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IAG 1150 Closed Deck 2.35L Destroked Long Block Engine w/Drag Heads

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$33,749.95
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Description

IAG 1150 2.35L DESTROKED LONG BLOCK ENGINE WITH IAG 1150 DRAG HEADS FOR 01-14 WRX, 01-21 STI, 03-13 FXT, 04-09 LGT

 

POWER RATING

The IAG 1150 Destroked Long Block has a power output rating of 1150BHP and a maximum 9000 RPM.


DROP IN AND DRIVE

The IAG Performance hand-built Subaru 1150 2.35L Destroked Long Block Engine package is a complete, valve cover to valve cover, crate engine. This engine provides a straightforward "drop-in" solution for those looking to upgrade their 2002-2014 Subaru WRX, 2004-2021 Subaru STI, 2004-2013 Subaru FXT, or 2005-2009 Subaru LGT. This long block features a combination of our proven IAG EJ25 2.35L Destroked Closed Deck Short Block and IAG 1150 Cylinder Head packages, along with a full range of carefully selected high-performance components to complete the assembly. When paired with our Long Block Installation Packages, you’ll have a true plug-and-play solution to get you back on the road, FAST! All components included are BRAND NEW and there is NEVER A CORE CHARGE required.


HAND-BUILT WITH 100% NEW COMPONENTS

IAG’s 1150 2.35L Destroked Long Block Engine package delivers track-level power, making it ideal for high-performance applications that support up to 1150 BHP. This comprehensive Long Block package features our IAG 1150 Closed Deck Short Block that utilizes a brand new Subaru EJ25 engine case that is converted to closed deck and is bored and honed to 99.75mm. The IAG 1150 2.35L block features 14mm head stud machining, as well as our Fire-Lock™ 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 combination of the alloy compression shims and gaskets assure maximum sealing for Subaru EJ25 turbocharged engines. The IAG 1150 internals include custom JE 99.75mm FSR 2618 pistons, JE Pro Seal Ring Set, along with .240" H13 tool steel wrist pins. Also included are custom IAG spec +2mm Tri-beam forged connecting rods, IAG Spec billet 75mm crankshaft, ACL Race Bearings and ARP case bolts.

The IAG 1150 block is then paired up with our IAG 1150 Fully CNC Ported Cylinder Heads to deliver maximum flow for high horsepower applications. The heads start as brand new Subaru OEM cylinder head castings that are CNC machined ported inside the intake and exhaust runners. The heads are resurfaced and then outfitted with complete Ferrea valve train components. The heads include +1mm oversized Comp Plus intake and exhaust valves, Ferrea Dual Drag Valve Springs, Titanium Retainers, GSC Manganese Bronze Valve guides as well as your choice of GSC Billet Stage 2 or Stage 3 camshafts and Kelford DLC Coated Lifter Buckets. To complete the package, we add a 14mm ARP head stud set, our Fire-Lock™ head gasket solution and all required gaskets to complete the valve cover-to-valve cover assembly.

 

THE IAG 1150 EJ25 2.35L DESTROKED CLOSED DECK SHORT BLOCK

IAG’s 1150 EJ25 2.35L Destroked Closed Deck Short Block is built for power, capable of handling up to 1150 BHP. While still a streetable block, the 1150 is optimized for the track. This hand assembled block is based off of our 1150 short block and features an IAG Spec billet 75mm crankshaft, custom IAG Spec +2mm Tri-beam forged connecting rods and ARP 625+ rod bolts. Also included in the assembly are JE 99.75mm FSR 2618 custom pistons that have been treated with electroless nickel-plating, creating a hard-wearing surface that offers detonation resistance and heat reflection. This strengthened short block, combined with a billet crank, race bearings, along with forged connecting rods and pistons delivers a rock-solid foundation that is able to endure intense engine loads generated by large turbochargers and high-powered racing conditions, including competition drag racing.


DESTROKED FOR HIGH-REVVING APPLICATIONS

Featuring a shorter stroke, these +2 rod engines reduce piston speeds, optimizing the rod-to-stroke ratio and increasing piston dwell time at top dead center. This results in improved combustion efficiency and reduced stress on engine components at high RPMs. In terms of performance, this means increased power output, extended ring life, and the ability to rev higher—making this short block an ideal choice for track days, racing, or competition drag racing applications. Our recommended maximum rev limit is 9,000 RPM for these short blocks.


