Long - oil filter anti-drain valve - the die is cast

[Michael Murphy <mmurphy@nais.com>]

Wish I could have made this shorter, sorry.

Gentlemen, Ladies - the game is afoot and if I can name it, the thread
is:  Anti Drain Valves in Oil Filters, hereafter posted as ADVs (just
wait 'til we get to bypass valves (BPV)).

In my corner:
Messrs. Newton (Law of Gravity fella), Bosch, Hastings, Mann, Mobil and
that "F" word filter company. Representatives from all the above (Mr.
Newton declined to comment for obvious reasons) agreed to speak with me
and/or send filtering information.

The distinguished opposition:
List members that think otherwise from a statement I made:
> you need an antidrain back valve _only_ if you mount the filter
> w/the > filter opening at an angle that would allow gravity to drain
> the  filter.  Please correct me if I'm wrong here.
All of list members (well most - that's my ego and 35 years of side-walk
mechanic mentality speaking) have more Audi knowledge/experience than
me.

Rules of engagement:
1.  Seek the truth.
2.  See rule #1.

PLAY . . . 
Chris Newbold wrote in response to my statement above:
> I believe that the main purpose of the anti-drain valve is to prevent
> oil from draining out of all of the oil gallies in the entire engine
> lubrication system (most of which are higher up than the filter).
> The idea is that at start-up there is little delay before full 
> pressure reaches critical components. Without it, oil drains back down 
> from the top of the engine, though the filter, and back into the sump; 
> at start-up, it would take time to pump oil to the top of the engine 
> again.

I respond with reference to all the converations I've had with filter
manufacturers' and their catalog writings (I paraphrase): The ADV works
in ONE direction - preventing oil from draining out of the filter if it
is inverted (hole facing down or at an angle that would allow gravity to
drain most/all of the oil in it).  So, when the engine starts, the
engine oil pump does not have to fill the filter (holds ~1 liter and can
take up to 5 seconds to fill) ergo, critical engine/turbo parts get oil
faster.

Phil Payne wrote:
> No problem.  You're wrong.  I think.
> . . . but to stop the upper galleries and most particularly the
> lifter feeds from draining.
Phil went on to mention how Audi "double speaks" the issue.  BTW, AoA
sent me a 1st class post of their "Maintain the Advantage" advert with,
yep you guessed it, a FREE oil/filter change coupon.  Enclosed brochure
mentions, "We've recently reduced prices on many of our most popular
parts up to 60%". Great, so now they are just 50% higher than anywhere
else.

Mr. Payne, you are always the gentleman and diplomat, but again I
counter with Mr. Newton's gravity missive and the filter manufacturers'
statements about the ADV.  Then pose the question:
Regardless of the height of the filter mount, relative to any engine
part; and in a position where the filter outlet it facing the sky
(metaphorically speaking) as it is on my NF engine and I'm guessing most
I5s/V6/V8/L4 engines; how is oil going to be sucked out of it when the
valve only goes in one direction - that is to prevent oil from coming
out of the filter if it is inverted?

Remember the rules of engagement above; and I eagerly await all
responses, including yours Mr. Cur, but remember - just the facts
please. 

MJ Murphy
-eof-