Exam Question
(a) Draw sectional diagram of main engine piston showing each part (8)
(b) Show cooling passages for oil cooled piston (4)
(c) What is material of crown and other parts of piston (4)
Class 4 (4th Engineer)
MEKM
📅 Jul 2023
Reference Answer
### (a) Sectional Diagram of Main Engine Piston & (b) Cooling Passages
A sectional diagram of a modern, large two-stroke marine diesel engine piston is required to illustrate its composite construction and internal cooling passages. The piston's primary functions are to transmit the force from combustion gases to the crankshaft via the piston rod and connecting rod, and to act as a gas-tight seal.
**Key Parts of a Main Engine Piston:**
1. **Piston Crown:** The uppermost part of the piston, directly exposed to the extreme temperatures and pressures of combustion. It is typically a separate component from the skirt.
A sectional diagram of a modern, large two-stroke marine diesel engine piston is required to illustrate its composite construction and internal cooling passages. The piston's primary functions are to transmit the force from combustion gases to the crankshaft via the piston rod and connecting rod, and to act as a gas-tight seal.
**Key Parts of a Main Engine Piston:**
1. **Piston Crown:** The uppermost part of the piston, directly exposed to the extreme temperatures and pressures of combustion. It is typically a separate component from the skirt.
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