Airflow Research

About Air Flow Research (AFR)

Air Flow Research, widely known as AFR, has spent more than 45 years at the forefront of high-performance cylinder head manufacturing and flow dynamics. Founded on the principle that airflow is the single greatest factor in engine performance, AFR has built a reputation among professional racers and serious street performance enthusiasts alike for producing components that deliver measurable, real-world power gains.

AFR's engineering philosophy centers on precision. Every casting, every port, and every valve seat is designed with one goal in mind: maximizing the volume and velocity of the air-fuel charge moving through the engine. The result is a line of components trusted by some of the fastest cars in the United States — from bracket racers and drag cars to high-powered street machines.

Cylinder Heads: The Core of AFR's Lineup

At the heart of the AFR catalog are their legendary cylinder heads. AFR offers a broad range of performance heads covering Chevrolet small block, big block, and LS/Vortec platforms, as well as Ford small block applications. Each head is engineered for immediate bolt-on installation, requiring no additional porting, relieving, or valve work straight out of the box. This ready-to-run quality is a hallmark of the AFR approach — serious performance without the guesswork.

For builders looking for catalog-grade heads with race-level specifications, AFR's engine cylinder head offerings cover a wide range of displacements and combustion chamber sizes, making it easy to find the right match for a street strip or dedicated race build.

Valvetrain & Supporting Components

Cylinder heads are only as strong as the valvetrain that operates them. Under aggressive cam profiles and high-pressure valve springs, rocker studs can flex — robbing power and shortening component life. AFR's engine rocker arm stud girdles are engineered specifically to eliminate that stud flex, keeping the valvetrain stable across the entire RPM range. Designed to work in harmony with AFR's own head castings, these stud girdles are available for small block and big block Chevy as well as small block Ford applications.

Completing the top-end package, AFR produces engine valve covers designed to pair directly with their cylinder head castings. These aren't afterthoughts — they're purpose-built components sized and shaped to work with AFR's specific head geometries, including proper clearance for stud girdles and high-lift valvetrain setups.

Rounding out the lineup, AFR also manufactures engine exhaust valves, giving builders the ability to source valvetrain internals from the same engineers who designed the head. Using matched valves ensures proper seat geometry, correct stem dimensions, and optimal flow characteristics that complement AFR's carefully developed port work.

Why Builders Choose AFR

• More than four decades of specialization in cylinder head design and flow optimization
• Bolt-on ready heads with no additional machining required
• Comprehensive coverage for popular Chevrolet and Ford performance platforms
• Supporting components — stud girdles, valve covers, and valves — engineered as a complete system
• Proven on both the street and the race track across countless applications

Whether you're building a weekend cruiser or a purpose-built race engine, Air Flow Research offers the engineering depth and product breadth to take your build to the next level.