CLOSED DECK WITH 100% NEW COMPONENTS

The 1150 EJ25 Short Block starts with brand new Subaru 2.5L engine case halves. Our expert machinists machine the assembled case halves in our Haas VF-4SS CNC mill to accept the IAG Closed Deck inserts, transforming the block into a solid deck. Next, a deck pair of deck plates are attached and the short block is bored and honed to 99.75mm in our in-house Sunnen SV-30 computer controlled cylinder hone. IAG's in-house honing process allows us to set custom piston to wall clearances to ensure quiet operation and reduced oil consumption. The Haas mill also cuts a groove at the top of each cylinder to accept the Fire-Lock™ head gasket rings and drills each head bolt hole for 14mm head studs. The modified case halves are then assembled using a new IAG Spec billet 75mm crankshaft, custom IAG Spec +2mm Tri-beam forged connecting rods and ARP 625+ rod bolts, along with JE 99.75mm FSR 2618 custom pistons. IAG Short blocks feature ACL rod and main bearings and are all balanced and blueprinted. Finally, the case halves are sealed with new ARP main/case bolts and sealant.


IAG’S FIRE-LOCK SYSTEM: NO MORE HEAD GASKET WORRIES

The IAG 1150 EJ25 2.35L Destroked Closed Deck Short Block features our proprietary "Fire-Lock™" Head gasket system. This system has been proven in our record setting race cars to be the strongest Subaru head gasket system ever produced. To achieve these results, our engineers separated the combustion chamber sealing from the fluid sealing aspects of the head gaskets. Our machinists carefully machine a lip at the top of each cylinder to accept the "Fire-Lock™" ring. With the ring locked in place, it stands proud above the deck, providing a superior seal. The separate gasket bodies take care of sealing oil and coolant passages and keeping them out of the combustion chamber. 14mm Head studs hold the assembly together.


CLOSED DECK FOR EXTRA STRENGTH

Our innovative closed deck system significantly increases the strength of the OEM case halves. This process supports the cylinder walls at the top of the case in order to prevent flexing and possible cracking where the case bolt reliefs are cut into the back of the cylinder wall. During the installation process, we machine the assembled case halves in our Haas VF-4SS CNC mill to accept the IAG Closed Deck inserts. Once the case has been machined we heat it in an oven while freezing the specially machined inserts with liquid nitrogen. The inserts are then pressed into place and then machined to a mirror finish. The 1150 Short Block also features our exclusive case bolt reinforcement plugs, which are threaded and indexed to the deck surface for additional case strength. Our distinctive inserts feature small passages that allow needed coolant flow to the deck surface. This means that the closed deck system does not affect the block's cooling ability and will not cause overheating, even in daily drivers.


CUSTOM JE PISTONS

The IAG 1150 Short Block features JE 99.75mm FSR 2618 custom pistons, engineered to deliver outstanding performance for both street driving, as well as for drag, road and rally racing applications. These pistons feature thicker ringlands and are treated with electroless nickel-plating, resulting in a stronger piston that can stand up to highly boosted applications. Additionally, they come equipped with .240" H13 tool steel wrist pins, providing a significant upgrade over standard chromoly pins, ensuring enhanced reliability under extreme conditions.


BUILT TO PERFORM

A common failure point of the OEM Subaru short block are the piston ringlands. The metal ledges on the pistons that hold the compression rings in place can withstand regular usage but are prone to failure when used with modified components. Cracked or broken ringlands often lead to increased oil consumption and eventual bearing failure if the oil is not closely monitored. In contrast, the increased ringland thickness on the custom JE pistons used in the IAG 1150 Short Block are designed to match up to 1150’s capabilities, ensuring durability and reliability even under high-performance conditions.


FORGED ALUMINUM ALLOY

The OEM EJ25 pistons continue to be produced using a hypereutectic cast design. This casting method is susceptible to irregularities in both the casting process and the materials used, leading to potential weaknesses in the pistons. This is where our custom JE pistons come in; forged from a durable 2618 T6 Alloy with a unique silicone additive, these JE pistons effectively absorb the direct shock and impact of combustion. Engineered to withstand ringland damage due to detonation and preignition, they feature a higher strength material and have been custom designed to feature thicker ringlands.

 

IAG 1150 CNC PORTED DRAG CYLINDER HEADS PACKAGE 


MAXIMUM POWER FOR DRAG RACING

The IAG 1150 CNC Ported Drag Cylinder Heads are designed for drag racing and competition. These fully CNC ported heads provide a significant upgrade in long term performance over the IAG 950 heads. These heads work great for cars where getting the most power with maximum reliability is the goal. The IAG 1150 heads are the best heads available for high-horsepower drag racing. They are designed to support up to 1150 BHP with supporting mods. These heads include upgraded Ferrea Comp Plus Valves, GSC Viton Valve Stem Seals, Upgraded GSC Valve Guides, Ferrea Dual Drag Valve Springs with Titanium Retainers, and Ferrea Keepers. GSC S2 or S3 Camshafts are available with Kelford DLC Coated valve lifter buckets.


