The IAG Stage 2.5 short block starts with new Subaru FA 2.0L engine case halves that are machined for improved oiling. Then IAG machines the case halves assembled together in our Haas VF-4SS CNC mill to accept the IAG CLOSED Deck Inserts that transform the block into a solid deck. The unique inserts feature small passages that allow needed coolant flow to the deck surface. Next, the short block is Deck Plate bored and honed that to 86.25mm on our in-house Sunnen SV-30 the most advanced automotive cylinder hone available. IAG’s in-house honing process is able to set piston to wall clearances tighter for a quieter running engine. The short block is measured and assembled using a new 2015-20 Subaru 2.0L WRX crankshaft that is matched to King main bearings. Brian Crower H-Beam rods with ARP2000 rod bolts are utilized along with King or ACL rod bearings. The case halves are sealed with new OEM case bolts and sealant. Finally, IAG-Spec 86.25mm forged pistons are spec’d and installed along with an OEM oil plug finishing off the short block.
Stage 2.5 FA20 Includes:
Case Halves -Converted to Closed Deck using brand new Subaru OEM case halves
Case Machining – Modified for improved oiling
Case Machining – Bored and honed to 86.25mm
Pistons -IAG-Spec 86.25mm Forged Pistons, Ring Set, and .150″ x 2.250″ Chromoly Wrist Pins.
Connecting Rods -Brian Crower H-Beam / ARP2000 Rod Bolts
Rod -ACL or King XPG
Main Bearings -King XPG
Crankshaft -New Subaru FA20 DIT WRX crankshaft
Case / Main Bolts -Standard Subaru case bolts
Hardware – OEM Oil Plug – comes preinstalled at the oil pan location