Napa Silver #31085 Cut Open

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This started as a cheap $2.54 experiment, I had never tried one of these and the "combo" valve intrigued me so I thought I'd give it a shot.

Here's a thread I did that explains the Silvers somewhat when I first started experimenting.

Original Napa Silver thread

I figured it would be another 500 mile experiment and I could add this to the long list of filters my Jeep didn't like. NOPE! I ran this Napa Silver 41085 for 3,200 miles, mostly with Trop Artic 5w30. It was subjected to quite a few weather swings including some -10 below abuse (which is as cold as it will ever get here). This filter ran and started better for me than any filter I've ever tried, including my pet Motorcraft FL-400s. I was mighty surprised but that is why you experiment.

On to the carnage.



Typical Wix manufacture base plate



This shows how the combo valve sits in the center tube. This is one of the more interesting points. The combo valve goes right in and is just a smidge undersized for the center tube. This will allow a little bit of oil past the valve at all times. At first I thought this was sloppy manufacture. After looking it over multiple times and stewing on it for a few days it hit me, it HAS to be that way. The tiny oil flow past the valve is what it needs to allow consistent reliable further opening of the valve if pressures get too high. Brilliant once I figured that out. If the valve "plugged" the center tube, it would be difficult or impossible to regulate when it actually opened further, and failure to open at all could be a possibility. As designed, those issues appear to be eliminated.



Here's another shot of the portion of the combo valve that actually slides down into the center tube. The ADBV sits snugly around the threads.



Here's a shot of the media cartridge. Metal endcaps as you'd expect from Wix, and a whopping 60 pleats of media. A huge amount for a "budget" filter. There is a trade off, the media is quite thin and my guesstimate would be efficiency ratings are fairly low. The media cartridge was measured a 2.5", a little shorter than I would have expected, but more on that later.



Here's the seam side. There was some waviness but everything was solid, the glue seam very tight also I'd have needed a knife to get it apart.



Here's the typical Wix coil spring and the bottom endcap which is fits into to stay secure. I definitely like the spring design! This filter was under far more compression when I opened it than any leaf spring filter I've dissected, it literally smashes the nitrile ADBV into the base plate hard. No wonder it held the oil up so well and gave me such great starts. The downside though, the spring takes more room than a leaf spring and the length of the media suffered as a result. By comparison calculations with other filters, the coil spring costs about a 3/8 of an inch of media space.



Inside the can. I think the grit is likely from opening with a hacksaw, although when I pulled the pleats away from each other carbon grit the filter had caught was visible. I've gotten so proficient at opening filters with a hacksaw I can't justify buying a filter cutter.



Here it is all laid out.



Here is the media cartridge compared to my pet FL-400s. The FL-400s was longer, the Napa had more pleats and the pleat depth was a quarter inch deeper per pleat on the Napa than the Motorcraft.



All in all I found this filter to be an incredible value (typically about a buck less than the Motorcraft) as well as a very interesting design. It worked so well for me I will use one again soon, however the next one will be the oversize 31515 which has an additional 1.5" of media but is otherwise identical. If I didn't have a filter stash to work through I'd happily use these exclusively.

My conclusion is these are a relatively high flow, moderate efficiency filter with an incredibly well sealing ADBV, and of surprising quality for the price. Good job Wix!
 
Originally Posted By: KCJeep

This shows how the combo valve sits in the center tube. This is one of the more interesting points. The combo valve goes right in and is just a smidge undersized for the center tube. This will allow a little bit of oil past the valve at all times. At first I thought this was sloppy manufacture. After looking it over multiple times and stewing on it for a few days it hit me, it HAS to be that way. The tiny oil flow past the valve is what it needs to allow consistent reliable further opening of the valve if pressures get too high. Brilliant once I figured that out. If the valve "plugged" the center tube, it would be difficult or impossible to regulate when it actually opened further, and failure to open at all could be a possibility. As designed, those issues appear to be eliminated.


Hummm ... don't know if I agree with the "design theory" of a sloppy fitting combo valve. Seems to me that the combo valve could certainly fit snug enough to prevent constant bypass, and it's simply the pressure delta on the annulus of the combo valve ring that would cause it to open up and bypass oil (blue arrow path in sketch below). Red arrow path is normal oil flow path going to the media for filtration.

