Exam Question

(a) Procedure for Complete Inspection of Cylinder Liner and Piston Assembly:
As a second engineer, inspecting a cylinder liner and piston assembly is an important maintenance task. The procedure begins with examining the cylinder liner. First, inspect for any carbon accumulation around the scavenge ports, clean them thoroughly, and check for damage, such as cracks. Then, ensure the liner's internal surface is smooth; any signs of burns or protruding metal should be addressed using an oil stone or portable grinder as per recommendations. Pay special attention to the quill areas for corrosion or cracks, and manually pump oil to ensure all quills are functioning correctly. Additionally, inspect the liner for honing marks; the absence of these and the presence of a mirror finish indicate lubrication failure. Black patches on the liner surface suggest leaking piston rings, which need replacement. It's also essential to measure the cylinder liner wear and compare it to previous records, ensuring the wear rate is within the manufacturer's limits. If the liner is withdrawn, examine the water side for scale or deposits and clean as necessary. Also, check the condition of the O-rings and renew them if needed.
The piston assembly inspection involves checking for burns at the top of the piston, wear on the side walls of the crown, and ring grooves. Look for any cracks due to thermal or mechanical stresses, high-temperature corrosion, or sulfuric acid corrosion. Ensure the piston rings move freely, and check the ring grooves for wear, steps, and scuffing. If the piston is water-cooled, inspect the underside for scaling, or if oil-cooled, check for carbon deposits. Finally, inspect bolts, locking wires, studs, and O-rings for integrity.
(b) Faults in cylinder liner: