After disassembling the engine, the source of all of the metal in the oil filter (
http://986forum.com/forums/general-discussions/52494-aos-more.html) was pretty obvious - lifter carrier and lifter.
The consensus is that the lifter carrier cracked and when it failed pieces broke off and some of the larger pieces were pounded under the lifter. This damaged the lower skirt of the lifter and created all of the debris that was found in the oil filter.
The piece of lifter carrier being held by the tech is well worn and almost smooth from knocking around in the engine.
The original IMS bearing (136,000 miles + 89 track days) hasn't been removed from the intermediate shaft yet but it feels firm, has no play, and is perfectly smooth when rotated by hand.
Variocam actuator pads and cam chain tensioners were in surprisingly good condition (I was expecting them to be well worn and ready to fail).
The remainder of the engine was in very good condition except for two crank bearings that were pretty well scored.
Engine rebuild pic's will be posted under my Spec Boxster thread in the racing section (
http://986forum.com/forums/boxster-racing-forum/46070-spec-boxster-build.html).
