Engine displacement is a fundamental characteristic describing the total volume swept by all pistons inside the cylinders of an engine during a single complete stroke. It is typically expressed in cubic centimeters (cc) or liters (L). The calculation involves determining the volume displaced by one piston (bore squared multiplied by pi/4, then multiplied by the stroke length) and multiplying that value by the number of cylinders. For example, an engine with a bore of 86mm, a stroke of 86mm, and four cylinders would have a displacement calculated as: ((86mm)^2 /4) 86mm * 4. This yields the total swept volume.
Understanding the swept volume is crucial for comparing engine performance and for classifying vehicles based on engine size. Historically, displacement has been a key factor in determining vehicle taxation and regulatory compliance. Larger volumes generally correlate with greater power output, though advancements in engine technology such as turbocharging and variable valve timing have led to increased power from smaller units. The knowledge of this volume is thus important not just for the consumers in the selection of vehicles with needed power, but for manufacturers seeking to optimize engine design for efficiency and performance.
