Jim Bow,

I don't know what Tim's link shows, but basically as the air comes roaring in through the inlet side of the air cleaner it travels down a passage and is required to make a 180&deg turn. The air makes the turn but the dust particles don't and are flung into Lake-o-Lube and trapped for life.

I haven't done extensive research on this subject so I might be in very deep sh#t with Mr. Lederman...but I have serviced hundreds of these units when I was shop flunky...work experience...does that count!

Stuart