Engine displacement, expressed in cubic inches (or cubic centimeters), represents the total swept volume of all the cylinders within an engine. It’s calculated by multiplying the cylinder bore area, the stroke length, and the number of cylinders. For example, a single cylinder with a bore of 4 inches, a stroke of 3 inches, has a displacement of (4/2)^2 3 = approximately 37.7 cubic inches.
This measurement provides a crucial indication of an engine’s potential power output. Generally, larger displacements correlate with greater power potential, though factors like engine design and aspiration significantly influence final performance. Historically, cubic inches served as a primary metric for classifying and comparing engines, particularly in the American automotive industry. While other metrics like horsepower and torque are increasingly prevalent, displacement remains a fundamental specification for understanding an engine’s size and capabilities.