To carry out 24K Niigata engine overhaul services
(make model 6L28AHX) (Port & STBD) and execute a comprehensive marine crankshaft repair on the STBD engine, ensuring full compliance with OEM standards and restoring operational reliability.
Challenge / Problem Context
Crankshaft Surface Damage: Deep fitting marks were observed on the crank pins and journal pins of the STBD crankshaft, potentially affecting engine balance and lubrication.
Bearing Wear & Tolerance Mismatch: The wear on the crankshaft required oversized bearings, which had to be aligned precisely post-machining.
Engine Alignment and Deflection Correction: After crankshaft machining, precise alignment and crank web deflection were needed to ensure mechanical integrity.
What Did We Do?
Crankshaft Surface Damage: We machined all crank pins and main journals of the STBD crankshaft to remove deep fitting marks and restore smooth bearing contact surfaces.
Bearing Wear & Tolerance Mismatch: We replaced the existing bearings with 1mm undersized main and crank pin bearings to compensate for the machined material, ensuring a perfect fit and oil clearance.
Engine Alignment and Deflection Correction: We realigned the STBD engine and measured crankshaft deflection in accordance with Niigata OEM specifications to avoid future wear and ensure dynamic balance.
Verification of Post-Repair Engine Health: We performed pre-commissioning checks including fuel, water, and lube oil flow tests, followed by successful 100% load sea trials to validate engine performance.
Results That We Achieved
Crankshaft Surface Damage: The machining process restored the crankshaft surface to OEM standards, eliminating all visible damage and ensuring smooth operation.
Bearing Wear & Tolerance Mismatch: Installation of undersized bearings restored optimal clearances, resulting in improved oil flow and reduced friction within the crankshaft system.
Engine Alignment and Deflection Correction: Alignment and deflection readings post-repair were within OEM limits, minimizing stress on rotating components and extending engine life.
Verification of Post-Repair Engine Health: The engine operated seamlessly during sea trials, achieved 100% load without overheating or vibration, and was handed over with full customer satisfaction.
