Cosworth EJ25 (STI) short block has gone through countless hours of dyno evaluation to determine the best combination of parts to guarantee performance and reliability. Each EJ25 short block starts with a brand new Subaru case. The case is inspected and then the bores are honed to perfection to receive Cosworth Forged Pistons. We then balance the rotating assembly that includes a new STI Forged crank and Cosworth Forged H-Beam Connecting Rods to within .5 gram. The select parts are professionally assembled by one of Cosworths skilled engine builders using our own coated , tri metal race spec bearings. Options include: Billet 81mm crankshaft, Billet timing belt guide. For added performance, please see our Cosworth CNC ported Big Valve Cylinder Heads and high performance camshafts.

Specifications:

• Cosworth EJ25 short block includes the following:
• New Subaru EJ25 STI Engine case
• Cosworth Billet Steel 81mm Crankshaft
• Cosworth Forged H-beam Connecting Rods
• Cosworth Forged Pistons and rings
• Cosworth Coated, Tri-metal bearings
• Balanced to within .5 gram
• Complete blue-print assembly
• Ring gap checked
• Bearing clearance checked
• Deck height checked
• Connecting Rod side clearance checked
• Crankshaft end float checked