MDE 14 Q4

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Question 3:
How does the timing of the air start valve's opening relate to the inlet and exhaust valves' operation in a four-stroke diesel engine?

D) The air start valve opens when the inlet valve is closed and the exhaust valve is open

B) The air start valve opens when the inlet valve is open and the exhaust valve is closed

C) The air start valve opens when both the inlet and exhaust valves are open

A) The air start valve opens when both inlet and exhaust valves are closed

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Question 1:
At what approximate crank angle does the air start valve typically begin to open on a four-stroke diesel engine during the starting process?

C) 270° after TDC

A) 0° (TDC)

B) 90° after TDC

D) 360° (BDC)

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Question 2:
During which stroke of a four-stroke diesel engine cycle is the air start valve usually open?

B) Compression stroke

D) Exhaust stroke

A) Intake stroke

C) Power stroke

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Question 1:
Which of the following interlocks is most commonly fitted to a direct air start medium-speed diesel engine to prevent the engine from starting if the turning gear is engaged?

A) Over-speed trip interlock

B) Turning gear engagement interlock

C) Lube oil pressure interlock

D) Fuel injection interlock

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Question 4:
What is the significance of the crank angle at which the air start valve closes on a four-stroke diesel engine?

B) It prevents the backflow of exhaust gases into the starting air system

D) It guarantees maximum compression during the power stroke

A) It ensures that the exhaust valve opens immediately

C) It allows the inlet valve to open at the right moment

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Question 3:
Which interlock prevents a medium-speed diesel engine from being started if the engine's crankcase doors are open?

C) Exhaust valve interlock

B) Crankcase door interlock

A) Crankcase explosion relief valve interlock

D) Cooling water pressure interlock

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Question 4:
The low lube oil pressure interlock in a direct air start medium-speed diesel engine is designed to:

D) Ensure that the governor is set to the correct speed

C) Ensure the fuel pumps are correctly aligned

A) Prevent starting if the oil temperature is too high

B) Prevent starting if lube oil pressure is below a safe threshold

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Question 2:
What is the function of the starting air interlock in a direct air start medium-speed diesel engine?

C) To prevent starting if the main starting air valve is not fully open

A) To prevent the engine from starting if the cooling water temperature is too low

D) To ensure that the crankcase doors are properly secured

B) To ensure that the fuel valves are in the open position

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