(Also known as how to waste an hour-plus and $3.33 of a new filter. Previous deconstruction I've seen were of a used filters, which I can imagine as being quite messy to handle.)

Anyways, here's a little deconstruction of the ever popular Mann W917 ...


The details:

- Overall inner dimension of 3-1/4" diameter.
- Metal caps on both ends (unlike Fram which uses cardboard).
- An anti-drainback check valve, consisting of a full circumferance nitrile rubber flap.
- A strong, spring loaded bypass valve with nitrile rubber seal.
- 90 pleats, pretty evenly spaced, each glued down very tightly. The paper is ribbed to keep the pleats separate.
- The filter pleat measured 2-1/4" tall, with 89 of the pleats measuring to 25/32" deep. The pleat at the crimp measured to 3/4".
- Each pleat offers 2 sides, for a total of 180 sides of filter surface.

(2.25*0.78125*178) + (2.25*.75*2) yields just over 316 sq.inches.

By comparison from the other oil filter study out there, the gigantic Ford/Motorcraft FL-1A offers 400 sq.inches of filtering area. In this same size, the Fram PH8 offers just 193 sq.inches. With the Volvo filters being shorter, you can imagine how little filtering area the Fram will offer.

More pics:
Anti-drainback check valve. Its effectiveness also relies on the the metal spacer plate seen in the above pic.
The metal crimp on the element. This pleat is a little less than full depth.
Side profile view of the filtering element.

-- Kane
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Blossom II - '91 745Ti/M46 ... Bubbles - '74 144GL/BW35 ... Buttercup - '86 245GL/AW70 ... The Wayback Machine - '64 P220/M40