In a message dated 11/10/02 1:33:04 AM Eastern Standard Time, dhomstad@xxxx writes: > This is what I did to my 56 Dodge 4 barrel air cleaner. It looks totally > stock on the outside. All 55/56 Mopar 4 barrel air cleaners are the same. > > Dave, I read this and want to commend you for the effort you put forth to research the project. I can't remember how the oil-bath cleaners were put together any more but that doesn't matter now. A low restriction paper filter with a stock look is neat! What I DO want to mention is this: I was working in the Chrysler Engineering Air Cleaner Lab as a test technician during the transition from oil-bath to paper filter elements, and was the one that conducted filter efficiency tests. We used "Calibrated" dirt supplied by a division of Generous Motors. It was about the consistency of flour, and had certified percentages of various particle sizes. Oil-bath cleaners will eat a ton of dirt without appreciable increase in restriction. The dirt gets trapped by the oil film, then drains back into the sump at shutdown. As I recall, efficiency averaged about 84-87%. Paper filters operate at 0ver 98% efficiency new and get slightly better as they get dirty with a corresponding increase in restriction until they get unusable. The absolute worse air cleaner elements I ever tested were the ones made from a thin layer of oiled foam. They didn't filter very well to begin with, clogged soon because of the dirt collecting on the surface layer, and if you waited a little too long to service them, they would suddenly collapse and deliver a large handful of gritty, oily dirt to your engine, usually at wide open throttle. Joe Savard Lake Orion, MI [Non-text portions of this message have been removed]