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Reusable oil filter

Well, does the S15 have an internal pressure relief valve?

Yes it does - a spring-loaded ball that opens with excessive pressure. It does NOT have an anti-drainback diaphragm however. So far, I have been running four of them, two on angle adapters, two on straight-back, and have had no issues, and what looks like good filtering (based on inspections).

Paul
 
Can you clarify for me? I understood the S15 would be a drop in replacement for the 48108. Is it potentially not? If so, what exactly would I be looking for where I screw the filter on? (FWIW I have an Aerosport Power 0-320-D2A with the oil filter pointing aft toward the firewall recess.)

Using an oil filter that has a bypass valve, on an adapter that has a bypass valve, means that the lowest bypass valve pressure is the one that will protect the filter. And the other bypass will not be triggered.

Looks like you can use the S15 on any adapter because it has it's own bypass to protect the media of THAT filter.
 
Yes it does - a spring-loaded ball that opens with excessive pressure. It does NOT have an anti-drainback diaphragm however. So far, I have been running four of them, two on angle adapters, two on straight-back, and have had no issues, and what looks like good filtering (based on inspections).

Paul

curious to know the increase in the time to reach full OP after start up, if you know. Little concern there is no anti drainback. This helps to get oil to the bearings a bit faster after startup and very few filters these days don't have one.

Larry
 
curious to know the increase in the time to reach full OP after start up, if you know. Little concern there is no anti drainback. This helps to get oil to the bearings a bit faster after startup and very few filters these days don't have one.

Larry

Honestly, by the time I look at oil pressure (a few seconds) it is up. I will admit that I have never been an oil pressure hawk on start-up, so is it a few second s more or less than before? Can’t tell you.
 
curious to know the increase in the time to reach full OP after start up, if you know. Little concern there is no anti drainback. This helps to get oil to the bearings a bit faster after startup and very few filters these days don't have one.

Larry

I do have a 45* adapter on the filter. Oil pressure comes up about the same as it did with the paper filters. Even without the anti-drain back, there is a bunch of oil in the filter. Oil light off in a second or two from start and oil pressure in the green about the same time. With an empty (clean) filter, I see pressure come up about a second or two longer. I am always prepped to shut the engine down at 5 seconds after an oil change if I dont see pressure. Glad I have never had to do it.

First oil change with the new filter, I pulled the filter ~30 mins after shutdown (had to remove cowl) and start to drain the sump. Was expecting a near empty filter, needless to say was surprised with the amount of oil still in the filter. Almost still at full capacity based on what was in the bag under the filter.

Second change, I waited 24 hours to pull the filter since I had to run to other commitments. Definitely less what I saw the first time, but still about 3/4 full based on the oil in the bag under the filter.

Maybe after a few month or two the oil will drain out, but I haven't gone more than 2 weeks without flying with the new filter.
 
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The Kitplanes article said the Challenger and K&P permanent filters are less restrictive of oil flow. For those who've used either, has your oil pressure changed?

On my 320 I haven’t noticed any difference in oil temp or pressure with the change to K&P. But what I have noticed is a significant reduction in the length of time I hold my breath between starting and seeing oil pressure. Even with an empty filter following an oil change, oil pressure comes up very quickly, it’s almost instant and that gives me the impression there is better flow, although the smaller filter volume may be contributing. Whatever the reason, I like not having to watch the engine run for a few seconds without oil pressure.
 
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Honestly, by the time I look at oil pressure (a few seconds) it is up. I will admit that I have never been an oil pressure hawk on start-up, so is it a few second s more or less than before? Can’t tell you.

Thanks. I also never look at OP at start up. Figure if it was making good pressure when shut down, it will make good pressure at next start up. Nothing in there that can really break without the engine running.
 
curious to know the increase in the time to reach full OP after start up, if you know. Little concern there is no anti drainback. This helps to get oil to the bearings a bit faster after startup and very few filters these days don't have one.

Larry

I had a conversation with the owner of K&P a few years ago about this. His position was that (a) anti-drainback valves provide some amount of additional resistance to oil flow and (b) given a few hours - the oil will drain back through the filter media anyway on a filter mounted vertically or near vertical. His said the surgical stainless filter has less resistance than the paper media and the housing will fill faster than a standard filter - allowing oil pressure to build quicker. He also said that filters with high efficiency ratings (like the Mobil 1 and Amsoil filters) end up bypassing frequently with cold oil.

Not saying he is right or wrong, but this was his position.

If you mount one of these filters vertically on the firewall, the filter always stays full of oil and the lack of an anti-drainback valve isn't a concern.
 
Let's have some fun.

Consider the two filter grids below.