In any case, if the combo valve really is that sloppy of a fit and bypasses some oil all the time, that's just another reason to not like them IMO.
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I made this up a while back trying to explain how the combo valve worked. I'm wondering if anyone else can verify if their combo valve was a sloppy fit in the center tube like you found, or a more snug fit like I think it should be.

OilFilterComboValve.jpg
 
Sloppy isn't a very accurate term for it IMO. There's a video on Utube of a dissection and it is the same way though. You can barely get it to move, there is a little play it doesn't squish itself in. The ADBV side does.
 
Thanks for the info on these Napa Silvers. I put a NS on my Mother In Law's Crown Vic last week, no problems to report with it. The x1085 Napa/Wix filters also fit my Dakota. I have a stash of oil for my truck and wife's car but no filters on hand. On our next oil changes I may very well try a NS, they appear to be just as good and on an even plane with my Puro Classics. Thanks for posting the pics.
 
Originally Posted By: R80RS
Nice writeup. Thanks for the effort to put this report together.


Thank you, I appreciate that!

I should mention that this is a "spec" filter for my Jeep, a PH16 or Mopar MO-090 equivalent. The Motorcraft Fl-400s I compared it to is NOT a spec filter for my Jeep but is one that works very well on it, (it's Jeep application is actually a Jeep Liberty filter).

I also failed to add in the initial post that this filter was holding a tremendous amount of oil. I diligently drained it 6 or 7 times over a few days, and it was still spewing oil when I cut it. The coil spring not only gives the ADBV a lot of support, it creates a lot of room for oil at the bottom of the filter, and all that media holds a lot too obviously.

The 31515 I will use next is an FL-1A equivalent for reference.
 
This filter looks great for the price! I'm currently running one now on my Jeep, and it seems to be doing well. It seems to be much sturdier than the Purolator Classic for less money.

I'd like to add that I can't believe you cut that with a hacksaw. If I didn't read it I would've guessed you used a filter cutter.
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When I used a hacksaw it literally looked "hacked" open with a bunch of jagged edges.

I'll be sure to cut mine open after I run it.
 
Been using these on our 2004 on the last two OCI's. Even in the sub-zero temps it has been quite on start-ups. I'll probably stick with them and pick them up during the NAPA specials.
 
Some thoughts on the commentary and conclusions about the Napa Silver shown here.

I don't agree with the conclusion that it's primarily the coil retainer spring that is responsible for the shortness of the media, the element and thus the area in comparison to the Motorcraft. Similar to the Wix/Napa Gold it's mostly the space taken up by the thread end bypass. Only in the of the case of this Silver it's the rubber grommet looking combo valve(see space taken up between adbv portion and nitrile combo bypass grooves), rather than the standard metal coil spring bypass used on traditional Wix/Napa Gold. The coil retainer spring space upon compression would quite be similar to the leaf spring. And whether a coil spring is better than a leaf spring been much discussed here with the conclusion that it's a wash, and mostly a matter of preference. Perhaps (speculation) Wix uses the coil spring to better hold the non-attached thread end bypasses tight to the element endcaps.

As for the unscientific/unproven conclusion that the combo valve bypass "has tiny oil flow past the valve is what it needs to allow consistent reliable further opening of the valve if pressures get too high", all I can say is, really? So the conclusion is that this Silver filter using a combo valve is in constant bypass by design? I wonder if Wix would agree with this conclusion. I would doubt it. What I find ironic though, in the recent Motorcraft metal endcap release upon dissection that caused apoplexia among some even though the common sense posts said that as long potting was intact, any bypass chance was next to nil. Yet 'if' this Silver combo valve is designed with constant bypass in mind it get's a pass? But that aside, I'd need to see proof beyond an anecdotal opinion that this combo valve is designed to have constant bypass. At this point I believe the combo as designed isn't suppose to bypass oil constantly as concluded and see no conclusive evidence to the contrary. But to conclude that if it did it would be ok, imo shows the 'halo effect' at work in that subjective conclusion.

As for the anecdotal conclusions regarding a 'filter running better' because less noise was noticed. Imo, there's too many unaccounted for variables to say a filter is better because of noise reduction. As often noted, the vehicle could be most responsible for any noise issues with other filters, and the filter be perfectly fine as designed.

Now to the filter. Generally speaking, while a 3200 mile oci shouldn't show any issues with a filter from a reputable brand, it appears this filter held up and did it's job. Good to see the waviness and wider pleat spacing by the seam pleat noted as no issue as long as no breach occurred. That would make it the same as Purolator and other brands that show similar on post use dissection here, though very frequently with a less benign response conclusion. Though the Silver with a combo valve wouldn't be my first choice, Wix makes a good filter and I have several Napa Golds obtained on sale in my stash.

