0w40 is significantly thicker at 0 degrees than 0w20.
Thick vs. Thin
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Look at your showerhead as just a funny branched system not guaranteein g equal flow through the individual nozzles, PD or else. PD has no chance of sending as much fluid as high in jet 1 as in jet 2 and jet 3. I never made up much more analogy than that but understand that you like the arteries and heart chambers even less ;-)
Why not read a line or two from time to time, need not be mine, just something beyond the troops'.
Why not read a line or two from time to time, need not be mine, just something beyond the troops'.
It's still a "0W" rated oil ... so I wouldn't call it significantly thicker. If it was that much thicker it would have a different W rating.
wemay
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I've never said that every branch of an oiling system gets "equal flow" of oil flow. I'm sure you understand that each branch flows a volume based on either the volume being forced through it (if PD pump supplied volume) or the resulting flow volume as a function of a fixed supply pressure.
I think I see your hang-up. The reason a shower head has different flow and stream height is because the holes that have a higher height have smaller orifices. The whole head is getting the same supply pressure, and the height of each individual hole stream depends on the exact size of each hole. That's why it's not "equal flow" for water jet.
What happens to every one of those individual water jets as the supply pressure on the shower head increases or decreases? Every one of those jets heights do up with more pressure, and go down with less pressure proportional to the supply pressure. None of them stop flowing unless the supply pressure goes to zero.
Showerheads for piston cooling jets including funny free pressures for travels into and throughout the piston – please take them over there, that linked thread is still open.
Take strokes and coronaries for pushrods and lifters now ;-) And a heart as a positive displacement pump. Or just read up elsewhere if you prefer. Actual data can be found, right? Even regarding engines as if those weren't much less important than Adonisissies hearts.
Take strokes and coronaries for pushrods and lifters now ;-) And a heart as a positive displacement pump. Or just read up elsewhere if you prefer. Actual data can be found, right? Even regarding engines as if those weren't much less important than Adonisissies hearts.
I just can't see 10w oils being that bad even in colder temperatures down to at least 0F. I know 5w oils have been around for a long time but they weren't used excessively until the 1980's. It wasn't extremely uncommon to see engines with 200K+ miles in the late '60's through the '70's when nearly everyone used 10w30 or 10w40. I'm still using 10w40 year around in all my cars with no noticeable issues. I'm not in the coldest area of the US but I'm far from being in the warmest.
You keep bringing up shower heads ... oil cooler jets are essentially a flowing orifice. If you increase or decrease the flow through the jet (regardless if PD forced or pressure supplied), the jet will go up or down proportional to the pressure. Just like when you increase or decrease the supply pressure to the shower head - each jet will go up or down proportionally to the supply pressure going up or down.
The cause of a stroke is a lack of blood flow ... either caused by a blockage (ie, sludge in an engine analogy) or a lack of flow from a defective PD heart. If you block oil flow in an engine or have a defective PD oil pump, you're going to lose oil flow too. So not sure why you're going of into these weeds now, lol.
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How old is that study? -20 F is pretty cold. Four of those oils tested had a pour point of -20F, which basically means that they almost stopped flowing via gravity all together. Even though all those oils are supposedly "10W", it's evident that their specific formulation is causing different pumpability in that specific engine.
And again, the specific design of that engine is a factor - a different engine may have much different outcomes if the pump inlet and pump design is worse or better. What was the pump's pressure relief set to? - if relatively low, that could really impact a test like this. Dependent on their specific VII additives, some of those oil may be solidifying (waxing up) more significantly than others at -20F, causing more pumpability issues vs another. If you can't get the oil into or out of the pump correctly, there's going to be an impact on flow through the oiling system.
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50 years, but they already had positive displacement pumps not guaranteeing positive displacement distribution, fundamentals are fundamentals to accept. 40 psi were a threshold in measuring, that's easily enough to get their ideas and discard the own. Do you want an idling engine to force the lube through the pushrods under 120 psi?
Different engines are different all the time, younger than 50 years they for example can use capped pressures from idle to redline which only means no compensation over rising pressures. That fact alone annihilates half of the other thread if one only begins to accept realities.
