Why I just tossed my K&N filter....

[Wilbur]

So I am not sure if this is in the "RIGHT" spot but I don't know where else to put it so here goes. I have had a K&N oiled filter in my Yukon for prob 8 to 10 years or so (its a 2003). I just have the stock 5.3 L engine with nothing else done, 100% stock. But at the time I read their website, saw a fair number of them being used and felt it was probably better than stock. For some reason the whole "oiled filter" thing seemed like it would trap more dirt. In the back of my mind I remember clogged air filters on the old Chevy/GM pickups I have had with the typical round air filter on top of the carb. The filter would be BLACK and clogged right by the input tube and the rest would be reasonably clean. But keep in mind that the Yukon has a filter box with the filter sitting on TOP of the box where the air getting pulled to the engine exits through the top (As I don't have a newer pickup or Duramax I don't know if they are similar- I suspect they are but not sure) so I never saw that single "black/clogged" spot on it. But it seemed to make sense to me, and I wouldn't have to buy any more air filters. Not that air filters are crazy expensive but whatever.

As an aside (I will DOT my own thread) the first time I saw the configuration of an air filter on top of a box like the Yukon has was in my 80 something VW Jetta. I could not understand why it was like that, so I studied it a while. It had a tube that entered the "box", then the filter on top sucked the air out to the engine intake. It then dawned on me, and partly it was cause I saw "dirt" in the bottom of the box while the filter was still pretty clean. The air comes in under pressure (not "high pressure" but more than atmospheric given its small size) then goes into a bigger area ("the box") which results in a drop in air pressure and lets the debris fall to the floor of the box. Then the "relatively" clean air is sucked through the filter to go to the engine. As a comparison to my round filtered small blocks in pickups with the clogged single part of the filter this seemed like genius to me!

Sorry....back on track.....but over the years I have seen people saying that K&N are junk, get rid of them, yada yada yada. And I have never really understood why some make that claim. So a couple of days ago I did some dedicated searching to try to figure out the problem. I ran across this link:

http://www.nicoclub.com/archives/kn-vs-oem-filter.html

This seemed to make a lot of sense to me. If you want to read it please do, but the basic issue is that YES, K&N filters do allow more air through to the engine. But unless the engine is pushing HUGE amounts of horsepower then the additional air is not doing anything. In a stock engine, the air flow through a conventional OEM filter is satisfactory for the power being produced (duh....). But the other issue is that to allow that much air through, the K&N filters also allow a ton of dirt through. This was the first time I ever saw the whole thing measured from start to finish scientifically with the amount of dirt introduced, the length of time to clog the filter, the amount of dirt that got through the filter etc etc.

Anyway. After reading all this I went to WalMart today, got a new air filter and tossed my K&N in the trash. Is it the right thing to do? I don't know. I welcome different opinions on the subject. But it made enough sense to me to do it. Do I think the K&N HURT me? No I don't think so.....I have 240K miles on the Yukon so something's working. But would I prefer cleaner air to the engine? Yup. YMMV.   

[Flyin6]

Wil,

Point of order here

Do we need another section? TO discuss parts and pieces

I run into the problem as well, cram it onto the build thread section but it's not a build per-see...

Opinion???

[Flyin6]

Good read, great info


I just put a K&N on SquareD !!!!! :o

[Wilbur]

Wil,

Point of order here

Do we need another section? TO discuss parts and pieces

I run into the problem as well, cram it onto the build thread section but it's not a build per-see...

Opinion???

I don't think so Don.....maybe change the "Build Thread" Section to "Vehicle Info- Build threads, mods, all things vehicle related" or something similar?

Good read, great info


I just put a K&N on SquareD !!!!! :o

Um....in all honesty I saw the K&N you had and that made me look this all up. I have started to do the investigation a few times about K&N when I see comments on line but when I saw one of your pics on the airbox changes that made me go an finally do the search. Once I found the info I said to myself "sheesh....I hope Don didn't just get that"  :-\

I did find it compelling though....at least for me running an all stock motor.

[TexasRedNeck]

I gave mine up a long time ago too.  But for a different reason.  Any excess oiling fouls the MAF.

I love all the hype about S&B and Banks and what not over on Dmax Forum.  Unless you have twins and are moving massive air...you just validated what I suspected.

Thanks for sharing

[Flyin6]

I gained my confidence in the K&N in the combat theater

Yep, sure did

In an emergency measure the Army strapped really big K&N filters on the front of the 4,500 HP Lycoming turbines on my Chinook to fight back the unreal dust from the recent combat areas.

Even the Super Hueys I flew on contract with the mini-guns had K&N filters replacing the standard filters that Bell Helicopter supplied. They would just get caked after a day of takeoffs and landings from planet dirt, and our engines never hiccuped

[KensAuto]

I throw them in the trash all the time, right after cleaning or replacing a MAF sensor or throttle body (fly by wire style)

[TexasRedNeck]

I gained my confidence in the K&N in combat
Yep, sure did

In an emergency measure the Army strapped really big K&N filters on the front of the 4,500 HP Lycoming turbines on my Chinook to fight back the unreal dust from the recent combat areas.

