hey,
by golly I *am*  going to say something.
This is  one of the most comprehensive and detailed enough, and clearly
written explanations,  I have ever read.
Extremely well written, in more ways than one too.
I mean , damn ! it starts right  out with the 'whole thing' right there in
the first line.
Like that's a thesis statement for the rest of the piece.
Like if that's all the time you have to read, you've got it all right there.

and then it just expands on that with details.
excellent writing and a joy to witness !

----- Original Message -----
From: "Michael Snow" <slowmachine82@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, September 28, 2009 10:47 AM
Subject: Re: Bypass oil filter

On Mon, Sep 28, 2009 at 12:18 PM, Old Volks Home <oldvolkshome@gmail.com>
wrote:
> And why would anyone use a bypass oil filter when both air and waterboxer
> Vanagons have full-flow oil filtration? Just curious......

Using a bypass filter in addition to the full-flow filter provides a
way to filter much smaller particles from the oil.  The stock filter
is a compromise; it filters poorly enough to enable sufficient flow to
the bearings and has a bypass valve that permits oil to flow around
the filter media when flow is insufficient for proper lubrication.
Much finer filters are available that will not flow sufficient oil for
bearing lubrication.  Combining the two systems enables very fine
filtration with sufficient flow for the bearings.  I won't say
anything about the cost-effectiveness, only that it is possible to
filter much more of the fine particulates from the engine oil than the
stock system can support.

--
Michael Snow
1982 Westfalia 1.9TD
http://slowmachine82.blogspot.com/