Motorcraft University

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ID has greatest impact: should energized fluid of a common pressure drop enter three ID’s at a given plane … they will not flow the same volume … rather they flow the same velocity … largest ID (same length) will take a higher percentage of flow. In the realm of motor oil viscosity … that’s probably the most exaggerated parameter on this site … pretty low.
 
What goes in comes out... That's neither questioned nor is it a question of PD or non PD.

Oil flow through the pistons' cooling circuits will not remain the same for higher viscosities. If "not starving" these were all you'd need to correct the MC professor, then you'd be right to an extent.
Positive displacement pumps are about a characteristic, not for guaranteeing fixed distribution. Your showerhead's individual jets, when turned upside down, will reach different heights. When raising pressure to compensate for a second showerhead on the house's roof that second showerhead will see more rise in flow or height than the first showerhead maxing out. Shares will shift, ratios not remain fixed. Same for finer jets, capillaries, more viscous water to get compensated via raised pressures...

I'm going to bed, too sick and tired to keep reading halfway seriously.
 
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Oil flow through the pistons' cooling circuits will not remain the same for higher viscosities. If "not starving" these were all you'd need to correct the MC professor, then you'd be right to an extent.
Just how much do you think the flow volume coming out of a piston cooling jet will change when comparing 5W-20 vs 5W-30 vs 5W-40 vs 5W-50 at 100C when in each case the PD oil pump is putting a constant 5 GPM into the oiling system?

Engine oiling systems are designed with big main supply galleries throughout the engine, and all the smaller circuit branches feed off the main galleries. Piston oil jets feed off larger galleries, not long skinny galleries.

Positive displacement pumps are about a characteristic, not for guaranteeing fixed distribution. Your showerhead's individual jets, when turned upside down, will reach different heights.
Since you like the shower head thing to analogize piston cooling jets, what do you think would happen if you forced 1 GPM of water through the shower head with a PD pump, and then did the same 1 GPM of forced liquid that was 3 times thicker than water?

When raising pressure to compensate for a second showerhead on the house's roof that second showerhead will see more rise in flow or height than the first showerhead maxing out. Shares will shift, ratios not remain fixed. Same for finer jets, capillaries, more viscous water to get compensated via raised pressures...
Remember that your house water system is not supplied by a PD pump. Instead it is fed by a constant supply pressure (ie, the pressure in the water main outside your house, which is typically around 70~90 PSI). PD pumps just keep increasing the output pressure to force the same output volume through the system it's feeding - constant supply pressure sources do not do that.

A house water system runs on a constant supply pressure. If your house water system fed off of a big water supply line that was at a constant 80 PSI, and if you turned on 2 shower heads and 3 faucets, they would all flow at whatever that 80 PSI of supply inlet pressure would result in. And if you increased the supply water line supply pressure to 120 PSI, every one of your open faucets and shower heads would increase in flow, and they would all increase in flow rate at basically the same percentage of change.

Let's say when you turned on 2 shower heads and 3 faucets, the resulting water flow rate was 4 GPM with 80 PSI of supply pressure. If you then tried to flow 10 cSt motor oil (10x water viscosity) through your house water system (hooked up to a giant oil tank) at the same constant 80 PSI supply pressure, then the flow rate will be cut way down on all turned on shower heads and faucets because of the increase in fluid viscosity. But if you hooked up a PD pump between the oil tank and the house to force 4 GPM through the system (at whatever pump outlet pressure it took), then the flow though all the turned on devices will be essentially the same as it was with water flowing through them at 4 GPM. That's the beauty of a PD pump.
 
Positive displacement references strokes or revolutions of the device itself, PD looks backwards, looks at generation of pressure. Informs about a characteristic performance.
Showerhead means: one pressure throughout a large showerhead but still not one height for all its individual jets' outputz aimed at your pistonhead to refrigerate it. As long as pressure is maintained there's not even a difference between more positive displacement and else. When viscosity pushes pressures those pressures may be kept higher with the simple PD than with a simple non-PD but these are not around. The pressure pushed by viscosity doesn't necessarily compensate for keeping up the individual jet's flow and the further transport as you'd want it to.
(Capped pressures aren't totally uncommon throughout operation anyway, among the sidenotes to accumulate.)

