Cosworth CNC Big Port Heads w/ Cams Dual AVCS (08+ STi)

Cosworth Big Valve Cylinder heads for the Dual AVCS 2008 STI EJ257B engine. Machine Ported for maximum accuracy and performance, complete with larger (+1mm) valves and dual valve springs for maximum flow. Cosworth Big Valve Cylinder heads are the key to high power and unlocking the performance potential in your Subaru engine.

These heads include S2 version camshafts (20007935) 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 13.63% (average) 19.38% (max) increased flow
• Exhaust 31.44%(average) 37.78% (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 ports
• Includes S2 Camshafts and cam followers