The Four-Stroke Cycle of an Engine What really makes a car go? There are many parts to an engine that are visible, like an alternator, starter, hoses, wires and a bunch of other things. But what is in the inside and how does it work? The process is really just a mixture of parts, moving in sync in a distinct pattern called the four-stoke cycle. To understand the components of a four-stroke engine better, a little background information may be needed. "In a gasoline engine, exhaust and intake manifolds (tunnels) and valve ports(inlets or outlets) are needed to supply air and fuel on the intake (first down) stroke of the cylinder