The IAG 800 Short Block is designed for modified FA20 DIT Subaru WRXs that need a stronger short block to support increased cylinder pressures created by additional boost pressure and larger turbochargers. The IAG 800 short block features our proprietary closed-deck cylinder support system to strengthen the OEM FA20 cylinder walls. The short block is fitted with IAG Spec H-Beam forged connecting rods. Head gasket sealing is handled with the addition of an o-ring and 1/2″ head studs for additional compression of the head gasket. These upgrades are ideal for those seeking to get the most out of their full bolt-on and upgraded turbo WRXs.

The IAG 800 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 86.1mm on our in-house Sunnen SV-30 cylinder hone. 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 2020 Subaru 2.0L WRX crankshaft that is matched to OEM or King main bearings. IAG-Spec 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 86.1mm forged pistons are installed, along with an OEM oil plug finishing off the short block.

Adequate oil flow is critical to performance and relibility. It’s no secret that the OEM cases from Subaru leave something to be desired in the oiling department. Our machinists carefully inspect and modify the internal oil passages of each new OEM case used in the IAG 800 Short Block to ensure proper flow and reliability.

Each IAG 800 Short Block features IAG Spec JE FSR 86.1mm Forged Pistons. These 2618 T6 Alloy high-strength pistons have been specifically designed to support increased cylinder pressures which come with more boost. FSR forgings reduce mass and wear caused by friction without sacrificing strength. This is accomplished by using an asymmetrical skirt design instead of the traditional full-round skirt, also this reduces weight significantly. Featuring smooth flowing radii on the domes and dishes, the design promotes excellent flame travel. The pistons are secured to the rods with .905 x 2.250″ x .210″ wall carbon steel wrist pins with Tru Arc locks.