Enginemasters new episode 4/30 oil filter showdown!

[ZeeOSix]

Read this post before you respond to me again please:
https://bobistheoilguy.com/forums/t...il-filter-showdown.340735/page-2#post-5760711

To add .... another give away that the pump was in relief is the fact that the oil pressure only increased 9.6 PIS between 3,000 and 6,000 RPM. If the oil was hotter and the pump not near or in relief at the start of the run, then the oil pressure would have been lower at 3,000 RPM and then increase much more per 1000 RPM before the pressure started cutting off to a max pressure way closer to 6,000 RPM. If the oil was thin enough, and the pump relief set high enough, the pump would never hit pressure relief in a test like this.

The pressure increase "creep" of 9.6 PSI between 3,000 and 6,000 RPM as shown in OVERKILL's screen shot below is because the pump's pressure relief is not a prefect system to hold the pump outlet pressure dead nuts at the relief spring setting. It wasn't from the oil filter "starving" flow and reducing oil pressure - oil pressure and flow was actually still increasing throughout the RPM range.

The only thing the test showed is which filter has the lowest flow delta-p when the pump is in relief (ie, when the pump supply pressure is maxed out) and no longer a positive displacement system, but basically a constant pressure supply system. But if the oil was hot and thin enough, and the pump never hit relief at 6,000 RPM, then the flow and pressure would have been pretty much the same for all oil filters tested. That's what I saw when I did oil pressure vs RPM with oil at a constant 200F testing on my Z06. With 5W-30 at 200F the oil pressure was 55 PSI at 3,000 RPM, and the pump was getting close to hitting relief at 5,500-6,000 RPM.

Also, here's flow vs delta-p data from member here @Ascent Filtration Testing that shows all the filters he tested only have ~5 PSI (150 in-H2O) of delta-p with oil that is basically xW-40 weight at 200F at 7.5 GPM (28 LPM) of flow (max flow in the Engine Masters test). So in reality, oil filters do not cause much restriction to flow in an oiling system. At idle with hot oil, they are pretty much invisible in terms of added flow restriction.

 

[Davejam]

That's a misconception too ... go do some research and you will see many studies that show that particles less than 20 microns actually do the most wear.

References please. Don't tell me to go do some research, that's rude.

4 micron particles can be in the tens of thousands. 6 micron particles in thousands-hundreds. 14 microns in the hundreds.
Are you saying that a 4 micron particle does more wear than a 20 micron particle? Because that is false.
Or are you saying that because filters don't catch smaller particles that they are in more abundance and therefore contribute to wear? I can buy that to an extent. But filtering smaller and smaller particles just isn't that critical in an ICE.
Wear is correlated to particle size AND count. Hence the ISO cleanliness codes.

 

[ZeeOSix]

References please. Don't tell me to go do some research, that's rude.

4 micron particles can be in the tens of thousands. 6 micron particles in thousands-hundreds. 14 microns in the hundreds.
Are you saying that a 4 micron particle does more wear than a 20 micron particle? Because that is false.
Or are you saying that because filters don't catch smaller particles that they are in more abundance and therefore contribute to wear? I can buy that to an extent. But filtering smaller and smaller particles just isn't that critical in an ICE.
Wear is correlated to particle size AND count. Hence the ISO cleanliness codes.

Here's one pretty in depth SAE study ... there are more that conclude similar outcomes, do some Googling.

https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.404.7165&rep=rep1&type=pdf

 

[Davejam]

Here's a link to that full paper, by Pall corporation - which produces filter media.
https://p2infohouse.org/ref/31/30453.pdf
I don't really have a comment on this one, it does support your point of view.

SAE Paper # 881825
Conclusion: Compared to a 40-Micron filter, Gasoline Engine wear was reduced by 50 percent with 30-Micron filtration. Likewise, wear was reduced by 70 percent with 15- Micron filtration.
My comment here is that most of the wear was reduced by filtering at 30 microns. Then incrementally down to 15 micron.

These are all fairly old studies as well.

We see that oil filters for gas engines nominally filter to 20 microns. And this works pretty well. The higher the efficiency at 20 microns the better, no argument there, but there is diminishing returns. And frankly while I personally believe that, there isn't a lot of evidence that i've seen that 99+% at 20 micron was noticably different than 95% at 20 micron.

So, if you had to choose the same # of particles of size 21, 14, 4 microns, which would you choose to be circulating in your engine oil?

 

[ZeeOSix]

Here's a link to that full paper, by Pall corporation - which produces filter media.
https://p2infohouse.org/ref/31/30453.pdf
I don't really have a comment on this one, it does support your point of view.

