- Engines & Components
- Cylinder Heads
- AFR Big Block Ford 300cc Bullitt Aluminum Cylinder Heads
The Ultimate 14° BBF Race Heads
''Blue Oval'' big block performance is alive and well at Air Flow Research with a much needed clean sheet redesign of the aging BBF cylinder head. Starting with the needlessly large OEM port their design team decreased overall runner size while giving it a more consistent cross sectional area. This change is designed to increase peak power while notably boosting the torque, responsiveness and fuel efficiency. They carefully shaped the combustion chamber and positioned the valves to compliment intake and exhaust port design while efficiently utilizing the cylinder bore. The improvement in valve positioning allowed them to address the ''Achilles Heel'' of the BBF head, the exhaust port.
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By filling the floor of the exhaust port without raising the height AFR has improved high flow lift while increasing flow at low and mid lifts, achieving a 75% intake to exhaust flow ratio with their exhaust port in the stock location reaching 284 cfm with these 142cc ports. These high flow heads feature a .250'' raised exhaust port location. Stock header and chassis fitment may be an issue for tight engine compartments and chassis.
The 300cc heads are AFR's largest and best flowing BBF heads! They feature 100% CNC ported intake, exhaust & chambers, A356 aluminum castings, and high quality components throughout. These heads are best suited for large displacement high RPM Big Block Ford racing engines or radical ''Pro Street'' style builds. Application specific pistons or fly cutting of your current pistons are required due to the revised valve locations and angles of the AFR Bullitt heads. .
300cc Bullitt Street Cylinder Head Features:
- 100% CNC Ported Combustion Chambers
- 100% CNC Bowl Blend Exhaust Ports
- 100% CNC Bowl Blend Intake Ports
- Competition 5-angle Valve Job
- 300cc Intake Ports
- 142cc Exhaust Ports
- Intake Valve, 2.300'' x 5.245'' Overall Valve Length
- Exhaust Valve, 1.760'' x 5.050'' Overall Valve Length
- Hydraulic Roller Valve Spring: 1.550'' OD Dual Spring, 175 lbs. on seat, .725'' max lift (Max RPM 6500-6700)
- Solid Roller Valve Spring: 1.625'' OD Dual Drag Race Spring, 275 lbs. on seat, .850'' max lift (Max RPM 7400-7600)