Here the common points are PD doing nothing for anything but total flow through the pump (as they clearly state that it's not a "pumpability" problem on the suction side) because of ratios or biases shifting in branched systems. Therefore times to lubrication are of interest and PD ideas shoving is not. It's plain wrong to ever consider "PD" a clincher for anything beyond the first ramifications - and not exclusively because of relief settings.
Good night, take your time - I'll take a sleep and probably even one more shower, so...!
Different engines are different all the time, younger than 50 years they for example can use capped pressures from idle to redline which only means no compensation over rising pressures. That fact alone annihilates half of the other thread if one only begins to accept realities.
Here the common points are PD doing nothing for anything but total flow through the pump (as they clearly state that it's not a "pumpability" problem on the suction side) because of ratios or biases shifting in branched systems. Therefore times to lubrication are of interest and PD ideas shoving is not. It's plain wrong to ever consider "PD" a clincher for anything beyond the first ramifications - and not exclusively because of relief settings.
Good night, take your time - I'll take a sleep and probably even one more shower, so...!
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Re: The bolded sentence. You're using examples where pumpability is right on the edge of a high degree of degradation. They tested oils that were at or not far from their pour point. Look up what pour point means ... it essentially means the temperature where the oil won't move under gravity. This causes all kinds of pumpability issues - and most of the pumpability issues are simply getting the oil sucked into the inlet side of the pump. The exact oil pick-up and oil pump (including its pressure relief setting) can have a big impact on what goes out the pump to the oiling system under conditions like this test. The real test of the pump performance would be to take all those inlet pumpability factors out of the equation.
Then you use this as a means to claim that PD oil pumps don't properly supply "equal flow" to all circuits within an oiling system, or that oil jets don't work correctly if the exact oil viscosity isn't used (the other thread). It's a lot of out of context tangents and spinning.
How do you explain the gigantic test difference in time between the two runs of Oil L under the same exact test conditions? Something going on there, and that's what can happen when the oil is basically on the verge of loss of pumpability. Then look at Oil G where there had to be 100% full pumpability in order to achieve 2 sec to 10 PSI and 6 sec to 40 PSI at -20F. Same deal with Oil R which shows complete pumpability. It's not necessarily a PD pump issue when the performance to achieve pressure is poor at super cold temperature and almost non-flowing oil ... it's the lack of flow into the pump inlet so it can actually have some oil to pump. Remember, this is all on the same test engine so same PD pump.
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You aren't asking me me me to explain Table 3 first? Same wonder as last time when a mere -15°C made a difference between 5W-40 and 10W-30 at the rocker arms but made none of you want to explain.
PD needing several minutes in -15°F – whatever your PourPoints – once more illustrates the nature and worth of PD ideas around. Unless we and our J300, CCS, MRV and Brookfield begin to tell people that 10W is great down to -15°Whatever because minutes aren't hours. After all we have positive displacement pumps, positive displacement pumps would never allow minutes to become hours – you discard the idea.
PD is somewhat expressive in a volumetric sense for the cross section of the pump outlet. Not expressive in pressures and times measured at points of lubrication or cooling or actuation or else.
PD needing several minutes in -15°F – whatever your PourPoints – once more illustrates the nature and worth of PD ideas around. Unless we and our J300, CCS, MRV and Brookfield begin to tell people that 10W is great down to -15°Whatever because minutes aren't hours. After all we have positive displacement pumps, positive displacement pumps would never allow minutes to become hours – you discard the idea.
PD is somewhat expressive in a volumetric sense for the cross section of the pump outlet. Not expressive in pressures and times measured at points of lubrication or cooling or actuation or else.
The source of above: https://www.jstor.org/stable/44731383?seq=4#metadata_info_tab_contents
Read up to find them fully aware of pumps having screens even fifty years ago. They looked but didn't find minutes making hours of cavitation. Shall we try to reread that of last time to maybe find the big 15°C vacuum in 5W-40 and 10W-30 of the Chevron guys only twenty years ago? Or shall we bury them all and find independent data for freshest attempts to extract five minutes of vacuum?
Read up to find them fully aware of pumps having screens even fifty years ago. They looked but didn't find minutes making hours of cavitation. Shall we try to reread that of last time to maybe find the big 15°C vacuum in 5W-40 and 10W-30 of the Chevron guys only twenty years ago? Or shall we bury them all and find independent data for freshest attempts to extract five minutes of vacuum?
