IAG 800 FA20 DIT Closed Deck Short Block for 2015-21 WRX – 800 BHP

IAG 800 FA20 DIT Short Block – Strengthened Bottom End for Subaru WRX

DESIGNED FOR STRENGTH

The IAG 800 FA20 DIT Short Block is engineered for modified 2015–2021 Subaru WRX vehicles that need a stronger bottom end to support increased cylinder pressures created by higher boost and larger turbochargers. It features a proprietary closed-deck cylinder support system that strengthens the OEM FA20 cylinder walls, providing a robust foundation for high-power builds. :contentReference[oaicite:0]{index=0}

BUILT WITH 100% NEW COMPONENTS

This short block starts with brand new Subaru FA20 engine case halves machined for improved oiling. IAG’s closed deck inserts are installed using precision Haas CNC equipment, transforming the block into a solid deck while maintaining coolant flow. The block is then CNC machined with O-ring receiver grooves and drilled and tapped for ½″ head studs to greatly reduce head gasket failures under high cylinder pressure scenarios. After deck plate boring and honing to 86.25 mm, the short block is assembled with a new Subaru FA20 DIT WRX crankshaft matched to high-performance ACL or King bearings. IAG-Spec H-Beam rods with ARP2000 rod bolts and IAG-Spec 86.25 mm forged pistons complete the bottom end build. :contentReference[oaicite:1]{index=1}

MODIFIED OIL PASSAGES & PISTONS DESIGNED FOR BOOST

IAG carefully inspects and modifies the internal oil passages of each new OEM case to ensure adequate oil flow for performance and durability. The IAG-Spec JE FSR 86.25 mm forged pistons are crafted from 2618 T6 alloy and feature an asymmetrical skirt design to reduce weight and improve combustion efficiency while supporting higher cylinder pressures. :contentReference[oaicite:2]{index=2}

IAG 800 FA20 DIT SHORT BLOCK INCLUDES

• Case Halves – Brand new OEM Subaru FA20 case halves, bored and honed to 86.25 mm
• Case Machining – Modified for improved oiling and O-ring deck surface
• Head Stud Provisioning – Case drilled and tapped for ½″ head studs (studs sold separately)
• Pistons – IAG-Spec JE 86.25 mm forged pistons with ring set and .230″ x 2.250″ wrist pins
• Connecting Rods – IAG-Spec H-Beam with ARP2000 rod bolts
• Rod / Main Bearings – ACL or King race bearings
• Crankshaft – New Subaru FA20 DIT WRX crankshaft
• Case / Main Bolts – Standard Subaru case bolts
• Hardware – OEM oil plug preinstalled at oil pan location

COMPRESSION RATIO

• 10.5:1 compression on standard gasket thickness

POWER RATING

• Rated for up to 800 BHP

Please Note: This item is not eligible for standard ground shipping and must be delivered via freight. 
STOCK NOTICE: This item is built to order and carries a minimum 6-8 week build time.

IMPORTANT DELIVERY NOTE: Your order is shipping Via Truck Freight which requires you to be available at the time of receipt. There is a possibility the trucking company will try to schedule a delivery time with you. At the time of delivery, the driver will hand you the delivery receipt also referred to as the bill of lading, you will use this to notate any damages to the shipment. It is important that you fully inspect the shipment from all sides and notate any dents, punctures or rips in the outside packaging on the delivery receipt. Once you've inspected your shipment from the outside, you will need to open it and check the product in its entirety for damages and notate them if any. If there is no damage sign for the package and enjoy! In the rare case, you do find that your order arrived with damages, it is important you follow these steps. - Do not refuse the product- Document the damages in as much detail as possible on the Bill of Lading
- Take numerous photos from all angles (including packaging)
- Keep the product and contact the shipping company to start the damage claim
- Contact us either by phone or email for the next steps In the situation where the delivery driver is unable to wait for you to open and inspect your product, simply document "driver was unable to wait for inspection." All damage must be noted on the Bill of Lading before signing and initiating a damage claim. If the damage is not notated before signing for the item it is assumed to be in good condition. This will forfeit the ability for a shipping claim and you will not be eligible for refund or replacement.