Exam Question
(a) Draw sectional diagram of main engine piston showing each part. Show cooling passages for oil cooled piston (12)
(b) Name the different materials used for the various components of the piston as indicated to the answer above. (4)
Class 4 (4th Engineer)
MEKM
📅 Aug 2025
Reference Answer
### (a) Sectional Diagram and Construction of an Oil-Cooled Main Engine Piston
A piston for a large, slow-speed, two-stroke marine diesel engine is a composite component designed to withstand extreme thermal and mechanical loads. Its primary functions are to transmit the force from gas combustion to the crankshaft via the piston rod and connecting rod, and to act as a gas-tight seal for the cylinder.
**Key Components of an Oil-Cooled Piston:**
1. **Piston Crown:**
A piston for a large, slow-speed, two-stroke marine diesel engine is a composite component designed to withstand extreme thermal and mechanical loads. Its primary functions are to transmit the force from gas combustion to the crankshaft via the piston rod and connecting rod, and to act as a gas-tight seal for the cylinder.
**Key Components of an Oil-Cooled Piston:**
1. **Piston Crown:**
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