K&P Reusable 35 Micron "Rock Catcher" Oil Filter. Fleet Conversion Complete!

Joined
Feb 22, 2009
Messages
280
Location
Gig Harbor, WA
Well, I've been running a K&P reusable oil filter in my Harley for over 10 years and I love it. I've been slowly completing the conversion to K&P oil filters on all of my other vehicles. Car, diesel truck, Roadtrek camper van and my Formula boat, in addition to the Harley. Super high quality construction and I love the ease of being able to thoroughly inspect the media, along with the strong magnet to capture ferrous particles. My oil analysis have always come back fantastic using these oil filters. I know many on here say that an oil filter has little to nothing to do with wear metal counts on UOAs and that's fine. Obviously there are filters with better micron ratings (98% @ 20mic etc) but I'm ok with 35 absolute. Still better than a Wix XP and flows way better I'm pretty sure. 😂 I don't do extended OCIs so I'm not too concerned. I was tired of seeing high end filters such as Fram Ultra, Purolator PureOne and Boss, and Amsoil with ungodly amounts of excess glue everywhere and distorted pleats and poor crimps. Has anyone done a particle count with OAI? I'm thinking I should do some with the oil going thru the various K&P filters I'm running .
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Most people don't know what "35 absolute" means. Other filters 98% @ 20 microns will let a lot bigger than 20 microns pass thur. I'm pretty sure these K&P filters are FAA approved for certified aircraft. Flame suit on too!!!!!
 
Most people don't know what "35 absolute" means. Other filters 98% @ 20 microns will let a lot bigger than 20 microns pass thur.
Only 2% of the particles passing through a 98% @ 20u filter are greater than 20u. That's what the efficiency rating is saying.

"35u absolute" means that the wire mess in that K&P filter will basically let the mass majority of the particles smaller than 35u through because that's the smallest window in the metal screen. The K&P works a bit different than a filter made of fibrous media that has some depth to it.
 
Folks be careful with terms like "flame suit on" "BITOG hates" and phrasing posts in an adversarial context.

No one here cares what oil filter you use. Thats facebook.

Review Filter Forum Rules and Standard of Conduct. Every member agreed to follow them.

They are not suggestions. Being uncivil will have consequences.
 
Folks be careful with terms like "flame suit on" "BITOG hates" and phrasing posts in an adversarial context.

No one here cares what oil filter you use. Thats facebook.

Review Filter Forum Rules and Standard of Conduct. Every member agreed to follow them.

They are not suggestions. Being uncivil will have consequences.
Thanks for the education. I wasn't aware. Would you kindly advise me how to edit my post and I will gladly abide by the guidelines so everyone is happy? I certainly didn't mean to be "uncivil" or be adversarial. I can delete it also if you like. I've learned a lot on this site and I welcome opinions from everyone.😎
 
My warning was general and directed at folks who post only to bicker.

If I thought your post was intended to cause bickering, you would have been warned formally and the topic locked.
Ok thanks. So is there a way I can edit my post? I will gladly do so if someone can tell me how. I can edit my replies it seems but not the original post, which is odd to me.
 
I'm curious from where 35um "absolute" (98.7%) derived? Also, the test procedure used? When I go to K&P website FAQ's, question #4) regarding efficiency I see nothing about the word "absolute". Though they do seem to imply 100% @35um.

Currently ISO 4548-12 is the efficiency testing standard for oil filters. K&P mentions using, ASTMF316 as 'their' testing method. Then states at the end regarding filtration, "we meet or exceed the filtration performance of OEM filters, eliminating any warranty issues." What little is known about OEM OF efficiency ratings, not saying much.

That said, if K&P works for you, (y)
 
How much does it matter in an automotive environment?

35 or 20 microns, both are bigger than the moft in any bearing so if harder than the bearing material is sure to get embedded if not scoring.
 
The amount of solvent used to clean must be correctly disposed of. Other than that quicky lube places using cheap made to the lowest cost china filters are not killing cars, this is probably better.
 
I think as long as you are doing frequent oil changes, you'll be flushing out the stuff the oil filter isn't catching, anyway.
Well let's all remember that usually the best oil filter is top quality filtration that starts with the air filter. If I was going to use one of these specialty filters I would probably get a fresh dry flow air filter with a nylon pre-filter, probably performed an oil flush, and stuff like that. I actually wouldn't be worried running that filter as long as I knew that my air filter and all the other parts and hoses were secure. I don't know what it would take to clean one of these k&p filters out and sometimes I feel that it might be more trouble than just tossing away a OEM style filter. But at least now I know they existed and I didn't before
 
I'm curious from where 35um "absolute" (98.7%) derived? Also, the test procedure used? When I go to K&P website FAQ's, question #4) regarding efficiency I see nothing about the word "absolute". Though they do seem to imply 100% @35um.

Currently ISO 4548-12 is the efficiency testing standard for oil filters. K&P mentions using, ASTMF316 as 'their' testing method. Then states at the end regarding filtration, "we meet or exceed the filtration performance of OEM filters, eliminating any warranty issues." What little is known about OEM OF efficiency ratings, not saying much.

That said, if K&P works for you, (y)

I went and looked at the ASTMF316 test. It’s a bubble point test.

When I worked on the space shuttle program, we used 10 µm absolute filters on some of our ground support equipment. We had to remove those filters once a year and send them out to be bubble point tested. If they failed, we would send them back again just to be sure. If they came back failed the second time they were discarded. There is no way to repair them.

That’s the problem with these absolute filters. How do you know their integrity is still intact after using them for a while unless you send them out to be tested?
 
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