🔍 Key Concepts

• Relationship between cam profile (shape) and valve motion in a diesel engine • How cams control timing, lift, and speed of valve movement • Whether one cam characteristic can influence more than one aspect of valve operation

💭 Think About

• If you slightly change the cam’s shape, what aspects of the valve’s movement will change when the engine runs? • Does the cam only decide when the valve moves, or also how far and how fast it moves? • Think about how the follower rides on the cam surface: what does that contact actually control in the valve train?

✅ Before You Answer

• Verify which items in the choices are directly controlled by the cam profile rather than other engine parts or adjustments • Consider whether timing, lift, and velocity of valve motion are independent, or all linked to the cam shape • Double‑check if any answer choice is too narrow when compared to what a cam lobe actually does in a diesel engine