You never answered my request in post #54. Tell me why Oil G and Oil R worked perfectly fine at -20F while many others didn't. I said why - because if you can't get the oil into the PD effectively (the oil's "pumpability") then you don't get the proper volume amount that the pump is mechanically capable of pumping out. It's pretty obvious that with Oil G and Oil R, there is 100% pumpability. The oils that show much longer pump-up times (like Oil L, M & P) are showing the lack of pumpability.
It's not the PD pumps fault, it's the oil and/or the design of the intake screen and tube to the oil pump, along with the level of pumpability of the oil that is causing what this study shows. A PD oil pump can't do what it's designed to do if the intake flow of oil to the pump is degraded to a severe degree because the oil is not adequately pumpable.
Look at the title of the study article - "Pumpability of Multigrade Engine Oils at Low Temperature"
It's the pumpability of the oil that is being studied, and it's the pumpability of the oil that is causing the lack of quickly establishing flow and pressure ... it's not the fault of the PD oil pump. The PD oil pump is trying to mechanically do exactly what it's intended design is, but if it can not get the adequate intake charge of oil on every rotation, it's not going to work 100% as designed.
When you start talking about PD oil pumps that are not trying to operate on the ragged edge of the correct oil pumpability, and then prove they don't operate like intended to adequately lubricate an oiling system, then I'll be interested.
You're incredible, without ever rethinking or answering anything you need to stray away by all means, here to the galleries, but when "looking" at the gallery content you again don't read what they note: Said differences for them were "no statistically significant differences" in that regard. Did I get that wrong? Not necessarily taking my time reading up since
I of course had been referencing very different aspects when finding this for the pushrod-lifter-rocker route we'd been coming from. Never been talking about faults of PD pumps either by the way.
So, what ragged edges? Your ideas are all too well known, they must have been flooding the forum for ...50 years?
What is the correct "W" rating for the conditions from now on? Differences between 5W-40 and 10W-30 for just -15°C in testing had been better but not good enough to accept the findings. Are the measurable delays even for these deemed explained on the suction side?
Correct such oils should be down to -25°C and below.
Table 3 again illustrated the problem, and there's 14 pages to skim in case of interest: What are your slow oils doing in lifters and pushrods for three out of five minutes after it took them half as long to get to the lifters? And why is PD allowing them to do so much nonsense? Findings are common, pressure sensors on engines therefore get relocated from a near end on an easier bank to the far end on the more difficult bank for example. Watching blobs of the pudding appear at one end much earlier than at the other illustrates the lack of positive displacement distribution, similar interest provided....
Perfectly fine to never be interested, but you're ideas are not reflected by the findings and so some poor hypothetical other guy that missed the other thread may still see and read here the way they noted them. Let's let him give the MC professor my regards
He could even point Project Farm to persistant video demand in that area – at least until the day you feel funny and start explaining where and how your ideas were ...developed.
I of course had been referencing very different aspects when finding this for the pushrod-lifter-rocker route we'd been coming from. Never been talking about faults of PD pumps either by the way.
So, what ragged edges? Your ideas are all too well known, they must have been flooding the forum for ...50 years?
What is the correct "W" rating for the conditions from now on? Differences between 5W-40 and 10W-30 for just -15°C in testing had been better but not good enough to accept the findings. Are the measurable delays even for these deemed explained on the suction side?
Correct such oils should be down to -25°C and below.
Table 3 again illustrated the problem, and there's 14 pages to skim in case of interest: What are your slow oils doing in lifters and pushrods for three out of five minutes after it took them half as long to get to the lifters? And why is PD allowing them to do so much nonsense? Findings are common, pressure sensors on engines therefore get relocated from a near end on an easier bank to the far end on the more difficult bank for example. Watching blobs of the pudding appear at one end much earlier than at the other illustrates the lack of positive displacement distribution, similar interest provided....
Perfectly fine to never be interested, but you're ideas are not reflected by the findings and so some poor hypothetical other guy that missed the other thread may still see and read here the way they noted them. Let's let him give the MC professor my regards
He could even point Project Farm to persistant video demand in that area – at least until the day you feel funny and start explaining where and how your ideas were ...developed.
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