What was found
WHILE IN CRUISE POWER, COULD FEEL AN ENG STARTING TO RUN ROUGH. UNTIL THE RT OIL PRESS & RT CYLINDER HEAD TEMPERATURE STARTED TO DROP HE WAS UNSURE WHICH SIDE. IT WAS APPROX 3 - 4MIN FROM WHEN HE FIRST FELT THE ROUGHNESS UNTIL THE RT ENG OIL PRESS & CYLINDER HEAD TEMPERATURE STARTED TO DROP. THE OIL PRESS DID FALL TO 0 & THE ENG WAS SHUTDOWN. IT WAS ALSO REPORTED BY A PAX THAT THERE WERE SPARKS COMING FROM THE BACK OF THE ENG. AN EMER WAS DECLARED & THE PLANE LANDED SAFELY. INITIAL INVESTIGATION INDICATES A BROKEN EXHAUST VLV IS THE SOURCE OF THE PROBLEM. MX IS ON SITE. THE ENG IS BEING R & R, SENT FOR TEARDOWN.