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K&N
https://www.slantsix.org/forum/viewtopic.php?t=57622		 Page 1 of 2
Author:  '67 Dart 270 [ Sat May 02, 2015 8:34 pm ]
Post subject:  K&N
I have K&N air cleaners. As Dan pointed out, they are too porous, they let too much stuff through. I can't find a paper element to fit my K&N housings, but I like the oval shape.

I have some headliner material, thin open cell foam with some soft black material attached. I can see light through it if I hold it up to the light. I'm wondering if I can use that as a pre-filter, wrap around the K&N filter elements as an extra measure of filtration. I did a non-scientific "blow" test, I blew through the K&N filter element with literally zero resistance, it's like there was nothing there. Then I tried the headliner material and there was a noticeable resistance to blowing through it. Not hard to blow through, but definitely more than the K&N element. I'm wondering if it is too restrictive...

I know that thin open cell foam is commonly used for pre-filter on K&N's, as well as motorcycles and such for dusty conditions, it's just whether that extra layer of cloth is too much. Anyone ever use this for air cleaner material? I have a snail gauge, does anyone know what minimum flow I should get through an air cleaner element?

brian
Author:  NEVjr [ Sat May 02, 2015 9:52 pm ]
Post subject: 
there is no minimum, but the less flow, the less power. this is a consideration for all flow related parts. i have used K&N air filters for some time, and I prefer them. there are more than a few Dakar vehicles that run them through a 5000 mile desert course. you will find many a story of many a vehicle that has lasted for years with no filter at all with a quick google search. also, with more restriction comes worse fuel economy, and buying filters all the time isn't cheap. how much quicker will your motor wear out vs how much extra expense in filters and fuel?
i dont know what your setup looks like, but could you put a second k&n inside the outer one? perhaps a t-shirt material prefilter "sock" could be made? you want the maximum number of the smallest possible holes for a filter
Author:  SlantSixDan [ Sat May 02, 2015 10:05 pm ]
Post subject: 
It's one thing to run K&N filters on a race/competition vehicle that gets an engine rebuild every season. It's quite another to do so on an engine you actually want to keep for awhile. K&Ns will keep out spiders, seashells, small children, and chunks of concrete. Actual dust and grit flies right through 'em and into your engine. See here and here ("After only 24 minutes the K&N had accumulated 221gms of dirt but passed 7.0gms. Compared to the AC, the K&N plugged up nearly 3 times faster, passed 18 times more dirt and captured 37% less dirt") and here. That's objective science, and anecdotal "Gee, I've never had a problem with 'em" stories really can't stand up to it. As for cars that have lasted eleventy million miles with no air cleaner: yeah, and there are people still alive who've been smoking cigarettes and driving without a seatbelt for 40 years. So?

The idea that real (i.e., pleated paper) air filters are inherently restrictive is a myth fabricated by the K&N people to sell their filter-shaped toys.

And no, headliner material is not an appropriate air filter or prefilter medium. There really isn't a shortcut; you're gonna hafta find or fabricate a housing for a real filter(s). You may want to draw some inspiration from this.
Author:  Damraider [ Sun May 03, 2015 12:58 am ]
Post subject: 
I read that but was curious if the filter was oiled that they were testing ( I must have missed it if it was said) .
Author:  slantzilla [ Sun May 03, 2015 4:39 am ]
Post subject: 
I ran a K&N on my Dakota R/T for 8 years and 160,000 miles. Washed and oiled it every 20K or so. Motor still ran like a top when I sold the truck with 200K on it.
Author:  SlantSteve [ Sun May 03, 2015 6:17 am ]
Post subject: 
You can find anything you like on the internet,from what I have personally seen I don't have issue with a CORRECTLY serviced KN filter...they don't get an FAA PMA approval for nothing. I've seen the results of aircraft engines operating in conditions your slant will never see and protect the engine through its service life...that's around 2000 hours at 75% rated power. These filters were serviced by people who actually know what they are doing at intervals of 25 hours of operation due to the extreme conditions . Why KN? Well,the reason did have a lot to do with cost,as you could imagine anything aviation comes with a price premium,including paper filters,the KN lasted for ages and is of course serviceable....Is the paper filter a superior filter? In this application I'd say no,paper filters wouldn't last and the paper media would basically get eroded to the point that the dirt could be ingested...in a vehicle application with comparatively softer rings and bores such as the slant perhaps a paper filter could be argued to be better...Do your own investigation and come to your own decision...when you stripped your engine did it show signs of ingestion? I think you can buy a foam pre filter if you wish,I think uni filter do them over here...personally I don't run the foam filter media as the prime filter,one backfire and it's gone! Maybe they are a more fire resistant material now,but that was always the risk with the dome shaped foam filters. I have used KN on my cars,my 318 stroker has I don't know how many miles on it,the car was my daily driver,LOTS of night driving and it had a fresh air intake for the propane system,lots of bugs and debris would find their way into the filter,not one child,rock,spider or lump of concrete ever went past the filter ,the post filter induction track was also inspected and found clean. But hey...if it concerns you then go for paper,you obviously drive in a relatively clean environment and the paper should last a long time and give you peace of mind.
Author:  '67 Dart 270 [ Sun May 03, 2015 10:55 am ]
Post subject:  Thanks for all the input guys...
Good stuff.

I've only had backfires when my dizzy gear shredded during the cam/oil gear bad interactions. I suppose that foam disappearing in an instant would be the least of my worries at that point.

I do properly service my K&N's as per instructions and I get a ton of dirt out of them (that's not to say they stop everything). I may add a thin fabric sock to the outside, K&N recommends these in fact. And, I'll keep working on the "ultimate" filter solution for me.

