Date:         14 Nov 1996 13:02:11 -0800
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Harvey Chao" <Harvey_Chao@smtp.svl.trw.com>
Subject:      About Oil filters

I came across the following post on a BMW digest, and thought that it would be
of interest/use to the VW community as well.   Public thanks to Matt for his
info.
Harvey
============
>From: "Matt R. Brumwell" <mbrumwell@icx.net>
Date: Thu, 14 Nov 1996 02:44:52 -0500
Subject: <Misc> Oil Filter Follow Up

As promised here's an update on the oil filter 'testing' that I had the NDT
guys do at 
work. 

As a quick summary, I went to NDT (non destructive testing) with an oil sample
I pulled 
from my 2002 at 500 miles.  The engine died at 700 miles so I was curious what
they 
would find.  They did find unusual amounts of bearing material in my sample. 
If I had 
only tested sooner, I could've saved my block and crank....

Anyway, while there we started talking about oil filters and a test they had
run.  In 
the test they took a large vat of dirty oil, mixed it, drew samples and then
filtered 
them through various filters (Fram, Duetch, Pulorator, Motorcraft, Cat,
Hastings, Wix, 
AC)  Fram was the winner with Wix a close second in filtering ability. 
Hastings was 
dead last.  They also said that the bypass in a filter typically bypasses oil
until the 
oil is warm, this could explain the pressure diffences that someone posted
earlier.  It 
also helps explain why short trips kill engines, the oil doesn't get filtered.
 The 
final comment was that you should use the biggest filter that will fit on the
car.  A 
quick check showed that the large Fram PH8A (Ford 2.3 liter) would fit the
mounting of 
BMW 4 cylinder cars.  Larger filters hold more oil and increase overall
capacity and 
they are quicker to actually start filtering.

I wanted to see how an OEM BMW filter compared, so I brought in an OEM 11 42
125 8039, a 
Fram 3816, a Fram PH8A and a Hastings LF 157.  These filters are for 1602's
through E30 
M3's.

We cut each one open and examined the paper.  Below is a listing of the square
inches of 
paper and how the two ends of paper were joined (Fram use to have a problem
with this 
joint failing).  The check valve keeps unfiltered oil from flowing back out of
the 
filter.

Filter		Paper size	End Fastened			Check Valve

Fram 3816	95.5 in2	glue / punched metal clip	No		
Fram PH8A 	191 in2		glue / punched metal clip	Yes	
Hastings	107.5 in2	glue				Yes
BMW OEM		211.9 in2	glue / punch metal clip		No

The surprise was that the small OEM filter had more paper than the big Fram.  

The Fram 3816 claimed on the box that it had 'been designed for typical BMW
high 
pressure systems'.  What we found was that the spring in the by-pass valve was
in fact 
stiffer than the typical Fram spring of the same size.  The Hastings spring
was a joke.
The Fram PH8A had a large spring built into the top of the filter, along with
the check 
valve.  The OEM filter is obviously made to higher standards.  There is a
large, almost 
valve spring sized spring in the bottom.  In fact, when we cut it open the
whole filter 
sprung open like a jack in the box.  The filter medium height, which is
supported by 
steel on either end (Fram used cardboard, Hastings steel) is controlled by
this spring. 
This is the first by-pass valve spring.  The top of the OEM contained a second
bypass 
system that we had to use a hack saw to get into.  Again, a large well made
spring 
controlled oil flow.

It was very obvious that the OEM was the best made filter and I plan on
sticking with it 
for the time being.  Hell, it had more than twice the parts of the 3816 or 
Lf157.  However, the PH8A has the potential to perform well.  It does have a
check 
valve, a larger (than the 3816) bypass spring, larger oil capacity and close
to the same 
paper size as the OEM.  Next time NDT tests the actual filtering I'm going to
provide a 
few PH8A's and some OEM's to see if the extra paper is actually filtering
better.  They 
may be able to test to see when bypass stops also.  I've already talked to one
club 
racer / shop owner / race engine builder who uses the Fram PH8A in his 318i
race car 
because of the increased oil capacity.  I'll keep the list posted.

matt brumwell
smoky mt. chapter 'cca, #77654
'75 2002	'87 535is	'88 M3


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