IAG 1150 EJ25 2.5L SUBARU SHORT BLOCK
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. 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.
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. 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.
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 in our Haas VF-4SS CNC mill 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. The case halves are then CNC machined for our new Fire-Lock™ head gasket solution that is loosely derived from 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 new 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 in our in-house Sunnen SV-30 cylinder hone. IAG’s in-house honing process is able to set custom piston to wall clearances to ensure performance and reliability.
OUR STRONGEST PISTONS EVER
The IAG 1150 Short Block uses our strongest pistons ever – The IAG-Spec 99.75mm Custom Forged Pistons with .250″ / .927″ wrist pins feature electroless nickel plated tops and ring area. IAG’s custom pistons feature a lightweight design while increasing strength where you need it and are designed to work exclusively with the IAG +2mm Tri-Beam connecting rods. The wrist pin is short and is made from strong H13 tool steel. The pin piers are profiled to increase pin boss strut. Finally, IAG’s pistons feature a 25% larger oil ring for reduced oil consumption and added gas ports that aid ring sealing in high boost conditions.
IAG 1150 Closed Deck EJ25 Short Block Includes:
- Case Halves –Converted to Closed Deck from brand new OEM Subaru case halves, bored and honed to 99.75mm.
- Pinned Mains –Machine case for 9.5mm pinned mains and lined honed.
- Fire-Lock –IAG Fire-Lock™ receiver groove machining, latest solution to prevent head gasket failure on high horsepower and high boost Subaru’s – *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.
- 8.5:1 on D Cylinder Heads (EJ255)
- 8.2:1 on B, V and W EJ257 Heads with standard thickness gasket.
Power: The IAG 1150 Short Block has a power output rating of 1150 BHP
Head Gasket Required:
After years of research and development testing, the IAG Performance Fire-Lock™ head gasket is the newest solution to preventing head gasket failure on high horsepower and high boost Subaru EJ25 engines. This solution is loosely derived from 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 shims are designed to create a compression seal once the heads are installed and torqued into place. IAG fire rings are manufactured to a very strict tolerance from a proprietary alloy and are then put through a heat treatment process. The gaskets are manufactured from an asbestos-free composite raw material and feature a silicone based beading applied to critical areas to improve sealing around all water and oil passages. The combination of the alloy compression shims and gaskets assure maximum sealing for a Subaru EJ25 turbocharged engine.
*The IAG Fire-Lock™ gaskets require machine work for installation and are recommended for use with 14mm head stud hardware.
*The gaskets are sold in pairs with four Fire-Lock™ rings.
- Composite Material
- IAG-Spec Alloy Ring
- Specifically designed for 14mm Head Studs
- Silicone Beading
- 100mm Bore
- .051″ Thickness
- Intended for High Horsepower, High Boost applications
- IAG ARP 14mm Head Studs Required
- Gaskets sold in pairs
1. If a block or cylinder head was previously o-ringed the groove must be filled and resurfaced before using this type of gasket.
2. These gaskets require IAG ARP 14mm head studs to achieve the required torque necessary for proper installation.
3. Due to the required torque, any block that was previously honed will need to go to the next size overbore.
4. Future servicing will require cylinder head resurfacing due to an imprint left from the Fire-Lock™ rings.
- *IAG Fire-Lock™ .051″ Head Gaskets with IAG-Spec Alloy Ring Set* PN# IAG-ENG-1740 – Add to your order for an extra $299.99
14mm Head Studs Required:
- IAG / ARP 14mm Head Stud Set Part# IAG-ENG-1711 – Add to your order for an extra $579.99