Comp Cams Pro Magnum Hydraulic Lifters - Set of 16

Comp's Pro Magnum (Anti Pump Up Style) premium hydraulic lifters are the recommended choice for all the Comp Hydraulic cams we sell above. These are mandatory for any type of racing use, or in any application in which the engine will see over 5000-6000 RPM. At these higher RPM's Comp has done extensive testing. They have found not only were the Pro-Magnums good for about 10-15 more horsepower, but they also do not succumb to lifter "pump-up," a condition where the internal piston inside the lifter can fill up with oil and not have enough time to drain or "bleed down." This can result in the piston being in an improper position as it "pumps up," which can lead to holding valves open, which in turn can lead to greatly reduced power output, or in some cases (if that open valve happens to strike a piston top) there can be extreme engine failure. These must be used with an adjustable type of valve train, such as adjustable rocker arms (preferably roller rockers) along with the associated pushrods required. These lifters are considered essential to ensure that your cam has the longest possible life and is fully covered under Comp's warranty policy. And, since this is Comp we're talking about, you can be assured of two things: The product is 100% made in the USA, and the quality is second to none. Seat height on these is 1.84".