Question about oil filter design

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My basic question is - are oil filters with the bypass valve at the base plate a better design than oil filters with the bypass valve opposite the base plate? My Ford F150 uses the Motorcraft FL-500S filter and it has the bypass valve at the base plate end. The majority of other filters I have found for this application have the bypass valve opposite the base plate. I suppose there are engineering reasons for choosing which bypass valve design, but I don't know what those would be. I'm interested in being educated on these designs.
 
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IIRC, in the case of the Motorcraft oil filters, FORD engineers want any oil(including unfiltered oil) getting to the engine under certain pressures/situations which is why Motorcraft filters are designed with the bypass valve at the base plate. I can't answer for other filters and IDK if I even said that right. But others can describe it better than I can.
 
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Ford prefers the thread-end bypass to better retain unfiltered oil in the filter during startup to prevent it from getting "backwashed" into the engine. Here's a link to a powerpoint with a motorcraft filter cutaway & comparison that explains it a little better

Having a thread-end bypass also reportedly helps prevent cam phaser ticking on 3v Modular motors.

Most other filters use a dome-end bypass because it's cheaper and for pretty much any other application, it doesn't matter one way or the other.
 

2gumby2

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Ford prefers the thread-end bypass to better retain unfiltered oil in the filter during startup to prevent it from getting "backwashed" into the engine. Here's a link to a powerpoint with a motorcraft filter cutaway & comparison that explains it a little better

Having a thread-end bypass also reportedly helps prevent cam phaser ticking on 3v Modular motors.

Most other filters use a dome-end bypass because it's cheaper and for pretty much any other application, it doesn't matter one way or the other.
So, it seems that other than certain Ford vehicles it doesn't matter much. My Ford Explorer also uses the FL-500S and my Subaru Crosstrek uses a filter with the bypass valve opposite the base plate.
 
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So, it seems that other than certain Ford vehicles it doesn't matter much. My Ford Explorer also uses the FL-500S and my Subaru Crosstrek uses a filter with the bypass valve opposite the base plate.
Correct. Anti drainback valve material matters more in my opinion. Having a silicone ADBV makes motorcraft filters one of the best budget filters.
 
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Correct. Anti drainback valve material matters more in my opinion. Having a silicone ADBV makes motorcraft filters one of the best budget filters.
Isn't the filtration of a motorcraft 80% at 20 microns while the Sunkist is 95.7% Also has a silicone adbv too. I'd actually use the fram but it appears that at Walmart the ph10575 which crosses to the fl 500 and is what I need on my new truck is $6.12. but fram filters like the ph5 which are much larger cost just 3.88 which is stupid.
 
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Isn't the filtration of a motorcraft 80% at 20 microns while the Sunkist is 95.7% Also has a silicone adbv too. I'd actually use the fram but it appears that at Walmart the ph10575 which crosses to the fl 500 and is what I need on my new truck is $6.12. but fram filters like the ph5 which are much larger cost just 3.88 which is stupid.
I think motorcraft filter efficiencies are underrated based on the media surface area and I think that 80% @ 20um was from 2005-ish.

Amsoil tested an FL820s in 2011 and had them at 94%@20um and they are still the same filter today.

I don't know much about the FL500 and its equivalents. I
 
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I think motorcraft filter efficiencies are underrated based on the media surface area and I think that 80% @ 20um was from 2005-ish.

Amsoil tested an FL820s in 2011 and had them at 94%@20um and they are still the same filter today.

I don't know much about the FL500 and its equivalents. I
yeah i saw that but that appeared to be the 820 which was in between 93-94. the 500 still specs at 80% @20um in many places which i find weird. A lot of sites spec 80% for the motorcraft filters. May be incorrect data as the media type should be the exact same unless the suppliers are different but i don't think so. Ford should just list the data themselves on their site to stop old or unreliable information.
 
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I find it funny that Ford (or any other company with similarly designed filters) hasn't put out a simple drawing that shows filter media being washed down by oil in by-pass in Brand X filters.

Also, I have a tack-on question re the dome end by-pass method. When circumstances make the by-pass activate, the element shifts "backwards" and the oil isn't filtered. After by-pass, does the element always go right back to its proper position? These are not precision contraptions.
Who's to know if the element sits crookedly resulting in no filtration.
 

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I think motorcraft filter efficiencies are underrated based on the media surface area and I think that 80% @ 20um was from 2005-ish.
When an ISO efficiency test is done, it's done on the whole filter assembly, and filter makers will typically use a relatively large filter model to conduct the test. Only time a very low media area might affect the overall filter efficiency rating is if near the end of the test the delta-p due to high loading increases enough to dislodge already captured debris and hurt the overall average efficiency.

