AFR 15° LS Cathedral Port Cylinder Head 245cc Fully CNC Ported, 65cc Chambers, Large Bore

The AFR 15° LS Cathedral Port Cylinder Head is designed to take your LSX platform to the next level, offering unmatched performance for race applications or radical "Pro Street" builds. With a 245cc intake port, fully CNC ported combustion chambers, exhaust, and intake ports, this head is built for high-performance builds with engine displacements up to 454 cubic inches and operating at or below 6800 RPM. It requires a minimum bore size of 4.000" to clear the supplied 2.165" intake valve, and is CARB legal for 2005 and older emission-controlled vehicles under CARB EO #D-250-4 with 65cc combustion chambers.

Piston Specifications

Intake Valve: 8mm Bead Lock, 2.165" x 4.900" Overall Valve Length (AFR #7211)
Exhaust Valve: 8mm Bead Lock, 1.600" x 4.900" Overall Valve Length (AFR #7228)
Valve Springs: PAC Racing Spring 1.270" OD Hydraulic Roller Dual Valve Spring, 155 lbs. on seat, .650” maximum lift (AFR #8019)
Titanium Retainers: 7° Titanium Retainers 1.245" O.D x .885" I.D x .655" I.D (AFR #8512)
Valve Keepers: 7° Bead Lock Valve Keepers (AFR #9007)
Valve Seals: Viton Valve Seals .600" O.D x .495" I.D (AFR #6612)
Valve Spring O.D Locator: Hardened Valve Spring O.D Locator 1.380" O.D x .570" I.D (AFR #8042)
Valve Seats: Ductile Iron Intake Valve Seats 2.200" O.D x 1.750" I.D x .375" Deep (AFR #9060), Ductile Iron Exhaust Valve Seats 1.650" O.D x 1.350" I.D x .375" Deep (AFR #9069)
Valve Guides: 8 mm Bronze Valve Guides .502" O.D x 2.100" O.A.L (AFR #9051)

Technical Details

Material: A356 Aluminum
Intake Port Volume: 245cc
Intake Port Dimension: 3.315"H x 1.145"W x 11/32 top 13/32 bottom
Intake Port Location: Stock
Exhaust Port Volume: 88cc
Exhaust Port Dimension: 1.495" H x 1.730" W
Exhaust Port Location: Stock
Combustion Chamber Size: 65cc or 73cc
Valve Cover Bolt Pattern: Center Bolt
Valve Angle: 15°
Valve Spring Pocket Diameter: 1.510" O.D
Deck Thickness: .750"
Minimum Bore Diameter: 4.000"
Spark Plug Dimensions: 14mm x .750" w/Tapered Seat

Performance & Compatibility

AFR's 245cc LS1 Cylinder Head is a top-tier solution for serious racers, offering high-flow characteristics and exceptional CNC porting. The maximum flow data for the intake and exhaust ports showcases the capability of this head to handle massive power. With the added benefit of CARB legality for older vehicles, this product is perfect for a dedicated race engine or Pro Street builds looking for a competitive edge.