Although there are many types of cams, including wheels, shafts, discs, tooth, drum, cylinder to vinyl record disc grooves, they usually serve a similar role, as they are all designed to convert rotational (or occasionally sliding) motion into reciprocating or oscillating motion (cyclic) or even single motion (occasional), such as axle position adjusting snail cams. Commonly, this is linear motion, but there are rare exceptions, which needn’t worry us. Before the advent of modern, cheap electronics, cams were employed for a huge range of electrical control systems.
Valve control by lobular cam
The cam lobes are applied to cam wheels, often singly or doubly, or camshafts; sometimes (and rarely) singly, but more commonly in multiple. With four-stroke engines, cam wheels usually rotate at half engine speed.
For our older motorcycles,…