Supposedly, all Motorcraft oil filters are suppose to now meet USCAR-36, which stipulates it must meet a minimum efficiency. Search YouTube for Ford Tech USCAR-36.
 
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yeah i saw that but that appeared to be the 820 which was in between 93-94. the 500 still specs at 80% @20um in many places which i find weird. A lot of sites spec 80% for the motorcraft filters. May be incorrect data as the media type should be the exact same unless the suppliers are different but i don't think so. Ford should just list the data themselves on their site to stop old or unreliable information.
As a general rule the OEM OFs keep their filter efficiencies proprietary. The Amsoil ISO 4548-12 test is rare in that it tested multiple OEMs including the 820S. Result noted is correct for that filter.

Before that (and since) MCs [email protected] is what they publish. That said, the understanding in that figure, it's just 'a minimum'. 'Imo,' the actual is likely closer to what the Amsoil test found.

As for topic, Ford is picky about the "dirty oil wash" over the pleats possibly getting through during bypass. As it's basically understood that bypass events are rare and of very short duration, much ado imo. Even though I use Napa Gold(Wix), I think thread end or dome end, both work fine.
 
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When an ISO efficiency test is done, it's done on the whole filter assembly, and filter makers will typically use a relatively large filter model to conduct the test. Only time a very low media area might affect the overall filter efficiency rating is if near the end of the test the delta-p due to high loading increases enough to dislodge already captured debris and hurt the overall average efficiency.

Supposedly, all Motorcraft oil filters are suppose to now meet USCAR-36, which stipulates it must meet a minimum efficiency. Search YouTube for Ford Tech USCAR-36.
And to save everyone some clicks, it's 95% at 30um minimum.
 
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And to save everyone some clicks, it's 95% at 30um minimum.
yeah i saw the vid and wasnt too impressed with that. they squealed about engine cleanliness but it should be 99% at 30um or 95% at 20um. heck the wally can is 99% at 30. does anyone know what a filtration efficiency of 95% at 30um could ballpark to at 20um.
 

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yeah i saw the vid and wasnt too impressed with that. they squealed about engine cleanliness but it should be 99% at 30um or 95% at 20um. heck the wally can is 99% at 30. does anyone know what a filtration efficiency of 95% at 30um could ballpark to at 20um.

WAG would be probably around 80% @ 20u ... wait, that sounds familiar. :D
 
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As a general rule the OEM OFs keep their filter efficiencies proprietary. The Amsoil ISO 4548-12 test is rare in that it tested multiple OEMs including the 820S. Result noted is correct for that filter.

Before that (and since) MCs [email protected] is what they publish. That said, the understanding in that figure, it's just 'a minimum'. 'Imo,' the actual is likely closer to what the Amsoil test found.

As for topic, Ford is picky about the "dirty oil wash" over the pleats possibly getting through during bypass. As it's basically understood that bypass events are rare and of very short duration, much ado imo. Even though I use Napa Gold(Wix), I think thread end or dome end, both work fine.
So what does that mean exactly? Is the materials or manufacturing process so variable that some filters are 80% and some are 94%?
 
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If the base is up, the bypass valve is better at the base. If the filter base points down, a dome end bypass is best. The theory being any settled dirt will be opposite the bypass valve due to gravity, and have less chance to be swept through it.
 
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So what does that mean exactly? Is the materials or manufacturing process so variable that some filters are 80% and some are 94%?
I think I posted that apparently they publish(ed) a minimum standard [email protected] That's what the 820S was published. The testing for that filter showed something significantly greater, 93-94%@20um. The second part says 'my opinion' others likely closer to latter than minimum.

As for why they did or do a minimum, guess you'll need to take it up with them, Ford/Motorcraft. If it really is that important though, likely should choose another brand with more definitive information. I will say this though, the minimum listed still more information than other OEMs willing to publish, eg., Honda, Toyota.
 

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As for why they did or do a minimum, guess you'll need to take it up with them, Ford/Motorcraft. If it really is that important though, likely should choose another brand with more definitive information. I will say this though, the minimum listed still more information than other OEMs willing to publish, eg., Honda, Toyota.
If the USCAR-36 minimum is 95% @ 30u, and translates to the guesstimate of 80% @ 20, then that seems to align with that Motorcraft published minimum spec.
 
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