Speedmaster Aluminum Bare Cylinder Heads

Speedmaster aluminum bare cylinder heads give engine builders a strong base for a custom performance build. Each head is a bare aluminum cylinder head (also called a bare aluminum head or build-your-own head). You choose the valves, springs, retainers, locks and rocker hardware to suit your cam, intended use and power goals.

Key Features:

• Aluminum construction: Aluminum is much lighter than stock cast iron. It also dissipates heat well, so you can run higher compression with less risk of detonation.
• Gravity die-cast aluminum: Speedmaster describes its heads as gravity die-cast. This keeps weight down while giving performance beyond many OEM heads.
• Natural as-cast finish: Heads are ready to be machined, ported or finished to your plans.
• Valve guides and seats: Bronze valve guides are installed. Seats are machined with a 3-angle valve seat cut in ductile iron.
• Accessory bolt holes drilled: Accessory mounting holes are already drilled.
• Improved port design: Many applications use redesigned intake ports for better flow than OEM heads.

Bare Head Configuration: Valves, valve springs, damper springs, retainers, locks, valve stem seals, rocker arms, rocker studs and nuts, and guideplates are typically not included. Add the valvetrain components that match your build.

Speedmaster offers its aluminum cylinder head line across a wide range of popular engine families. Combustion chamber volumes, runner volumes and port shapes vary by part number. Whether you are building a street engine, a weekend cruiser or a race motor, these heads are a cost-effective upgrade over factory castings.