High Energy Hydraulic lifters have a patented constant orifice metering valve that precisely meters oil to the rocker arms. Continuous contact between the metering valve and pushrod seat is maintained, eliminating excessive oiling at high engine speeds. The pushrod seat is made of a special powdered metal iron alloy that is heat-treated for strength and wear resistance. In addition, High Energy Lifters have a lightweight check valve disc that allows for quicker response, which results in increased engine speed before valve float. This check valve disc also maintains added control at all engine speeds and loads. COMP Cams High Energy Hydraulic Lifters also contain a longer piston than conventional Hydraulic lifters, which provides more load bearing surface and increases lifter longevity.