- Engines & Components
- Cylinder Heads
- AFR Big Block Ford 285cc Bullitt Aluminum Cylinder Heads
14° Aggressive Street/Strip Performance 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 276 cfm with these 142cc ports. The high flow stock exhaust location allows for stock header and chassis fitment, but for those with more room AFR offers their BBF cylinder head with the exhaust port raised .250'' .
AFR's 285cc heads feature 100% CNC ported intake, exhaust & chambers, A356 aluminum castings and high quality components throughout. Recommended for more aggressive or street/strip or racing builds with displacements up to 512 cubic inches, operating up to 6500 RPM. 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. .
285cc 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
- 285cc Intake Ports
- 142cc Exhaust Ports
- Intake Valve, 2.250'' 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)