DanH said:
Are STC applications public documents? The STC number appears to be SE02352CH. Responsible office is AIR-7C0: Chicago ACO Branch. Does this group know anyone there?



Gary, I'm working with data listing the efficiency of three filters, for 16 different particle sizes recorded at 10 minute intervals. They do not filter better as they load, although some columns spike a bit just prior to termination at 10 psi deltaP. Please see post #11 for an example.
Click to expand...
STC applications and the design and compliance data used to receive the STC are generally not public domain. They are considered proprietary to the applicant. However, a FOIA request can be made and if the STC holder has no objection the data can be released. No STC holder generally agrees and it would take a court order.

The original Lycoming was certified with a pretty coarse mesh screen filter. They recommended 25 hr oil change intervals. The spin on filter was introduced as an option that moved the recommended oil changes for some operations to 50 hrs.

The new mesh filters have a pretty low standard to meet to show “equal to or better than“ performance than the original.
 
In hind sight, I remember taking my K&P S15 out of the package and thinking, "gee, 35 microns doesn't really seem like a fine enough filter", but I didn't know about the standards. And also, in fairness, sometimes standards are written to prescribe performance that is already being achieved, as if in this case paper media spin-on filters were in common use, so they may have just written the standard so that the available filters were in compliance, rather than based on some practical criteria. However, Dan's posting of the oil film thickness graph pretty much shows what filtration level is effective at protecting cylinder walls from wear. Seeing that, we all collectively said "duh - 35 microns is not sufficient".

I had another thought - about half in satire, and half as a realistic "maybe"question: how much toilet paper would you have to wrap that stainless screen with to get the proper amount of filtration? Yes, like I said, half kidding. But what if there was a simple drop-in paper element that would enhance the filtration and be disposable. The stainless steel screen would be relegated to just a support framework for the paper element I suppose. Still it would be a tidy package.

A lot of modern cars have filters now that rather than change out the metal filter housing, they have a plastic housing that you just swap out the paper element and put on a fresh o-ring. Oddly, those filters seem to cost just as much or more than the regular metal spin-on's. A lot less material, and yet the same or more cost. Why? cuz they can I suppose.

If we don't all flood the market at once, maybe we can sell these things on Ebay?
 
scsmith said:
In hind sight, I remember taking my K&P S15 out of the package and thinking, "gee, 35 microns doesn't really seem like a fine enough filter", but I didn't know about the standards. And also, in fairness, sometimes standards are written to prescribe performance that is already being achieved, as if in this case paper media spin-on filters were in common use, so they may have just written the standard so that the available filters were in compliance, rather than based on some practical criteria. However, Dan's posting of the oil film thickness graph pretty much shows what filtration level is effective at protecting cylinder walls from wear. Seeing that, we all collectively said "duh - 35 microns is not sufficient".

I had another thought - about half in satire, and half as a realistic "maybe"question: how much toilet paper would you have to wrap that stainless screen with to get the proper amount of filtration? Yes, like I said, half kidding. But what if there was a simple drop-in paper element that would enhance the filtration and be disposable. The stainless steel screen would be relegated to just a support framework for the paper element I suppose. Still it would be a tidy package.

A lot of modern cars have filters now that rather than change out the metal filter housing, they have a plastic housing that you just swap out the paper element and put on a fresh o-ring. Oddly, those filters seem to cost just as much or more than the regular metal spin-on's. A lot less material, and yet the same or more cost. Why? cuz they can I suppose.

If we don't all flood the market at once, maybe we can sell these things on Ebay?
Click to expand...
Somebody posted a drop in paper filter in a prior thread. It used a toilet paper roll!
 
scsmith said:
In hind sight, I remember taking my K&P S15 out of the package and thinking, "gee, 35 microns doesn't really seem like a fine enough filter", but I didn't know about the standards. And also, in fairness, sometimes standards are written to prescribe performance that is already being achieved, as if in this case paper media spin-on filters were in common use, so they may have just written the standard so that the available filters were in compliance, rather than based on some practical criteria. However, Dan's posting of the oil film thickness graph pretty much shows what filtration level is effective at protecting cylinder walls from wear. Seeing that, we all collectively said "duh - 35 microns is not sufficient".

