In a pushrod engine, which engine component moves the pushrod directly?

In a pushrod engine, which engine component moves the pushrod directly?

• A. Lifter
• B. Camshaft
• C. Rocker Arm
• D. Piston

Answer: (A)

In a pushrod engine, the direct mover of the pushrod is the lifter. The camshaft rotates and its lobes push on the lifter, which sits in contact with the cam. This contact converts the cam’s rotational motion into a vertical, or up-and-down, motion in the lifter. That lifter then pushes straight on the pushrod, transmitting the motion upward to the rocker arm so the valve opens and closes. The camshaft itself doesn’t touch the pushrod directly—there’s a lifter between them—while the rocker arm is driven by the pushrod, not directly by the cam. The piston is part of a separate subsystem and doesn’t move the pushrod at all.

In a pushrod engine, the direct mover of the pushrod is the lifter. The camshaft rotates and its lobes push on the lifter, which sits in contact with the cam. This contact converts the cam’s rotational motion into a vertical, or up-and-down, motion in the lifter. That lifter then pushes straight on the pushrod, transmitting the motion upward to the rocker arm so the valve opens and closes. The camshaft itself doesn’t touch the pushrod directly—there’s a lifter between them—while the rocker arm is driven by the pushrod, not directly by the cam. The piston is part of a separate subsystem and doesn’t move the pushrod at all.