The Cosworth CNC ported cylinder head for the EVO 9 (with Mivec) features 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 and designed for excellent torque and turbo response.

-CNC Ported/Machined finish port- New Castings -Hand blended finish work -Intake 20% (max) increased flow -Exhaust 22% (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 -Knife edged port divider