| Result |
Formula |
| Displacement |
3.14 * R(squared) * S * C
Where as R = radius (1/2 diameter) of the bore; S = Stroke; C = The number of cylinders. |
| Simpler formula for displacement |
B * B * .7854 * S * C
Where B = Bore; S = Stroke; C = Number of cylinders. |
| Engine CFM |
(engine RPM / 2) * (engine displacement / 1728) |
| Another CFM formula is |
maximum engine RPM * (cubic inch displacement / 3456) |
| Compression Ratio |
displacement of 1 cylinder / volume of 1 combustion chamber |
| Volume |
displacement of 1 cylinder / compression ratio |
| To convert cc's into cubic inches |
Multiply by .061 |
Piston Speed
Should be in the 4,000 to 4,500 per minute is about the limit |
RPM * stroke / 6 |
| Miles Per Hour |
(RPM * T) / (R * 168)
Where T = 1/2 the tire diameter; R = Rear end ratio |
| Axle Ratio |
Count the number of revolutions the driveshaft makes to turn the tire once. If only one tire is jacked up, count for two tire revolutions. |