(My attempt to explain the calculation)
Inches | |||||
Cylinder Bore Diameter | 4.1212" | ||||
Cylinder Bore Radius | Diameter / 2 | 4.1212 / 2 | = | 2.0606" | |
Cylinder Head Area | Pi * Radius * Radius | 3.14159 * 2.0606 * 2.0606 | = | 13.3394 sq inches | |
Stroke | 3.75" | ||||
Displacement/ Cylinder | Area * Stroke | 13.3394 * 3.75 | = | 50.023 cid | |
Engine Displacement | Disp/ Cyl * # of Cyl | 50.023 * 8 | = | 400.18 |