The first has 100 holes, all equal area. We'll assign 1 = area, so 1 x 100 = 100

The second has 196 holes, each of which has half the above area, and one additional hole with twice the area. (196 x 0.5)+2 = 100

In other words, they have exactly the same open area.

Which one filters better? Which one looks bad when tested under ASTM F316?
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Honestly, by the time I look at oil pressure (a few seconds) it is up. I will admit that I have never been an oil pressure hawk on start-up, so is it a few second s more or less than before? Can’t tell you.


Don,

I think you meant your post #79, with data showing the oil pressure rise times between the two different filters.

Direct link --> https://vansairforce.net/community/showpost.php?p=1625050&postcount=79
 
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Let's have some fun.

Consider the two filter grids below.

The first has 100 holes, all equal area. We'll assign 1 = area, so 1 x 100 = 100

The second has 196 holes, each of which has half the above area, and one additional hole with twice the area. (196 x 0.5)+2 = 100

In other words, they have exactly the same open area.

Which one filters better? Which one looks bad when tested under ASTM F316?
.
The filter with the big hole will catch some smaller particles, but also let some larger particles through. I would postulate that over time, the one with the big hole would have liquid with smaller maximum particle sizes.

If testing is "single pass", and the thing tested is "max particle size that got through the filter" then the first filter would be better.

If the engine has a target max particle size that can be in the oil, and the #1 filter will block that particle size, then the #1 filter will be "best". If the engine does not care if big particles get through from time to time, then over time, the particles in the oil filtered by the #2 filter will be smaller.
 
The filter with the big hole will catch some smaller particles, but also let some larger particles through. I would postulate that over time, the one with the big hole would have liquid with smaller maximum particle sizes.

Correct. The overwhelming majority of the oil (like 96~98%) is being filtered through the smaller holes. The remainder may pass a larger particle, but statistically, that particle is unlikely to hit the big hole when it comes around on the next pass.

Now, which filter grid can be made to look bad with an ASTM F316 test? Why?
 

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Correct. The overwhelming majority of the oil (like 96~98%) is being filtered through the smaller holes. The remainder may pass a larger particle, but statistically, that particle is unlikely to hit the big hole when it comes around on the next pass.

Now, which filter grid can be made to look bad with an ASTM F316 test? Why?

The second one, because it can pass a larger particle through the big hole.
 
Let's have some fun.

Consider the two filter grids below.

The first has 100 holes, all equal area. We'll assign 1 = area, so 1 x 100 = 100

The second has 196 holes, each of which has half the above area, and one additional hole with twice the area. (196 x 0.5)+2 = 100

In other words, they have exactly the same open area.

Which one filters better? Which one looks bad when tested under ASTM F316?
.

I'll bite, though disadvantaged as have not read the ASTM report. 2 obviously filters better, if by better you mean captures more particles smaller than #1's pore size; they are relatively equal in capturing particles larger than #1's pore size. #1 tests better (though how much better would depend upon the viscosity of the liquid being filtered as well as it's surface tension characteristics) due to the larger pore size of #1 and with #2 creating all of the issues that small pore sizes create, none of which help with desired fluid flow characteristics. That is the balancing act; filtering smaller particles requires more compromise in flow characteristics and vice versa. Therefore, accepting a large enough particle size to pass in order to achieve desirable flow characteristics or filtering smaller particles and engineering around the negative flow characteristics, some of which (e.g. bypass) actually make filtration performance worse.
 
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The second one, because it can pass a larger particle through the big hole.

Again correct.

K&P quote: "We use the ASTM test because it offers the smallest amount of manipulation of the testing process."

Reality is the ASTM test is an inappropriate standard.

ASTM F316 is a bubble test. It identifies the largest individual capillary pore in a membrane filter. It's not a mesh filter or fiber filter test. It is not an oil filter test. It's not a filtration test of any kind. In fact, it's not valid for pore sizes in excess of 15 microns.

https://www.astm.org/f0316-03r19.html
 
Unless there's a beta ratio (pseudo inverse efficiency per se') attached, the micron rating proper doesn't mean much.
 
Unless there's a beta ratio (pseudo inverse efficiency per se') attached, the micron rating proper doesn't mean much.

The answer, as with most things in the engineering world, frequently is "It depends." Living in a world filled with 15 second sound bites, it is difficult to get people to understand that it's not always as simple as it seems.
 
The answer, as with most things in the engineering world, frequently is "It depends." Living in a world filled with 15 second sound bites, it is difficult to get people to understand that it's not always as simple as it seems.