PD will never guarantee equal distribution, all it means is pressures at entries – like pressure in the showerhead which is the same for each and every beginning individual jet. Jet's that don't reach same height although running off the same feed pressure. Not true in your bathroom when you turn one upside down to make it look like piston cooling jets?
Pressures in our house are not constant, to raise pressure it suffices to stop flow through one faucet and see pressure restored at others. Water's relatively low viscosity of course becomes more relevant where the individual jets begin, all running from the same pressure. And through the pores of skin then they're aiming at.

Multiple showerheads mean unequal supply but essentially only two individual jets not yet furred-up already mean unequal supply which you can easily see reaching different heights (meant to illustrate differing cooling effects). How well will system pressure (which still ain't really one pressure throughout the system) translate to pressure and flow in the cooled piston between piston's inlet and outlet? Pressure before beginning orifice is more or less known we say...
Pressure drop from there? Free flow or flight? Coupled flow?

We generally began disregarding a bunch of things, not much left and you'll be there, right?: Same pressure along the block's gallery would mean same flow through travelling piston to get chilled regardless of viscosity? At least insofar same cooling effect? Guess I'm about to fit me a positive displacement pump to a spinning bearing and in parallel a chocolate fountain. Guess I'm ripe.
 
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48FC1978-5556-4BEC-9A85-5CADED65A5B6.webp
 
Provided that the friendly MC professor wanted to be so kind as to just plug all pump and regulator relief we – finally stripped of most things we implicitly and explicitly never want to wrap our minds around – now can focus on the last mile:

Water or wine, oil or mustard? Dr. Strangelove's jet forming, anti-misting and dynamic pressure promising piston refresh additive or extra dense OSP of lower coking propensity than regular fountain chocolate? As you can see I took a shower for about an hour, but we should probably let our stomachs decide.

https://player.admiralcloud.com/?v=136da3e0-d70c-4798-99ab-66809e119639

 
All I can say is ...

Just Crossed Over into the Twilight Zone.webp


And that engine oiling systems and PD oil pumps are pure ...

Its Magic.gif


If piston cooling jet performance was so sensitive to oil viscosity (as the "M/C Professor" claims), OMs all over the world for vehicles with cooling jets wouldn't specify oil viscosity from xW-16 to xW-50. It's the PD oil pump that ensures that oil supply and lubrication to all areas of the engine will be satisfied. If it wasn't a PD pump, then it might be a different story.
 
All I can say is ...

View attachment 41895

And that engine oiling systems and PD oil pumps are pure ...

View attachment 41896

If piston cooling jet performance was so sensitive to oil viscosity (as the "M/C Professor" claims), OMs all over the world for vehicles with cooling jets wouldn't specify oil viscosity from xW-16 to xW-50. It's the PD oil pump that ensures that oil supply and lubrication to all areas of the engine will be satisfied. If it wasn't a PD pump, then it might be a different story.

LMAO!
I have piston cooling jets, it spec's 0w-40. BMW has used them on engines that spec'd everything from 5w-30 to 10w-60. PD pumps don't care.
 
If "not starving" these were all you'd need to correct the MC professor, then you'd be right to an extent.

He hardly expressed concern of starving piston cooling when trying to be graphic.
Either way: PD reflexes had not been a valid counter and never can be.
 
He hardly expressed concern of starving piston cooling when trying to be graphic.
Either way: PD reflexes had not been a valid counter and never can be.
Listen very carefully what he says about the cooling jets and oil viscosity (from where the video below starts, and especially at time 2:43). He's making false claims - there is no way that using any viscosity between xW-16 and x-50 is going to cause any issue with piston oil jets. The magical PD oil pump will ensure an adequate supply of oil in every gallery inside an engine.

 
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My understanding is that he talks about engineers not wanting Hinz und Kunz to change viscosities and thereby alter some temperature for half a dozen Kelvin or whatever. Temperatures they are modelling and designing and testing all day long to make them part of the right package including the right oil. Those aren't doing their jobs, looking into a wealth of things like these or similar (random alternative pics from a Mr. SAE20 in a forum in a better state), without being reminded of us from time to time obviously. That's when a friendly MC professor takes over to take a bit of his country back from the average mansplaining Bitog millionaire troops...



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But maybe ask him to clarify nuances and minutiae. And teach him your ideas of positive displacement distribution providing constant impact fountains and other Scotty beaming et al. having a chance of being fine with all sorts of alternative facts.
 