I had another thought - about half in satire, and half as a realistic "maybe"question: how much toilet paper would you have to wrap that stainless screen with to get the proper amount of filtration? Yes, like I said, half kidding. But what if there was a simple drop-in paper element that would enhance the filtration and be disposable. The stainless steel screen would be relegated to just a support framework for the paper element I suppose. Still it would be a tidy package.

A lot of modern cars have filters now that rather than change out the metal filter housing, they have a plastic housing that you just swap out the paper element and put on a fresh o-ring. Oddly, those filters seem to cost just as much or more than the regular metal spin-on's. A lot less material, and yet the same or more cost. Why? cuz they can I suppose.

If we don't all flood the market at once, maybe we can sell these things on Ebay?
Click to expand...
Mine will be used as a paperweight/conversation piece.
 
Toilet paper filters are a thing and have been since at least the 50's: the Frantz filter which filters down to 2 microns. But, these are partial-flow so you still need a full-flow filter. The Frantz is an auxiliary filter which you connect via a Tee into the oil pressure sender fitting and the outlet of the filter just goes back into the crankcase.

Some people swear by these things.

Frantz Filters | Advanced Oil Filtration Solutions

Established in 1953 by John Frantz, the Frantz Filter Company became a mainstay product and process for cleaning automotive oil worldwide.
www.frantzfilters.com www.frantzfilters.com

1713059597538.png
 
DanH said:
Downstream, another counter records the number and size of the particles which passed through the filter. For each particle size from 5 through 40 µm (microns), efficiency ratio = 1- (particles out/particles in).
Click to expand...
I must be missing something, but does the table not suggest that Wix is most efficient (i.e. highest efficiency ratio across all particle sizes), but then what to make of lower capacity (grams of material trapped and longer run time) ? Tempest looks to be the worst of the paper filter, with both low efficiency ratio, smaller capacity and shortest runtime. Am I interpreting that correctly ?
 
scsmith said:
A lot of modern cars have filters now that rather than change out the metal filter housing, they have a plastic housing that you just swap out the paper element and put on a fresh o-ring. Oddly, those filters seem to cost just as much or more than the regular metal spin-on's.
Click to expand...
I’ll bet it would be worth the time to cruise the Wix catalog and search for a drop in filter element for your existing housing. Seems likely that the K&P folks sourced a COTS stainless mesh that has some standard key dimensions. If that’s the case, there MUST be a compatible cellulose element out there.

And as suggested elsewhere, the toilet paper filters are not suitable for full flow oiling - they are extremely effective at cleaning, but they really only “ooze” oil through. If installed, they should be considered an auxiliary oil purification processing service that just happens to be bolted to your engine.
 
A while back, we all discussed cleaning the oil inlet screens on a lycoming when we replace the filter. A few posters showed pictures of oil screens clogged with carbon. Just curious what size those carbon particles are and if this screw on filter is effective on this particles.
 
PilotjohnS said:
A while back, we all discussed cleaning the oil inlet screens on a lycoming when we replace the filter. A few posters showed pictures of oil screens clogged with carbon. Just curious what size those carbon particles are and if this screw on filter is effective on this particles.
Click to expand...
I removed the suction screen on my -10. If I remember correctly, the perforation hole size was around .050”, which is a bit over 1200 microns.

Inspecting that screen is nearly impossible (I have CAI) and I replaced it with a scavenge screen located in the oil sump tee. The new screen is 750 microns and is easily inspected at every oil change.
 
rocketman1988 said:
I removed the suction screen on my -10. If I remember correctly, the perforation hole size was around .050”, which is a bit over 1200 microns.

Inspecting that screen is nearly impossible (I have CAI) and I replaced it with a scavenge screen located in the oil sump tee. The new screen is 750 microns and is easily inspected at every oil change.
Click to expand...
Pictures? Parts source/numbers? That oil suction screen is the bane of my existence when changing oil........:mad:
 
Darin Watson said:
I must be missing something...
Click to expand...