SAE Paper # 881825
Conclusion: Compared to a 40-Micron filter, Gasoline Engine wear was reduced by 50 percent with 30-Micron filtration. Likewise, wear was reduced by 70 percent with 15- Micron filtration.
My comment here is that most of the wear was reduced by filtering at 30 microns. Then incrementally down to 15 micron.

These are all fairly old studies as well.

We see that oil filters for gas engines nominally filter to 20 microns. And this works pretty well. The higher the efficiency at 20 microns the better, no argument there, but there is diminishing returns. And frankly while I personally believe that, there isn't a lot of evidence that i've seen that 99+% at 20 micron was noticably different than 95% at 20 micron.

They may be relatively old studies, but their findings were solid. Nothing has changed in the wear vs particle size world since then. Cleaner oil results in less wear than dirtier oil ... it will always be that way.

Agree, there may not be much different between 95% @ 20u and 99% @ 20u, but there is between 50% @ 20u vs 99% @ 20u, or 99% @ 40u vs 99% @ 20u. Of course the closer two filters are to each other in efficiency the less difference will be seen.

Engine wear is also dependent on what I call the product of oil cleanliness times miles ran. A more efficient oil filter helps keep oil cleaner the longer the oil is ran. If the oil was dumped from the sump every 500 miles you wouldn't even need much of a filter, if any.

So, if you had to choose the same # of particles of size 21, 14, 4 microns, which would you choose to be circulating in your engine oil?

Based on the studies, the 4u and 14u particles would probably have the most potential for wear. And as most know, if a very efficient filter is used, the number of all sized particles decrease - that's an advantage of a high efficiency oil filter that some may not realize. If a filter is 99+% @ 20u, it can also be 75-80% @ 5u.

The bottom line is that trying to keep oil as clean as possible doesn't hurt anything and is helping reduce some engine wear. And it's a misconception to believe that particles less than 20u aren't doing anything. They do as shown in studies, and that's why big rigs, etc use bypass filtering in order to remove more particles less than 20u when they run oil for a super long OCI.

 

[adams355]

@ZeeOSix @OVERKILL

The oil was hot he even says he is going to burn himself (@29:06) then has a helper do it instead. If you can see the main dyno screen after the first 2 dyno runs the coolant temp is 176 F. The oil pump moves a pre-determined volume of oil for RPM, when it reaches the filter there will be a change in flow rate for that volume of oil.

 

[ZeeOSix]

The oil pump moves a pre-determined volume of oil for RPM, when it reaches the filter there will be a change in flow rate for that volume of oil.

Every drop of oil that leaves the pump and goes into the main gallery to the oiling system goes through the oil filter, even when the pump is in pressure relief. The filter doesn't change the flow rate of what's already left the pump. And every drop of that oil also goes through the oiling system after it leaves the oil filter.

 

[adams355]

Every drop of oil that leaves the pump and goes into the main gallery to the oiling system goes through the oil filter, even when the pump is in pressure relief. The filter doesn't change the flow rate of what's already left the pump. And every drop of that oil also goes through the oiling system after it leaves the oil filter.

The oil pump only generates a volume of oil then it hits the filter. Are you saying the oil pump is generating an amount of oil after the filter? The oil pump doesn't change the amount of volume outside of rpm and viscosity. Your thinking psi instead of flow. If your theory was correct we could run by-pass filters on the motor.

"When you think about it, the positive-displacement pumps used in automobiles deliver flow to the oil filter and then on to the engine at a rate proportional to the engine's speed."

https://www.machinerylubrication.com/Read/30697/choose-oil-filter

Do you really think these guys at engine masters who work in the industry as professionals have got it wrong with all their knowledge?

 

[ZeeOSix]

The oil pump only generates a volume of oil then it hits the filter. Are you saying the oil pump is generating an amount of oil after the filter? The oil pump doesn't change the amount of volume outside of rpm and viscosity. Your thinking psi instead of flow. If your theory was correct we could run by-pass filters on the motor.

"When you think about it, the positive-displacement pumps used in automobiles deliver flow to the oil filter and then on to the engine at a rate proportional to the engine's speed."

https://www.machinerylubrication.com/Read/30697/choose-oil-filter

I think you missed my point. You said:

"The oil pump moves a pre-determined volume of oil for RPM, when it reaches the filter there will be a change in flow rate for that volume of oil."

My comment was about your comment in bold. If say 5 GPM of oil volume leaves the pump, how can the flow magically change to something different than 5 GPM when it hits the oil filter? There is no way that can happen.

