Feuling Race Series Hydraulic Lifters For Harley Feuling Race Series Hydraulic Lifters for Milwaukee Eight engines have a relief machined into the lower body to clear the flange on the camshaft front exhaust lobe on grinds using smaller than stock base circles. These lifters are full travel hydraulics, machined from a cold forged steel body and designed to exceed the needs of larger lift camshafts and higher valve spring pressures with a slower bleed down rate. Race Series lifters maintain proper oil flow to the top end, increase engine Rpm, valve-train stability, decreasing valve float promoting maximum valve lift. Due to the unstable nature of this 4 valve engine design with 1 rocker arm activating 2 valve springs, Feuling highly recommends the use of these lifters for Milwaukee Eight engines running a higher lift cam and higher than stock valve spring seat pressures. This lifter will help reduce valve-train separation and can result in a quieter, better performing engine. Race Series lifters are compatible with Feuling Oe+, HP+ or Race Series and factory oil pumps and are designed for use with both street and strip engines. Spin-Tron dyno developed and track proven made in the Usa. Features: Precision ground needle roller bearing with high chromium steel axle for long life and minimal friction Cold forged extra long piston, precision ground and fitted for controlled leak down and pump up High flow disc style quick reacting check valve for better reaction at higher Rpm. Full-travel hydraulic lifters made from machined steel Exceeds the needs of large-lift camshafts and higher spring pressures with a slower bleed-down rate Maintains proper and critical oil flow to valves, springs, rockers, shafts and valve guides Increases engine RPM and valve train stability decreases valve float for maximum valve lift Available in oversize diameters Recommended for both strip and performance street engines Sold in a set of four Made in the USA