...This particular now rare oil-filter housing https://pbase.com/image/53033763 replaces the BEHR engine mounted oil-cooler https://pbase.com/image/53177851 used on the 'street' Porsche 911 engines. Since they are a factory racing part, you will not find them in a street application as they are not recommended for 'stop-n-go' driving.

These housings are 'servicable' as they were designed to use a 'multi-disc' oil-filter element (Porsche Part Number 901 107 293 00 - in German, is called 'Einsatz') https://pbase.com/slidevalve911rsr/image/53108323 composed of several fine mesh-screen discs https://pbase.com/slidevalve911rsr/image/53108321 which can be taken apart hundreds of times and easily cleaned with solvent https://pbase.com/slidevalve911rsr/image/53108322.

There are 2 basic types of filter-elements; (1) The Steel-Disc https://pbase.com/image/53111392 and; (2) The Plastic-Disc https://pbase.com/image/53111413 type. You may also come across this lighter color steel-disc element https://pbase.com/image/53111416 and they are all pretty much the same. It appears that the 'steel-disc' type elements are the more desirable.

When tightening the cover https://pbase.com/slidevalve911rsr/image/53111405, one must be careful NOT to over-tighten the 4-nuts since you will 'over-compress' the 'cork-gasket' https://pbase.com/slidevalve911rsr/image/53111410 running the risk of creating an unnecessary oil leak. The cork-seal https://pbase.com/image/53111411 is much harder to find and the rubber o-ring replacement does not work as well.