You said "there will be a change in flow rate" when the oil reaches the filter. I'm saying that can't happen because every drop that leaves the pump must go through the filter and through the oiling system.

 

[adams355]

I think you missed my point. You said:

"The oil pump moves a pre-determined volume of oil for RPM, when it reaches the filter there will be a change in flow rate for that volume of oil."

My comment was about your comment in bold. If say 5 GPM of oil volume leaves the pump, how can the flow magically change to something different than 5 GPM when it hits the oil filter? There is no way that can happen.

You said "there will be a change in flow rate" when the oil reaches the filter. I'm saying that can't happen because every drop that leaves the pump must go through the filter and through the oiling system.

There is a restriction in flow rate when it moves through the filter even though the volume of oil in the circuit will not change, the higher the restriction the more HP is needed to move it through that's why a high flow oil filter is beneficial in any type of street/race car.

 

[ZeeOSix]

There is a restriction in flow rate when it moves through the filter even though the volume of oil in the circuit will not change,

I think your use of terminology is showing some confusion. The same exact flow that leaves the pump also flows through the filter. The filter has a delta-p across it from the flow. But it's still true that every drop of oil leaving the pump goes through the filter.

What you said above: "when it reaches the filter there will be a change in flow rate for that volume of oil." ... can not physically happen. There is not a change in flow volume when it hits the filter - that's physically impossible.

... the higher the restriction the more HP is needed to move it through that's why a high flow oil filter is beneficial in any type of street/race car.

Going off topic. Look at the filter delta-p vs flow curves that have been shown, and see that with hot oil there's only ~5 PSI of delta-p at high flow volume for good flowing filters. Realize that an oil filter producing 5 PSI of delta-p is only 1/15 of the total pressure drop across the oiling system running at 75 PSI. Oil filters add a very small increase in required pump outlet pressure. The oiling system down stream of the filter is 90+% of flow resistance the pump needs to fight against.

If the delta-p was 8 or 10 PSI instead of 5, the change in required HP is miniscule - you couldn't even see the HP difference on a dyno, which are not dead nuts repeatable anyway. Run the hydraulic pumping HP equation with one system needing 3 PSI more to pump the same volume and you'll see for yourself.

 

[adams355]

What you said above: "when it reaches the filter there will be a change in flow rate for that volume of oil." ... can not physically happen. There is not a change in flow volume when it hits the filter - that's physically impossible.

No, that is exactly what happens and the oil pump will tax RPM (HP) to move the same amount of oil. That's why you don't see it. So, are we calling the engine masters fibbers are we, you are saying they don't understand the system.

 

[ZeeOSix]

No, that is exactly what happens and the oil pump will tax RPM (HP) to move the same amount of oil. That's why you don't see it. So, are we calling the engine masters fibbers are we, you are saying they don't understand the system.

Explain how the oil flow rate changes when it gets to the oil filter. That is what you keep saying happens ever since post #66.

If 5 GPM leaves the pump, then 5 GPM goes through the filter, regardless of how good the oil filter flows or not.

 

[ZeeOSix]

If an oil filter had 5 PSI of delta-p at 8 GPM, and the oil pump outlet pressure was 80 PSI to force that 8 GPM through the filter and engine, then the HP to drive the pump (assume 85% efficient) would be 0.44 HP. Google hydraulic pump HP equation.

If no oil filter was on the engine (the 5 PSI from the filter removed from the flow path), then the pump would move that same 8 GPM at 75 PSI outlet pressure, and the required power would then be 0.41 HP.

So the oil filter only added a whopping 0.03 HP (22.4 watts) to flow 8 GPM through it. A decent flowing oil filter is pretty much invisible to the engine.

 

[adams355]

Yes that's HHp, you have to convert to BHp. You can do the maths.

https://www.sciencedirect.com/topics/engineering/hydraulic-horsepower

 

[ZeeOSix]

Yes that's HHp, you have to convert to BHp. You can do the maths.

https://www.sciencedirect.com/topics/engineering/hydraulic-horsepower

I did, that's the "assume 85% efficient" pump in post #74. Since the PD oil pump is not ran by an electric motor, it's pretty safe to say there is only about 15% mechanical drive loss in HP between driving the pump and the HHP to move the fluid.

You still haven't explained what I asked in post #73 - please elaborate: Explain how the oil flow rate changes when it gets to the oil filter.

 

[adams355]

I did, that's the "assume 85% efficient" pump in post #74. Since the PD oil pump is not ran by an electric motor, it's pretty safe to say there is only about 15% mechanical drive loss in HP between driving the pump and the HHP to move the fluid.

