Its mostly a trigonometry thing, three sine waves 120 degrees out of phase balance out to constant torque. Also see electrical 3-phase power.
Note that internal combustion cylinder pressure is by no means a perfect sine wave LOL but its a close enough approximation to run smoother.
Its partially a physics thing, in that ICE are usually 4-cycle so they fire every other rotation so if you want three firing pistons per rotation separated 120 degrees you'll need six cylinders total.
Note that internal combustion cylinder pressure is by no means a perfect sine wave LOL but its a close enough approximation to run smoother.
Its partially a physics thing, in that ICE are usually 4-cycle so they fire every other rotation so if you want three firing pistons per rotation separated 120 degrees you'll need six cylinders total.