Pretty much everyone here knows that running anything from xW-20 to xW-50 in the approprate ambient temperature recommendation (ie, the focus on correct xW rating for cold weather) never causes any engine issues. Engines can run xW-20 to xW-50 and in normal street driving you will not see enough change in oil temperature to make any difference. And all those piston oil squirter jets will still be working just fine.
 
Looks like a normal PD oil pump flow vs RPM operation and kicking in of the pressure relief valve as thicker oils are used. Up to 2250 RPM, the flow rate is the same regardless of viscosity (pump not in relief). Above 2250, the pump's pressure relief valve starts kicking in later and later as the viscosity goes up ... no surpises there. What's that got to do with the discussion about piston cooling jets - ??
 
En parenthèses. Go back to start all over around #5 or so if you ever choose to wish to mind.
Heck, you could even try to really listen to the poor prof instead of celebrating all too well known and once more useless reflexes. It's not that I ever weren't corrective.
 
Nah ... #5 is where things go into the Twilight Zone. I'm not really sure you really understand how a PD pump even works (not like your house's water system) and why it's used on engine oiling systems. You might want to do that experiment you mentioned in post #24. :D
 
There is a positive displacement pump but still no positive displacement distribution in your engine that would translate to what you keep trying to insinuate.
But I'm at an advantage: Renesis beyond the usual has a positive displacement distribution unit called a metering oil pump that doesn't pump much, doesn't really generate pressure or flow, it only allows metered portions of sump oil to flow for just the right amount of infusion. This thing has individual outlets for each of four nozzles. And not only individual outlets ;-) It's kind of a four cylinder feeding the two-rotor. For reasons.
What you have is a few centimetres or inches where positive displacement means somewhat expectable flow. Beyond these first few inches at some early point or two there only begins your last mile.
Take a shower, start holding this thing with the bunch of nozzles upside down for a morning routine and get going. Trust me, it sees same internal pressure at each beginning nozzle...

I wouldn't even know how Ford calls its more serious documentation of advancements, research and development efforts etc., I tended to find things for the rotary lately, but suggested already to get in touch with the prof or another to understand what he's essentially saying when he sounds like "helps maintain the temperatures in the correct operating range".
Even if he might actually be sitting in a marketing department he's ultimately communicating – whatever he personally might think he'd be thinking or knowing anyway – greetings from the kitchen, from people that are pursuing R&D, design or production to at least more actual standards and more real ideas than ours between ignorance and ignore switches.
No idea if Ford has a scientist or two but a few engineers they will have and probably have had some for quite some time now. Those do mean to model engines operating with efficiency, with emissions and cleanliness et al. while making their noises according to standards. Cleanliness as in cleanliness up and down a few millimeters of a piston e.g. My reception of this video cannot be like yours, I cannot watch as if I imagined anyone's standards judging an oil viscosity for a Ford being dominated by questioned fitness for survival. Which is telling as I'm none but your Hinz or Kunz, you know? Think about some serious briefing before contacting the poor MC prof.

Either way, all too well known conditioned reflexes – positive or negative displacement – remain just that, very special fitness of very special troops between evermore beliefs and misheard lyrics noises. Shall I call it what it is to let us have some mod ban me now? Or some time we all meet again?
We could ramp up oil pressures in mystic fountains some more...
 
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One thing now awaits correction: The MOP part is not four segmented but a twin unit of two registers unfortunately. Blingo, beware of your own double standards!
I suddenly remembered that when I went shopping again. Driving is always when I learn my brilliant entries by heart like the hour of shower is always when I'm the most brilliant Dreadnought.
 
There is a positive displacement pump but still no positive displacement distribution in your engine that would translate to what you keep trying to insinuate.
What's your definition of "positive displacement distribution"?

Do you think oil fed galleries by the PD pump are "starved" (including those galleries that feed piston cooling jets) if a thicker oil is used (at operating temperature)? If so, why?

True or false? - The oil flow rate increases in every PD pump pressurized oil gallery as engine RPM increases. See post #25.

Why do you think engine oil pressure goes up throughout the engine RPM range when a thicker oil is used?
 
No starved galleries, no. And yes, let pressures rise, that's not the point, that's only why it wouldn't even matter if somebody didn't know how to read "positive displacement pump" – we'd easily make it an extra fifty percent more positive for you and agree that so much positivity would always guarantee the same total flow. It would pump the more viscous oil under higher pressure. You're welcome, never questioned for the purpose of helping you. We'd even clear the regulator and pump reliefs away to minimize your losses.