Consider this detail: the previously posted efficiency values (post #1) are the average for the entire test from beginning to termination at 10 psi deltaP. Performance declines as the filter loads with increasing amounts of test dust, which drags down the average. All of the depth media filters performed better early in the test.

As a practical matter, it means any of the three does a reasonable job if changed before they can load up with a lot of contamination material. We typically change at 50 hours or less, when most engines will have deposited very little material in the filter. You could probably run a filter 200 hours if willing to accept reduced efficiency as the filter loaded with more metals, silica, and carbon.

Here's hard data, in two formats, (a) comparison at 10, 30, and 60 minutes into the test, and (b), each filter at 10, 30, and 60.

Yes, there are differences in performance. However, before running out to grab a Wix 51515, note there are other very important factors in a filter decision, like bypass valve opening pressure and enclosure burst pressure. This chart only looks at filtration.

10-30-60 Comparison.jpg
 
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Suction screens are a 100 hour, after the first initial inspections, at least on my engine, so, you can skip inspection on one oil change if that helps. I have never found anything concerning that would tell me I needed to do it more often.
Check your engine manual.
 
Great testing and reporting, what oil filter do you use Dan? Inquiring minds want to know…….
 
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DanH said:
Consider this detail: the previously posted efficiency values (post #1) are the average for the entire test from beginning to termination at 10 psi deltaP. Performance declines as the filter loads with increasing amounts of test dust, which drags down the average. All of the depth media filters performed better early in the test.

As a practical matter, it means any of the three does a reasonable job if changed before they can load up with a lot of contamination material. We typically change at 50 hours or less, when most engines will have deposited very little material in the filter. You could probably run a filter 200 hours if willing to accept reduced efficiency as the filter loaded with more metals, silica, and carbon.

Here's hard data, in two formats, (a) comparison at 10, 30, and 60 minutes into the test, and (b), each filter at 10, 30, and 60.

Yes, there are differences in performance. However, before running out to grab a Wix 51515, note there are other very important factors in a filter decision, like bypass valve opening pressure and enclosure burst pressure. This chart only looks at filtration.

View attachment 60647
Click to expand...
Dan,
Did the lab record deltaP prior to introducing the particulate? I would be interested in seeing what type of flow restriction each filter has. I would then look to see if the engine companies have any data on how the restriction would affect the oil pump.
Mark
 
Skid said:
Dan,
Did the lab record deltaP prior to introducing the particulate? I would be interested in seeing what type of flow restriction each filter has. I would then look to see if the engine companies have any data on how the restriction would affect the oil pump.
Mark
Click to expand...
Oil pump is positive displacement and the filter is downstream. clogged media will result in a bypass or housing rupture. Oil pump will not care - it’s going through one way or another.
 
isosceles said:
It seems to replicate an old result: https://web.archive.org/web/2001040...olf.com/Articles/Articles-OilFiltersAMust.htm
Click to expand...

Overall, yes. The average efficiencies for the Champion are lower in the ISO-4752 test performed by MSOE, as compared to the more recent 4548-12. However, I can't find any information about ISO-4752 test; it's not listed at the ISO website. IF (big if) the test was run with hot 50W (as it is in an ARP-1400 test), the higher viscosity would drag down the efficiency values.
 
This last table is much more enlightening than the first one. The Champion filter is as advertised, screening >96% of 35 micron particles, an hour into a test that purposefully loads contaminant into the oil (which isn't what happens in our planes). It's better than the Tempest for all above 10 microns. Yes, the Wix is more efficient, but in an unloaded (no or low dirt actual system), there is only <3% reduction in filtration at 35 microns with the Champion. Also when we consider how many times the oil passes through the filter and only a small percentage of particles get through the filter each time, I'd think the oil stays very clean for all practical purposes.