Even the Super Hueys I flew on contract with the mini-guns had K&N filters replacing the standard filters that Bell Helicopter supplied. They would just get caked after a day of takeoffs and landings from planet dirt, and our engines never hiccuped

Don, not sure govt is the yard stick for efficiency or purchasing logic.  It's also possible that the fact that the K&N lets more through and the military can rebuild those things regularly that it made more sense than it does for a civilian street application.

.02


Sent from my iPad using Tapatalk

[cudakidd53]

How about "After Market Part Discussions" ?

[JR]

Or the "General Maintenance, How to/DIY projects" forum

[EL TATE]

I concur w/ JR. Thanks for the post though, I'm replacing my filter tonight and will be sticking w/ paper.

[Flyin6]

I think I am going to stay with the big K&N in SquareD

I agree with the findings and reasons stated accurately in this presentation.

However Square D has a high mounted air intake, and that is significant

Most dust happens and collects, and settles down low. Tires stir the stuff up and most intakes are going on around headlight level.

As you move upward the amount of dust in the air decreases rapidly. That's the primary reason for high mounted air intakes, not for deep water fording.

Additionally, my intake "Hat" has a spinning set of vanes which sweep the heavier particulate complementing the centrifuge spinning effect of the air entering the thing. These vanes push any solids out the vanes and back into the slip stream.

Secondly the K&N resides in a cavernous plenum chamber, and near the top. This provides a secondary filtering system using two physical properties, gravity and change in velocity. When air enters the chamber from the 5" tubing it immediately opens into a big area. The velocity of the intake stream slows a bunch. The energy necessary to transport a particle of size-X, is no longer present. Gravity will take over and the bigger stuff will fall to the bottom which is a foot below the filter!

The filter area is spread out so the suction effect of the inlet pipe is spread out and the corresponding "Vacuum" effect. All in all, dust is not going to have as much of an opportunity to even reach the filter as with a conventional system...
And for that reason, I'm in with K&N! 

^^^See, I rhymed it there^^^ ;)

[wilsonphil]

Well I will be going back to a paper filter, I have already gotten rid of the Oil filter the one that clogged so bad it limited my boost to 18psi (30psi normal)  this was not to long after I just "cleaned and re-oiled, from new it only lasted 10K before it was almost clogged and my filter is Up high also.

[wilsonphil]

  Most people don't know that K&N was sold back in 2011 to an investment firm Gryphon Investors they have since moved most of the production out of the USA to Korea and quality has suffered.  I do not use any of their products anymore.

Also Disclaimer in the subject of K&N, I used to race with Jerry Mall the previous owner of K&N filter.  I was giving him and his wife a Tour a few years ago and he told me the same thing that Gryphon just wanted the name and nothing else, its sad because he really built that company from nothing to a real powerhouse but he said he just got tired of dealing with all the government BS.

[Sammconn]

I've ran them in the past on a few vehicles.
I feel in a reasonably low dust environment they are ok.
Now with this new news of the sale, maybe not so much anymore?

I found maybe this very test when I bought my LBZ back in 06.
Was going to go this route, and it changed my mind. His very reason is also why I haven't twinned yet, as 200 miles of dirt road and a foam element scare the heck out of me.

Now Don has seen first hand some extreme uses of them, proving they are serviceable in nasty circumstances.

[Flyin6]

I've ran them in the past on a few vehicles.
I feel in a reasonably low dust environment they are ok.
Now with this new news of the sale, maybe not so much anymore?

I found maybe this very test when I bought my LBZ back in 06.
Was going to go this route, and it changed my mind. His very reason is also why I haven't twinned yet, as 200 miles of dirt road and a foam element scare the heck out of me.

Now Don has seen first hand some extreme uses of them, proving they are serviceable in nasty circumstances.

I have...
And those things seemed to work on both Chinook and Super Huey engines

However to the point of this argument two factors to consider

That was then and now is now (After said sale of a good American company)

And I was operating turbine engines. No piston rings touching cylinder walls. Just a lot of blades spinning really fast.
Dust tends to first polish, then sharpen the leading edge of the turbine blades thus changing their shape slightly. Each blade is a highly scienced airfoil that acts to provide maximum effect. Change anything, air density, add moisture or modify the shape and you change specific effect which for the stick wiggler means a change of power.

Because this is Satan's world down here, the engines do not grow more powerful, no, they suffer the opposite effect.

Being an instructor pilot, I oftentimes had to take new pilots out and "Qualify" them in the dust landing technique which is a controlled crash you barely know is coming. So the instructor pilot selects a particuliarly dusty area, then thrashes the machine, the people, his muddy eye sockets and airways in his lungs until none of that stuff functions. He then announces the training is over and the brown filthy machine with it's brown, filthy inhabitants land somewhere where some angry mechanics go about the business of washing it inside and out and doing other things like replacing the seals everywhere, and removing those filters. I have see those K&N's caked, literally caked with 2" of dirt or sometimes ice in places. I notice it on my EGT gage. It climbs when the engine starts to starve for the atmosphere which it gobbles at the rate of something like a standard american house every 20 seconds.

So I can say the filters worked on turbines, back then and kept us fliggin. But to say they will keep a dirty-max alive for 500K, well, I think the test results bear out that.

K&N: Was nice knowin' ya!

[Farmer Jon]

My cousin use to brag them up. I never had extra money to buy one. Over the years he changed his mind. Im glad I never got one. Now the pickup I just got has one and its getting tossed here shortly.