<VV> K&N dirt

[Joel McGregor]

I've never had the oil tested but I've run K&Ns on motorcycles and seen dirt coating the throat of the carb.  It's always extremely fine but it's dirt.  They do flow better.
Which brings up a question - how large does a particle have to be before it hurts to run it through your engine?  Obviously no filter blocks all particles.
If the dirt K&Ns pass shows up in oil tests then it's too small for the oil filter to catch.

Joel McGregor
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On Monday, January 28, 2013 6:03:40 PM UTC-8, Gordon wrote:

  Karen,

      I would caution you on the K&N filter.  Many years ago, I had
      a study on K&N filters done by a mining company who had 1000
      vehicles from head office cars which never went near the mine, to
      200T trucks in the pits.  The engineers took oil samples of all
      vehicles before switching 500 of them to K&N and for 1 year
      after.  The results were very conclusive that the K&N filters
      passed larger particles and a greater volume of dirt than the
      standard paper element.  For a few dollars, oil sample kits are
      available from Air Craft Spruce and others.  The only K&N
      filters I have personally tested were on Goldwing Motorcycles and
      when, by oil samples I proved theY increased crud in the oil to my
      friends , we all took them off.   You can find more opinions on
      the NET.  IIRC Emery points out, if you are meticulous about
      cleaning and oil them just right, they provide adequate
      protection.  Most small aircraft engines use a similar style
      filter, but the air is a lot cleaner where they spend most of
      their time and they are serviced every 50 hours.

      Gordon