Even at 10 micron, the Champion is 26% efficient unloaded. So 26% is removed on each pass. On 15 passes through the filter 10 micron particles are <1%. So one has to ask, "how quickly are 10 micron particles created"?

At 35 micron, two passes and we are at 0.01%.

I'll support that Champion filters are effective in our application based on this last table.

Dan: great work!
 
Skid said:
Dan,
Did the lab record deltaP prior to introducing the particulate? I would be interested in seeing what type of flow restriction each filter has. I would then look to see if the engine companies have any data on how the restriction would affect the oil pump.
Mark
Click to expand...

What Mike said. For the most part, the pump is going to move the same quantity of oil regardless of downstream restriction. If the restriction is a clogged filter element, the bypass will open. If I recall correctly, a typical bypass opening point for a Lycoming is 13~15 psi deltaP across the element...but allow me to look it up before setting it in stone.

The 4549-12 test ended at 10 psi deltaP across the element, so none of the filters opened their bypass port. The total terminal pressures were as listed below. Subtract 10 to know the clean deltaP for the entire filter asembly.

Tempest 17.56
Wix 17.12
Champion 17.72
Challenger 15.52
S-15 15.60
 
scsmith said:
A lot of modern cars have filters now that rather than change out the metal filter housing, they have a plastic housing that you just swap out the paper element and put on a fresh o-ring. Oddly, those filters seem to cost just as much or more than the regular metal spin-on's. A lot less material, and yet the same or more cost. Why? cuz they can I suppose.
Click to expand...
There's a more economical reason why they cost the same: Volume. Spin-on filters are made in much higher volumes than replaceable-element filters. The benefit is that for (about) the same cost, you're throwing one less thing into the landfill every time you do an oil change.

For those of us who cut open the disposable filter to inspect the element, it saves the effort and some of the mess of doing that cutting. But if we cut open, we can separate the metal bits out and take them to the metal recyclers, so maybe the environmental benefit is on par with a replaceable element.

It seems likely that almost *any* of the paper-filter filters will perform better than the permanent filters... I'm thinking the ideal solution would be to find a replaceable element filter in the automotive world that fits into the space on the back of the Lycoming. Ideally one that's a little shorter than the usual one that hits the firewall when you're spinning it off (on the -6). Then just replace the element (and maybe o-ring) each time, and save the effort of cutting the filter open.
 
DanH said:
Yes, there are differences in performance. However, before running out to grab a Wix 51515, note there are other very important factors in a filter decision, like bypass valve opening pressure and enclosure burst pressure.
Click to expand...
Have you got the bypass valve opening pressures and enclosure burst pressures for the units under test?
 
Snowflake said:
Have you got the bypass valve opening pressures and enclosure burst pressures for the units under test?
Click to expand...

You'll have to look up the manufacturer's data. Bypass opening pressure was not tested as part of a 4548-12.
 
slight thread drift - does the Champion CH48110-1 have a bypass valve and/or anti drain back? Is there a downside to using the WIX that has those features; would it be belt+suspenders or a hangman’s noose?
 
bjdecker said:
slight thread drift - does the Champion CH48110-1 have a bypass valve and/or anti drain back?
Click to expand...

No.

bjdecker said:
Is there a downside to using the WIX that has those features; would it be belt+suspenders or a hangman’s noose?
Click to expand...

Depends on the choice of filter. Screw a 51515 (which has a bypass in the filter) on a Lycoming horizontal filter adapter (which has a built-in bypass valve), and the oil will simply bypass at the lower of the two opening pressure settings. In this example, the Wix 51515 bypass would open first, as it's only rated at 8 to 11 psi. I have no data, but I suspect that's really too low, in particular if the user runs straight 50W rather than multigrade. There are choices with higher bypass settings, or no bypass, just like the 48110 aviation filter.

Again, we did not test for bypass setting, and as we've seen, sometimes manufacturer data isn't accurate. However, there are clues. I went back and averaged the efficiency values for the last five time increments. A bypass opening should have tanked the efficiency values, and it didn't happen here. The values are as expected when the deltaP makes a sharp rise near max loading, dropping a little due to increased pressure creating increased velocity through fewer pathways in the media, as well as some distortion of the media. It appears the Wix "8 to 11 psi" spec is actually closer to 11.

