O-320Lycoming O-320

Parts most often named Cylinder (81) · Cylinder Head (45) · Exhaust Valve (37) · Valve (36)

POSITION # 1 &2 CYLINDER EXHAUST PORT CRACK FROM THE INBOARD EXHAUST STUD EXTENDING TO THE BACK OF THE PORT. CRACK VISIBLE THROUGH THE FINS. SUPERIOR CYLINDERS PN: SL32006W-A1 [S/N removed] 326W000003625 & 326W000003623.

I HAVE MULTIPLE CRACKED CYLINDERS BETWEEN O-320-D2J AND O-320-D3G ENGINES, THE CYLINDER IS ALL CRACKING IS IN THE SAME LOCATION NEAR THE INTAKE PORT OF THE CYLINDER. THE FAILURE TIMES HAVE BEEN BETWEEN 1087.1 SFRM, 1980.5 SFOH, 1282.1 SFRB, MOST RECENTLY I HAVE HAD 2 CRACKS ON CUSTOMER AIRCRAFT AT 600 SMOH AND 500 SFRM. THE COMMON POINT IN ALL THESE FAILURES IS ALL CYLINDERS ARE LYCOMING FACTORY CYLINDERS

EXHAUST VALVE FAILED DUE TO HEAT STRESS, CAUSING LOW COMPRESSION, LOW ENGINE SPEED AND ENGINE VIBRATIONS WHILE AT CRUISE.

Parts most often named Magneto (79) · Impulse Coupling (20) · Rotor (16) · Gear (14)

MAGNETO REMOVED FOR IMPULSE COUPLING INSPECTION. CHAMPION PRODUCED IMPULSE COUPLING FOUND INSTALLED. BOTH RIVETS HOLDING THE PAWLS IN WERE FOUND TO BE BENT.

ENGINE WAS INSTALLED JULY 2025. TIME SINCE OVERHAUL IS 100 HOURS. FOUND ENGINE DAMAGE DUE TO LEFT MAG BEING ADVANCED 15 DEGREES. PULLED ENGINE AND SHIPPED BACK TO AVIAN AERONAUTICS FOR REPAIR.

AIRCRAFT REPORTED TO BE HARD TO START OVER MULTIPLE STARTS. DURING 100HR INSPECTION REMOVED LEFT MAGNETO P/N 4371 AND DISASSEMBLED FOR INSPECTION. DURING INSPECTION OF MAGNETO FOUND 1 PAWL PIN SHEARED FROM IMPULSE COUPLING.

Parts most often named Carburetor (79) · Float (23) · Screw (14) · Tube (9)

ACFT RETURNED TO BASE DUE TO VIBRATION AT 300FT ON 2/8/25. PILOT REPORTED ENGINE STARTED SHAKING SIGNIFICANTLY. HE PULLED CARB HEAT HOT SAW NO CHANGE. TOLD TOWER HE WAS LANDING. CARB HEAT SYSTEM WAS INSPECTED WITH NO DEFECTS FOUND. CARB WAS REPLACED. CARB [S/N removed] MS06CV14, S/N ON MS02BH01. RAN ENGINE, LEAK AND OPS TEST GOOD. AIRCRAFT RETURNED TO [S/N removed]. NO FURTHER VIBRATION REPORTED.

FOLLOWING A POST-INSPECTION ENGINE RUNUP, FUEL WAS FOUND LEAKING FROM THE CARBURETOR VENTURI. IT IS SUSPECTED THAT AN UNDETERMINED DEFECT IN THE CARBURETOR FLOAT OR ASSOCIATED VALVE ALLOWED THE CARBURETOR BOWL TO OVERFILL AND RESULTED IN FUEL OVERFLOWING INTO THE CARBURETOR VENTURI.

FOUND LOOSE CARBURETOR LOCK TAB AND FUEL STAIN. NO OPERATIONAL ABNORMALITY WAS NOTED RELATIVE TO THE DISCREPANCY. CARB WAS CHANGED INSTEAD OF REPAIR FOR CONVENIENCE.

Parts most often named Crankshaft (73) · Camshaft (22) · Crankcase (16) · Tappet (12)

DURING SB388C, EXHAUST VALVE GUIDE INSPECTION FOUND 4EA PUSH RODS P/N 15F28835-10 & 4EA ROCKERS P/N 17F19357 TO HAVE HEAVY SCUFF - SCORING. ENGINE TT: 2741.1 SINCE FACTORY REBUILT.

