Reusable vs. Disposable Air Filters - Is it Worth the Trouble?

[Gary Hatt - Publisher BCM]

I recently bought a bus with an 8V92 and I discovered it had a (reusable) K&N Air Filter.  I bought the K&N Air Filter Cleaning Kit and spent two hours cleaning the filter.  It is now drying.  I have yet to oil it.

I am now wondering if it is worth all of this work and time, let alone the Hazardous Waste disposal of 25 or so gallons of oil contaminated water issue.  (I forgot what I did with it)

I am wondering if next time it will just be easier to purchase a disposable filter instead and just take the old dirty element out and replace it with a clean one.  I am a full-timer and RV parks are my home, so any work I do on my coach could be scrutinized.

Suggestions from those of you who have been thru this?  Are the disposable Air Filters just as good even though it may cost more over time.  I will probably put less than 3000 miles a year on this bus.

Gary

[kyle4501]

I read an article in the FMCA magazine about those K&N air filters. To get less restriction, they have larger openings which will pass larger dirt particles. The engine manufacturers don't like them. One of the engine reps said they worked fine at keeping stones out.

If they were half as good as the marketing hype, every OEM would be using them.

If the big diesel engine manufacturers aren't using them, that should tell you something.

If it were mine, I'd replace it with what was recommended by the engine's manufacturer.

[H3Jim]

I second Kyle's comments and concerns.  I would go back to stock.

[tekebird]

I have had K&N filters in two of my pickups.

1988 F-150 with 300 6 cyl..............200k miles when I sold it...and another 30k before that guy sold it.


This truck saw at least 50k in off road high dust driving...I think I had to clean the filoter 4 times in that 200k ( had a airflow meter so I did it when flow was restricted

1998 F-150 with 5.4 L 8 cyl 150k miles when I sold it.

OEM don't like them because they weed into their filter sales....you know how those Car dealership service writers are.......dirty filter, 10.00 and 1 hr labor to put it in.

There are alot of off road racing teams using K&N and other siimilar filters.......and it's not because they pay them that much......and beleive me those guys do not want to be rebuilding their motors because of poor filtration.

Keep in mind these things work better when they are a bit dirty.

[tekebird]

Can of worms..........

Stock is Oil Bath,

[H3Jim]

As bus owneres we tend to want to get the most mileage from our engines.  Race teams want max power and air flow.  They rebuild so often its not a good comparison.  Your example of the truck mileage is convincing though..

I don't think the K & N's filter as well as a stock paper filter - there is a price for that increased air flow.

And yes going to an oil bath does sound like a can of worms.  I was thinking of my stock paper filter that comes with series 60s.

[tekebird]

Jim,

I have owned dirtbikes even before I could legally drive......they all come with foam filters (wet- Oiled).......these have much larger holes than the K&N and it is clear that they do thier job as the outside cover of the airbox is always filthy....even after a short ride........and after a 6 hour enduro ( even a desert enduro) the inside of the airbo and throat going to the carb are always clean as a whistle.)

although there is alot of snake oil out there......K&N is not one of them.

They do need to be cleaned, properly...and they do filter better when dirty ( not clogged)

[Gary Hatt - Publisher BCM]

I thought I remember that my Diesel Mechanic said the 8V92 would suck the oil right out of the air filter.  He said the original engine used one, but it was not recommended for that big sucker.

But that was the same Mechanic that put the multi-weight oil in my engine which I had to change out with 40W.

Comments?

Gary

[tekebird]

your riginal air filter was an Oil Bath Air Filter......different design and principle.

I Do not beleive your engine will suck the oil out of the filter. 

