from the fordsix forum:
PostPosted: Tue Apr 17, 2007 5:04 pm
2) I have ran accros several good studies done in the 60's that clearly document that paper air filters are better than oil breathers. The usual quoted numbers are about 95% efficiency for oil bath and 99% efficient for paper -- and that was 30 years ago, before some of the better filters came around that are now available.
Finally, and perhaps most troublesome -- most oil breather filters do not actually allow to have a good look at the fiber mesh in the breather. Its encased in such a fashion that you cannot replace it or look at it without destroying the breather. Overtime, old oil breathers will develop voids in the mesh. Once there is a void, that will become the path of least resistance and ALL the air will go there, bypassing the rest of the mesh. It will arrive in the engine essentially unfiltered.
3) If you really desire the "look" then hollow out the oil breather and find a paper air filter that will fit in there. Old look, modern guts.
I washed many an oil breather out as a kid, and I was impressed at the ammount of dirt in there (old tractors and dust). Then in the 70's they went paper. At the end of the season when we replace filters AFTER THE SAME # HOURS, the dirt was so caked on that it became clear that we had been running a lot of that dirt THROUGH the engine prior to the use of the paper filters.
Just my observations and opinions...