Abstract: This invention comprises a birotational pump for the movement of air fluid through a conventional pumping mechanism. It is comprised of cylindrical piston housing, a pump shaft running through the piston housing, a piston linkage assembly secured to the pump shaft, a pair of valve plates which cover the ends of the piston housing and a cylindrical pump housing surrounding the piston housing to allow for the free movement of the piston and piston linkage. This invention will permit the free flow of fluid or air through the piston housing by creating a suction chamber in the piston housing. The fluid enters the valve plates which contain openings which line up with openings in the piston housing. As the shaft rotates the openings on the first end of the piston housing cease to line up with openings in the piston housing and openings in the second end line up to expel the fluid contained within the chamber of the piston housing cirutier of rotation of shaft can be changed.