K&N vs. paper filters

[markrinker]

Today I was changing fluids and decided to knock the bugs and chunks of whatever gets stuck in a K&N filter out.

As I carefully tapped the filter, watching the debris collect on my driveway, I realized something was missing from this picture. Dust. That fine, grey cloud that you get when you tap a paper Fram filter for the same purpose.

Now I know that most of you reading this are thinking - "Its all stuck to the oil in the gauze, dummy..." but that's where I am concerned. My filter looks as nice and red and 'un-dirty' as the day I installed it, about 12,000 miles ago. And yes, it is still nicely soaked with with red filter oil - not dried out.

Are fine dust and particles passing through this type of filter and the bugs and chunks don't get through?

More airflow = more power, but with a cost down the road...?

Comments?

[rjschoolcraft]

If you want to see the dust (dirt or mud now), use the K&N cleaning fluid and hose the thing out. You'll see some really nasty looking stuff come out.

A while back, I posted some pictures of the inlet duct (rubber elbow) from my Suburban. It had over 224,000 miles on it with most of that running a K&N...very little debris in that elbow. I'll see if I can find that post.

On edit:

Here's a link (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=3;t=008403) to a thread in the Duramax forum where this is discussed and my pictures are posted.

[markrinker]

I'll let it go until the next oil change and clean it properly. Hard to imagine all that dirt without changing color...but I'll wait to see firsthand.

[Kennedy]

http://www.trueflow.com/video.php


True Flow elements are basically Uni. I've seen Greg do this same demo with the Amsoil filter and MP did a test a few years back. Seeing is believing in my opinion.

[rjschoolcraft]

http://www.knfilters.com/facts.htm

[Kennedy]

The video doen't appear to want to be correct. I'll have to see where it went, but seeing is believing.

I've seen the evidence of downstream dirt on mine as well as a member's Suburban running a round K&N. I've also seen Denny B (Inspector) travel from UT to OH with an Amsoil foam element and have no outward signs of grit past his filter.

AFE released their Proguard 7 (7 layers) and recommends this media for diesels because they can pull dirt thru the std media. I'll agree.

FWIW, my 2002 typically runs single digit silicon in analysis. Running a std AFE gaugze for a short time put that up to 45ppm...

[rjschoolcraft]

Originally posted by kennedy:
I've seen the evidence of downstream dirt on mine as well as a member's Suburban running a round K&N. I've also seen Denny B (Inspector) travel from UT to OH with an Amsoil foam element and have no outward signs of grit past his filter. Granted, at this point I don't have any oil analysis data to back up my position. However, the photos in the quote below from the thread that I referenced before are telling.


Originally posted by ronniejoe:
I don't own a Duramax, but I have used a K&N on my 6.5 for over 154,000 miles. Not the first indication of problems from air filtration. Here are some pictures that I just took of the air inlet elbow, that has never been cleaned...

http://www.schoolcraftpowertrain.com/Pictures_&_Data/IM000753.JPG

http://www.schoolcraftpowertrain.com/Pictures_&_Data/IM000754.JPG

Total mileage is 224,094. I'd say the K&N has done a good job of filtering. I have not been "religious" about cleaning it either. This elbow has traveled from one coast to the other and from Canada to the Keys, has over 150,000 miles on it, has operated in very dirty environments and still shows no signs of dirt past the filter.

I'll allow that the foam may be better. I can't definitively argue that...at this time. However, my point is that the hysteria is not warranted. AFE has data showing their element to be better. K&N has data showing their element to be better. Each is trying to sell a product. Take it all into consideration and make a wise choice.

[Kennedy]

Greg's test, MP's test and the True Flow video (lost in cyberspace) all show simple results that are clear to the naked eye.

That elbow is filthy.

[More Power]

Though I couldn't find it on www.aempower.com (http://www.aempower.com) , A recent AEM ad in Four Wheeler magazine announces a new dry/cleanable synthetic air filter from AEM that is advertised to filter better than the available oiled-gauze filters. I was hoping they would have an oiled foam filter included in their tests, but their web site wasn't much help and their search function worthless.

Still, a new dry/cleanable synthetic element might be worth investigating.

Jim

BTW - I saw the True Flow video, and even accounting for it being produced by them to promote their products, it would be hard to explain it away. Clearly, oiled foam performed best.

[jspringator]

My oil analysis silicon actually went up when I switched from a KN to a paper filter.

[ANXIOUS-SUBMAN]

"That elbow is filthy."

