Nothing brings more attention to a car than the sound of its engine, especially at a car show or cruise-in. Comp Cams’ new ThumprTM Series of camshafts provides power you can feel and hear! In the past most cam designs that produced a noticeable thump in the idle sacrificed economy and drivability. These cams have been engineered with lobe profiles that maximize the rough-idling characteristics of the cam without negatively impacting the power output or streetability of the engine. These retro-fit hydraulic roller camshafts are designed for use in 1955-1998 262-400 cubic inch Small Block Chevrolet engines that were originally equipped with flat tappet camshafts.
Part numbers available are:
Comp Cams 12-600-8 - Designed for operating ranges of 1900 to 5600 RPM. Advertised duration is 283in./303ex. with valve lift of .511/.497. This cam is designed for high performance street engine builds. Works okay with a stock converter, but works best with a 2000+ stall converter and gears. Choppy idle
Comp Cams 12-601-8 - This cam is designed for high performance street builds that may see some time at the strip. Designed for operating ranges of 2200 to 5900 RPM. Advertised duration is 291in./311ex. with valve lift of .521/.507. Needs a massaged engine with 9:1 compression ratio minimum. We recommend a dual plane manifold, preferrably the Edelbrock Air Gap 2601, and headers. Drivetrain needs gears and a 2500+ stall converter. Rough idle!
Comp Cams 12-602-8 - This cam is designed for high performance hot street and drag strip engines. Designed for operating ranges of 2500 to 6200 RPM. Advertised duration is 299in./319ex. with valve lift of .531/.517. Needs a minimum compression ratio of 9.5:1. Manifold, headers,gears and a 2800+ stall converter are required. Very rough idle!