Cylinder position sensors use three permanent magnets and push-pull plunger assembly to control a set of dry contacts. The sensor through the cylinder-housing wall detects the magnetic field of a magnet embedded in the piston. These electronic magnetic field sensors are reliable, wear-free. These cylinder sensors with their engineered mounting bracket kit can be fit virtually in cylinder shape or size.

Cylinder rotor mounted in housing for rotation about a first axis of rotation, defining a central crankshaft chamber and having three pairs of cylinders located outwardly of the crankshaft chamber. Each cylinder being closed at a radially outer end by a cylinder cover affixed to the cylinder rotor. Its opposite sides of a plane that includes the cylinder axis and the first axis of rotation, at least one side wall of each said one chamber of each cylinder has overflow channels, and at least one side wall of each said other chamber of each cylinder has gas-exchange ports.