- Per cylinder (usually cam based)
- Per revolution (crank based)
- Per cycle (usually cam based)
Per cylinder, aka, distributor style patterns could be generated from the crank just as much as the cam, if not for the distribution of spark issue. On a two-stroke per-cylinder could only be done from the crank.
So, then, the following cases exist:
- Four stroke, cam sync signal, 720 cycle
- Four stroke, crank sync signal, 360 cycle repeated twice
- Four stroke, per-cylinder sync signal, 720/cyl-count cycle, repeated cyl-count times
- Two stroke, crank sync signal, 360 cycle
- Two stroke, per-cylinder signal, 360/cyl-count cycle, repeated cyl-count times
- Wankel, "crank" sync signal, 360 cycle
- Wankel, per-combustion signal, 360/rotor-count cycle, repeated rotor-count times
Fred.