As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE CLIMBING OUT FROM RAWLINS, WY ON A FLIGHT TO HOLLISTER, CA., THE ENGINE STARTED TO RUN ROUGH AND THE PILOT NOTICED THAT THE OIL TEMPERATURE WAS RED LINED. THE PILOT RETURNED TO THE AIRPORT FOR EMERGENCY LANDING UNDER PARTIAL ENGINE POWER. THE AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. THE ENGINE WAS INSPECTED FOR THE ROUGH RUNNING AND IT WAS FOUND THAT THE CRANKCASE WAS DAMAGED BY THE CRANKSHAFT AT THE REAR OF THE FRONT THRUST BEARING AREA.