Diesel Engine Overhaul | Diesel Engine Repair | Crankshaft Main Bearing Replacement

RA Power Solutions was informed regarding the failure of three nos Crank pin Bearings of MAN B&W 5L60MC main engine onboard a vessel near South Africa.

RA Power experienced team of technicians boarded the vessel in a short time of 18 hours of receipt of intimation regarding the problem faced by the vessel. Following jobs were executed for overhaul and replacement of crankpin bearings in order to operate the engine satisfactorily after Engine repair and Engine overhaul.

MAN B&W 5L60MC Engine Repair & Overhauling is in Process
MAN B&W 5L60MC Engine Repair & Overhauling is in Process
DESCRIPTION:

I) Inspection and overhaul of the cylinder covers including the fuel and starting valves located in the covers.

II) The cylinder covers cooling spaces were also inspected, cleaned and fitted back with new O-rings.

III) Dismounting, Inspect and overhaul of the exhaust valves, renewed the seats and grinding the valve spindles.

IV) The cylinder liners were cleaned, calibrated and honed in order to restore the liners running surfaces and remove ovality. This ensured that the piston rings perform better and this will lead to a better overall cylinder condition, compared to if honing had not been done. The cylinder liners cooling spaces were also inspected, cleaned and fitted back with new o-rings.

Inspection of Engine Spares is in Process
Inspection of Engine Spares is in Process
Inspection and Repair of Crankshaft
Inspection and Repair of Crankshaft
V) The Crank pin  bearing caps were dismounted, both top and bottom bearing shells renewed

VI) The Crankshaft Crankpin  diameter was checked for the following parameters:

a) Visual inspection to check the presence of any Bearing Line marks or rough surface.

b) All the Crankpins were calibrated for taper & ovality.

c) Hardness was checked and observed within limits.

d) MPI was done to check the presence of any crack.

e) Crankshaft all pins were polished by onsite Crankshaft Grinding Machine removing the bearing line marks and for improving the Crank pin surface finish.

Onsite Repair of Crankpin by Crankshaft Grinding Machine
Onsite Repair of Crankpin by Crankshaft Grinding Machine
VII) Adjustment of the variable injection timing (VIT)

VIII) The bearing clearances were taken using lead wire

IX) Crankshaft alignment measurement was taken with a dial gauge.

Conclusion: After replacement of Bearings & Jobs described above undertaken at the time of Engine overhaul & Bearing replacement the engine was tested on the load & performance was observed satisfactory.

Repair of Crankpin is in Process
Repair of Crankpin is in Process
Inspection of Connecting Rod on Moving Vessel
Inspection of Connecting Rod on Moving Vessel

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