[TR] Independent air filter test

[Michael Porter]

thenicholls at verizon.net wrote:
> Justin, Randall and list,
>
> Did some searching around and found this test very interesting:  http://www.bobistheoilguy.com/airfilter/airtest1.htm 
>
>   
I'd already put in a couple of cents' worth on this thread, but, I guess 
it was too big.  This test reminds me of a couple of things from the 
heavy-duty diesel market.  Filtration is a big deal with big 
diesels--every manufacturer wants high mileage between rebuilds because 
that's a reputation builder.  I know of no HD diesel manufacturer that 
has certified K&Ns for use. 

More importantly, they do test filters.  One of the things that was 
found was paper filters get better over time (up to a point), and the 
general recommendation was that instead of changing them frequently, the 
filter should be cleaned, not by blowing air through the filter, but by 
tamping them on a hard surface to shake off the surface dust, clean the 
housing and reinstall, and change the filter every other cycle (or if 
the filter drop reached 28-30" H2O--this certainly wouldn't be 
recommended with a naturally-aspirated engine, but, all diesels today 
depend upon turbos and the suction on the inlet side of the turbo is far 
higher than for a conventional gasoline engine).  The thinking was that 
larger particles blocked smaller openings in the weave of the paper and 
kept more small particles out.

That said, the testing mentioned at the link above certainly could have 
been more scientific.  Color is only a rough indicator.  I would have 
been more impressed with a test that took a tare weight of the second 
filter, and weighed each sample to see the total filter load by weight, 
and an analysis by particle size would have been more illuminating, but, 
that's probably beyond the guy's research budget.


Cheers.

-- 


Michael Porter
Roswell, NM


Never let anyone drive you crazy when you know it's within walking distance....