You still haven't explained what I asked in post #73 - please elaborate: Explain how the oil flow rate changes when it gets to the oil filter.

I have explained it the pump compensates by taking more HP. Do a calculation for me 15GPM at 80psi with 15w-50 oil hot. You haven't converted by just one variable that would mean the calculation is of water and that is still only HHp. The delta p tells us nothing it is only related to the filter itself.

 

[OVERKILL]

@ZeeOSix @OVERKILL

The oil was hot he even says he is going to burn himself (@29:06) then has a helper do it instead. If you can see the main dyno screen after the first 2 dyno runs the coolant temp is 176 F. The oil pump moves a pre-determined volume of oil for RPM, when it reaches the filter there will be a change in flow rate for that volume of oil.

The coolant temp in the run I screen captured is clearly 86F throughout the entire run.

No, the oil pump only moves a specific amount of oil until it is on the relief, then that relationship is decoupled as oil is bypassed back into the feed side of the pump. That's why I provided that cute little snapshot of the SBC relief springs and their associated pressures.

 

[OVERKILL]

The delta p tells us nothing it is only related to the filter itself.

The delta-p tells you the resistance across the filter, something they didn't measure for, even though they had the equipment to do so. That would have been valuable information and I covered that in the post of mine I instructed you to read.

There are two bypass assemblies in the oil circuit:
1. The pump relief pressure spring
2. The media bypass assembly located either in the block or in the filter canister itself. On many GM applications, this is in the block.

On #1, this comes into play once the pressure the relief is calibrated for (via a spring) is reached. The relationship between oil entering the pump and oil exiting the pump and through the engine ceases being 1:1 as oil is bypassed back to the feed side from the outlet side. This decouples the relationship between RPM and volume through the engine. Of course with an HV pump it's quite possible to overwhelm the relief and so you'll see pressure continue to rise past the relief pressure, but it's not at the same rate as it was below being on the relief. This is very common on SBC's with an HV pump.

On #2, this comes into play once the delta-p across the filter media exceeds spec. This is usually 12-15psi. This is an artifact of the resistance encountered by forcing the oil through the media, which will be more difficult with thicker oil (cold, heavy....etc).

I provided some example scenarios as well earlier in the thread where the relief and bypass operations were discussed.

An HV pump is usually a waste with sane bearing clearances but very common in hot rodder circles. The main driver behind their use is guys wanting to see high oil pressure on the gauge, which is just wasted power. As I noted earlier, even if this engine had the 70psi relief spring, providing for a 4psi delta-p across the media, that means that we were on the relief at the beginning of the run; volume was already decoupled from RPM before the test even began. This is the result of:
1. Too much pump
2. Too thick of oil/too cold of oil

86F coolant temps and an HV pump are pretty much a guaranteed recipe for being on the relief, making this setup an awful choice for trying to run an oil filter volume test. These results are even worse if we consider the possibility that this has the 58psi spring in it and the results are all within the context of the relief being overwhelmed, which isn't outside the realm of possibility.

A better rig would have been a warmed-over SBF with a factory pump which would have given a much better volume/pressure curve.

 

[ZeeOSix]

I have explained it the pump compensates by taking more HP.

The only way that could ever happen is if all the oil passages and filter were completely empty of oil, then the engine is started and a volume of oil gets send down the main gallery to the empty filter. But that's not what's happening, and that's not what the discussion is focused on. We are talking about an engine that has been running for awhile.

So how can the following per your words happen?: "The oil pump moves a pre-determined volume of oil for RPM, when it reaches the filter there will be a change in flow rate for that volume of oil."

Please explain how that can happen on an engine that's been running for awhile.

Do a calculation for me 15GPM at 80psi with 15w-50 oil hot. You haven't converted by just one variable that would mean the calculation is of water and that is still only HHp.

The hydraulic HP equation works for any liquid, the density factor is invisible. If the liquid is thicker (more dense) it takes more pressure (and therefore more HP) to pump the same volume through the same flow path. It takes way more pressure (and therefore more HP) to pump cold thick oil vs water or hot thin oil.

The delta p tells us nothing it is only related to the filter itself.

If the output pressure at the pump is 80 PSI, then the delta-p of the entire oiling system (including the filter) is 80 PSI since all oil going through the system exits at 0 PSI gauge pressure. The delta-p across the oil filter is a very small fraction of the total delta-p of the entire oiling system - the filter is typically less than 10% of the total oiling system delta-p. Example: Pump output at 80 PSI, filter delta-p of 5 PSI, pressure after the filter of 75 PSI (where the oil pressure sensor is located), and pressure at the exit of pressure fed bearings, etc is 0 PSI.