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Out of curiousity I took the cap off of the end of my air cleaner assembly, it is held by 2 wire springs. That round section is apparently a dust trap, and there was some dirt inside. I noticed how much of the air filter was exposed with the end off, so I left it off. A quick calculation revealed that the normal inlet is about 3 square inches, the end cap exposed about 10 times that amount, about 30 square inches. Less restriction is good, right? Kind of why we used to turn air cleaner tops upside-down in High School.
With the end off, the engine is noisier, but sounds like a small V-8, mostly during acceleration. No real power increase, and too soon to tell on the MPG. The air cleaner assembly acts as a muffler, something I didn't know until now.
Give it a try and see what I mean. I may put the end back on, maybe not. Only filtered air gets into the engine, so I don't think any damage will result.

The end piece of the air cleaner that you removed is supposed to also collect dirt before it hits the filter. I always wondered how it works but whenever I change my air filter there is plenty of dirt in there.
Sounds like a V-8 huh? Gotta try that!

pinzinator wrote:Out of curiousity I took the cap off of the end of my air cleaner assembly, it is held by 2 wire springs. That round section is apparently a dust trap, and there was some dirt inside. I noticed how much of the air filter was exposed with the end off, so I left it off. A quick calculation revealed that the normal inlet is about 3 square inches, the end cap exposed about 10 times that amount, about 30 square inches. Less restriction is good, right? Kind of why we used to turn air cleaner tops upside-down in High School.
With the end off, the engine is noisier, but sounds like a small V-8, mostly during acceleration. No real power increase, and too soon to tell on the MPG. The air cleaner assembly acts as a muffler, something I didn't know until now.
Give it a try and see what I mean. I may put the end back on, maybe not. Only filtered air gets into the engine, so I don't think any damage will result.

The inlet is the same size as the outlet. Not sure how you could be bringing more air in? I can tell you with EFI. take the stock filter off and you have one hell of a whistle . I have had two mechanics comment that the stock filter canister was one of the nicest designs they have ever seen. From what I can tell a lot of thought went into the factory canister and I'd use it as it was designed to be used.

The entire vehicle is the result of some amazing engineering, the Pinzgauer never ceases to amaze me. The air cleaner was one item I figured I could alter without harming the driveline mechanics or performance. And that was by simply removing a section of it.
The stock inlet to the air cleaner is 2 inches in diameter, which equals 3.14 sqaure inches for air to pass through. The outlet of the air filter to the carbs is about 4 inches in diameter, which equals about 12 square inches for air to pass through, a 4-fold increase, therfore less resistant. Be taking the end cap off you allow the filter to be exposed to about 28 square inches for air to pass though, or 2.3 times the area of the air filter opening. This makes the filter itself the biggest restriction between the atmosphere and the carb throat. I'm just an armchair mechanic, and I could be all wrong. But at least it sounds good when driving!

pinzinator wrote: The outlet of the air filter to the carbs is about 4 inches in diameter,

The outlet to the filter canister is the same as the inlet. You're measuring the inlet of the air intake. Take the boot off and measure the filter canister.

pinzinator wrote: This makes the filter itself the biggest restriction between the atmosphere and the carb throat. I'm just an armchair mechanic, and I could be all wrong. But at least it sounds good when driving!

There are so many other constraints in the pinz airflow that the pinz factory filter is unmeasurable. In fact, in some EFI testing HP/torque went down without the airfilter.

Gotta remember: The pinz is a low cfm, low rpm engine with very odd cam timing.

I've got the runner cross section area somewhere, but the even the relatively small intake runners are somewhat oversized for the CFM of the pinz.

Unlike V-8's, you have only one cylinder at a time pulling air, and even that for just a fraction of a second.

With air filters & throttle bodies there is definitely a point where bigger is not better. Or less restriction does not translate to improved performance. Big enough is big enough.

I'd not trade off dust capture, which is what you are doing.

Have fun,

Alan

Pinztrek,

Good point, looking at some high performance engines (including 4 cylinder) the intake runner diameter is based on the valve size.
1" valve=0.785 sq.in. x 4 = 3.14sq.in. total area, or to look at it another way a 2" tube gives you the same area!

Jake found on his EFI system that it is really hard to beat the performance of the stock filter system. Dyno plots proved that.

I'll take the cyclonic filter (commonly called centrifugal) system also, it helps keep the filter cleaner.

SAV sales a direct K&N filter for the Pinz. Has anyone tried it and noticed any improvements? Is it worth it?

chacaocop1 wrote:SAV sales a direct K&N filter for the Pinz. Has anyone tried it and noticed any improvements? Is it worth it?

Jake for what it is worth, the K&N filter is a piece of crap. In an off road environment it allows too much particulate matter to pass causing scoring of the cylinder walls(experience is the best deterrent)
Also they tend to twist and collapse in the housing(have removed several this way

Good to know. Thanks a lot.

SAV offers a filter that goes into the air cleaner assembly. Here's one that is a drop-in replacement of the entire unit.


