Date:         Sat, 18 Dec 2004 14:39:45 -0700
Reply-To:     jimt <camper@TACTICAL-BUS.INFO>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         jimt <camper@TACTICAL-BUS.INFO>
Subject:      Re: Just interesting observation & More Questions(oil filters)
In-Reply-To:  <41C47D34.7010201@mchsi.com>
Content-type: text/plain; charset="ISO-8859-1"

About a year ago I was busy tearing down several subaru engines.  I still
had all the filters in my drain pan a few months ago when cleaning up stuff.
So I cut them all open and checked type of media, bypass, and pressure
(relative) of the valves.  I had a purolator, fram, subaru, and AC Delco.
Reading the small print on the subaru, it was also purolator.

The fram bypass was extremely hard to press compared to the others and I
immediately thought of oil starved cold engines.

The ac delco was extremely easy to push open so I had thoughts of oil
filtering performance.

The subaru branded version of the purolator seemed to be built to a slightly
different spec than the off the shelf purolator.  The filtering media itself
felt different and under a magnifier was different.

Everything else on the purolator and subaru version was the same.

I sent an email to one filter mfr asking questions and to not send me the
canned answer.  Was surprised when I got a real answer about two weeks after
the canned answer that I expected and got.

Basically stated..
The specs that filter manufacturers use are compromises to make the filter
work for several makes of engine using the same size filter and realizing
that customers donšt always do the right thing. Quality filters are
generally made well above the minimum needs.

 The automotive mfr however goes to the other extreme of overbuilding its
filter specs because it wants to make absolutely sure that a couple dollar
filter is not the weak link in 20 to 40 thousand dollar item that can get a
lot of warrantee costs.

Personally though I do not buy Fram or AC Delco from the FLAPS.
And I never buy discount filters.  (the filter note also had a comment on
filters "noname ....sized to fit not spec")
jimt

On 12/18/04 11:55 AM, "Al and Sue Brase" <albeeee@MCHSI.COM> wrote:

> John:
> I'd have to say I agree with some of your points and disagree with others.
> I agree that a check valve in the filter should make no difference at
> all. It may be a bigger factor in the WBX.
> A good quality filter has LOTS more media in it. I often cut the filters
> apart to look for swarf. German filters sometimes have two to three
> times as much as a Fram (total junk in others ways, too). Purolators are
> almost as good and I found an Italian built house brand that was very
> nice, too, but its name is forever lost in my old brain. A quality
> filter will flow more and therefore give you more volume and pressure at
> the lifters.