Going to respectfully disagree with "depends". What is the assumption for filtration efficiency at the point of rating if it isn't listed? There was a lot of f_uckage associated with the old nominal/absolute rating system. Nothing stops that here as a media supplier could list the smallest "filtered" particle as its rating even though it let the vast majority of similar particulate through. I'll state again, without a listed beta ratio (ISO IIRC) or other eff# and associated test standard, the number by itself is pretty meaningless.
 
Unless there's a beta ratio (pseudo inverse efficiency per se') attached, the micron rating proper doesn't mean much.

Absolutely correct. The only arguable exception would be a filter with a micron rating termed absolute. Industry standard says an absolute rating is always at 75 beta.

Need an example? Assume a filter is rated as 20 micron absolute. Beta 75 is assumed, meaning "one in 75". For every 75 particles of 20 micron or larger which enter the filter, one passes through. Put another way, the filter catches 98.67% of particles 20 microns or more.

Filters which do state beta ratings may list them for two different particle sizes. A Champion aviation filter has a 4 beta at 25 microns (catches 75%) and a 10 beta at 40 microns (catches 90%). Most Wix auto filters are dual rated, although their nomenclature can be confusing. The NAPA Gold 5151 (often thrown around as a replacement for a 48108 aviation filter) is actually a Wix 51515. It has a 2 beta at 6 microns (catches 50%) and 20 beta at 20 microns (catches 95%).

Like those Wix numbers? There's a catch. Yes, the media catches a greater number of smaller particles as compared to the Champion, but the pressure relief bypass opens at 8 to 11 psi, roughly a third lower than the aviation standard. Pick a filter with a bypass rated closer to 15 psi, or switch to multigrade oil so cold viscosity is lower.

Which brings us back to K&P. What is the opening pressure for the ball-type pressure relief bypass?
 
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Which brings us back to K&P. What is the opening pressure for the ball-type pressure relief bypass?

Couple related questions, just to give myself some assurance that using the K&P S15 isn't a careless attempt to save money at the expense of safety:

1. Given that the FAA has given it's blessing to the Challenger filter as a suitable replacement for the standard 48108 and 48110 filters that most of us use, is the argument over the opening pressure for the ball-type pressure relief valve bypass merely an academic argument? Or, is the better question...

2. Are we instead debating whether the S15--what is widely believed to be the non-certified version of the Challenger--perhaps has a different opening pressure for the ball-type pressure relief valve than does the Challenger that might make the S15 an unsuitable replacement?
 
No argument or debate, at least not yet. No one here seems to know the opening pressure. I've sent an inquiry to Challenger.

I measured the force needed to open the bypass ball, and it was about 1.7kg. The ball is about 8mm in diameter (hard to measure exactly) and it looks like about 6mm is exposed.

The math gives me about 48 psi, so I guess that is differential pressure between the two sides of the filter.
 
I measured the force needed to open the bypass ball, and it was about 1.7kg. The ball is about 8mm in diameter (hard to measure exactly) and it looks like about 6mm is exposed.

The math gives me about 48 psi, so I guess that is differential pressure between the two sides of the filter.

Mickey, you sure about that 6mm diameter? Sure looks larger in the photo you posted previously.
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Mickey, you sure about that 6mm diameter? Sure looks larger in the photo you posted previously.
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I'm not sure if the sun will come up tomorrow! :)

I've attached a drawing of what it looks like - very accurate numbers using a kitchen scale, and the little lady's sewing tape measure. The size of the ball and the amount of the ball exposed externally is not that easy to measure.

Oil Filter pressure bypass.png
 
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No argument or debate, at least not yet. No one here seems to know the opening pressure. I've sent an inquiry to Challenger.

Constructed a test fixture to capture the crack pressure on the K&P type 15 filter, results were a slight dribble <20, > 20 psi the ball became unseated and flow occurred.
 

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Couple related questions, just to give myself some assurance that using the K&P S15 isn't a careless attempt to save money at the expense of safety:

1. Given that the FAA has given it's blessing to the Challenger filter as a suitable replacement for the standard 48108 and 48110 filters that most of us use, is the argument over the opening pressure for the ball-type pressure relief valve bypass merely an academic argument? Or, is the better question...

2. Are we instead debating whether the S15--what is widely believed to be the non-certified version of the Challenger--perhaps has a different opening pressure for the ball-type pressure relief valve than does the Challenger that might make the S15 an unsuitable replacement?


Good question.

I see that the bypass opens around the 20 psi. I'm not sure what the other aviation filters open at but on the automotive end this appears to be somewhere in the average.

The pressure loss while circulating through it or one of them is like half a pound or so?

So, would we all feel secure in using these KP filters? The price is right.

