COMP CAM 11-600-4 THUMPR 227/241 Hydraulic Camshaft Kit | HP Lifters | Double Roller Timing | LIFT: .498/.483 | FITS: Chevrolet BBC Big Block 454 427 402 396 | Choppy/Thumping Idle

Description

Give your Big Block Chevy the attitude it’s been missing with the Competition Cams 11-600-4 Thumpr Camshaft. Designed for Mark IV BBC engines (396, 402, 427, 454), this hydraulic flat tappet cam is the ultimate upgrade for muscle car owners who want that distinct, head-turning “hot rod” sound without building a dedicated race engine. If you want your Chevelle, Camaro, or C10 pickup to sound like it has 800 horsepower while sitting at a stoplight, the Thumpr is the industry standard for delivering that aggressive, choppy idle profile.

The secret behind the 11-600-4 is its unique engineering. Competition Cams designed this grind with a tight 107-degree Lobe Separation Angle (LSA) and a significant duration split (227 intake / 241 exhaust @ .050”). This combination creates massive valve overlap, which is what generates that heavy, rhythmic lope. But it’s not just about noise; the valve lift of .498”/.483” is optimized to deliver a broad, usable power curve from 1,600 to 5,400 RPM. This means you get strong low-end torque for getting heavy cars moving, followed by a hard-pulling mid-range that makes highway cruising and passing effortless.

How does it feel in the driver’s seat? It feels muscular and eager. The idle is rough and noticeable—you will feel the cam “hitting” through the chassis, giving you that visceral classic car experience. On the street, the throttle response is snappy, and the exhaust note is deep and throaty. While it is aggressive, this standard “Thumpr” grind is the most street-friendly of the series. It produces enough vacuum for power brakes (though a canister is helpful on some setups) and works best with a 2,000+ RPM stall converter and moderate gearing to really unlock its potential.

Why buy the 11-600-4? Because Competition Cams is the most trusted name in valvetrain performance. You are getting a precision-ground camshaft that balances durability with high-performance geometry. Whether you are restoring a vintage street machine or building a weekend cruiser, this cam offers the best bang-for-your-buck in terms of sound and mid-range power. Don’t settle for a boring stock replacement; install the Thumpr and make your Big Block sound as mean as it looks.

Manufacturer: COMP CAM / ENGINETECH
Model: THUMPR 227/241
Included components: 1-CAMSHAFT 16-LIFTERS 1-TIMING SET
Warranty: LIFETIME – IF INSTALLED BY A CERTIFIED MACHINIST