la_strega_nera wrote:What thread did you make the block side of the adaptor?
My adapter is useful only on the original photo where there are no threads. The adapter fits into the early 24V oil housing, sealing with an o-ring. The adapter provides a 2.5 mm extension to fill the gap from the block to the filter housing. An existing gasket fits between the adapter and block. AFAIK, only the late 1998-2007 engines do not have a threaded fitting on the block.
My 164 24V engine came with the o-ring fitting shown in the pic above of various threaded fittings. I have this same fitting on a 1997 2.0 V6 12V turbo engine. Another reference point, with minor modification, a 1993 12V 3.0 engine will fit the aluminum housing from the turbo engine. Minor mods is just adding the o-ring fitting, drill and tap a few M8 mount points.
Alfa used many filter variations, yet all filters or filter housings mount onto the same location.