Tim
 
Constructed a test fixture to capture the crack pressure on the K&P type 15 filter, results were a slight dribble <20, > 20 psi the ball became unseated and flow occurred.

Really nice work Don.

Ballpark, the range is 12 to 15 psi for the bypass built in to a standard Lycoming horizontal adapter (use a 48110 filter), and the same for the bypass inside a Champion or Tempest 48108, as used (for example) on a B&C right angle adapter.

Auto filters can vary; assume nothing. The Wix 51515 (NAPA Gold 1515) opens its bypass at only 7 to 9 psi. I think makes it a questionable choice, in particular with 50w oil, where it's probably bypassing a lot when cold. If you wish to use an internal bypass auto filter and your application will accommodate some additional can diameter, look at a Wix 51601 to get a 13 to 19 psi bypass. Look at a Wix 51647 if no internal bypass is desired, i.e. it's going on a standard Lycoming horizontal adapter.

I don't think there is any issue with a 20 psi bypass in the S15 screen filter. I assume the manufacturer is confident the element won't collapse at less than 20 psi, so the worst case is simply unfiltered oil flowing through the bypass if the screen should clog.

There is one interesting variation in design. The aviation filters and the S15 locate the bypass valve at the far end of the element. When the bypass opens, oil flows along the length of the filter OD to get to the bypass. At 7 gallons per minute, that oil is going to sweep trash off the surface of the pleats if it is not firmly embedded. The Wix filter is the opposite, locating a modular bypass valve just inside the filter base, thus there is no flow across the surface of the pleats when it opens. It packages a rubber drainback valve in there too. Module and drainback disk below.

So, would we all feel secure in using these KP filters?

Big picture, I don't think there is a safety question. That said, I sincerely doubt the S15's screen will filter oil down to a micron level as low as any decent fiber filter. And as noted previously, the K&P "technical page" would make P.T Barnum proud, claiming superiority based on an entirely inappropriate standard which few customers will actually read. Here is a link, if you are so inclined: https://www.danhorton.net/VAF/Reusable Oil Filter/ASTM F-316.pdf

The two major standards for engine oil filtration are SAE J3236 (formerly J806) and ISO 4548.
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I sincerely doubt the S15's screen will filter oil down to a micron level as low as any decent fiber filter

Same here.
My observation over several hundred hours with 50h oil replacement/S15 filter check, is that the only visible byproduct of the filtering are easily crushed carbon crumbs.
In contrast, when I was still using the standard paper cartridge filter, I always found a very small amount of minute metal chips, mostly non-magnetic.

The oil analysis performed at every oil change show no change since the move to the S15, so this points to a lower filtering effect.
 
Same here.
My observation over several hundred hours with 50h oil replacement/S15 filter check, is that the only visible byproduct of the filtering are easily crushed carbon crumbs.
In contrast, when I was still using the standard paper cartridge filter, I always found a very small amount of minute metal chips, mostly non-magnetic.

The oil analysis performed at every oil change show no change since the move to the S15, so this points to a lower filtering effect.

Interesting. In my couple of cleanings of the S15 filters, what I have found in my “rinse solution” is an extremely fine set of particles that were non-magnetic and dried to essentially a black powder. I have assumed (no proof) that this size material is simply trapped in a fiber filter so we never see it, while it rinses out of the stainless mesh. Yes, I also se a few of the typical small chunks of carbon that prove that the S15 is taking out the “big stuff”…..

Just another data set.

Paul
 
Speaking of "big stuff", does anyone have a copy of SAE 881825, titled "Correlating Lube Oil Filtration Efficiencies With Engine Wear"? It was a GM study of wear vs particle size.
 
Serious questions and not trying to be snarky -

Since we are talking air cooled engines with large tolerances, does it really matter that a K&P/Challenger filter might not filter particles as small as a paper one? They certainly flow better and oil pressure builds quicker on our RV-7 versus when we had a Champion filter on it.

I suppose if we were talking about a Rotax with it's tight tolerances, that might be a different matter and filtration of smaller particles could be important.

Didn't early Lycomings and Continentals only have a screen and no filter? Aren't oils, metallurgy and manufacturing better today than they were then?

I'm just wondering if we are worrying unnecessarily about the K&P style filters.
 
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Serious questions and not trying to be snarky -

Since we are talking air cooled engines with large tolerances, does it really matter that a K&P/Challenger filter might not filter particles as small as a paper one? They certainly flow better and oil pressure builds quicker on our RV-7 versus when we had a Champion filter on it.

I suppose if we were talking about a Rotax with it's tight tolerances, that might be a different matter and filtration of smaller particles could be important.

