AFR 23° SBC Cylinder Head 235cc Competition Package Heads, Standard Exhaust, 70cc Chambers

The AFR 23° SBC Cylinder Head 235cc Competition Package is a high-performance solution designed for enthusiasts looking to maximize power and efficiency. These 100% CNC-machined heads deliver top-tier flow with precision-crafted intake, exhaust ports, and combustion chambers. Ideal for racing applications, they are equipped with high-quality components like Titanium retainers and PAC Racing Springs, ensuring durability at high RPMs.

Piston Specifications

Piston Top: 100% CNC Ported Intake, Exhaust Ports, and Combustion Chambers
Approximate Compression Ratios:
- 70cc Combustion Chambers
*For exact compression, use a compression calculator for precise adjustments.*
Engine Compatibility: Small Block Chevy (SBC)
Engine Sizes Supported: Suitable for applications requiring 235cc intake port volume and 80cc exhaust port volume

Technical Details

Material: A356 Aluminum
Intake Port Volume: 235cc
Intake Port Dimensions: 2.200" H x 1.290" W 5/16 Radius
Exhaust Port Volume: 80cc
Exhaust Port Dimensions: 1.430" H x 1.540" W
Combustion Chamber Size: 70cc
Valve Cover Bolt Pattern: Perimeter Bolt
Valve Angle: 23°
Deck Thickness: .750"
Spark Plug Dimensions: 14mm x .750" w/Gasket Seat

Performance & Compatibility

These cylinder heads feature advanced 5-angle valve jobs, 60/40 valve spacing, and a competition-level valve train that demands shaft-mounted rocker arms for optimal geometry. Ideal for racing, they deliver exceptional flow, making them perfect for high-performance drag race setups.

Included Components

100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
Competition 5-angle Valve Job
8mm Bead Lock Intake Valve, 2.125" x 5.00" long O.A.L. (AFR #7253)
8mm Bead Lock Exhaust Valve, 1.600" x 5.030" long O.A.L. (AFR #7254)
PAC Racing Springs 1.550" OD Solid Roller Dual Drag Race Spring, 250 lbs on seat, .800" max lift
10° Titanium Retainers 1.500” O.D x 1.120” I.D x .705” I.D (AFR #8505)
10° Bead Lock Valve Keepers with lashcap recess (AFR #9009)
ARP 7/16" Rocker Studs (AFR #6405)
Adjustable 5/16" Guide Plates (AFR #6103)
Viton Valve Seals .600" O.D x .495" I.D (AFR #6612)
Hardened Valve Spring I.D Locator 1.550” O.D x .780” I.D (AFR #8048)
Ductile Iron Valve Seats & Guides (AFR #9060, #9070, #9051)

235cc Competition Flow Chart

Intake: 159 @ .200", 336 @ .800"
Exhaust: 120 @ .200", 250 @ .800"

*Test conducted at 28" of water on Superflow 600 with a 4.155" bore size.*

Important Notice

These products are illegal to operate on any public highway, including public paved or unpaved roadways or in a public park. They are only legal if used on a dedicated racing vehicle. Violations are subject to penalties, including a maximum fine of $37,500 per violation per vehicle, revocation of registration by DMV, loss of use on public rights of way, and proof of correction of the tampering.