Abstract: A rotary van engine composed of less parts than previous types. Rotors turn unidirectionally, and fire similar to a reciprocating four cylinder 4 cycle in line upright or inverted piston engine. In front section, induction and compression occurs with transfer of charge in volumetric crescented chamber when vane in rotor sweeps through first revolution completing two cycles. In rear section, combustion and exhaustion occurs from transfer of charge in volumetric crescented chamber when vane in rotor sweeps through second revolution completing two more cycles, for a total of four cycles in two revolutions. The center plate is stationary including adjacent coupling, case and flange parts to become a monolithic entity. A single engine block, the center plate has fuel air transfer slots and port allowing opening for charge to pass between front and rear sections.