As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE SHUT DOWN IN-FLIGHT DUE TO LOSS OF OIL PRESSURE. INVESTIGATION REVEALED BROKEN COMPRESSION RINGS ON 1 CYLINDER AND SEVERELY WORN RINGS ON ANOTHER. THESE WERE NUCHROME CYLINDERS WITH 153.2 HOURS SINCE NEW. ENGINE OVERHAUL AGENCY INDICATED THEY HAVE SEEN THIS PROBLEM BEFORE AND ATTRIBUTE ITS CAUSE TO AN EXCESSIVELY LEAN MIXTURE CREATING HIGH HEAD TEMPERATURES. ENGINE HAS BEEN REPAIRED.