I agree and thought the same when I first looked at those pictures. I run an Amsoil oiled foam filter and my inlet elbow is shinny black like brand new and has no oil residue.

[rjschoolcraft]

The oil residue is from the CDR tube... Tough for any filter to stop that.

To the naked eye, it looks shiny black, just like your "fantastic foam" protected elbow (oops, sarcasm is slipping out, sorry). The camera flash illuminated reinforcing fibers in the rubber itself. Rubbing my hand in the elbow did not produce a gritty feel. I tried several shots with different lighting and could not reproduce the "look" of the naked eye.

So, I categorically disagree with your "that elbow is filthy" assessment. There is no dirt in the elbow. To the naked eye it looks no different after I cleaned it than before.

I know this is an emotionally charged issue, but let's be reasonable.

[ 07-22-2005, 07:23 PM: Message edited by: ronniejoe ]

[DA BIG ONE]

I find my K&N works best w/pre-filter like superfine mesh panty hose. Keeps lots of sand, and other debris from getting to filter.

When I remove pre-filter medium there is a fine dust that can be gently tapped off of filter.

I find I have to remove the airbox to get all the dirt/debris out about once a month.

[markrinker]

This has got to be the most fun a guy can have for under twenty bucks a year...

I am envisioning a side by side test of my two 6.5 powered trucks - one running the stock paper filter and air box, the other running a K&N cone style filter.

My plan is to place a clean white filter medium in the airflow on the engine side of the filter to trap and better visually expose particles that pass through the filter. Both trucks will be driven the same distance, over the same dirt roads, gravelpits, and job sites.

Still searching for the right medium...more soon on this. Any suggestions where I could find it? Something like we used in Chemistry lab to filter parciptates from solutions...

[JD Diesel]

The thing that I remmber about kn claim to fame about there air filters was the dirtier it get the better it cleans, that scares me. I dont know about you. Yes I have seen the flow partical test that is really scary. And you would run a kn or any guaze filter after that.just look at akn in the light and see all the big holes there that are 1/256 on an inch I dont have to be a brain dude to see that. But if you like kn you most have more money than I do. Cause are engines are not cheap to rebuild and repair. JD :D

[Kennedy]

Originally posted by JD Diesel:
The thing that I remmber about kn claim to fame about there air filters was the dirtier it get the better it cleans, that scares me. I dont know about you. Yes I have seen the flow partical test that is really scary. And you would run a kn or any guaze filter after that.just look at akn in the light and see all the big holes there that are 1/256 on an inch I dont have to be a brain dude to see that. But if you like kn you most have more money than I do. Cause are engines are not cheap to rebuild and repair. JD :D That statement from K&N was an old one and it has gone by the wayside near as I can tell. I think that consumers started to realize the true implications of such a design.


RJ, The oil is always there as a "second filter" or dirt trap of sorts, but It sure looks like there is a lot of grit in the oil residue and the tan-ness of the non oiled part...

[rjschoolcraft]

Originally posted by kennedy:
RJ, The oil is always there as a "second filter" or dirt trap of sorts, but It sure looks like there is a lot of grit in the oil residue and the tan-ness of the non oiled part... I know... but it didn't look that way with the naked eye. That's why I was so eager to take pictures of it.

[GMC Hauler]

You cannot judge a filter's effictiveness by how clean the elbow is... The dirt does not necessarly have to stop and stay in the elbow.

If you live in a clean environment, then you don't need as much filtering.

You have to look at the side by side test with standard conditions to determine relative effictiveness.

I run the same K&N filter and when I clean the elbow, I can feel some fine gritty particles in the CDR oil residue of the oil. Some particles were stopped, some were not... Yes, the box is properly sealed.

[JD Diesel]

Kennedy Yes I know it's an old claim, but I still hear it pushed by some sellers. JD

[rjschoolcraft]

For the record...

The elbow cleanliness issue was used as a tool to bash the K&N in the past. My photos were posted originally in response to that. So, no, I'm not using that as the sole measure of performance.

I have a copy of SAE J726 in my hands this very moment (well, I just laid it down on the desk so I could type). I've read it and have even had experience testing filters in accordance with the standard (in my work at Allison).

I looked into getting a real comparison test run a couple of years ago at Southwest Research Institute. The cost was prohibitive and I could not get anyone to sponsor it. K&N said that they pay for that kind of testing every year (at SWRI) and referred me to published results. AMSOIL never responded to my inquiries. I spoke with K&N directly at the SEMA show in Las Vegas in 2003.

