Cosworth Big Valve Cylinder Head with Camshafts Subaru WRX STI EJ25 2.5L 04-06
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. These heads include Consworths S2 version camshafts (KK3920- Japan/European) with the correct cam followers included. This is the perfect head/camshaft combination for serious performance and track day use.
- CNC Ported/Machined finish port
- New Castings
- Hand blended finish work
- Intake 14.63% (average) 22% (max) increased flow
- Exhaust 30.56%(average) 41% (max) increased flow
- 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
- In stock- ready to ship
- Knife edged ports
- Includes S2 Camshafts and cam followers installed
About Manufacturer: Cosworth
Over the last 50 years Cosworth have developed an in-depth knowledge of engines, electronics and a range of high performance technologies. This has been used to supply some of the most successful motor sport teams and vehicle manufacturers in history.
Our unprecedented success has fueled customer demand globally from diverse market sectors designing and developing technologies and components for aerospace, automotive, defense and sport applications.