Careful cylinder offset was also necessary to combat vibration inertial forces.Limiting vibration in large double row radials requires masterful engineering with master rod offset, crankshaft design, vibration dampers, gear reduction and propeller selection etc
So what is the exact angular difference between the two parts of the crankshaft ? I would have always assumed 180° (as it is easiest forged that way in a simple die), but with the offset of half a cylinder pitch, this would of course mean that always two cylinders fire simultaniously, which increases torque pulses hence excites torsional oscilations. If the cylinders rows are aligned, there is always only one zylinder firing at a time.
So is the crankshaft offset different from 180° or the cylinder offset different from half a cylinder pitch ?