The total volume of all the cylinders in an internal combustion engine determines its size, often expressed in liters (L) or cubic centimeters (cc). For a piston engine, this volume is determined by the cylinder bore diameter, the piston stroke length, and the number of cylinders. For a rotary engine, a more complex formula involving the chamber volume and the number of rotors is used. This measure is a critical factor influencing an engine’s power output, torque characteristics, and fuel efficiency. For instance, a single-cylinder engine with a 50 mm bore, a 60 mm stroke, will have a volume of approximately 118 cc.
Determining this engine volume provides a standardized way to compare engines of different configurations and manufacturers. Historically, it’s been a key parameter for regulatory classifications, taxation, and motorsport categories. A larger value often correlates with increased power potential, although other factors like forced induction and technological advancements can significantly impact performance. Understanding this measurement is vital for engineers, mechanics, and consumers when selecting, modifying, or evaluating engine performance.