Manufacturer's Part Number:
COMP Cams Thumpr Retrofit Hydraulic Roller Camshafts
Summit Racing Part Number:
Hydraulic roller tappet
Basic Operating RPM Range:
Intake Duration at 050 inch Lift:
Exhaust Duration at 050 inch Lift:
Duration at 050 inch Lift:
227 int./241 exh.
Advertised Intake Duration:
Advertised Exhaust Duration:
283 int./303 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:
Exhaust Valve Lift with Factory Rocker Arm Ratio:
Valve Lift with Factory Rocker Arm Ratio:
0.547 int./0.530 exh.
Lobe Separation (degrees):
Valve Springs Required:
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COMP Cams is bringing the musclecar sound back and it's nastier than ever! Let's face it, few things serve to grab our attention at a car show or cruise night more than a car with a thumping high performance idle. In fact, one of the most frequent questions fielded when customers call our tech line is, "what camshaft will give my car that mean-sounding idle?" In an ongoing quest to provide you with the performance and sound you demand, COMP Cams' engineering team proudly introduces the Thumpr series of camshafts. The Thumpr camshafts are a new series of retrofit hydraulic roller camshafts designed for use in engines that were originally equipped with flat tappet camshafts. The lobe profile and grind characteristics of these new Thumpr camshafts use a combination of an early exhaust valve opening, a long exhaust duration, and a generous amount of intake and exhaust overlap to maximize the rough-idling characteristics of the cams. They give you a seriously aggressive exhaust note without negatively impacting the power output or streetability of the engine. Thumpr camshafts are available in three different grind profiles; each one will produce a rough, racy exhaust note and impressive amounts of horsepower and torque within a different rpm range. These Thumpr series camshafts feature a cutting-edge hydraulic roller design that delivers a substantial power increase over identical hydraulic flat tappet grinds without sacrificing reliability or ease of maintenance.