AFR 24° BBC Cylinder Head 335cc Fully CNC Ported, 121cc Chambers, Competition Package

The AFR 24° BBC 335cc Cylinder Head is designed for radical street/strip or "Pro Street" applications with engine displacements up to 572 cubic inches, operating at or below 7000 RPM. Featuring fully CNC-machined intake runners, exhaust ports, and combustion chambers, these heads deliver exceptional airflow performance, reaching up to 410 CFM at 0.800" of lift.

Included Components

100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
Competition 5 Angle Valve Job
11/32" Intake Valve, 2.300" x 5.500" O.A.L (AFR #7626)
11/32" Tulip Exhaust Valve, 1.880" x 5.450" O.A.L (AFR #7631)
PAC Racing #1224 1.625” OD Solid Roller Dual Valve Spring, 275 lbs. on seat, .850” max lift, Max RPM 7400-7600 (AFR #8031)
10° Steel Retainers 1.500" O.D x 1.168" I.D x .844" I.D (AFR #8518)
10° 11/32" Valve Locks with lashcap recess (AFR #9005)
ARP 7/16” Rocker Studs Intake (AFR #6407)
ARP 7/16” Rocker Studs Exhaust (AFR #6406)
Adjustable 3/8" Guide Plates (AFR #6109)
11/32" Viton Valve Seals (AFR #6613)
Hardened Spring Cup 1.740" O.D / 1.650" I.D (AFR #8046)
Intake Valve Seats 2.450" O.D x 2.000" I.D x .375" Deep (AFR #9065)
Exhaust Valve Seats 2.000" O.D x 1.580" I.D x .375" Deep (AFR #9064)
11/32" Intake Bronze Valve Guides .502" O.D x 2.10" O.A.L (AFR #9041)
11/32" Exhaust Bronze Valve Guides .502" O.D x 2.25" O.A.L (AFR #9042)

Performance Flow Chart (335cc Competition)

Lift (inches)	.200	.300	.400	.500	.600	.700	.800
Intake (CFM)	164	240	304	352	385	401	409
Exhaust (CFM)	135	199	249	276	288	295	305

Test conducted at 28" of water (pressure) on Superflow 1020 Bore Size: 4.600", intake 3/4" radius plate exhaust, 2 1/8" curved pipe.

Technical Specifications

Material: A356 Aluminum
Intake Port Volume: 335cc
Exhaust Port Volume: 135cc
Combustion Chamber Size: 121cc
Valve Angle: 24°/4° Int, 15°/4° Exh
Deck Thickness: .750"
Minimum Bore Diameter: 4.250"
Flat Mill: .006" per cc / Maximum 114cc
Angle Mill: .009" per cc / Maximum 104cc
Spark Plug Dimensions: 14mm x .750" w/Gasket Seat

Legal Disclaimer

THESE PRODUCTS ARE ILLEGAL TO OPERATE ON ANY PUBLIC HIGHWAY. THEY MAY ONLY BE USED ON A DEDICATED RACING VEHICLE. VIOLATION MAY RESULT IN FINES UP TO $37,500 PER VEHICLE, REGISTRATION REVOCATION, AND LOSS OF USE ON PUBLIC ROADS.