CNC Ported Big Valve Cylinder Head w/ Cams 2004-2006 Subaru STI 2.5L
Cosworth CNC ported cylinder heads feature dyno tested and flow bench proven ports, engineered for maximum usable power. Each new cylinder head is ported on a 5 axis machine to ensure consistency and perfect port shape every time. Additionally, larger intake (+1mm) and exhaust valves (+1mm) are utilized to help increase flow. Cosworth CNC ported Big Valve cylinder heads come complete with a performance valve job, hi rev (max 10,500rpm) valve springs with titanium retainers and are ready to install. Perfect for high performance applications.
Note: These heads include our S2 version camshafts (KK3766) with the correct cam followers included. This is the perfect head/camshaft combination for serious performance and track day use.
Specifications:
- CNC Ported/Machined finish port
- New Castings
- Hand blended finish work
- Intake 13.02% (average) 20.26% (max) increased flow over stock 05 casting
- Exhaust 36.62%(average) 48.98% (max) increased flow over stock 05 casting
- 4-angle Inlet Valve job
- 3-angle & radius Exhaust Valve job
- Valves are lapped
- Back-Cut Inlet Valves
- Heads are Ultra Sonic cleaned prior to assembly
- Heads are Serialized and sport a machined Cosworth logo
- +1mm Stainless Steel Intake Valves (1800 degrees max.)
- +1mm Inconel Exhaust Valves (2400 degrees max.)
- Performance Valve Springs
- Titanium Retainers
- Hardened Steel Spring Platforms
- Knife edged ports
- Includes S2 Camshafts and cam followers installed
