Engine Systems

The engine, which seems so complex, is a collection of simpler systems whose sole purpose is to efficiently perform the engine's power-making and power-transmitting functions. Virtually all automobile engines are multi-cylinder designs, in which a number of individual pistons and cylinders are joined together in a common housing or cylinder block, transmitting their power to a common crankshaft.

A camshaft, driven by the crankshaft, precisely times and controls the opening and closing of the intake and exhaust valves. Since each valve must cycle open and closed once for every two turns of the crankshaft, camshafts always turn at one-half crankshaft speed. The rest of the engine assembly is made up of systems which supply the essential fuel, air, and ignition, and provide for continuous operation of the pistons, crankshaft, and valves. A cutaway view of the engine is shown in Fig. 1-4. For more information, see ENGINE.

Fig. 1-4.

Cutaway view of 4-cylinder overhead-cam engine.