Wix End of Test.jpg
 
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DanH said:
What Mike said. For the most part, the pump is going to move the same quantity of oil regardless of downstream restriction. If the restriction is a clogged filter element, the bypass will open. If I recall correctly, a typical bypass opening point for a Lycoming is 13~15 psi deltaP across the element...but allow me to look it up before setting it in stone.

The 4549-12 test ended at 10 psi deltaP across the element, so none of the filters opened their bypass port. The total terminal pressures were as listed below. Subtract 10 to know the clean deltaP for the entire filter asembly.

Tempest 17.56
Wix 17.12
Champion 17.72
Challenger 15.52
S-15 15.60
Click to expand...
Dan,
Thanks.
Disregard the second part of my question I understand the bypass should open, my question was more regarding clean filter media Vs deltaP. The higher the filtration value, one would expect higher clean deltaP, this assumes filter area and media being equal, which is not likely.
Based on the numbers in your reply the Challenger and S-15 have a less restrictive filter media and as the data shows are less efficient. The others being very similar, one could expect similar filtration, again assuming the filter area and media is the same.
Mark
 
Skid said:
Based on the numbers in your reply the Challenger and S-15 have a less restrictive filter media and as the data shows are less efficient.
Click to expand...

As in "nearly worthless".

Skid said:
The others being very similar, one could expect similar filtration, again assuming the filter area and media is the same.
Click to expand...
Area and media would be the wildcards negating the assumption. For example, a manufacturer might use a more restrictive media, but stuff more of it into the can, i.e. provide more media area. Result might be the same clean deltaP as a filter with a less restrictive media and less area.
 
scsmith said:
A lot of modern cars have filters now that rather than change out the metal filter housing, they have a plastic housing that you just swap out the paper element and put on a fresh o-ring. Oddly, those filters seem to cost just as much or more than the regular metal spin-on's. A lot less material, and yet the same or more cost. Why? cuz they can I suppose.
Click to expand...
You must own a 2018 F-150 because that's exactly what I just did yesterday and you described it perfectly :ROFLMAO:
 

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DanH said:
As in "nearly worthless".


Area and media would be the wildcards negating the assumption. For example, a manufacturer might use a more restrictive media, but stuff more of it into the can, i.e. provide more media area. Result might be the same clean deltaP as a filter with a less restrictive media and less area.
Click to expand...
Yes, and yes.
 
Less sophisticated than the tests conducted for Dan, but similar conclusions in this video test:

I cleaned my K&P for the last time last night. We ran it for well over 1000 hours and my only data point is anecdotal - when we overhauled the O-320 at almost 2800 hours to do a prop strike inspection, the thing looked almost new inside. Per the IA I was working with, the main and rod bearings were great, the cylinder walls had all the cross-hatching intact (compressions in the mid/hi 70s), the lifters and cam shaft were smooth and going strong. It used a qt about every 18-20 hours. The crank only needed a very light polish at the engine shop. He said we could have run it much longer. I only say this so that anyone that had run a K&P does not panic.

However - The lab tests don't lie - better is better. Time to make a change.

I was coming up on time for the K&P element replacement anyway, so not much lost, and it got me thru the Pandemic Filter Panic of 2022(TM). I installed a Wix 51601 from a LAPS (it's huge!) last night, and flew an hour + flight today with no drama.

This other Wix looks to meet many of our needed criteria, but it is an $18 transmission filter with bypass: Wix 51624

Part Number:​
51624​
UPC Number:​
765809516243​
Style:​
Spin-On Transmission Filter​
Service:​
Transmission​
Type:​
Full Flow​
Media:​
Cellulose​
Height:​
4.354 (111)*​
Outer Diameter Top:​
3.701 (94)*​
Outer Diameter Bottom:​
Closed:​
Thread Size:​
3/4-16​
By-Pass Valve Setting-PSI:​
13-19​
Anti-Drain Back Valve:​
Yes​
Burst Pressure-PSI:​
500​
Max Flow Rate:​
7-9 GPM​
Nominal Micron Rating:​
19​
 
petehowell said:
I cleaned my K&P for the last time last night. We ran it for well over 1000 hours and my only data point is anecdotal - when we overhauled the O-320 at almost 2800 hours to do a prop strike inspection, the thing looked almost new inside.

