IAG 800 CNC Pocket Ported Competition Cylinder Heads Package (Does NOT Include Kelford A "272" Cams, Cam Towers, Lifters & Rockers) - 2015-2021 Subaru WRX / 2015-2016 STI

IAG 800 CNC Pocket Ported Competition Cylinder Heads Package

GEARED TOWARDS WEEKEND RACING

Crafted with the weekend racer in mind, the IAG 800 CNC Pocket Ported Competition Cylinder Heads offer a substantial improvement in airflow compared to the IAG 600 heads. These heads are well-suited for vehicles that see occasional track use, including road racing, rally, auto-x, or drag racing, and are engineered to support up to 800 BHP with the necessary modifications. Enhanced with upgraded GSC +1mm Stainless Steel Valves, GSC Viton Valve Stem Seals, improved GSC Valve Guides, and Kelford Dual Valve Springs with Titanium Retainers, these heads deliver exceptional performance. For FA20 Heads, which have a different configuration than their EJ counterparts, the casting is divided into "lower" and "cam towers." Opting for Kelford "A" cams with the IAG 800 Cylinder Heads includes new OEM cam towers, rockers, pivots, and valve shim caps, providing a comprehensive upgrade package.

 

CONSTRUCTED WITH ALL-NEW COMPONENTS

Each set of IAG 800 FA20 DIT Cylinder Heads begins its journey with pristine OEM castings sourced directly from Subaru of America. 

Following a meticulous visual inspection and the removal of OEM guides, the heads are meticulously positioned within our state-of-the-art Centroid 5-axis CNC Machine, renowned for its precision in engine machining. The Centroid CNC undertakes a meticulous "pocket port" beneath the valves, skillfully enlarging and blending the opening. This CNC porting not only streamlines the machining process but also ensures consistent port results that are challenging to replicate manually. Subsequently, the heads are drilled to accommodate larger 1/2" or 14mm head studs commonly used in high-performance applications. To prevent coolant leakage, OEM press-fit freeze plugs are replaced with threaded plugs after being tapped and threaded. GSC Manganese-Bronze valve guides, optimized to enhance airflow, are then carefully pressed into position, followed by diamond-honing of all intake and exhaust guides in our honing station. The heads undergo further refinement in our Newen Valve Guide and Seat Machine, which executes a multi-angle valve job tailored to the flow characteristics of GSC's +1mm valves. Resurfacing of the heads' decks is carried out using our TS-3000 BlockMate to achieve a smooth, even finish. To eliminate machining residue and oils, the heads undergo ultrasonic cleaning before final assembly, which includes the installation of Kelford Dual Cylindrical Valve Springs and Retainers, accompanied by GSC Viton stem seals.

 

WHAT IS A POCKET PORT?

Pocket porting entails enlarging and blending the area beneath the valve seat, a pivotal aspect of porting procedures. Our Centroid 5-axis cylinder head porting machine ensures precise execution with consistency. This technique specifically targets the region approximately 1" beneath the valve, ensuring a seamless transition and enhancing power output. Unlike other sections of the port, where additional volume may not be necessary at these power levels and could potentially compromise airflow velocity, pocket porting focuses solely on optimizing this crucial area.

 

UPGRADE YOUR CAMS FOR IMPROVED PERFORMANCE

Consider opting for the Kelford "A" camshafts to enhance the power output of your IAG 800 Head Package. These cams are designed for drivers looking to boost the performance of their modified FA20 WRX. With the capability to support up to 800 BHP, these camshafts are perfect for those seeking maximum power. The package also includes all-new OEM cam towers, rockers, pivots, and valve shim caps. After installation, our specially designed fixture ensures precise bench lash adjustment, although it's advisable to verify and fine-tune the final lash post-installation.

 

PREVENT COOLANT AND OIL MIXING WITH IAG'S FA20 CASTING PLUG MODIFICATION SERVICE

During the development of the FA20 cylinder heads, Subaru opted for cost-saving measures, including the use of pressed-in casting or "freeze" plugs. While these plugs are intended to seal the holes left during the casting process and contain coolant within the cylinder head, they are prone to loosening over time. If these plugs dislodge, it can lead to coolant and oil mixing inside the timing cover, resulting in significant damage and potentially requiring engine replacement. To address this issue, IAG offers a solution: threading the opening for the casting plugs and installing new threaded plugs that are secure and resistant to popping out. This modification is essential for FA20-equipped WRX vehicles aiming for higher horsepower levels, ensuring dependable performance without the risk of coolant contamination.

 

IAG 800 CNC Pocket Ported FA20 DIT Cylinder Heads Package Includes:

• (x2) Brand New Subaru OEM AW20 FA20 WRX DIT Cylinder Head Castings
• (x8) GSC 35mm (+1mm) Intake Valves
• (x8) GSC 30mm (+1mm) Exhaust Valves
• (x16) Kelford Dual Cylindrical Valve Springs & Retainers
• (x16) GSC Manganese-Bronze Valve Guides
• (x16) GSC Valve Stem Seals
• IAG Performance CNC Pocket Porting
• Multi-Angle Valve Job
• Drilling for compatibility with ½" or 14mm Head Studs
• Threaded Coolant Plug Upgrade
• Resurface
• Ultrasonic Cleaning

 

NOTE: This Package does NOT include Kelford A "272" Cams, Cam Towers, Lifters & Rockers