Oil filter mounting positions

[TC]

"As soon as you shut off your engine all of the oil in the galleys will drain down to the sump." Really? Prove it. If all engines had the exact same configuration and sizing of oil passages, one might be able to make such a broad assumption. But I've changed filters on a few engines in which a small torrent of oil purged once the holes-up filter was removed. Clearly, on such engines, not all of the passages drain, or at least fully drain. Whether by design or accident, it clearly would be of benefit to keep these passages filled at shut-down, just as one wants the filter itself filled prior to start-up. Perhaps it's by design on some engines that certain passages retain their oil, unless you can somehow PROVE it's an engineering accident. I'm looking at an illustration of a 60's era inline-6 lube system (make unknown) in an old repair manual I have, and it shows an "air bleed" at the connecting rod's lower journal. I assume it's there to speed air purging of that feeder channel so oil can get to the bearing faster. If air can't get past the bearing fast enough so that a bleed is required, this might explain how that same resistance to flow at that bearing (whether the medium is air or oil) can restrict oil from draining in at least some engines. Once again, accident or design?

"The adbv was never designed or intended to keep oil in the engine's galleys..." Another assumption stated as fact. From memory I think it may have been my Dad's '73 Olds that I hated changing the oil on because I knew there'd be an impressive flood of oil purging from the holes-up filter mount, always making a mess. Must have been imaginary oil coming from imaginary passages.

[ June 22, 2004, 05:52 PM: Message edited by: TC ]