What was found
DURING A CLIMB THROUGH 8,500' MSL TO 10,000' ON SBN APPROACH CONTROL, NOTICED RT ENGINE LOW OIL PRESSURE (RED) ANNUNCIATOR ILLUMINATE. ALSO NOTICED RT ENGINE MANUAL MODE WHITE ANNUNCIATOR ILLUMINATED & OIL PRESSURE GAUGE ZERO FOR RT ENGINE. WITHIN A FEW SECONDS, NOTICED SMOKE IN COCKPIT. DECLARED AN EMERGENCY, PULLED RT POWER LEVER TO IDLE & PUT ON OXYGEN MASKS. WORKED CHECKLIST & SHUTDOWN RT ENGINE. FOLLOWED RADAR VECTORS FOR AN ILS. CONTINUED WITH SMOKE EVACUATION CHECKLIST & DEPRESSURIZED CABIN TO EVACUATED SMOKE. A NORMAL, SINGLE ENGINE, APPROACH & LANDING ACCOMPLISHED. AFTER LANDING, TAXIED TO FBO. SHUTDOWN NORMAL. ENGINE MFG SERVICES PERFORMED BORESCOPE INSPECTION THROUGH COMPRESSOR BLEED VALVE, NO DEFECTS NOTED. PERFORMED MOPLO TEST ON NR 4 BEARING CARBON SEAL. RECORDED VALUE OF 54 PSIA AT TO POWER OF MOPLO TEST FOUND TO BE WITHIN MM LIMITS. RAN ENGINE FOR 1 HR AT VARIOUS POWER SETTINGS, NO DEFECTS NOTED. ENGINE DETERMINED TO HAVE BEEN OVER SERVICED WITH OIL."