Thanks for the pics.
 
Yeah, I agree. rubber-to-metal with plenty of spring pressure is enough to keep oil from slipping by the combo valve. This filter appears to have held up well in the short term use for which it was intended. I would advise treading very lightly when it comes to extended use, as the design of the bypass lends itself to changes in bypass pressure as the material heat ages.

I'm not a fan of combo valves. I had some doubt about their long term durability planted in my head by a couple of engineers in the oil filter field and considering all the engineering factors involved, those comments passed the smell test in my mind. That doesn't make them immutably bad in reality... after all at least on major brand is using them... but since they usually come in the low rent filter/short FCI lines, I have not had to face doing any personal R&D. It will be a LONG time before one of them graces any of my engines. I'll let the evidence pile up first and others do the R&D.
 
Originally Posted By: sayjac

I don't agree with the conclusion that it's primarily the coil retainer spring that is responsible for the shortness of the media,


Had you actually handled the filter it would be obvious to you, there is a large cavity at the bottom of the can. The coil spring is 1" tall and the competitor's leaf springs only 1/4" to 3/8" (yes I measured). That's 5/8 to 3/4" of an inch difference in spring length.

I won't even bother to attempt to discuss the combo valve with you I knew in advance you'd nitpick it no matter what I posted, and your previous post history strongly indicates an argumentative stance as opposed to actual discussion.
 
Jim these have been mass produced since 2007. If inherently flawed don't you think we'd know about it by now? The ecore is a good example, internet pictures of those with blown media began to surface shortly after their introduction.

I was curious about these and digging on the internet didn't reveal to me one single documented failure, just a host of speculative negative armchair comments. I did find some positive testimonials (one BITOG'er commented on good starts at -30 with one) though. And now I've run one, subjected it to the worst use I could and dissected it. I can find nothing lacking. My Jeep is so picky about filters is something wasn't working properly believe me it would let me know.

Anyway we have a host of filters to choose from in the $4 and under range and everybody wins in the end as a result.
 
KC - you must be a surgeon with that hacksaw, looks better than mine come out with an exhaust cutter.
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Interesting writeup and pics, thanks for cutting and posting.
 
Quote:
....I won't even bother to attempt to discuss the combo valve with you I knew in advance you'd nitpick it no matter what I posted....

Guess I touched a nerve. As you actually can't dispute the logic regarding the questioning of the opinion that the combo valve is designed to be in constant bypass, attack the messenger. And, I'd hardly call it a nitpick to question the subjective conclusion that the combo valve is designed to be in bypass as claimed. Provide proof with a citing(s) or links to back up the claim that it's specifically designed to be in bypass then it might more than a subjective opinion.

As for the coil spring, seeing as I have a recently dissected a Napa Gold 1348 with a coil spring now, I'm well aware of the 'unsprung difference' in length between a coil and leaf spring. That said, it's generally accepted on this board and has been for some time that the biggest difference in media element size (top to bottom) comes from the space occupied/required for the thread end bypass mechanism, the Wix combo valve design being no exception. As proof all one needs to do is find one of the rare Wix/NG with dome end bypass, (FL820S equivalent (5/1372) and some others) still using a coil spring and note the significant increase in media element size.

However, compared to the conclusion that the combo valve in constant bypass as designed opinion, that was an insignificant point. Your perception of questioning a conclusion that would go against basic filter design is as a nitpick, obviously differs from mine. And based on the comment from at least one other member on this thread, I'm not the only one that finds that conclusion dubious.
 
Originally Posted By: sayjac
Quote:
....I won't even bother to attempt to discuss the combo valve with you I knew in advance you'd nitpick it no matter what I posted....

Guess I touched a nerve.


Nope we've already been there done that. Now you want to argue simple math too? Thank you for making my point.

You make some good contributions here perhaps my post was a bit harsh, let's just agree to disagree on this.

Hey all I also have some more filters to post later today I hope.
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Originally Posted By: KCJeep
Jim these have been mass produced since 2007. If inherently flawed don't you think we'd know about it by now? The ecore is a good example, internet pictures of those with blown media began to surface shortly after their introduction.

