AFR 24° BBC Cylinder Head 345cc Partially CNC Ported, 117cc Chambers, Race Ready

The AFR 345cc BBC Cylinder Head is a race-ready, high-performance cylinder head designed for radical street/strip, Pro Street, or racing applications. Ideal for displacements up to 572 cubic inches, these heads operate effectively at or below 7000 RPM. The intake runners and exhaust ports are partially CNC machined, and the combustion chambers are offered with either partial or full CNC machining with a bowl blend, making them capable of flowing 401 CFM at 0.700" lift. Get maximum airflow and power with AFR’s high-quality CNC porting and competition-grade components.

Piston Specifications

Piston Top: 50% CNC Ported Combustion Chambers
Approximate Compression Ratios:
- 345cc Intake Port Volume
- 132cc Exhaust Port Volume
- 117cc Combustion Chamber Size (As Cast)
*For exact compression, use a compression calculator for precise adjustments.*
Engine Compatibility: Big Block Chevrolet (BBC)
Engine Sizes Supported: Up to 572 cubic inches

Technical Details

Material: A356 Aluminum
Valve Cover Bolt Pattern: Perimeter Bolt
Valve Angle: 24°/4° Int, 15°/4° Exh
Valve Spring Pocket Diameter: 1.725" O.D
Deck Thickness: .750"
Minimum Bore Diameter: 4.250"
Spark Plug Dimensions: 14mm x .750" w/Gasket Seat

Included Components

50% CNC Ported Combustion Chambers
20% CNC Ported Exhaust Ports
30% CNC Ported Intake Ports
Competition 5 Angle Valve Job
11/32" Intake Valve, 2.300" x 5.500" O.A.L
11/32" Tulip Exhaust Valve, 1.880" x 5.450" O.A.L
PAC Racing #1224 1.625” OD Solid Roller Dual Valve Spring
10° Steel Retainers 1.500" O.D x 1.168" I.D x .844" I.D
Adjustable 3/8" Guide Plates
ARP 7/16” Rocker Studs (Intake & Exhaust)
11/32" Viton Valve Seals
Intake & Exhaust Valve Seats and Valve Guides

Performance & Compatibility

The AFR 345cc BBC Cylinder Head is designed for high-performance applications, delivering exceptional airflow and performance with a full CNC chamber option that provides even higher flow numbers. It is perfect for racing engines with displacements up to 572 cubic inches, providing an optimal balance of power and efficiency, and is ideal for street/strip or competition applications.

CARB Status: THESE PRODUCTS ARE ILLEGAL TO OPERATE ON ANY PUBLIC HIGHWAY. THEY ARE ONLY LEGAL FOR USE ON DEDICATED RACING VEHICLES.