(CAN) ENGINE HAS 825 TT SINCE OVERHAUL (OTHER MTCE FACILITY 2018). AT 682 HRS TIS, CAMSHAFT REMOVED BY THE OTHER FACILITY DUE TO FAILURE. MARCH 2019 MAINTENANCE ENTRY INDICATES A NEW CAMSHAFT INSTALLED AT THIS TIME. 142 HRS TIS, ENGINE RECEIVED DUE TO METAL CONTAMINATION, CAMSHAFT FAILED. EXAMINATION OF FAILED CAMSHAFT NOTED: REGRIND [S/N removed] FROM XXXX (WAS A SUPERIOR SL16511 CAMSHAFT, DATE CODE 2004). (TC# 20190717008)

PILOTS REPORTED THAT THE AIRCRAFT STARTED RUNNING ROUGH, VIBRATING, LOSS POWER, THEN STOPED. THEY MADE EMERGENCY PERCIEDURES AND LANDED, IN A NEARBY EMPTY CORN FIELD. UPON REMOVAL AND INSPECTION OF THE ENGINE, AFTER REMOVING THE NUMBER FOUR CYLINDER WE DISCOVERED THAT THE CRANKSHAFT BROKE JUST FORWARD OF THE NUMBER FOUR PISTON ARM.

Parts most often named Engine (34) · Rocker (3) · Wheel (2) · Crankshaft (2)

PILOT REPORTED LOW POWER AND VIBRATION ON TAKEOFF AND ABORTED TAKEOFF. CLEANED GASCOLATOR AND AGGRESSIVELY FUEL TANKS AND BELLY SUMPS. NO WATER WAS PRESENT. VERIFIED PROPELLER TORQUE AND CHECKED DYNAMIC BALANCE DUE TO A RECENT PROPELLER INSTALLATION. PROPELLER VIBRATION INDICATED -GOOD- ON DYNAMIC BALANCE. CHECKED ENGINE COMPRESSION, MAGNETO TIMING AND SPARK PLUGS. ALL WERE NORMAL. RUN-UP AND FLIGHT CHECK SATISFACTORY.

TOTAL INTERNAL CRANKSHAFT FAILURE AT CHEEK BETWEEN #3 AND #4 CONNECTING ROD JOURNALS CAUSING CRANKCASE TO COMPLETELY SEPARATE IN THE CENTER. CRACK APPEARS TO HAVE STARTED IN THE REAR THRUST RADIUS OF #3 CONNECTING ROD JOURNAL. PILOT HAD REPORTED ENGINE ROUGHNESS THE PREVIOUS DAY OF THE INCIDENT AND CONTINUED ENGINE ROUGHNESS AND ABNORMAL ENGINE NOISE THE DAY OF THE INCIDENT. SLIGHT METAL FOUND IN OIL FILTERS

LYCOMING FACTORY REBUILT O-320-D2J, TSN / TT: 2089.1. DURING ROUTINE MX, LYCOMING SB388C (EXHAUST VALVE GUIDE INSPECTION) FOUND 6EA VALVE PUSH RODS P/N 15F28835-10, 6EA ROCKERS P/N 17F19357 & 1EA TAPPET SOCKET P/N 15B21319 TO HAVE MECHANICAL DAMAGE (HEAVY SCUFF-SCORING)

Parts most often named Oil Filter (7) · Line (4) · Gasket (4) · Dipstick (3)

UPON REMOVING OIL FILTER DURING ENGINE OIL CHANGE THE OIL FILTER SEEMED TO BE VERY DIFFICULT TO BREAK LOOSE. AFTER EVENTUALLY GETTING THE FILTER REMOVED IT WAS NOTICED THAT THE THREADED STUD WAS STILL THREADED INTO THE ENGINE THOUGH NOT TIGHTLY. THIS WAS A NEW FILTER.

(CAN) ENGINE FOUND TO HAVE EXTREME LOW OIL PRESSURE WITH EXTREME HIGH OIL TEMP ON INTIAL POST ENGINE INSTALLATION. ENGINE RUN-UP WITH A NEW REFURBISHED O-320-H2AD.

AFTER SHUTDOWN, THE PILOT REPORTED OIL ALL OVER THE ENGINE COWL. AFTER INSPECTION, NOTICED OIL LEAKING FROM OIL COOLER. THE OIL COOLER END SEAM FAILED.

Parts most often named Starter (14) · Drive Assy (7) · Gear (5) · Solenoid (3)

STARTER DRIVE MOTOR WAS FOUND LOOSE FROM BENDIX ASSEMBLY DURING 100 HOUR INSPECTION. MOTOR IS ATTACHED TO BENDIX WITH 2 BOLTS THREADED INTO BENDIX HOUSING. BOTH BOLTS HAD LOCKING TAB WASHERS STILL IN-PLACE AND UNDISTURBED. FEMALE THREADS WERE PULLED LOOSE FROM BENDIX HOUSING CAUSING BOLTS TO BECOME LOOSE.

(CAN) BETWEEN 2014-06-20 TO 2014-12-16 STARTER WAS CHANGED 5 TIMES, 2 OF THE TIMES IT WAS A LOADER STARTER AFTER THE O/H STARTER DID NOT WORK PROPERLY. THE STARTER USED WAS PN MZ 4222.

(CAN) STUDENT HEARD GRINDING NOISES WHEN ATTEMPTING TO START ACFT. MAINTENANCE FOUND THE BENDIX SHAFT FWD BUSHING MISSING ON STATER, WHICH ALLOWED BENDIX ASSEMBLY TO MOVE AROUND WHEN STARTING.

