Continental GTSIO520M Reciprocating engine power section—bearing incorrect assembly. SDR 510022093 (photo above)
Upon disassembly of the engine for a bulk strip inspection the following was found—on the left hand half of the crankcase the four crankshaft bearings P/N 634503 were found to be fitted to the L/H and R/H lower reduction gear bearing saddles. Also the four reduction gear bearings P/N 630571 were found to be fitted to the L/H crankcase half where the crankshaft lies. The difference between the bearings is the P/N 634503 crankshaft bearings have a larger oil feed groove machined into them to feed the crankshaft. P/No: 634503AND630571. TSO: 610 hours.
Continental IO360HB Reciprocating engine cylinder section—rocker arm broken. SDR 510021982
After spin recovery the aircraft experienced engine vibration. Inspection found the exhaust rocker assembly detached and rocker studs broken. Engine inspected for FOD and metal contamination nil contaminates evident. Cylinder, valve assembly, rocker arm assembly and push rod assembly replaced and all other cylinder assemblies and rocker arms inspected for condition and security nil defects evident.
Continental IO520F Engine starter—screw missing. SDR 510022190
The pilot reported ‘starter motor noisy during start’. Investigation revealed one of the armature screws had fallen out of the starter motor allowing the armature to move inside the starter motor. The starter motor was replaced with a serviceable item. P/No: 6462751R. TSO: 5 hours/6 cycles.
Continental IO550B Engine exhaust system—heat exchanger incorrect dimensions. SDR 510022082
Found exhaust pipe (L/H and R/H banks) rubbed thru firewall—R/H exhaust heat exchanger rubbed thru frame. Tailpipes incorrectly adjusted on hangers, allowing pipes to rub (inadequate maintenance) Heat exchanger to long by 0.75″ (design).
Continental TSIO520VB Magneto/distributor—contact assembly closed. SDR 510022029
Pilot conducted a mag check pre-flight and had a dead cut on the R/H mag, L/H engine. Fault confirmed and R/H magneto removed for inspection. This confirmed the contacts in the magneto were not opening at all. Contacts adjusted IAM TCM 4000 manual. Magneto refitted and timed to engine. L/H magneto inspected and contacts adjusted also. Engine ground run carried out serviceable.
Lycoming IO360A3B6 Reciprocating engine cylinder section—exhaust valve unserviceable. SDR 510022096 (photo above)
Exhaust valve failed, engine was last overhauled in 1981. P/No: LW16740. TSO: 1050 hours
Lycoming IO540 Engine fuel pump—pump broken. SDR 510021966
Aircraft lost fuel pressure in flight. Investigation found engine driven fuel pump body had fractured. Suspect the tapered blank fittings at point of fracture had been over torqued. One similar defect reported. P/No: RG9080JI. TSO: 297 hours.
Lycoming IO540K1A5 Reciprocating engine internal oil system—baffle cracked. SDR 510021994
Oil sump baffle is cracked from four of the six mounting holes as well as two other places. Cracks are approximately one to two inches long. Defect found during disassembly for unrelated matter. These IO-540-K1AS engines suffer from bad vibration problems when installed in GA-8 Airvans. Despite the sump and baffle being a new design, the baffle has still cracked from the mounting holes. One similar defect reported. P/No: 56G26069.
Lycoming LTIO540J2BD Reciprocating engine cylinder section—valve guide worn. SDR 510021869 (photo above)
In cruise R/H engine had a partial loss of power down to 30 inches of manifold pressure. A compression test was carried out and found that the No. 6 cylinder on the R/H engine had a differential compression of 3/80. The cylinder was replaced with a new item. On disassembly of the cylinder the exhaust valve guide was found to be excessively worn beyond limits. P/No: 75838. TSN: 1501 hours.
Magneto/distributor—magneto unserviceable. SDR 510022186
Left hand engine wouldn’t start. The magneto to engine timing was checked (as we have had previous magneto problems) and it was approximately 20 degrees advanced. The magneto was removed and bench checked and was founds approximately 20 degrees advanced with a weak spark below 1000 rpm. P/No: 4373. TSN: 48 hours.