How a Radial Engine Works

The cutaway demonstrates how a 7 cylinder radial engine operates. The master connecting rod is in the top cylinder (no. 1 cylinder). The other rods are connected to it, and the counter weight balances the crankshaft. The firing sequence is 1,3,5,7 in the first revolution, and 2,4,6 in the second revolution. The odd number of cylinders gives an equal spacing of power pulses.

Thanks San Diego Aerospace Museum