Hydraulic Roller Cams - Secret Lobes

The "HIT" column refers to hydraulic intensity, which is a figure derived by subtracting the duration at 0.050 number from the advertised duration number. This number relates to how quickly the lifter accelerates away from the base circle. In other words, if the lifter accelerates more slowly away from the base circle, this requires more degrees of duration between the opening checking point and 0.050-inch lifter rise. Most hydraulic flat tappet cams accelerate quicker off the base circle than hydraulic roller cams.

The Cost Of PowerIt always costs extra to make more power, and hydraulic roller motors are no exception. The following chart outlines the price difference for three small-block Chevy cam kits. The first is a Comp hydraulic flat tappet cam kit, the second is a hydraulic roller cam kit for a block configured stock with hydraulic roller tappets, while the third is a Comp retro-fit K-kit that allows you to use hydraulic roller tappets in a pre-'86 engine. As you can see, the price increases dramatically with the complexity of the kit. You would also want to run good roller rockers with this kit, which is an additional $230 to $280. All parts were priced through www.summitracing.com.