Engineers at COMP Cams developed Short Travel Race Hydraulic Roller Lifters using a design that maximizes the performance of hydraulic roller lifters at higher engine speeds. With full travel hydraulic lifters in performance engines, higher rpms are often limited by the incorrect positioning of the lifter's internal piston, which inevitably pumps up during the engine cycle. This improper location results in open valves and therefore leads to lost horsepower and sometimes even engine failure. With the COMP Cams Short Travel Race Hydraulic Roller Lifters, the patent pending design minimizes internal piston movement to cut down on the open valve issues and allow higher engine rpm and thus increase horsepower. The surface of these lifters has been black oxide to significantly reduce surface friction, wear and lubrication temperatures. This creates a high performance, high quality component. These high performance lifters are designed for any Small Block Ford applications originally equipped with a hydraulic roller cam or those utilizing the COMP Cams Retro-Fit Kit for Small Block Ford engines that don't require a link bar.