MDE 2 End of Unit Quiz

MDE 2 End Of Unit Quiz

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5. Role of the Cooling System in Efficiency

Question: How does the cooling system impact the thermal efficiency of a diesel engine?

C) It increases the mechanical friction in the engine

B) It prevents overheating, which helps maintain optimal combustion temperatures and efficiency

A) It directly improves the fuel atomization process

D) It reduces the power needed for engine accessories

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Correcting Slight Loss of Timing Drive Tension

Question: How can slight loss of tension in engine timing belts or chains be corrected?

D) By adding extra lubrication to the timing components

A) By replacing the timing belt or chain with a new one

C) By increasing the engine's operating temperature

B) By adjusting the tensioner or idler pulleys to restore proper tension

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Effects of Loss of Timing Drive Tension

Question: How does a loss of tension in engine timing belts or chains affect the engine?

C) It increases the engine's horsepower output

D) It enhances the performance of the turbocharger

B) It can lead to incorrect valve timing, causing engine misfires and potential damage

A) It improves fuel efficiency by reducing friction

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Importance of Clearances for Piston Rings

Question: Why are the clearances necessary for efficient piston ring functioning in a marine diesel engine?

C) To enhance the cooling of the engine

D) To reduce the overall size and weight of the engine components

B) To increase the friction between the piston rings and the cylinder wall

A) To allow for thermal expansion, prevent binding, and ensure smooth operation

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5. Timing Chain Tensioner Function

Question: What is the role of the timing chain tensioner in the timing chain system?

D) To adjust the engine’s idle speed

C) To enhance the engine’s power output

B) To maintain the correct tension in the timing chain

A) To regulate the engine’s fuel intake

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Clearances for Efficient Piston Ring Functioning

Question: Which of the following THREE clearances are necessary for efficient piston ring functioning in a marine diesel engine?

D) End clearance, side clearance, and oil clearance

B) Compression clearance, thermal clearance, and axial clearance

A) End clearance, radial clearance, and side clearance

C) Radial clearance, axial clearance, and lateral clearance

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Piston Ring End Clearance

Question: Why is piston ring end clearance necessary in a marine diesel engine?

A) To allow for thermal expansion and prevent the rings from binding in the cylinder

B) To increase the friction between the piston rings and the cylinder wall

D) To reduce the piston ring's contact area with the cylinder wall

C) To enhance the lubrication of the piston rings

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4. Effects of Engine Friction on Mechanical Efficiency

Question: What effect does engine friction have on mechanical efficiency?

B) It decreases the engine’s power output and mechanical efficiency

A) It increases the engine’s thermal efficiency

D) It improves the performance of the turbocharger

C) It reduces fuel consumption

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Components of a Timing Chain Link

Question: What components are typically found in a timing chain link?

B) Gears, sprockets, and tensioners

C) Pulleys, belts, and idlers

A) Chain links, rollers, and side plates

D) Camshafts, crankshafts, and valves

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1. Sources of Thermal Efficiency Losses

Question: In a diesel engine, where may thermal efficiency losses commonly occur?

D) In the electrical system and battery

C) In the cooling system and lubrication system

B) In the combustion chamber and exhaust system

A) In the fuel injection system and turbocharger

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Types of Piston Ring Ends

Question: Which of the following are THREE different types of piston ring ends used in marine diesel engines?

B) Flat, rounded, and serrated

C) Notched, grooved, and slotted

D) Straight, stepped, and curved

A) Butt, tapered, and bevel

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2. Role of Rollers in a Timing Chain

Question: What role do rollers play in a timing chain system?

B) They reduce friction and wear between the chain and sprockets

D) They support the camshaft alignment

C) They adjust the tension of the timing chain

A) They enhance the lubrication of the timing chain

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