Speedmaster Assembled Cylinder Heads

Jun 27, 2023

Speedmaster has cylinder heads available in as-cast or CNC-ported versions. The aluminum heads are gravity die-cast from heat-treated T6 aluminum. This casting process creates a more uniform and robust casting. That eliminates porosity and durability issues and makes for a dimensionally-accurate cylinder head.

Other features include:• Mounting surfaces and bolt holes are CNC-finished to exact tolerances for proper sealing• Three-angle valve job• Machined for screw-in studs and guideplates• Bronze valve guides• Ductile iron valve seats for use with unleaded gas• Drilled for OEM accessory bolt patterns

Speedmaster Assembled Cylinder Heads come ready to run with stainless steel valves; valve springs; and valve seals, locks, and retainers. They are sold in pairs.

Speedmaster As-Cast Cylinder Heads are designed for street performance and entry-level racing engines making power up to 6,500 rpm. They have as-cast intake and exhaust runners with plenty of material for porting to improve airflow. Most heads have as-cast combustion chambers; some heads for Pontiac V8, 429-460 Ford, and big Mopar are available with CNC-machined combustion chambers.

Speedmaster As-Cast Cylinder Heads are available for these engines:

Chevy• Small Chevy Gen I, hydraulic flat tappet, solid flat tappet, or hydraulic roller cam• Big Chevy Mark IV, Gen V, Gen VI, hydraulic flat tappet or hydraulic roller cam• GM LS1/LS2/LS6 and LS7, hydraulic roller cam only

Ford• 289-302-351W, hydraulic flat tappet, solid flat tappet, or hydraulic roller cam• 351C and 351M• 429-460, solid flat tappet, hydraulic roller, or solid roller cam

Mopar• 318-360 LA small block, hydraulic flat tappet or hydraulic roller cam• B/RB big block, hydraulic flat tappet or hydraulic roller cam

Olds• 400-455, hydraulic flat tappet cam

Pontiac• 350-455, hydraulic flat tappet or hydraulic roller cam

Speedmaster CNC-Ported Cylinder Heads have intake runners, exhaust runners, and combustion chambers that are CNC-machined to within .002-inch tolerance. Combustion chambers have the same volume and runners have the same cross-section, allowing equalized compression and airflow for each cylinder. That means the engine is capable of making more power, and also makes the engine easier to tune for additional power increases.

Speedmaster CNC-Ported Cylinder Heads are available for these engines:

Chevy• Small Chevy Gen I, solid flat tappet, hydraulic roller, or solid roller cam• Big Chevy Mark IV, Gen V, Gen VI, solid flat tappet, hydraulic roller, or solid roller cam• GM LS1/LS2/LS6, hydraulic roller cam

Ford• 289-302-351W, solid flat tappet, hydraulic roller, or solid roller cam• 351C and 351M solid flat tappet, hydraulic roller, or solid roller cam• 429-460, solid flat tappet cam

Mopar• 318-360 LA small block, hydraulic flat tappet or hydraulic roller cam• B/RB big block, hydraulic flat tappet or hydraulic roller cam

For more info: www.summitracing.com 1-800-230-3030