MDE 3 End of Unit Quiz

MDE 3 End Of Unit Quiz

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2. Role of Rollers in a Timing Chain

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

C) They adjust the tension of the timing chain

D) They support the camshaft alignment

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

A) They enhance the lubrication of the timing chain

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5. Timing of Fuel Injection

Question: In a four-stroke timing diagram, when does the fuel valve typically operate?

A) Just before the intake valve closes and the compression stroke begins

C) During the exhaust stroke

B) During the power stroke

D) Just after the exhaust valve opens and before the intake valve opens

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3. Alignment of the Camshaft and Crankshaft

Question: Why is it important to check the alignment of the camshaft and crankshaft during a drive inspection?

A) To ensure the engine’s visual appearance

B) To confirm the alignment of the engine's accessories

C) To ensure proper timing and efficient engine operation

D) To verify the lubrication system’s effectiveness

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Effects of Too Small Tappet Clearance

Question: What are the effects of having too small a tappet clearance on the exhaust valves of a four-stroke diesel engine?

C) Enhanced fuel injection timing and reduced engine noise

D) Increased power output and better acceleration

B) Overheating of the valves, potential for incomplete valve closure, and increased wear on the valve train

A) Improved valve sealing and increased engine efficiency

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Procedure for Setting Tappet Clearance

Question: What is the correct procedure for setting tappet clearance on diesel engine inlet/exhaust valves?

B) Set the engine to a specific RPM, measure the clearance with the engine off, and then adjust the tappets by removing the rocker cover.

A) Measure the clearance with the engine hot and running, then adjust the tappets by tightening or loosening the screws while the engine is operating.

C) Measure the clearance with the engine cold, adjust the tappets with a feeler gauge, and then recheck the clearance with the engine running.

D) Measure the clearance with the engine cold, adjust the tappets using a feeler gauge, and then recheck the clearance with the engine at top dead center of the compression stroke.

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6. Camshaft Gear Teeth Condition

Question: During a drive inspection, why should the condition of the camshaft gear teeth be examined?

A) To check for cracks or damage that might affect the gear's engagement with the chain

D) To inspect the gear for signs of rust

B) To verify the gear's color consistency

C) To ensure the gear matches the engine’s original specifications

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4. Valve Operation during the Exhaust Stroke

Question: What is the position of the valves during the exhaust stroke in a four-stroke engine timing diagram?

B) The intake valve remains closed, and the exhaust valve opens

A) The intake valve opens, and the exhaust valve closes

C) Both the intake and exhaust valves are open

D) Both the intake and exhaust valves are closed

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Meaning and Purpose of Valve Overlap

Question: What does the term "valve overlap" refer to, and what is its purpose in an engine?

B) Valve overlap refers to the period when both the intake and exhaust valves are open simultaneously. Its purpose is to enhance the engine’s performance by improving the scavenging of exhaust gases and increasing the intake of fresh air.

A) Valve overlap refers to the period when both the intake and exhaust valves are closed to maximize compression. Its purpose is to prevent exhaust gases from entering the intake manifold.

D) Valve overlap refers to the time when only the exhaust valve is open. Its purpose is to decrease the engine's fuel consumption.

C) Valve overlap refers to the period when the intake valve opens before the exhaust valve closes. Its purpose is to reduce engine noise and vibration.

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4. Inspection for Chain Slippage

Question: How does checking for chain slippage contribute to the maintenance of a chain-driven camshaft system?

C) It detects if the chain has skipped teeth, affecting engine timing

B) It ensures the engine is running at the correct temperature

D) It confirms the cleanliness of the engine components

A) It helps identify excessive fuel consumption

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3. Valve Operation during the Power Stroke

Question: In a four-stroke engine timing diagram, what occurs with the valves during the power stroke?

D) The intake valve is closed, and the exhaust valve opens

B) Both the intake and exhaust valves are open

A) The intake valve opens, and the exhaust valve remains closed

C) The intake valve remains closed, and the exhaust valve remains closed

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Importance of Tappet Clearances

Question: Why is maintaining proper tappet clearance important in an engine?

D) To reduce the engine’s overall weight and improve fuel efficiency

B) To prevent the engine from overheating by improving cooling efficiency

A) To ensure that the engine’s fuel injectors operate at optimal pressure

C) To ensure proper valve operation, avoid excessive wear, and maintain engine performance

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5. Chain Lubrication Inspection

Question: What should be checked regarding chain lubrication during a camshaft drive inspection?

A) The amount of chain lubrication and its distribution

B) The color of the lubricant used

C) The brand of the lubricant

D) The level of coolant in the engine

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