EKM-Jan-2021

Q1. Sketch and describe an overview Of the electronic controlled camshaft-less engine with respect to the following operations: a. Fuel Injection system. b. Exhaust valve actuator system. c. Cylinder lubrication system.

Q2. Suggest with reasons, which one or combination of the following conditions is likely to contribute most to persistent breakage / slacking of ‘holding down’ bolts: I. A scavenge fire; II. Small cracks in the traverse girder of the bedplate; III. Highly stressed holding down bolts; IV. Loose chocks; V. Partially balanced reciprocating masses; VI. One piston hung up.

Q3. With reference to 2-Stroke Slow Speed Engine: A. Sketch and describe Main Engine Exhaust Valve. B. List out a procedure for test of Main Engine Exhaust Valve after overhaul.

Q4. A. Discuss the nature of the forces to which a main engine crankshaft is subjected in normal service and explain how the resulting stress are maintained at a safe limit by design and efficient maintenance respectively. B. Indicate the circumstances under which the crankshaft may- i. over stressed; ii. Become defective without being over stressed.

Q5. Describe the methods of checking maximum cylinder pressure. What effects are likely to be experienced, following operation with too high and too low maximum cylinder pressure? How can the maximum cylinder pressure be increased or decreased?.

Q6.A. Outline the problems associated with effective lubrication of the liner and piston assemble of a large slow speed engine. B. Describe the appearance and state the causes of each of the following: i. Clover leafing; ii. Micro-seizure C. Describe the composition of a cylinder oil suitable for an engine operating on residual fuel..

Q7. Why does an explosion occur in the starting air line of an internal combustion engine and how can the possibility of such an occurrence be reduced? Sketch and describe devices, which may be fitted to reduce the severity of such an explosion. State the attention which air starting valves should be given before stand by.

Q8.An Auxiliary engine exhibits a tendency to hunt to such an extent that the engine speed variation prohibits the connection of the machine to the switchboard. A. Discuss the possible causes of hunting; B. Explain how the problem of hunting can be rectified.

Q9. Sketch and describe the arrangement of a main engine camshaft chain. Describe the repair procedure following fracture of one chain link during operation of the engine. Give possible reasons for the failure and explain how the chain is set initially at the correct degree of tension.