What component transforms motion from the pushrod to operate the intake and exhaust valves?

What component transforms motion from the pushrod to operate the intake and exhaust valves?

• A. Rocker arm
• B. Camshaft
• C. Crankshaft
• D. Valve lifter

Answer: (A)

The rocker arm is the part that converts the pushrod’s up-and-down motion into the valve’s opening action. In a typical pushrod engine, the camshaft drives a lifter, which moves the pushrod. The pushrod then pushes on the rocker arm, which pivots on a fulcrum. The far end of the rocker arm presses down on the valve stem, overcoming the valve spring and opening the valve. The camshaft provides the overall motion, and the lifter handles converting cam motion to pushrod motion, while the crankshaft isn’t directly involved in valve opening. So the rocker arm is the element that directly translates the pushrod’s motion into valve operation.

The rocker arm is the part that converts the pushrod’s up-and-down motion into the valve’s opening action. In a typical pushrod engine, the camshaft drives a lifter, which moves the pushrod. The pushrod then pushes on the rocker arm, which pivots on a fulcrum. The far end of the rocker arm presses down on the valve stem, overcoming the valve spring and opening the valve. The camshaft provides the overall motion, and the lifter handles converting cam motion to pushrod motion, while the crankshaft isn’t directly involved in valve opening. So the rocker arm is the element that directly translates the pushrod’s motion into valve operation.