ASVAB Automotive Information Practice Test 935172

Questions 5
Topics Camshaft, Distributor, Master Cylinder, Power Stroke, Shock Absorbers

Study Guide

Camshaft

The camshaft is linked to the crankshaft through a timing belt and regulates the opening and closing of the intake and exhaust valves in each cylinder in time with the motion of the piston. An engine designated OverHead Camshaft (OHC) locates the camshaft in the cylinder head. An engine with Double OverHead Camshaft (DOHC) has two camshafts, one to regulate the intake valves and one to regulate the exhaust valves.

Distributor

The distributor is driven by the engine's camshaft and is responsible for timing the spark and distributing it to the correct cylinder. The distributor cap contains a rotor that connects the ignition coil (and its high voltage) to the proper cylinder at the proper point in the stroke cycle.

Master Cylinder

The master (brake) cylinder converts pressure on the brake pedal to hydraulic pressure in the brake lines.

Power Stroke

During the power stroke, just before the piston reaches top dead center, the spark plug fires and ignites the compressed air-fuel mixture. The resulting expansion due to combustion pushes the piston back down the cylinder toward bottom dead center.

Shock Absorbers

Because a compressed spring will ex­tend violently, shock absorbers must be used to dampen the spring’s compression and extension cycles. Struts combine the spring and shock into one unit