That's what gets me about K&N's, they show all the signs of the classic scam. I'm not saying they are a scam, but when a company advertises a "life time" solution super filter that does everything, and then sells socks and pre-filters and such that "extend the life of your K&N filter element", then was it really what they said in the first place (a lifetime filter element)? Rhetorical question of course. They could have simply stated that these pre-filters are for super dirty conditions so that your lifetime K&N filter doesn't get overwhelmed/clogged up, but they add "extends the life of." Their foam pre-filter costs $30, for a 2 cent piece of foam, same with their wraps...seems disingenuous to me, market forces aside (if I could sell a 2 cent piece of foam for $30 and people would buy it, I might). Summit and others sell cotton gauze filter elements, service kits and the whole array of supporting products. I be surprised if they did any independent testing, they've likely just jumped on the profit bandwagon.

brian
Author:  SlantSixDan [ Sun May 03, 2015 10:56 am ]
Post subject: 
Quote:
I read that but was curious if the filter was oiled that they were testing ( I must have missed it if it was said) .
Yes, it was oiled. Yes, it was said.
Author:  SlantSixDan [ Sun May 03, 2015 10:58 am ]
Post subject: 
Quote:
You can find anything you like on the internet
Yup, that is true. Facts and science and conclusions and reality…stories and opinions and guesses and fantasies…it's all widely available on the internet!

If you drive in very clean, low-dust, humid conditions, a K&N bugscreen might be adequate because you have fewer concerns about engine-grinding grit than if you drive in dusty, dry conditions.

As for the thing about a K&N unlocking hidden power and mileage vs. a real air filter: for some strange reason, the "benefit" only shows up when K&N does (or sponsors) the test.

I've made up my mind; K&N fans have made up their minds, and neither of us is likely to change. For those who haven't put much thought into the matter and are interested in making up their minds: carefully sort evidence from promotion and anecdotes. Consider the source when listening or reading; it is human nature to defend our choices because we want to believe we made a wise choice. Look at the evidence, think about it, understand it...and then you're equipped to make a well-informed choice—whatever that means in your case—if you want to.

(Thanks for that story about airplane engine air filters, though; I'll save that for reference next time I'm driving my car up at 20,000 feet. :lol: )
Author:  NEVjr [ Sun May 03, 2015 11:38 am ]
Post subject: 
i agree that if i were driving something that could no longer be rebuilt with any ease (a stutz bearcat maybe?) i would do everything possible to exteand engine life, including finding the most "filtery" filter.

outside of diesels, which are more prone to damage from dust apparently, i would like to see an objective test to determine exactly how bad the dust passed by a k&n is compared to other filters. does it reduce average serviceable life by 100k miles? 3k miles? i bet that the carbon that builds up in a motor and the washed cylinder walls from a carb are more significant
Author:  Reed [ Sun May 03, 2015 11:56 am ]
Post subject: 
K&N air filter to fit a one barrel 225 75 Dart = $46
K&N air filter to fit a two barrel 225 78 Aspen = $51
K&N air filter oil and air filter cleaning fluid kit = $14

Assuming free shipping, this means a K&N air filter that will fit most slant sixes would be $60-$65. K&N recommends cleaning the filter every 50,000 miles in normal use and every 25,000 miles in dusty/dirty use. That means the cleaning kits will likely last a while.

Rockauto lists air filters for $1 to $8, both one and two barrel applications. These will last two three years in normal use.

For me, the cost of a K&N filter that has lower filtering ability for five to sixty times the cost doesn't pencil out.
Author:  SlantSteve [ Sun May 03, 2015 1:09 pm ]
Post subject: 
Quote:
Quote:
You can find anything you like on the internet
(Thanks for that story about airplane engine air filters, though; I'll save that for reference next time I'm driving my car up at 20,000 feet. :lol: )
Who mentioned 20000' in their "Aeroplane Story" ? Dan even you would run out of air at that altitude ,let alone a normally aspirated engine!!
My "story" is based on aircraft primarily engaged in cattle mustering....low level operations often in extremely dusty conditions.
It's fine that we all have preferences and opinions,I'm just relaying my actual real world experiences,that's all....later.
Author:  SlantSixDan [ Sun May 03, 2015 2:32 pm ]
Post subject: 
Quote:
Quote:
(Thanks for that story about airplane engine air filters, though; I'll save that for reference next time I'm driving my car up at 20,000 feet. :lol: )
Who mentioned 20000' in their "Aeroplane Story" ? Dan even you would run out of air at that altitude ,let alone a normally aspirated engine!
Fer serious…and traction would be a problem, too. All the more reason for me not to put a K&N screen where an air filter belongs on my car.
Image
Quote:
It's fine that we all have preferences and opinions
Yup. And everyone out there in Slant Sixland will have to make up his or her own mind which opinions are soundly based and which ones aren't.
Quote:
I'm just relaying my actual real world experiences
As measured objectively against the control, of course…right? ;-)
Author:  SlantSteve [ Sun May 03, 2015 3:42 pm ]
Post subject: 
Quote:
I'm just relaying my actual real world experiences
As measured objectively against the control, of course…right? ;-)[/quote]
I'd say yes...FAA PMA approval is not exactly given away! :roll:
Author:  wjajr [ Sun May 03, 2015 4:55 pm ]
Post subject: 
Dan:
Quote:
Thanks for that story about airplane engine air filters, though; I'll save that for reference next time I'm driving my car up at 20,000 feet. Laughing
20,000 feet? That's all? Man, you need to check that valve lash there Bub.[/quote]
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