Evolution Hydraulic Roller Lifters with Hydraulic Cartridge Technology is a revolutionary patented tappet. A combination of a self-contained hydraulic cartridge within a thick wall lifter body and accompanying reduced oil volume that is less effected by oil aeration delivers the most consistent bleed rates between each lifter on the market.

The smaller volume within the hydraulic cartridge creates one of the most responsive and quietest lifters on the market today. Startup noise is greatly reduced and a precision-controlled bleed down rate ensures excellent performance at high RPM. The cartridge design also allows for an incredibly stiff lifter body, greatly reducing body distortion and further ensuring consistent hydraulic performance. This patented HCT tappet is completely new design that was developed specifically by COMP Cams to meet the demanding performance and durability required for modern street and performance street engines. The HCT and proprietary manufacturing processes of these lifters ensure precision and longevity that exceed any lifter on the market. Other features include increased duration and lift to the camshaft and two oiling features. Another industry first is the fact that the hydraulic element of this patented lifter is serviceable, allowing anyone to rebuild lifters in his or her own garage.