A high pressure manually-actuated spray pump for dispensing a fluid. The spray pump comprises a nozzle through which the fluid is dispensed and a pumping engine. The pumping engine comprises a reservoir, a closure, and a plunger. The reservoir has an open top and a closed bottom and an interior surface. The plunger has an outer surface and a longitudinal passageway extending therethrough. The plunger further having an outlet valve mounted therein and an upper end and a lower end. The lower end being slidably disposed within the open top of the reservoir forming an interior chamber within the reservoir. The interior chamber has an annular chamber and a main chamber. The annular chamber being in fluid communication with the main chamber. The annular chamber is formed by the outer surface of the plunger being spaced away from the interior surface of the reservoir such that there is no frictional contact between the outer surface and the interior surface. The closure being attached to the open top of the reservoir allowing the plunger to slidably extend through the closure such that the interior chamber is sealingly closed. The nozzle is mounted on the upper end of the plunger such that the longitudinal passageway is in fluid communication with the nozzle. The interior chamber is separated from the longitudinal passageway by the outlet valve.