The 4-inch rubber opening fits over the carb manifold perfectly. You don't even need to use the straps. Clamp included. The doghouse fits over the filter like it was designed for it.


The filter comes pre-oiled and ready to install. I don't see how this will collapse, and I've never heard a K&N called crap before, at least not by anyone who has actually used one.
If you want one of these, go to Amazon and search for RD-1460. $31 includes shipping.

pinzinator wrote:at least not by anyone who has actually used one.

The quote I used was from this Forum one of Jim L. Post.

So Jim have you ever used or worked on a Pinz that had a K&N filter installed on it.


I had the K&N on my Pinz. for a couple of days while I was altering the filter housing to work with Jakes EFI. kit.

pinzinator wrote:and I've never heard a K&N called crap before, at least not by anyone who has actually used one.

I'll bite. They are crap. And yes, I've used them on several vehicles.

pinzinator wrote: and I've never heard a K&N called crap before, at least not by anyone who has actually used one.

You must not drive a big diesel, or follow the forums where they are discussed.

Airflow is a big issue in diesels as you uprate them. So many try to get HP by replacing factory filters with stuff like the K&N. But many cummins types also do oil analysis, and they absolutely see increased silica (meaning contaminants) and metal in the oil with the K&N's.

Filter companies like fleetguard publish SAE tests for their filters, and all filters have to meet certain specs (J276C). All the time, from brand new to fully clogged. These tests measure filter efficiency in terms of how much of the multisized test dust is passed vs retain. And also measure restriction.

Try to find SAE specs for a particular K&N filter. For years there was no reference to such a thing. Now the website says they test them, but that each filter would be different so they don't bother to post individual filters.

Never do they publish the results. They often do state that they filter within 99% of the factory filter. 1% does not sound like much, but as air filters are measured that's an unacceptable figure. Depending on the filter, that can be 15-30 times more small dust particles allowed to pass. And enough that measurable engine wear can be detected with oil analysis.

Put another way: A good quality paper or foam air filter will be 99.5 - 99.9% efficient. IE: Stops all but .1 to .5% of particles. So what happens to K&N's "we are 99% as good"? 99.5 * 99%= 98.5% efficiency. Pretty crappy!

So some folks did some independent tests. And yes, a K&N well loaded with grit did filter OK, not great, but OK. But it let the relative equivalent of boulders through when freshly cleaned/oiled and did worse on small particles. IE: It did not filter at an appropriate level.

Worse, you are putting your engine at risk trying to solve a non-existent problem. The pinz filter has plenty of airflow even dirty. Putting a less restrictive filter will not increase HP, as it's not the constraint. The valves, head, and intake runners are the constraint. You can't change that.

So back to diesels. I have an '03 High output cummins ram. All types of filter claims out there. So turbodiesel register did side by side dyno's of all the magic filters compared to the factory. Only one even showed a bit of improvement, and it was only 1-2% when you reached 500HP. All showed significantly increased noise. And all did not filter as well as the factory. So for $50-200 you can wear your engine out faster. On my particular model, the air filter is simply not the constraint. (nor is the exhaust for anything under 500HP, for that matter)

But don't listen to me, here's some links with the results of testing K&N's:

http://www.nicoclub.com/articles.php?id=180100

And Bob'stheoilguy also did some less scientific testing:
http://www.bobistheoilguy.com/airfilter/airtest3.htm

There is one situation that I would consider an oiled cotton filter: If I was a big dollar baja racer I might would consider one as engine wear is just not relevant. And dust is clearly a problem. But then again, many race engines don't even use air filters, just simple screens, as the engine won't wear out in the 500 miles it's used. The same reason many use plain oil. (Indy cars for years used plain jane oil, no synthetics, etc)

OK, so I won't call them crap. What I'll say is that they won't make your pinz work any better and will shorten it's life. If the "whosh" sound is worth that, then you have that option!

Sorry for the long post, but there is so much misinformation out there that it's worth looking at some hard data.

Have fun, and happy "whoooshing"!

Alan

I run a couple of 12 valve Cummins Dodge trucks. They make the coin for me to play with my toys. In 1999 I put a K@N on a 1998 Dodge and ran it for about 20K miles , much on dirt roads. The motor developed enough blowby that I had to replace it with a factory recon motor (busy season and no time to pull it apart and re ring/ rebuild). A lot of toys suffered,as the recon and install at Southwest Cummins cost near $11,000 ! When taken apart, the intake system ,intercooler, etc. was full of fine dust. The recon motor got the stock filter put back on it and it has 365,000 miles on it now. No excessive blowby yet. My pinz sees a lot of dust and dirt and the filter seams to be really clean on inspection. The dust collector cap always has dirt in it. All of the heavy equiptment that I have ever ran has had a very similar filtration system as the one on the pinz.The equiptment runs in dirt /dust conditions and seems to last .Maybe the K@N works wonders for some,not for this kid. Hell, even crap makes great fertilizer which makes for some pretty tasty strawberrys !