The K&N is a 20 micron absolute (not nominal) element, that flows 16 GPM

at

70 PSI. This is way more that required for a rotary. While there is no

doubt a

pressure drop across the element, I cannot detect it with a conventional

oil

pressure gage.
If you can find a better performing filter with a 550 pound burst can,

please

tell me about it. I run two in parallel on the race car for 32+ GPM
capability at 100 PSI.

The SAE dirt holding capacity or efficiency when half full of dirt is of

no

value as a requirement. I discard then each season. An element half full

of

stuff, means that your bearings are gone. Bearing stuff is real big. Even

a Fram

can stop a bearing, or a washer, or a screw driver. It just cannot protect

the

bearings against contamination.

Lynn E. Hanover

I wasn't referring to any efficiency when half-full.  The capacity of a
filter speaks to filter lifespan.  Anyone can make a paper filter that lasts
3000 miles.  Folks making filters for extended drain intervals have to have
more capacity.  Once the filter material plugs enough, the differential
pressure will reach the set point for the bypass valve.  From that point on,
you don't have an oil filter installed.

The K&N is reportedly made by Champion Labs, same as the M1.  The M1 is
reported to have a 600 pound burst.  K&N advertises a couple of different
media types on their web site.  The resin impregnated sounds like paper to
me, tho I could be wrong.  I know that the AMSOIL super duty line and the M1
filters use a composite media of cellulose, fiberglass, and synthetic fibers
and are designed to be more of a 'depth' type filter.  This is where they
gain their increased capacity.

The Fleetguard centrifugal bypass filter is only about 95% at 10 microns,
AMSOIL's BE-90 bypass filter is 99.8% at 5 microns and larger.  Neither of
these filters will handle full-flow duty.

Can you point me to tech info on the K&N?  My understanding is that to get
absolute at 20 microns you have to move into bypass filter territory due, at
least, to flow restriction.

Andy
Ahecker at satx.rr.com

Sorry this messages is delayed. I over looked it on Thursday.

Paul Lamar
 
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