I would suspect that unless you are driving on dirt roads, you should be able to go over a year on one filter cleaning/oiling.....perhaps more.

as I said My 88 Truck was operated regularly in very dsusty conditions......and over 10 years I only had to clean it 4 times, and I doubt the guy I sold it to ever did......thats 230k with 4 cleanings over 10 years.  with very good engine life

[kyle4501]

I work for an OEM, & I can tell you that if there is ANYTHING out there that will reduce required service before the warranty runs out, I'll put it on the machine! There is too much competition in the spare parts that are so easy to find elsewhere. We make money on spare parts only when we are the only source. That spare parts sales conspiracy is a urban legend as far as I'm concerned.

I have yet to see a meaningful flow curve or maximum passed particle size for the K&N filters. Would be great to know how they compare to the OEM specs.

I have one on my 454 suburban & I'm not impressed as there is no difference from the paper element as far as I can tell. Cleaning it is a real PITA as far as I'm concerned. I don't think I'll save any $$$ with it like the box promised when you add the cleaning oils.

I have a cousin who seldom, if ever runs an air cleaner on his cars or pick-ups. He puts lots of miles on the vehicles before replacing them & engine life is never an issue for him. Lots of people have apparant sucess ignoring/ disregarding the manufacturers recommendations, but to each his own.

Personally, I'm gonna side with the manufacturer specs on this one.

As far as going back to oil bath, well that may or may not be practical, it depends on what was removed. If not practical, do some research at a good truck service shop to find out what is available that will provide the required air flow & filtering. You might even be able to get a filter housing at a local truck wrecking yard that uses a common economical element.

The paper filters are best on a turbo engine because oil vapor will erode the turbine impeller. If you get the K&N filter sized large enough to get the air velocity low enough, it won't pick up oil from the filter, but I have no idea how you would size it since the data is elusive.

[Kristinsgrandpa]

Here is a link to a filter test, well sort of.


http://www.bobistheoilguy.com/airfilter/airtest3.htm


I found it interesting.

Ed

[NJT 5573]

Gary, I wanted a K&N for my diesel applications. K&N denies they make a large truck/bus filter. They won't sell me one. I like the product. If you switch to paper I'd like to know if there is a noticeable decrease in power. The K&N was worth a lot of power versus paper on my dirt bike. Did you notice if the turbo had dryed the oil out of the filter?

[TomC]

On my last truck, I got tired of replacing my throw away can type air filter (can was sealed and $85 a pop).  The can filter would last about 30,000 miles before having to replace it.  What bugged me was the fact that the can filter had 5 inches of restriction when new. When it gets to 20 inches, had to replace it.  I had a K&N filter made up for my old replaceable filter can (K&N is not making commercial filters anymore since they had to make them by hand and they were just breaking even on them).  I ran the filter for four years and about 300,000 miles of driving, cleaned it just two times, got way more air flow, and was generally pleased with it.  If the engine was prematurely wearing out, I would think that after 300,000 miles, you would start seeing oil consumption, or dirtier oil!  Neither was the case, and personally liked the filter (it is still on the truck now).  If you do use a K&N, don't clean it until the restriction gauge tells you to -it actually cleans better the dirtier it gets (because of the extra layer of dirt acting like additional filtration).
I wanted to put one on my bus, but since K&N doesn't make it anymore, installed a larger Donaldson with paper element.  Donaldson makes a few different types of paper elements.  Check out their web site.  Good Luck, TomC

[Gary Hatt - Publisher BCM]

NJT,

Regarding the air filter drying out, that was not a problem.  It was pretty well caked with crud and after going thru 3 cans of the automotive size cleaning spray bottles, I finally got it pretty clean but then again, as I am hearing, sometimes it is best left a bit dirty so it will filter better.  There was no evidence of the filter drying out.  Even the last time I rinsed it (the 10th time) there was still oil residue in the drain pan.

I didn't realize K&N didn't make filters for big engines anymore and I am surprised you can go so long between cleanings.  In fact, I think the cleaning kit said you can go 50k to 100k miles before it needs cleaning, so I guess 2 hours to clean it isn't so bad.  Furthermore, as I drive less than 5000 miles per year (till I retire), it will be another 10 years or so before I need to clean it again.

Gary