Didn't early Lycomings and Continentals only have a screen and no filter? Aren't oils, metallurgy and manufacturing better today than they were then?

I'm just wondering if we are worrying unnecessarily about the K&P style filters.
I think this is an excellent question. If there is a recommendation for a maximum size particle and particles of that size are filtered, then I guess we should be happy.

I think the wear vs particle size (and I assume hardness) study would be really helpful.

Some of the huge generators I used to manage had bypass filters:

https://www.machinerylubrication.com/Read/29026/engine-bypass-filtration

... perhaps something like this could be useful for an aviation engine. Interesting quote from the above article (with no supporting evidence):

In a case study performed by General Motors and published by the Society of Automotive Engineers (SAE), it was determined that engine service life could be extended eight times when 5-micron filtration is implemented vs. the standard 40-micron filtration.

Perhaps this is the report DanH mentions.
 
Serious questions and not trying to be snarky -

Since we are talking air cooled engines with large tolerances, does it really matter that a K&P/Challenger filter might not filter particles as small as a paper one? They certainly flow better and oil pressure builds quicker on our RV-7 versus when we had a Champion filter on it.

I suppose if we were talking about a Rotax with it's tight tolerances, that might be a different matter and filtration of smaller particles could be important.

Didn't early Lycomings and Continentals only have a screen and no filter? Aren't oils, metallurgy and manufacturing better today than they were then?

I'm just wondering if we are worrying unnecessarily about the K&P style filters.

Parts cooled by air will have larger tolerances. Tolerances between cam lobes & followers, bearings & races, bearing babbitt and crank journals, and other expensive parts are of similar tolerance. As long as other parameters are met, finer is better here.
 
Didn't early Lycomings and Continentals only have a screen and no filter?

The mesh size meant they were essentially unfiltered, as were cars back then.

I'm just wondering if we are worrying unnecessarily about the K&P style filters.

Serious question, so get a serious answer. Send one to the folks at Southwest Research, one of many qualified test labs.

https://www.swri.org/industry/filtration-contamination/fluid-filter-testing

Ask them to run an industry standard ISO 4548-12. Apples to apples.
 
Oil filters vs screen...

Didn't early Lycomings and Continentals only have a screen and no filter?

The C-90-8 on my J-3 Cub does not have a filter other than an oil screen. She keeps plugging away despite that as are most Vintage Continentals. When you think about it, ALL Lycoming and Continental engines are "early" designs.....
 
The mesh size meant they were essentially unfiltered, as were cars back then.

Serious question, so get a serious answer. Send one to the folks at Southwest Research, one of many qualified test labs.

https://www.swri.org/industry/filtration-contamination/fluid-filter-testing

Ask them to run an industry standard ISO 4548-12. Apples to apples.

As I said, I'm not worried about the filtration provided by the K&P filters, so I don't think it's necessary to have them tested. I use them on both of the RV's and most of my passenger vehicles.
 
One feature the S-15 filter assembly has that the typical spin on filter doesn't have, is a magnet inside the filter housing.

It is nice feature to be able to see the ferrous metal debris on the magnet and not have to cut the filter apart, flush the particles out and use a magnet hoping to separate the ferrous from non-ferrous.
 
And this is why we can't just believe what a seller writes on their marketing materials if they don't send their products to an independent lab to confirm the results of their specs.

In the case of K&P, they do claim test lab results...based on ASTM F316, an entirely inappropriate standard. F316 is a test to determine the largest pore diameter in a membrane. It is limited to pore sizes 15 microns or less, yet they claim to test a 35 micron screen. They further claim the results showed passage of large particles, when F316 is a bubble test fundamentally based on surface tension...no particles involved. And in any case, the largest pore diameter is not indicative of filtration efficiency when the largest size is accompanied by a variety of smaller sizes.

It's bulls**t.

Challenge accepted! Will send in K&P S15 FE and advise thread on the results.

Excellent!

If you wish I will gladly contribute a new Tempest or Champion 48110, and a Wix 51647. That would cover the field.
 
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In the case of K&P, they do claim test lab results...based on ASTM F316, an entirely inappropriate standard. F316 is a test to determine the largest pore diameter in a membrane. It is limited to pore sizes 15 microns or less, yet they claim to test a 35 micron screen. They further claim the results showed passage of large particles, when F316 is a bubble test fundamentally based on surface tension...no particles involved. And in any case, the largest pore diameter is not indicative of filtration efficiency when the largest size is accompanied by a variety of smaller sizes.

It's bulls**t.



Excellent!

If you wish I will gladly contribute a new Tempest or Champion 48110, and a Wix 51647. That would cover the field.

....now about that $1500 - $2000 :O
 
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