I was curious about these and digging on the internet didn't reveal to me one single documented failure, just a host of speculative negative armchair comments. I did find some positive testimonials (one BITOG'er commented on good starts at -30 with one) though. And now I've run one, subjected it to the worst use I could and dissected it. I can find nothing lacking. My Jeep is so picky about filters is something wasn't working properly believe me it would let me know.

Anyway we have a host of filters to choose from in the $4 and under range and everybody wins in the end as a result.


"Documented failures?" Well, if the filter starts to bypass at a lower or higher pressure that new/designed, how is the end user going to be able to tell? Even in a dissection, could you really tell unless it was falling to pieces or went rock hard? If it bypasses too easily, at a lower pressure, it's just going to take a chunk of your long term wear away and that might not be noticed. If you kept you car for decades and use the combo filter all that time, you might have cause to lament that your engine didn't last quite as long as they normally seem to do.

I think (hope) there has been enough testing done by the companies using the combo valves that they can generally track any changes in bypass operation so they know bypass stays within an acceptable range over the course of the designed FCI. That is why I cautioned to watch out when pushing past the designed FCI. I would also caution against using one if your engine commonly has, or is used in a way to generate, high engine oil temps... for the same reasons.

Yes, materials like those used in combo valves are getting better and better. Maybe they are good enough now. But when I hear two filter industry engineers take the time to express an opinion that the design is "not really ready for prime time" and explain why, I take notice. Like I said, I'll let you do the R&D on this product.
 
Originally Posted By: Jim Allen

"Documented failures?" Well, if the filter starts to bypass at a lower or higher pressure that new/designed, how is the end user going to be able to tell?


Kinda along my line of thinking also, how do we really know any bypass set up works like we think it should? Is the combo valve somehow evil simply because it's different and not what we are used to? Does it actually work as well or better than others? We don't really know but I don't know how we would on any of them in normal use.

Well I actually did experiment with a non-spec filter a while back and it wasn't going into bypass and I could tell, but that's a whole 'nother can of worms I won't open here.

I am doing the R@D if you can call it that when millions have already been sold, but I'm having fun anyway.
 
I would be a bigger fan if the combo valve was made of silicone-I've seen a lot of hardened nitrile ADBVs. Maybe the combo valve wouldn't harden as much-but I wouldn't push one too far. 3-5K would be my limit.
 
Originally Posted By: bullwinkle
I would be a bigger fan if the combo valve was made of silicone-I've seen a lot of hardened nitrile ADBVs. Maybe the combo valve wouldn't harden as much-but I wouldn't push one too far. 3-5K would be my limit.


Agreed for 3 bucks these are not longer OCI filters, nor are they intended to be.
 
Quote:
I would be a bigger fan if the combo valve was made of silicone-I've seen a lot of hardened nitrile ADBVs. Maybe the combo valve wouldn't harden as much-but I wouldn't push one too far. 3-5K would be my limit.

Using the oft posted Motorcraft FL820S filter dissection comparo as reference, if accurate Wix apparently tried that and quickly abandoned the idea in favor of now using a dome bypass design on the equivalent 51372 rather than the traditional separate thread end bypass. What that did do though is allow for increased media area in comparison to the traditional external metal thread end bypass. Why Wix abandoned the idea so quickly can be only speculation, but the fact they did says something about the design.

The most telling thing to me is that Wix does not now use a combo valve of any type in a 'Wix' labeled/branded filter. The nitrile combo valve grommet is only used on the second and third tier 'made for' filters. Thus the only logical conclusion and has been noted by Jim Allen on other threads, is strictly a cost saving design, one that Wix obviously doesn't want on it's own branded filters. But unlike a nitrile adbv as opposed to silicone where the worst that one might get is some oil drain back causing a start up rattle, a failed or compromised bypass function could cause far worse.

Otoh, one could accept the OP's incredible conclusion that the nitrile combo valve is designed to 'bypass oil all the time'. But as already noted by Z06 early on, 'if' that was the case, why anyone in their right mind would want to purchase and use such a design is beyond comprehension. That said, I'm 100% certain that if the Wix technical department was to weigh in on the subject, they would dispute that conclusion.

What's more interesting to me though, is why some Silver and NPS and other 'made fors' still use the Wix traditional separate metal spring bypass and nitrile adbv, but others use the nitrile combo valve. I'd like to know the major consideration in the differentiation process. Unfortunately, that's likely to stay a mystery.
 
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