What kind of idle sound can I expect from this camshaft?

This camshaft is part of COMP Cams' Thumpr series, specifically designed to produce an aggressive, hard-hitting, race-car idle. The early intake valve opening and long exhaust duration create significant valve overlap, resulting in a rougher idle sound.

What supporting modifications are absolutely necessary for this camshaft?

To properly utilize this camshaft, you will need an aftermarket torque converter with at least a 2500 RPM stall speed, lower gear ratios in your rear differential, and a performance intake and headers. Vehicles with power brakes will also require a vacuum canister, pump, or hydroboost system due to reduced vacuum at idle.

Does this camshaft come with any hardware or is it just the cam itself?

The manufacturer's description does not specify if hardware is included with this camshaft. It is common for performance camshafts to be sold separately from installation hardware like lifters, timing sets, or valve springs. Please refer to the manufacturer's installation instructions or contact them directly for a complete list of required components.

COMP Cams Hydraulic Roller Camshaft CB 291T HR-107 MT Th 11-

Name: COMP Cams Camshaft CB 291T HR-107 MT Th
Brand: COMP Cams
Price: 610.12 USD
Availability: InStock

COMP Cams Camshaft CB 291T HR-107 MT Th

$610.12

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 camshaft for Chevrolet Big Block 396-454. Creates a rough, race-car idle and improved power.

Key Features

Fits 92+ vehicle make/model combinations.
COMP Cams Mutha' Thumpr camshaft for Chevrolet Big Block 396-454 engines.
Hydraulic roller camshaft with 235/249 degrees of duration.
Designed for street/strip performance with a rough, aggressive idle.
Requires aftermarket torque converter (2500+ stall), lower gears, intake, headers, and potentially a vacuum assist for power brakes.
Intended for engines with at least 9:1 compression.

⚠️ 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

COMP Cams is well-known for making performance parts that help engines run harder, and their Thumpr camshaft series is a prime example. This particular camshaft, the CB 291T HR-107 MT Th, is designed to give your Chevrolet Big Block engine a serious attitude adjustment. It’s built for street/strip applications and is a great choice if you're looking to build a muscle car or street rod that sounds as aggressive as it performs.

What makes the Thumpr series stand out is its unique lobe design. It features an early intake valve opening and a long exhaust duration. This setup creates a lot of valve overlap, which is what gives the engine that signature, hard-hitting, race-car idle that many enthusiasts love. Beyond the sound, this overlap and the camshaft's overall profile are engineered to deliver noticeable horsepower gains and a broad torque curve, meaning your engine will pull strong across a wider RPM range. This camshaft is a hydraulic roller type, which generally means less friction and better performance compared to flat tappet designs.

Because this camshaft creates a rougher idle and reduced vacuum, it's important to note that it requires several supporting modifications to work correctly and safely. You'll need an aftermarket torque converter with at least a 2500 RPM stall speed, lower gear ratios in your rear differential to keep the engine in its powerband, and a performance intake and headers. For vehicles with power brakes, a vacuum canister, pump, or hydroboost system will be necessary to ensure proper brake function. This camshaft is intended for engines with at least 9:1 compression. It fits a wide range of Chevrolet vehicles originally equipped with Big Block engines, including models like the 1967-1972 Chevrolet Camaro, 1967-1976 Chevrolet Caprice, and 1968-1986 Chevrolet C20.