MDE 14 Q4

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

C) Power stroke

D) Exhaust stroke

B) Compression stroke

A) Intake 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?

D) Fuel injection interlock

C) Lube oil pressure interlock

A) Over-speed trip interlock

B) Turning gear engagement 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?

A) It ensures that the exhaust valve opens immediately

D) It guarantees maximum compression during the power stroke

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

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

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

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

D) To ensure that the crankcase doors are properly secured

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

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

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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?

B) Crankcase door interlock

D) Cooling water pressure interlock

C) Exhaust valve interlock

A) Crankcase explosion relief valve interlock

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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?

B) 90° after TDC

C) 270° after TDC

D) 360° (BDC)

A) 0° (TDC)

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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?

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

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

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

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

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

C) Ensure the fuel pumps are correctly aligned

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

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

A) Prevent starting if the oil temperature is too high

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