I had no intention of adding the cam system for the radial engine when
I started, but the engineering is so interesting I had to
at least make some rough illustration.
The engine fires on every other cylinder and with an odd
number of cylinders, it fires them all, first odd and then even.
The cam is actually a big ring gear with four cams spaced 90 degrees apart.
The thing that got my interest was that the firing cylinders are 80 degrees apart.
There are actually two cam tracks on the ring cam, one for intake and one for exhaust.
This illustration just shows one of them for clarity.
The cam ring is driven by gear reduction and reversal, moving
at 1/8 the speed of the crankshaft in the opposite direction.
I put a red dot on the push rod showing which valve
is open and tick marks every 10 degrees of rotation.
Remember the 10 degree difference from before?
Every 10 degrees another valve opens.