Parts most often named Mount (35) · Bolt (2) · Rail (2) · Spacer (1)

DURING ANNUAL INSPECTION, FOUND ENGINE MOUNT RT LOWER DIAGONAL TUBING HAS CHAFE DAMAGE DUE TO CONTACT WITH CARB HEAT CABLE.

(CAN) ENGINE MOUNT CRACK FOUND ON 50HR INSP. CRACK WAS FOUND IN THE LOWER LT CLUSTER PERPENDICULAR TO THE WELD RUNNING A TOTAL OF .7500" ALONG THE VERTICAL TUBE.

(CAN) INSPECTION FOR ISSUANCE OF A C OF A AIRCRAFT TOTAL TIME: 2.8 HRS DURING THE INSPECITON OF THIS AIRCRAFT BY CIVIL AVIATION INSPECTOR, IT WAS NOTED THAT AN ENGINE CONTROL SUPPORT BRACKET WAS CONTACTING THE LOWER TUBE OF THE ENGINE MOUNT. NO DAMAGE TO THE ENGINE MOUNT WAS NOTICED BUT THE PAINT FINISH WAS MARKED BY CHAFFING. ACTION TAKEN; ENGINE MOUNT BRACKET 760-02043-01 WAS SLIGHTLY RELOCATED ON 760-02041-01 CONTROL SUPPORT BRACKET TO ADD CLEARANCE FOR ENGINE VIBRATIONS AND MOVEMENTS. (TC# 20060426001)

Parts most often named Bulkhead (34) · Spinner (4) · Plate (1)

(CAN) UPON ACFT INSPECTION THE SPINNER WAS REMOVED TO DO VISUAL INSPECTION OF THE PROPELLER MOUNTING BOLTS AND SPINNER BULKHEADS, FORWARD AND AFT. THE FORWARD SPINNER BULKHEAD, PN 0550321-4, WAS OBSERVED TO HAVE 5 CRACKS PRESENT AROUND THE HOLES FOR THE MOUNTING BOLTS. ONLY 1 OF THE 6 MOUNTING BOLT HOLES WAS NOT FOUND TO HAVE A CRACK PRESENT.

(CAN) UPON ACFT INSPECTION THE SPINNER WAS REMOVED TO DO A VISUAL INSPECTION OF THE PROPELLER MOUNTING BOLTS AND SPINNER BULKHEADS, FORWARD AND AFT. THE FORWARD SPINNER BULKHEAD PN 0550321-4 WAS OBSERVED TO HAVE 2 CRACKS PRESENT AROUND THE HOLES FOR THE MOUNTING BOLTS. 2 OF THE 6 HOLES HAD A CRACKS PRESENT.

THIS FORWARD SPINNER BULKHEAD WAS INSTALLED NEW 1 APRIL 2010 AND THE PROP WAS DYNAMICALLY BALANCED. MULTIPLE CRACKS AROUND SEVERAL BOLT HOLES WERE FOUND VISUALLY DURING ROUTINE SCHEDULED INSP. THIS PART CRACKS VERY OFTEN NOT JUST ON THIS ACFT. IT SEEMS THE NEW REPLACEMENT IS NOT AS GOOD AS THE OLDER VERSION.

Parts most often named Alternator (16) · Bearing (4) · Brushes (2) · Volt Regulator (1)

(CAN) AT CRUISE RETURNING TO BASE CREW NOTICED ALTERNATOR DROPPED OFF. CREW CHECKED SWITCH AND CIRCUIT BREAKER. CHECKED OK. ON FINAL INTO CYBW INTERMITTENT FLAPS, RADIO AND LIGHT FAILURES. UPON INVESTIGATION AND INSPECTION THE POWER TERMINAL TO THE ALTERNATOR HAD [S/N removed] OFF AND WAS ARCHING TO THE ALTERNATOR. THE BATTERY WAS DRAINED BEYOND RECOVERY AND WAS REPLACED WITH NEW. THE ALTERNATOR WAS REPLACED AND ALTERNATOR WIRING REPAIRED AS REQUIRED. FUNCTION CHECKS CARRIED OUT WITH NO FURTHER DEFECTS.

(CAN) ALTERNATOR BRACKET FOUND BROKEN ON ENGINE UNSCHEDULED INSPECTION. NEW REPLACEMENT BRACKET NR 07A-21443 INSTALLED. REPLACEMENT PART SUPPLIED BY MFG DISTRIBUTOR AS REPLACEMENT FOR NR 76906.

ACFT PULLED OUT OF HANGAR FOR MORNING FLIGHT, WOULD NOT START - BATTERY DEAD. AME REMOVED BATTERY FOR CHARGING. CHECKED ELEC SYS, FOUND THAT THE ALTERNATOR BELT HAD FLIPPED OVER ON THE RING GEAR AND WHEN PROP WAS MOVED, ALTERNATOR PULLEY DID NOT MOVE. ALTERNATOR REMOVED, FRONT BEARING HAD FAILED AND SHAFT WOULD NOT TURN. NEW ALTERNATOR INSTALLED AND NEW ALTERNATOR BELT INSTALLED.