Camshaft - Thumpr - Hydraulic Roller - Lift 0.557 / 0.539 in - Duration 283 / 303 - 107 LSA - 1900 / 5600 RPM - Ford Cleveland / Modified - Each

T 227/241 HRlr351C

Designed to deliver an aggressive, hard-hitting exhaust note at idle, the Thumpr camshaft series from COMP Cams also delivers excellent horsepower gains and a broad torque curve. A perfect choice for muscle cars and street rods, the Thumpr series' early intake valve opening and long exhaust duration create optimum overlap for that race car idle. The Thumpr grinds all require an aftermarket torque converter and lower gear ratio to ensure the drivetrain always puts the engine in its powerband. Additionally, Thumpr camshafts typically deliver reduced vacuum at idle, making a vacuum canister, pump or hydroboost a requirement for vehicles running power brakes.

Additional Information

High performance street, stock converter ok, best with 2000+ converter and gears, choppy/thumping idle.

Application Summary

Fits Ford 351 Cleveland, 351 Modified, 351 Cobra-Jet, Boss 351, 400 Modified

Part Type

Engine Camshaft

These additional application notes are supplied by the manufacturer and collated from multiple year ranges. Not all of these notes may apply to every year or every variant. Please contact a StreetFX agent for clarification if required.

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Product Details

Product Downloads

#	Document Type	Download
1.	Catalog

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Reference Information

Camshaft, Hydraulic Roller Tappet, Advertised Duration 283/303, Lift .557/.539, Ford, Cleveland, Modified, Each

COMP Cams is bringing back the musclecar sound—and it's nastier than ever! Few things grab our attention at a car show or cruise night more than a car with a thumping high performance idle. In an ongoing quest to provide you with the performance and sound you demand, COMP Cams' engineering team proudly introduces the Thumpr retrofit hydraulic roller camshafts. They are a series of camshafts designed for use in engines that were originally equipped with flat tappet camshafts. The lobe profile and grind characteristics 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. COMP Cams 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.