BBF BULLITT 280CC COMPLETE 75CC CHAMBERS, SOLID ROLLER

Description

“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 our design team decreased overall runner size while giving it a more consistent cross sectional area. This change is designed to increasepeak power while notably boosting the torque, responsiveness and fuel efficiency. We then 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 allows us to address the “Achilles Heel” ofthe BBF head, the exhaust port. By filling the floor of the exhaust port without raising the height we have improved high flow lift while increasing flow at low and midlifts, achieving a 75% intake to exhaust flow ratio with ourexhaust port in the stock location reaching 275 cfm. Thehigh flow stock exhaust location allows for stock header and chassis fitment, but for customers with more room AFR offers their BBF cylinder head with the exhaustport raised .250″.
AFR’s270cc heads feature partially CNC ported intake, exhaust & chambers, A356 aluminiumcastings and high quality components throughout with standard exhaust port locations. Recommended for street, towing, or street/strip engines with displacements up to 477 cubic inches, operating up to 6200 RPM.
Please Note:
that due to AFR’s valve angle and location, custom pistons or notching your existing pistonswill be required.
Specifications & Features:
Material
A356 Aluminum
Intake Port Volume
270cc
Intake Port Dimension
2.230″ H x 1.815″ W x .525° Radius
Intake Port Location
Stock
Exhaust Port Volume
132cc
Exhaust Port Dimension
1.830″ H x 1.600″ W
Exhaust Port Location
Stock
Combustion Chamber
Size 75cc or 85cc
Valve Cover Bolt Pattern
Perimeter
Valve Angle
14° Intake/8° Exhaust
Valve Spring Pocket Diameter
1.750″ O.D
Max Valve Spring Pocket Machining
1.750″ O.D
Deck Thickness
.750″
Minimum Bore Diameter
4.360″
Components:
11/32″ Bead Lock Intake Valve 2.250″ x 5.245″ O.A.L.
11/32″Bead Lock Tulip Exhaust Valve,1.760″ x 5.050″ O.A.L.
PAC Racing Springs 1.550″ OD Solid RollerDual Valve Drag Race Spring 220 lbs. on seat, .680″ maximum lift Max RPM 7200-7400
10° Manley Steel Retainers 1.500″ O.D x 1.120″ I.D x .705″ I.D
10° 11/32″ Beadlock Valve Keepers with lashcap recess
ARP 7/16″ Rocker Studs
Adjustable 3/8″ Guide Plates
11/32″ Viton Valve Seals
Hardened Valve Spring I.D Locator 1.550″ O.D x .780″ I.D