Tuesday, November 6, 2012
Installation Instructions: Subaru STI Cylinder Heads
Subaru STI Cylinder Heads General Installation Instruction Congratulations, you are the new proud owner of a set of Subaru STI Cylinder Heads. Your Cosworth “Big Valve” CNC Ported Cylinder Heads are brand new Subaru castings. They feature a 4-angle intake, and radiused exhaust valve job. They are pressure tested, deburred, ultrasonically cleaned, serialized, and assembled with the highest quality valve train components available. Many hours have been invested in engineering the port design and valve seat angles providing you the highest flowing and most complete Subaru Cylinder Head assemblies available. Your Cosworth Big Valve Subaru Cylinder Heads are capable of supporting over 1000hp.
It is recommended that these heads be set up and installed by a professional engine builder. Cosworth Big Valve CNC ported Cylinder Heads are intended for racing applications only and are not intended for use on street operated or emissions controlled vehicles.Specific applications (STI) –Since these cylinder heads are Subaru factory castings, they are designed to be a direct bolt-on replacement for OEM stock cylinder heads. Therefore, the assembly procedures and torque specifications depicted in your Subaru Factory Service Manual must be followed. Cosworth Subaru Big Valve CNC Cylinder Heads are recommended for 2.5L DOHC EJ25 STI engines with variable valve timing (VVT) only. Our cylinder heads are not compatible with a standard WRX (or non-VVT) type engine system. These heads use a different means of camshaft lubrication, and may not include provisions to run a single camshaft sensor type engine management. If your specific application calls for anything other than an STI configuration, your cylinder heads may need to be modified.
Download Installation Instructions: Subaru STI Cylinder Heads