​
Click to expand...
Pete - what are your normal oil change and oil filter clean/change intervals? Thanks.
 
Interesting info, but I had no idea how big a micron is.

So, I asked my buddy Mr. Google-----------and here it is. .0000393701 inch. 40 micron is .0015748 inch.

Human hair is quite variable but Mr. Google says average 100 micron. https://www.pmpa.org/tag/thickness-of-a-human-hair/

So the worst case in Dan's test results are less than half of a human hair.

So--------when is "bad" really good enough?
 
petehowell said:
I installed a Wix 51601 from a LAPS (it's huge!) last night, and flew an hour + flight today with no drama.

This other Wix looks to meet many of our needed criteria, but it is an $18 transmission filter with bypass: Wix 51624
Click to expand...

The 51601 has a lot of merit. As you say, the only real drawback is the 4.282" diameter. It does have an internal bypass valve. In a major departure from the two aviation filters, note the bypass is located on the base end, not the far end of the element assembly. It means a bypass opening can't sweep garbage off the face of the element and into the engine.

Valve stack. Black rubber ring is a anti-drainback. Silver top hat is a modular bypass valve assembly.

51601 Valves.jpg

Bypass valve. When deltaP get high enough at the little holes around the perimeter, the spring is compressed and oil can flow to the filter core right above the baseplate.

51601 Bypass Valve.jpg

The above would be appropriate for applications currently using a 48108. For a no-bypass application currently using a 48110, look at the Wix 51647 (specs below). I would love to lab test both, plus the 51624. And please, I am not endorsing any of these filters at this time. They are merely potential alternatives.

WIX 51647.jpg

Filters.jpg
 
moosepileit said:
The bypass psid range and burst pressure sure look good!
Click to expand...

Those numbers appear to be ok. Wondering about the flow rate though. I was just reading a Kitplanes article from March 2016 where they said the Lycoming oil pump flow rate was 7-12GPM. Would there be an issue at the high end of the oil pump flow rate?
 
Mike S said:
So--------when is "bad" really good enough?
Click to expand...

Ask Mr. Google for research documents. Try SAE 881825, "Correlating Lube Oil Filtration Efficiencies with Engine Wear". Been around a long time (1988), and the field has advanced since then. The hot topic these days is diesel fuel filtration. Lube oil is pretty much a settled matter...except around here, apparently.


ScreenHunter_2207 Apr. 14 17.29.jpg
 
DanH said:
No.



Depends on the choice of filter. Screw a 51515 (which has a bypass in the filter) on a Lycoming horizontal filter adapter (which has a built-in bypass valve), and the oil will simply bypass at the lower of the two opening pressure settings. In this example, the Wix 51515 bypass would open first, as it's only rated at 8 to 11 psi. I have no data, but I suspect that's really too low, in particular if the user runs straight 50W rather than multigrade. There are choices with higher bypass settings, or no bypass, just like the 48110 aviation filter.

Again, we did not test for bypass setting, and as we've seen, sometimes manufacturer data isn't accurate. However, there are clues. I went back and averaged the efficiency values for the last five time increments. A bypass opening should have tanked the efficiency values, and it didn't happen here. The values are as expected when the deltaP makes a sharp rise near max loading, dropping a little due to increased pressure creating increased velocity through fewer pathways in the media, as well as some distortion of the media. It appears the Wix "8 to 11 psi" spec is actually closer to 11.

View attachment 60668
Click to expand...
Any chance that the efficiency drops near the end of the test are due to the bypass valves starting to ”weep”some unfiltered oil?

Skylor
 
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