K & N filters

Anybody using the K&N oil and air filters on their CJ's/258 ?

If so are they worth the extra expense ? thanks..........

 

Hi flow air filters are a waste on carburated engines (w/ EFI more air can be compensated w/ more fuel). Over time you may break even on cost but performance will not change. Oil filters is more of a get what you pay for. K&N are kinda pricey but for the added filtering could be worth it.:v6:

 

Well...as far as the air filter goes... K&N is a good quality high flow filter. I make my living building high horsepower engines, many which run no filter at all...Here is the thing about K&N air filters (and alike)...they let in more air (obviously) but they will also let in more dirt. Few things will beat a high quality paper filter for filtration. It's one of those trade off deals (like many things) A little more air flow for less filtration. I'm not sure what kind of filter that you are currently using...but chances are (unless you are running a nasty engine) that it has adequate air flow in paper form.
An engine is nothing more than an air pump... the bigger the engine...the bigger the cam...the higher the compression...the more efficient heads...the more air it can pump...for more air, you add more fuel to match the increased air...also known as carb jetting (tuning).
Anyway...generally speaking...a paper filter will by fine for most of us (and will filter more too). Oil filter...Wix is a great oil filter ...and cheaper than K&N.

 

If you use the Jeep in any kind of dusty conditions, I would forget the K&N. Somewhere on the web I found a long technical article about air cleaners. You could spend the time to Google, but the bottom line seems to be that the oiled cloth filters will flow more, but at the expense of filtration. I'd stick with the paper.

 

I ran one but have switched back to paper. My suggestion is go to a taller paper filter for more unrestricted air when it's really sucking air. I think I run a 3.5" tall filter. The original is less then 2".

 

100% true. They filter nowhere near as well as paper. Also...you would be very surprised how little difference in flow there actually is between a good paper filter and the K&N style when placed on a flow bench.

 

Guys, thanks for the responses. I was trying to justify the expense of the K&N's by their longevity but you can buy a lot of filters for the initial cost of these, plus their required recharge/cleaning products.

I was just looking for the best products period, and it seems like the WIX line is very highly regarded.(thanks mcgillacuddy) Turns out the Napa Gold oil filter 1258, I am currently using, is actually made by Wix .

The WIX 51258 oil filter is available on e-bay for $60.00 per case of 12
The WIX 42054 air filter is available on e-bay for $41.00 per case of 6

These are the least expensive prices I have found. If you have a Jeep with the 258, a stockpile of these would last a good long time and no more last minute trips to the autostore to pick one up. I use my jeep daily for short distance driving and am planning on changing my conventional oil every 3,000 miles and air filter every 10,000 or so, so these will last quite a while.

I use a suction device to remove oil from the crankcase via the dipstick tube, but I have yet to come up with a way to remove the oil filter on the 258 without creating a pretty good size mess. Anyone perfected a technique for spinning it off cleanly ? Thanks

 

The only thing I can think of for a "less" messy oil filter change would be to have a remotely mounted oil filter...like...easy to get to and straight up and down, so you would not lose much.

 

Note that Jeep used a foam air filter on all the vehicles of '70s vintage. From the factory, the paper air filter was wrapped with an oiled coarse foam filter. Under dusty conditions, this prevented having to replace the paper filter so often - though you had to take the foam element off, wash it in solvent, oil it and put it back. These were a fairly coarse foam, so I'd expect they didn't slow air flow much, and removed most of the large particles.

IIRC K&N has a foam wrap filter for paper elements that might be suitable.

Poke a hole in the filter can and let it drain? Haven't tried it - just a thought.

 

Yes...many desert racers still use the foam pre-filter...it works good.

 

Not sure if any of you guys have actually opened up an engine that was running a K&N, but I've got two engines running them now. One is a 7.4 Powerstroke that has had the filter on for 50,000 of its 65000 miles and the intake is perfectly clean with absolutely no indication of wear on the turbo vanes. The other engine is a 302 with a few thousand miles of trail use in very dusty conditions. It also has an absolutely spotless intake tract (fuel injection with a long intake tube.) I also used to believe that the claims around K&N were too good to be true, but I've seen enough personally to be a believer.

 

Yes..I have..many...as I mentioned...I am a performance engine builder for a living...
Here is what K&N filter will burn down to....
1...Not much power increase...I own a dyno and use it daily.
2...A higher cost.
3...Not near the filtration of a paper element...As a matter of fact...a handful of automakers were voiding the warranty if you used a K&N filter. This is not the case any longer...because of the Magnuson-Moss Warranty Act. This was a long fought out battle..the people won the right to choose what air filter they can use.
I personally would never go as far as to say a K&N filter does not work....But it cannot be compared to a paper filter for filtration...and K&N will even tell you that.
So you get a filter that cost more, does not filter as well and flowbench numbers and dyno number show little and sometime no increase in flow. There really is no reason to buy one unless you just like the idea of K&N.

 

IMO - I would stay away from the K&N unless you are using it for racing purposes. Shortly after I installed my new 6.5l engine in the K3500 the silicon reading were high in the oil sample analysis. I changed the air filter to a stock paper and the reading came back to normal. The K&N was allowing large amounts of dirt to pass into the engine. The filter had been re-oiled twice, once by me and once by a diesel shop. I am now using a later model updated stock GM air filter system, and the silicon levels have remained within acceptable limits.

 

I agree 100% and have had similar findings myself.

While I have performed a number of tests myself...None of them were done with anywhere near the caliber of equipment this guy had at his disposal.
Some decent reading

http://www.duramax-diesel.com/spicer/index.htm

When I was younger, I worked as a mechanic for a very large construction company. Someone had an idea to try and save a few buck by using the oil/gauze filters in the equipment...because the cost of the paper filter were VERY high (some were over 500 bucks)...So being able to wash and reuse a filter would seem like a good idea.
They also performed oil diagnostics at every change...and found that the amount of crud was considerably higher than it was previously. A decision was made to go back to the paper style...and the level returned to normal.
On a semi related note...Clean rooms and hospitals use paper filters.