Abstract: A hydraulic tappet includes a tubular cylinder sideable within a bore of a housing, a piston with a reservoir slideably mounted within the tubular cylinder, a lower piston spring biased away from the piston with the reservoir forming a pressure chamber therebetween. The reservoir being in open communication with pressure oil ports and the pressure chamber selectively being closed or open to said reservoir. The closing or opening of the pressure chamber being controlled by the lower piston and cylinder riding on tracks of a cam which control the relative position of the cylinder and lower piston.