K & N Air Filters??

[Vettepilot]

I always run a two stage, dry paper before oiled foam filter on my offroad buggies, and have had excellent luck with them.

One time, long ago, I installed a PROPERLY OILED K & N filter on a newly built VW engine in a buggy. Over ONE weekend of fairly hard offroad running, the engine ran worse and worse, and started smoking and using a lot of oil.

I found low compression on all cylinders, and tore it down. It was junk!! TOTALLY and completely worn out! Pistons, rings, valve guides, everything! Needless to say, I NEVER used a K & N filter again! EVER!!

So, how and why do they have such a market following?? I can't be the only one with a negative experience. Has anyone here used them offroad with success??

Thanks,
Vettepilot

[Alstrup]

Because the suburban warriors need not worry about fine Arizona sand. It is also common knowledge that if you use your vehicle in the dunes or in other "polluted" enviroments you need a dual layer filter.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[modok]

I have become a believer, I've seen it work.
The cotton gauze filter can work better than anything else under certain conditions.
the problem is that outside of those certain conditions, it doesn't work.
many engines destroyed.

in my next life I want to be a dust scientist. dust varies. What is it made of? what properties does it have? All dust is not created equal.

[Dan_Lockwood]

[richparker]

[slalombuggy]

I had a K&N on my last Colorado from day 1. Sold it to a friend with 200000km on it, he still has the same filter and over 300000km on the truck. Its all about the application.

[QRP]

I run a 6" tall K&N filter on my Baja for buzzing around town but when I go out in the desert dust I put a dry UNI filter over that.

[chrisflstf]

You can run outerwears also. Cb has them. They will filter down to about .010", which will stop the big stuff and add a 2nd layer

[oprn]

If an air filter is the same size or smaller than stock and the claimed to flow more air and make more power then it will let through more dirt. Simple physics. The slower the air moves through any filter the better the chance the dirt will be captured.

Big filters and multiple stages/layers. It never ceases to amaze me that guys will spend tens of thousands of dollars on the best of everything in an engine build and top it off with some $5 junk air cleaner just because it’s shiny. Or in some cases… none at all…

A good friend of mine who is a veterinarian (country roads) got talked into all the benefits of a K&N filter on his Cummins. It cost him a new engine. The mechanic told him worn out piston rings on Cummins engines is always the end result of using them.
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Our cars get old, we get old but driving an old VW never gets old!

[94touring]

[richparker]

I run UNI pre filters all the time on both of my Vw’s. They not only increase filtration but they also reduce induction noise.
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’71 Westy build
Adventure thread
’65 Deluxe Build

[YDBD]

Because they are actually really good filters. The user must make a decision on how much filtration is need for the conditions. Rear engine buggy's and sand rails with dual carbs usually put the filter in line with tire kick up-more filtration is needed-A LOT!

Two stage filter with K&N inside:

K&N filters with Outerwears:

Not K&N, but an interesting set up my dad ran with a Holley Bug Spray to get the filtration away from the tire kick up:

It's not the filter, it's the application the filter is used for. Go to the K&N website and look for more info on the application you need a filter for.
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'56 pan Dune Buggy since '69
don't live in the past...but when I did:
'67 bug
'64 baja
'60 dune buggy
'73 Personenkraftwagen Type 182 "Thing"

[QRP]

[Nitramrebrab72]

https://m.youtube.com/watch?v=YypvDEQyNBY


This test says it all.. ( 4.40 to 8.00)
Look for the red on the graph they are the particles that do the damage..

AEM seems to be the best performance filter. But none are any good for repeated dusty off road use, where air intake positioning and dusty air deflection are just as important as filter type.

[jimmyhoffa]

[QRP]

Let's not leave out the importance of the filter housing.
The base and top are just as if not more important than the filter itself.
Most of those tinfoil housings that come with said filters are garbage.
The best filter in the world is worthless if are and dirt are getting around it.
A good billet housing is a must in the dirt.

[Erik G]

[94touring]

Those outer wears are just the lunch lady hair net things you can see through right? You really need a proper oiled foam cover like the Uni foam filters linked above.

[oprn]

I concur with the need for better quality air filters. All it took for me to realize that was a half mile run on a gravel road on the first run of my new engine. When I took the air cleaners off to change jets the inside of the carbs were filthy already and there was no dust caught in the air cleaners at all. That’s the air cleaners that CB and others supply for IDFs. Those are just glorified window screens.

Outerwears made by my wife out of a single layer of diaper flanellet available at any fabric store made a HUGE difference. I no longer see ANY dust in the carbs at all but I have to take the outerwears off and wash them about every 3 weeks in the summer. I have 2 sets now and rotate them.
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Our cars get old, we get old but driving an old VW never gets old!

[Vettepilot]

I have a dim memory of the military operating in a super dusty area and having engine failures. As I recall, they solved it with ladies nylons stretched over the air filters.

I think I heard a similar story, but involving volcanic dust.

The memory fails me these days...

I did contact Uni about it, and they said "don't" as the oil and nylon together would be bad.

For dual carbs... doesn't someone make carb hats that route a hose to an air cleaner mounted in a better spot??

Vettepilot