Before revision: Crankshaft geometry The geometry of the system consisting of the piston, rod and crank is represented as shown in the following diagram: 500px|Diagram showing geometric layout of piston pin, crank pin and crank center Definitions From the geometry shown in the diagram above, the following variables are defined: rod length (distance between piston pin and crank pin) crank radius (distance between crank center and crank pin, i.e.
After revision: =Crankshaft geometry The geometry of the system consisting of the piston, rod and crank is represented as shown in the following diagram: 500px|Diagram showing geometric layout of piston pin, crank pin and crank center Definitions From the geometry shown in the diagram above, the following variables are defined: rod length (distance between piston pin and crank pin) crank radius (distance between crank center and crank pin, i.e.