Fram Endurance Flashlight Test in canister

[ZeeOSix]

“It’s ok to have a permanent leak”
Is that what I said???

Yeah, that's been your implication all along, lol.

How about this particular leak is a nothing burger?

Nobody has real proof one way or the other, because there's no real testing that has proven it one way or the other. Nobody has correlated leak gaps to the effect on efficiency. But physics says if there's a leak path for dirty oil, it should effect the ISO test efficiency because those particle counters in the ISO test are measuring real time particle counts upstream and downstream of the filter.

 

[Ronn]

Yep

 

[Glenda W.]

Wow , lot of people getting their pants all up in a bunch here….
Think I’ll take my car for a spin now, but I’ll make **** sure I pull that Endurance out first!!!

I’d recommend this one. Should filter most of the oil after a few passes.

 

[Chumango]

A quick sanity check might shed some light. With some simple assumptions regarding filter efficiency and percent of flow that bypasses the filter through a leak path, the effect of the leak can be determined using differential equations. Since I am pretty rusty with differential equations I set up a spreadsheet to calculate the particulate concentration over multiple passes through the engine and filter until equilibrium is reached. This is not quite exact since it assumes no mixing as the oil passes through the engine. It just adds an assumed particulate load at each pass and calculates how much particulate gets through the media and through the leak. This assumes a constant particulate generation rate each pass.

The assumed particulate generation rate does not affect the results. The filter efficiency does not affect the results, it only affects how many passes it takes to reach equilibrium.

Results, presented as the ratio of particulate load with leak path/particulate load without leak path. This is what the filter sees. The ratio in the engine is changing as the oil passes through the engine.

With 10% of total flow through the leak path, the ratio is 1.111 at the filter inlet.

With 5% of total flow through the leak path, the ratio is 1.053 at the filter inlet.

With 2.5% of total flow through the leak path, the ratio is 1.026 at the filter inlet.

With 1% of total flow through the leak path, the ratio is 1.010 at the filter outlet.

Ratio at filter outlet does depend on the assumed efficiency. For 99% efficient media, the ratio is 12.1 for 10% bypass, 6.26 for 5% bypass, and 3.56 for 2.5%. With 95% efficient media these numbers change to 3.22, 2.05, and 1.51, respectively. But the actual particulate count at filter outlet is small compared to the assumed particulate generation rate.

What is the ratio of flow through the leak? Who knows? But I would be very surprised if it is 10% with the vastly larger flow path through the media. Even 5% seems large. But as I said, who knows? It could be calculated with dimensions of the gap (length of gap, width of gap, length of flow path) and flow properties of the media, but that would not be a simple task.

 

[Ronn]

@Chumango…
Kudos for a valiant attempt to quantify various scenarios
Unfortunately logic is often challenged by unforeseen interactions that often elude assumptions.
The nuances of fluid dynamics and “hidden cluster f$&k” are always lurking.
So we await actual testing…
I’m going to rely on my background and “off the wall” intangible gut …” *** IS HAPPENING” and “What YA GONNA DO ‘BOUT IT” .. play book.

 

[ZeeOSix]

What is the ratio of flow through the leak? Who knows? But I would be very surprised if it is 10% with the vastly larger flow path through the media. Even 5% seems large. But as I said, who knows? It could be calculated with dimensions of the gap (length of gap, width of gap, length of flow path) and flow properties of the media, but that would not be a simple task.

It would be a parallel flow situation. It was calculated in the link in post 214. A small gap can flow quite a bit of volume. Knowing the size of the gap and the dP across it at a specific fluid viscosity gives the corresponding flow rate.

https://bobistheoilguy.com/forums/t...o-bypass-seal-area.386625/page-5#post-6998340

 

[Ronn]

It would be a parallel flow situation. It was calculated in the link in post 214. A small gap can flow quite a bit of volume. Knowing the size of the gap and the dP across it at a specific fluid viscosity gives the corresponding flow rate.

Stand back and use common sense.
You have a small leak of unfiltered oil which is continuously recirculated back into the filter. Period end of story. Get a grip and move on or test the dang thing. If you lose sleep over it, trash the filter and call it a day. If you think this filter is superior, flaws not withstanding, then leave the sucker in and rest assured it’s doing its job.

 

[Nesterenko]

Not to be insulting but @Glenda W. those hands sure don't look feminine unless my eyes are failing me in my old age. You did say in earlier posts that you were in fact a lady but we all know that usernames don't really mean all that much. G'day...

 

[ZeeOSix]

Stand back and use common sense.
You have a small leak of unfiltered oil which is continuously recirculated back into the filter. Period end of story. Get a grip and move on or test the dang thing. If you lose sleep over it, trash the filter and call it a day. If you think this filter is superior, flaws not withstanding, then leave the sucker in and rest assured it’s doing its job.

