The IAG Stage 3 Extreme 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. The case halves are then CNC machined with O-ring receiver grooves around the bore surface as well as drilled and tapped to accept 1/2" head studs that greatly reduce head gasket failure during high cylinder pressure scenarios. 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. Manley I-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 3 Extreme FA20 Includes: