How to Calculate Displacement

Displacement is the measure of the total volume of all engine cylinders. Ever wonder how to figure it out? This is for those who are curious, but geometrically-challenged.

How to Calculate Displacement

To show how the equation works, we'll use the H22 as an example. Keep in mind: π ≈ 3.1415926535897932384626433832795

Displacement = (87mm ÷ 2)² × π × 90.7mm × 4 cylinders
Displacement = (43.5mm)² × π × 90.7mm × 4 cylinders
Displacement = 1892.25mm² × π × 90.7mm × 4 cylinders
Displacement = 2156729.4319084178534884839225615mm³ (divide by 1000 because there are 1000mm³ in 1cm³)
Displacement = 2156.7294319084178534884839225615cm³ (round up to the nearest whole cm³)
Displacement = 2157cm³ or 2157cc

To show how quickly displacement increases, consider boring your cylinder by 0.25mm for oversized pistons. You've just increased your displacement from 2157cc to 2169cc.

--- Courtesy of Kronn 98SH ---