As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ENGINE WAS UNABLE TO MAINTAIN MINIMUM OIL PRESSURE IN CRUISE AND PROP CONTROL WAS DIFFICULT. ENGINE WAS DISMANTLED FOR INSPECTION WHICH REVEALED #2 & #3 MAINS HAD SPUN IN THE CRANKCASE. CRANKCASE ASSEMBLY OVERHAULED AND ENGINE WAS RETURNED TO SERVICE.