearing as per your premise...i.e. the "if that's not enough heat removal"...the IF part of the journals that you provided.

The big end is clearly intermittent, and clearly NOT full flow pressure fed.

If it can survive, then there's absolutely zero reason to intentionally over feed the mains.
 
http://www.eng.auburn.edu/~jacksr7/SAE2002013355.pdf

2002-01-3355 Lubrication, Tribology & Motorsport R.I. Taylor Shell Global Solutions (UK)

Quote:
In addition to oil film thickness, it is also important to know what flow rate of oil is required to lubricate the bearings. If the flow rate is not sufficient, lubricant starvation can occur which may lead to catastrophic damage to the bearings. Figure 8 shows the flow rates predicted by the modified Short Bearing Approximation.


Then goes on to work out the flows that need to be supplied...using the short bearing equations, and therefore side leakage and squeeze films...only mention is providing adequate supply...NOT pressurised operation.
 
Originally Posted By: Shannow
http://kingbearings.com/wp-content/uploa...ce-bearings.pdf

Again, bearing parameters determine the oil make-up requirement...which is what the pump needs to supply, NOT jamming oil through it...


This says otherwise. See page 827 in this PDF link:

http://web.iitd.ac.in/~hirani/rapid_perfromancce.pdf


Oil flow
The oil flow is an important factor to determine the
operating temperature and oil viscosity. Total side flow
prediction through bearing involves hydrodynamic flow
QH caused by relative shaft rotation and the resulting
film pressure, together with the feed
pressure flow, QP, which is the direct result of oil
being forced through the bearing by supply pressure
.
The oil-feed flow QP depends on supply pressure,
bearing geometry and oil feed configuration.


The part in red is the part you are not realizing is happening with pressure fed journal bearings, and what I've been saying all along.

So yeah, the pump actually is "jamming" oil through the bearings - and other components needing oil flow (oil squirters, chain tensioners, variable cam timing mechanisms, etc). So when designing a pressurized oiling system, the size and performance of the PD oil pump becomes a critical aspect to get the design flow (forced fed oil flow) to the engine components.
 
Big end ???

intermittent flow at the most crucial part of the system (i.e. not the pressure fed equations that you introduced for the "IF temperature is an issue" ?

Remember, the opening statement for your textbook example is "IF" temperature is an issue, then oversupply...but a big end is clearly intermittent, not full pressure/flow, and if it's not an issue, then clearly a main isn't either...and that's not how they are designed.

If you want, go back to the MC thread, where I was suggesting to BSS that squirter flow was reduced by artificially lowering OP through viscosity, and previous posts on Honda's problems with hydraulic devices when operating at lower pressures due to lowering viscosity for fuel economy.

Yeah, it's a complete package...bearings aren't lubricated by dropping viscosity to effect higher flow, and pistons aren't cooled by it either...And OIL PRESSURE which drives the latter and tensioners and actuators is an artifact of the bearings not requiring the entire pump delivery volume...my premise all along.
 
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