[GMC Hauler]

I've never heard of the elbow cleanliness issue before this, so my response had no overtones of any kind.

What about a test at the Rendevous? Doesn't Greg have some type of test rig to perform this test? Maybe a test rig could be made. Could be made with a shop vac, half of a air box, and a second air filtering medium.

Good, we're all on the same page. I'm from the government, and i'm here to help. :D

[rjschoolcraft]

Buy the 6.5 reprint book (this used to be in the 1998 book) and see the article MP wrote on this subject. He did a test like what you are describing and published the results.

I have argued that any test needs to be run in accordance with SAE J726 to stand up to scrutiny. That gets very expensive, very quickly.

On edit: I don't think that article made it into the 6.5 book. I don't know where Jim has put that now, but will find out. It was titled Air Filter Shoot-out and was originally published in the 1998 Feature Articles Volume.

[GMC Hauler]

Got it/read it. The article you describe is on page 37.

I have to reread these books every once in a while. I find something new every time.

Can you post SAE J726? I'm not familiar with this.

[ 07-23-2005, 07:27 AM: Message edited by: GMC Hauler ]

[rjschoolcraft]

That's the air filter test code written by the Society of Automotive Engineers. It is copyrighted so I cannot post it. It can be purchased at the SAE website.

[Tough Guy]

I use the NAPA oiled foam front with paper element air filter and have for many miles at least 70,000+ I tried the UNI, the locking parimeter was not thick enough for my air box and was getting "sucked" into the engine... same thing for the amsoil filter. The NAPA filter has a stiffer, thicker edge and seems to lock in nicely, I have had an oil analysis or two that indicated good filtration.... <10 silicon.

I think there are some airbox differences between trucks, I also think that the kind of usage varies widely....dusty roads, farms, off-roading etc...or clean cul-de-sacs and highway commuting etc...pick a filter that works for you and your truck.

The biggest concern is that the filter is cleaned or changed at all.... and your airbox is inspected, and the filter re-installed properly.

I would like to try the new AFE for the 6.5L maybe that would be the hot ticket.... :confused:

Cheers

[markrinker]

I strongly agree with matching your filter choice to how and where your truck is used. Since my work is 99% highway, my K&N style will remain in place.

If I was back on the dusty farm or in construction trades, I'd stick with OEM paper - changing it every 5,000 miles.

The engineers at GM know how to cover all the bases - sometimes at the cost of some mileage and horsepower.

[ 07-23-2005, 05:28 PM: Message edited by: Mark Rinker ]

[DA BIG ONE]

"Driving over the same roads using different filters, at different times to see which one filters more PPM of any medium is hardly fair, because you cannot guarantee weather, dust, moisture, or any other of many variables would be the same, it never is."

I like the high flow filters, but I also think a pre-filter is a must. Serious operators of sand rails, or dune buggies use a pre filter for a good reason, they have found it to offer the best protection around sand and fine dust.

I like the idea of an extra large filter, if you motor is breathing say 600 cfm under full boost, then 1000 cfm filter with a pre-filter is not such a bad idea, considering a pre-filter usally takes away 10 to 15% of total flow.

[JoeyD]

Originally posted by More Power:
Though I couldn't find it on www.aempower.com (http://www.aempower.com) , A recent AEM ad in Four Wheeler magazine announces a new dry/cleanable synthetic air filter from AEM that is advertised to filter better than the available oiled-gauze filters. I was hoping they would have an oiled foam filter included in their tests, but their web site wasn't much help and their search function worthless.
Jim

BTW - I saw the True Flow video, and even accounting for it being produced by them to promote their products, it would be hard to explain it away. Clearly, oiled foam performed best. I just bought a new filter for my shop vac and it is a synthetic washable dry filter. It has all the same claims about better filtration and all that and looks big enough for my truck.

[Kennedy]

If you find dirt/grit in the elbow it is getting past the filter pure and simple. I am not using this elbow cleanliness comparison so much as a way to compare RJ's K&N to my (formerly) 96' in WI environment. I am using it to compare before/after results. The before being visibly filthy on my 96 and after being much cleaner.

[JoeyD]

My K&N also let the intake get dirty. You could feel the grit when you wiped your finger over it. I went to the Amsoil foam and the seal for the filter was crap in my opinion so I went back to paper. I run a bead of RTV black around the duct before I slid the new paper filter on and the intake stays nice and clean.