What is the term for the distance the piston travels in an engine?

The term for the distance the piston travels in an engine is referred to as stroke. Stroke is a critical measurement in an engine's design, as it directly influences the engine's power output and overall performance. It is defined as the linear distance the piston moves from its lowest position (bottom dead center) to its highest position (top dead center) within the cylinder. A longer stroke typically allows for more air and fuel to be drawn into the cylinder, potentially increasing the engine's power and efficiency, while influencing the engine's revving characteristics.

Understanding stroke is essential when discussing engine configurations, as it plays a pivotal role alongside other dimensions, such as bore (the diameter of the cylinder), to determine the engine's displacement, which is a measure of the total volume swept by all the pistons.