Now this "total" would instruct you to have a look at ratios, biases, individual shares. With rising viscosity those may shift around, from smaller orifices to bearings' entrainments (or CAFE regulatory reliefs) or else. Therefore no fixed ratios, no constant shares. Would you prefer this paragraph underlined to the next paragraph set in bold? :)
Still no drama, from there we'd only continue following the lube making it via jets through crankcase air into the pistons (a fraction at least, hopefully) and subsequently through those pistons along new "paths of least resistance" for chilling effects. How much of your risen oil pressure do you think will stick to the higher viscosity travelling through the air and into the piston to reestablish more conventional flow for cooling effect all this was about? We agreed on ignoring reliefs and more, think of as much pressure there as possible. Hein? Two more videos were seen (and I guess I avoided any of them having dialogue to help refocus on what the prof had really said).

This and certainly more the poor MC prof tended to pack into a sentence or two for the video you didn't want to know how to watch. Unwanted differences of a few Kelvin somewhere in pistons, deviations from what Ford had been designing for. That's not a video about causing catastrophic failures by topping up with a litre of 20W-70, never was. With me you're reading videos straw-free.
 
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No starved galleries, no. And yes, let pressures rise, that's not the point, that's only why it wouldn't even matter if somebody didn't know how to read "positive displacement pump" – we'd easily make it an extra fifty percent more positive for you and agree that so much positivity would always guarantee the same total flow. It would pump the more viscous oil under higher pressure. You're welcome, never questioned for the purpose of helping you. We'd even clear the regulator and pump reliefs away to minimize your losses.

Now this "total" would instruct you to have a look at ratios, biases, individual shares. With rising viscosity those may shift around, from smaller orifices to bearings' entrainments (or CAFE regulatory reliefs) or else. Therefore no fixed ratios, no constant shares. Would you prefer this paragraph underlined to the next paragraph set in bold? :)
Still no drama, from there we'd only continue following the lube making it via jets through crankcase air into the pistons (a fraction at least, hopefully) and subsequently through those pistons along new "paths of least resistance" for chilling effects. How much of your risen oil pressure do you think will stick to the higher viscosity travelling through the air and into the piston to reestablish more conventional flow for cooling effect all this was about? We agreed on ignoring reliefs and more, think of as much pressure there as possible. Hein?

This and certainly more the poor MC prof tended to pack into a sentence or two for the video you didn't want to know how to watch. Unwanted differences of a few Kelvin somewhere in pistons, deviations from what Ford had been designing for. That's not a video about causing catastrophic failures by topping up with a litre of 20W-70, never was. With me you're reading videos straw-free.
These are the exact words the "M/C Professor" stated (ref time 2:43 in the video):
"If the oil isn't the right weight, which basically means thickness, it can't get through the oil jets to cool the pistons correctly and give you the cooling the engine needs".

Yeah, maybe a few degrees difference at the piston crown if you could even measure it. The PD oil pump is going to be moving basically the same oil volume regardless if the oil is xW-16 to xW-50 when the oil is hot and only a 10 cSt difference between 16 and 50. Piston cooling jets run off the same main gallery that feeds the crankshaft mains and rod big ends. With thicker oil, the pressure in all the main galleries will increase, which means the flow going through all the holes and smaller feed paths off the main galleries will also increase, trying to maintain the same flow rate because the oil is PD supplies. If 5 GPM leaves the pump, then 5 GPM will split up basically in the same distribution breakdown throughout the system, regardless if the oil viscosity is 8 cSt or 18 cSt.

You seem to believe the flow splits throughout the oiling system is going to go bonkers and cause problems just because the oil viscosity changed a few cSt. It's not, because of the PD oil pump - which is why a PD is used - that's my whole point. If engines were that sensitive to required flow throughout the oiling system over a few cSt change in viscosity (not to mention the HUGE viscosity difference between cold started oil thickness and full operating thickness), there would be blown-up engines all over the world. And if that was also the case, you wouldn't see owner's manuals all over the world specifying oil viscosity over the entire available oil viscosity range.

What would the "M/C Professor" say about the Ford Coyote engine which uses piston cooling oil jets when he realized that Ford says it's OK to run anything from 5W-20 to 5W-50 in them ... 5W-50 specifically for track use where the piston cooling jets are even more important. If they didn't work correctly with 5W-50, Ford would never specify such a huge range of oils for that engine.
 
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