UOA Silicon # vs air cleaner effficiency

[tdi-rick]

How effective are silicon numbers in evaluating air cleaner efficiency ?

I suppose what I'm trying to say, is a UOA valid in evaluating a K&N (or other oiled cotton filter) vs a high quality pleated paper filter in a specific application ?

Rick.

 

[Virtuoso]

Assuming both filters are sealing properly in the box, I belive it is a pretty good indicator.

 

[tec97]

It may be reasonable provided that is literally your only variable - IE not just the same oil, but all oil purchased at the same time and from the same lot (or if you have multiple lots, mix them the same at each change).

 

[Gary Allan]

My UOA indicate that my K&N works. Sure you can have variables from oil to oil..

Look here my UOA w/K&N conical filter

This is why I don't think the K&N bashing is valid. I clean mine semi-annually

 

[tec97]

Personally I'm suspicious of the bashing too - I got 2 ppm more Si w/ a K&N in my Protege than my g/f's Eclipse w/ a Wix after approximately 1300 miles more driving. Different cars, different engines, but the same oil and the same environment.

 

[RavenTai]

I do not need a UOA to tell me K&N's let dirt through, I have seen a layer of our famous Georgia red clay stuck to the inside for the intake hose down stream of the filter on a friends Tacoma, cleaned intake and replaced with paper intake tube stayed clean, K&N is not an acceptable off road filter in GA

if you live in a low dust area K&N is probably OK, especially Florida with its large grain sand based dirt that will not hang in the air like clay does

one other thing to consider is a spectro UOA will not catch larger SI particles only the very small ones, you would think that if there are large particles there should be a proportionate amount of smaller ones also but depending on the dirt composition in your area that may not be the case

 

[Not the Autorx Frank]

Doesn't insolubles in a uoa help tell the story?

 

[tdi-rick]

thanks everyone.
Nice explanation TooSlick.
Having done an 11 000km UOA with a K&N fitted, I can compare it to the current and next one with a Donaldson element.

FWIW, K&N claim an approx. 98% filter efficiency, Donaldson 99.99%.
I'll see if the wear numbers show up anything.

Rick.

 

[TooSlick]

The best way to evaluate air filter efficiency is to compare the wear metal concentrations of iron, chrome and aluminum, after the same # of miles. Run the same oil and oil filter and keep all the other variables like fuel, driving style, trip routes, etc the same. Do a fairly long oil change interval of say 6000-8000 miles, which will make the performance differences more obvious.

If one filter generates > 25% higher wear metal concentrations across the board, it's letting in more dirt, regardless of the silicon(e) level. If you switch to an aftermarket, high flow air filter and you start to see nickel in your analysis, that's a really bad sign. This would indicate abrasive wear of the intake and/or exhaust valves, which are generally stainless steel.

TS

 

[tec97]

quote:

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Originally posted by TooSlick:
The best way to evaluate air filter efficiency is to compare the wear metal concentrations of iron, chrome and aluminum, after the same # of miles. Run the same oil and oil filter and keep all the other variables like fuel, driving style, trip routes, etc the same. Do a fairly long oil change interval of say 6000-8000 miles, which will make the performance differences more obvious.

If one filter generates > 25% higher wear metal concentrations across the board, it's letting in more dirt, regardless of the silicon(e) level. If you switch to an aftermarket, high flow air filter and you start to see nickel in your analysis, that's a really bad sign. This would indicate abrasive wear of the intake and/or exhaust valves, which are generally stainless steel.

TS

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By that measure, the K&N panel in my Protege is doing fine. Wear is right in line w/ UAs and for a longer interval...