What supporting modifications are needed for this camshaft?

This camshaft requires a minimum of 9:1 compression, a 2500+ RPM stall speed torque converter, an upgraded intake manifold, and performance headers to function optimally. It is designed for a performance build.

What kind of idle can I expect with this camshaft?

The Mutha' Thumpr camshaft is known for its aggressive profile, which results in a noticeable rough idle. This is a characteristic sound associated with performance camshafts designed for increased airflow and power.

Does this camshaft come with lifters or other valvetrain components?

This product is for the camshaft only. It is designed to work with hydraulic roller lifters, but these are typically sold separately. Always refer to the manufacturer's instructions for a complete list of recommended components.

COMP Cams Hydraulic Roller Camshaft 31-601-8 for Ford Small

Name: COMP Cams Camshaft FS 291Th R7 Thumper R
Brand: COMP Cams
Price: 610.14 USD
Availability: InStock

COMP Cams Camshaft FS 291Th R7 Thumper R

$610.14

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

COMP Cams Mutha' Thumpr hydraulic roller camshaft for Ford 221-302 SBF engines. Offers a rough idle and requires supporting modifications for optimal performance.

Key Features

Fits Ford 221, 255, 260, 289, and 302 small block engines.
Hydraulic roller camshaft design for improved durability and performance.
Intake duration at .050 lift is 235 degrees, and exhaust duration is 249 degrees.
Requires a minimum of 9:1 compression ratio.
Best paired with a torque converter rated for 2500+ RPM stall speed.
Designed for street/strip applications and produces a rough idle.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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Will this fit your vehicle?

Product Details

This is the COMP Cams Mutha' Thumpr hydraulic roller camshaft, part number 31-601-8, designed for Ford 221, 255, 260, 289, and 302 small block engines. It's a popular choice for those looking to build a street/strip performance engine, offering a distinct, rough idle that signals serious intent. This camshaft is intended for applications where you're aiming for significant power gains and are willing to make the necessary supporting modifications.

To get the most out of this camshaft, you'll need a solid foundation. COMP Cams recommends a minimum of 9:1 compression ratio to effectively utilize the cam's profile. You'll also want a torque converter with a stall speed of 2500 RPM or higher to keep the engine in its power band during acceleration. Beyond that, expect to upgrade your intake manifold, gearing, and exhaust headers to match the camshaft's increased airflow demands. This isn't a simple bolt-in for a stock engine; it's part of a performance package designed to change the engine's character and power delivery significantly.

When installing this camshaft, remember that it's designed to work with hydraulic roller lifters, which are generally more durable and offer better performance than flat tappet systems. The 235/249 degree intake/exhaust duration at .050 lift is aggressive, contributing to that characteristic rough idle and strong top-end power. While it's not CARB approved and cannot be shipped to California, it's a well-known option for Ford enthusiasts looking to build a potent street machine or strip car.