IAG 1150 EJ25 2.5L Subaru Short Block - 1150 BHP

IAG 1150 2.5L Subaru Closed Deck Short Block for 02-14 WRX, 04-21 STI, 05-09 LGT, 04-13 FXT

BUILT TO WITHSTAND HIGH HORSEPOWER DRAG RACING

The IAG 1150 Short Block is designed for those who plan to drag race their high-horsepower Subarus regularly. While still a streetable block, the IAG 1150 is designed for the track. This block includes additional features to further strengthen the OEM case halves including Stage 4 Closed Decking and pinned mains secured with ARP case hardware. Our record-setting “Fire-Lock” Head Gasket system and 14mm head studs are used to ensure a tight seal even in extreme conditions. :contentReference[oaicite:1]{index=1}

The IAG 1150 Short Block features IAG Spec “Tri-Beam” +2mm forged connecting rods. An IAG Spec billet crankshaft is used to support additional oiling and prevent main bearing distortion. The upgraded block, billet crank, connecting rods, race bearings, and forged pistons are able to support additional engine load produced by the largest turbochargers and the most demanding uses including competition drag racing. :contentReference[oaicite:2]{index=2}

BUILT WITH 100% NEW COMPONENTS

Every IAG Short Block is built with 100% new components. The modified case halves are assembled using an IAG-Spec billet crankshaft that is matched to ACL or King race main bearings. Custom IAG Tri-Beam +2mm connecting rods with ARP 625+ rod bolts are utilized, along with ACL or King race rod bearings. The case halves are sealed with OEM sealant and ARP main bolts. :contentReference[oaicite:3]{index=3}

The IAG-Spec 99.75mm Custom Forged Pistons with .250" / .927" wrist pins as well as electroless nickel plated tops and ring area are chosen to finish the IAG 1150 Short Block. :contentReference[oaicite:4]{index=4}

IAG 1150 CLOSED DECK WITH FIRE-LOCK SYSTEM

The IAG 1150 Short Block starts with brand new Subaru 2.5L EJ25 engine case halves. The case halves are split and the main webs are CNC machined for 9.5mm pins to reduce distortion and movement of the case in extreme conditions. The case halves are then reassembled and IAG machines the case 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. :contentReference[oaicite:5]{index=5}

The case halves are then CNC machined for our new Fire-Lock™ head gasket solution that is influenced by diesel technology where a counterbore step is machined around each cylinder bore allowing specially sized fire rings to drop into the machined area and head gasket bores. The IAG 1150 case is CNC drilled and tapped to fit 14mm head studs. Utilizing the Fire-Lock™ gasket solution, along with larger IAG/ARP 14mm head studs, nuts, and washers reduce the chances of the heads lifting under extreme boost conditions. The short block is then deck plate bored and honed to 99.75mm. IAG's in-house honing process sets custom piston-to-wall clearances to ensure performance and reliability. :contentReference[oaicite:6]{index=6}

OUR STRONGEST PISTONS EVER

The IAG 1150 Short Block uses IAG-Spec 99.75mm Custom Forged Pistons with .250" / .927" wrist pins featuring electroless nickel plated tops and ring area. IAG's custom pistons feature a lightweight design while increasing strength where it’s needed most and are designed to work exclusively with the IAG +2mm Tri-Beam connecting rods. The wrist pins are made from strong H13 tool steel and the pin piers are profiled to increase pin boss strength. Finally, IAG’s pistons feature added gas ports to aid ring sealing in high boost conditions. :contentReference[oaicite:7]{index=7}

IAG 1150 CLOSED DECK SHORT BLOCK INCLUDES

What's Inside:

• Case Halves – Converted to Closed Deck from brand new OEM Subaru case halves, bored and honed to 99.75mm
• Pinned Mains – Machined for 9.5mm pinned mains and line honed
• Fire-Lock – IAG Fire-Lock™ receiver groove machining (IAG Fire-Lock™ head gaskets required)
• Head Studs – Machined for 14mm head studs
• Pistons – IAG-Spec JE FSR 99.75mm 2618 forged pistons, electroless nickel plated tops & ring area, ring set, .250" / .927" H13 wrist pins, clips (Perfect Skirt coating and offset wrist pins)
• Connecting Rods – IAG-Spec +2mm Tri-Beam connecting rods with ARP 625+ rod bolts
• Rod / Main Bearings – ACL or King race bearings
• Crank – IAG-Spec billet crank
• Case / Main Bolts – ARP main bolts

Compression Ratio:

• 8.5:1 on D Cylinder Heads (EJ255)
• 8.2:1 on B, V and W EJ257 heads with standard thickness gasket

Power Rating:

Power: The IAG 1150 Short Block has a power output rating of 1150 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.