| James
My 996S has produced several small "wire" pieces over many oil changes.
Pull out the rocker spindles with an M4?? screw and spacer, with the relevant valve closed to remove load, and examine the rocker return springs. If, like mine did, the spindles have been rotating in the head, the internal shoulder wears the first coil of the spring, and the heat generated may cause a small sliver of the hardened skin to break off. As a preliminery, check the inner surface of the small central rocker spindle cover, held on with 4 screws; spindle rotation causes annular wear on this surface, which should be completely smooth, in my case to a depth of 2mm. IMO, the outward extension of these spindles reduces the rigidity of the rocker support, and may lead to tilting of the rocker relative to the cam lobe, so that in use the chrome pad experiences the full force of the lobe from the sharp edge of the lobe, concentrated on a very small area, and thus leading to premature chrome pad failure. . . . just a theory, but perhaps worth checking out. In the fullness of time, I expect to have to modify the face of the spindles and make a "star" washer to hold all 4 still to prevent rotation, but for now I have just replaced the damaged springs and covers, in addition to all 16 rockers, to restore lateral spindle motion to desgn values.
Good Luck!
julian  |