Stand back and use common sense. Oil filters are suppose to filter all the oil, not just part of it and let the other part leak around the media. If your filter had a tear in the media would you say the same thing? … "Rest assured, it's doing its job".

 

[4WD]

This is interesting - bought two XG10575’s off the same shelf 5 months ago - cut one and it was metal on metal …
Decided to cut the other just now and well it’s got the elastomer seal that seems to fit tight …
Note: light shines through the plastic poppet - not around it and not around the spring to end cap seal …

 

[Glenda W.]

This is interesting - bought two XG10575’s off the same shelf 5 months ago - cut one and it was metal on metal …
Decided to cut the other just now and well it’s got the elastomer seal that seems to fit tight …
Note: light shines through the plastic poppet - not around it and not around the spring to end cap seal …

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Thanks for the test.

 

[Glenda W.]

Not to be insulting but @Glenda W. those hands sure don't look feminine unless my eyes are failing me in my old age. You did say in earlier posts that you were in fact a lady but we all know that usernames don't really mean all that much. G'day...

12 years turning wrenches and 30 on the railroad. Sorry if my hands are not up to your standards. Believe me I’ve heard it all.

 

[Glenda W.]

Stand back and use common sense. Oil filters are suppose to filter all the oil, not just part of it and let the other part leak around the media. If your filter had a tear in the media would you say the same thing? … "Rest assured, it's doing its job".

This!! Over and over. I’ve been saying this here and all the other threads. Thank you

Common sense would also say a couple gaps this size would not iso test at 99+% down to 20 microns. And if we’re all concerned it’s because we believe in using high efficiency filters. At the very least its ratty craftsmanship and common sense would be to simply choose a different filter.

 

[Chumango]

It would be a parallel flow situation. It was calculated in the link in post 214. A small gap can flow quite a bit of volume. Knowing the size of the gap and the dP across it at a specific fluid viscosity gives the corresponding flow rate.

https://bobistheoilguy.com/forums/t...o-bypass-seal-area.386625/page-5#post-6998340

The use of an equivalent orifice in that calculation overstates the leak flow. The hydraulic diameter of the gap is much smaller than the equivalent round hole, so the friction factor of the gap is larger than round hole. Additionally, the gap has a path length, not just a sharp edged orifice.

 

[Glenda W.]

Perhaps I can attempt to angle a feeler gauge into the gaps on both sides for a measurement.

 

[Fair enough]

Perhaps I can attempt to angle a feeler gauge into the gaps on both sides for a measurement.

Standard notebook paper is about .005”. A strip or layers of strips could be inserted and pulled while holding bypass spring slightly down. It can be made quite a bit narrower without cutting a feeler gauge. Yes it compresses a bit, but if pulled out easily then the gap is more than that. There are feelers with more pointed ends too. Not saying you didn’t know that.

 

[Fair enough]

Stand back and use common sense. Oil filters are suppose to filter all the oil, not just part of it and let the other part leak around the media. If your filter had a tear in the media would you say the same thing? … "Rest assured, it's doing its job".

I hear you, and hear the one you responded too also. There are all kinds of common sense ways to look at things. The oil has been filtered many times that is leaking. You keep saying dirty oil as if it isn’t a recirculating system. Common sense tells only the added dirt on that single trip back to the oil pan through the engine parts is seen. Then around it goes again, several times per minute.
I think this is how the bypass filters can clean up oil beautifully when put in an oil line. Night to day difference and fast. So far no one has exactly explained why. It probably is just math.

 

[Glenda W.]

@Fair enough genius idea on the note paper. The feeler gauges weren’t flexible enough. I was able to pull through 4 pieces of paper stacked with reasonable friction. 5 was a no go. I also measured the gaps at 3/4” long on each side.

 

[Fair enough]

@Fair enough genius idea on the note paper. The feeler gauges weren’t flexible enough. I was able to pull through 4 pieces of paper stacked with reasonable friction. 5 was a no go. I also measured the gaps at 3/4” long on each side.

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I would never think of it, but remember it from someone else long ago.

 

[ZeeOSix]

The use of an equivalent orifice in that calculation overstates the leak flow. The hydraulic diameter of the gap is much smaller than the equivalent round hole, so the friction factor of the gap is larger than round hole. Additionally, the gap has a path length, not just a sharp edged orifice.

The length of the leak path is very small, so that factor is very negligible. The shape of the gap is also a weak function, so the flow/dP calculator I used is going to be pretty close using a very low lflow length orifice. If you can come up with a better calculation and show why it's better, then please post it.