MAXIMUM POWER FOR DRAG RACING

The IAG 1150 CNC Ported Drag Cylinder Heads are designed for drag racing and competition. These fully CNC ported heads provide a significant upgrade in long term performance over the IAG 950 heads. These heads work great for cars where getting the most power with maximum reliability is the goal. The IAG 1150 heads are the best heads available for high-horsepower drag racing. They are designed to support up to 1150 BHP with supporting mods. These heads include upgraded Ferrea Comp Plus Valves, GSC Viton Valve Stem Seals, Upgraded GSC Valve Guides, Ferrea Dual Drag Valve Springs with Titanium Retainers, and Ferrea Keepers. GSC S2 or S3 Camshafts are available with Kelford DLC Coated valve lifter buckets.


WHAT MAKES CNC PORTING BETTER?

Cylinder head porting has been around since the invention of the internal combustion engine. It can be done by hand with a die grinder and some cartridge rolls, and a seasoned professional can likely get a good result that way. Unfortunately, doing porting this way requires a lot of experience and care. One slip of the die grinder can ruin your cylinder head. This is where CNC porting comes in. Using our Centroid 5 axis CNC porting machine we can achieve the same results every time we put a set of heads into the machine. Every cylinder head comes out exactly the same and uses our race-proven, computer controlled, CNC porting program to guarantee results.


OPTIONAL GSC S2 OR S3 CAMSHAFT AND LIFTER BUCKET PACKAGE

To get the most out of these heads you'll want to select the GSC Power-Division billet S2 camshafts for your IAG 1150 Head Package. These cams are built to suit the higher horsepower these heads will support. With a power range of 500 WHP and up, you need some additional supporting mods to utilize the true potential of the S2s. Our IAG 1150 Short Block, an upgraded turbocharger and fuel system, and a quality engine management system are key.

If you're targeting maximum power over 1000 WHP and willing to give up some low end drivability, the GSC S3 cams are the way to go. PLEASE NOTE THAT THESE CAMS REQUIRE A STANDALONE ECU AND MAY NOT FUNCTION CORRECTLY WHEN AVCS IS USED. Along with the camshafts we'll include all new Kelford DLC Coated valve lifter buckets and set valve lash so the engine will be ready to install and run.

 

QUALITY GURANTEED

We stand behind every hand-built engine we produce. IAG's Standard Long Block Workmanship Warranty covers your long block for 12 months or 12,000 miles.

 

Vehicle Fitment:

Additional hardware may be required to install this long block to the following vehicles, including but no limited to ECU, Sensors, Ancillaries, Covers, Pumps etc.

  • 1999-2014 Subaru WRX
  • 1999-2021 Subaru STI
  • 1997-2013 Subaru Forester XT
  • 2004-2009 Subaru Liberty GT
  • 2004-2009 Subaru Outback XT

Included Components

  • IAG 1150 Closed Deck EJ25 2.35L Long Block Includes:
  • IAG 1150 Closed Deck EJ25 Short Block:
    • Case Halves - Brand new Subaru OEM case halves
    • Pinned Mains - Machine case for 9.5mm pinned mains and line 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 - JE 99.75mm FSR 2618 Custom Pistons and .240" / .906" H13 Wrist Pins with JE Pro Seal Ring Set
    • Connecting Rods - Custom IAG-Spec +2mm Tri-Beam Forged Connecting Rods with ARP 625+ Rod Bolts.
    • Rod / Main Bearings - ACL Race Bearings.
    • Crank - IAG-Spec Billet 75mm Crank
    • Case / Main Bolts - ARP Case Bolts.
  • Compression Ratio: All Calculated with Fire-Lock Gaskets:
    • 9.2:1 on D Cylinder Heads (EJ255)
    • 8.8:1 on B, V, and W EJ257 Heads
  • IAG 1150 Fully CNC Ported Cylinder Heads:
    • Heads - Brand New Subaru OEM WRX STI Cylinder Head Castings
    • Machine Porting - CNC Ported Intake and Exhaust Runners
    • Intake Valves - Ferrea 37mm (+1mm) Comp Plus Intake Valves
    • Exhaust Valves - Ferrea 33mm (+1mm) Comp Plus Exhaust Valves
    • Springs / Retainers - Ferrea Dual Valve Springs & Titanium Retainers
    • Keepers - Ferrea Valve Keepers
    • Guides - GSC Manganese Bronze Valve Guides
    • Valve Seals - GSC Valve Stem Seals
    • Lifters - Kelford DLC Coated Lifter Buckets
    • Camshafts - GSC Stage 2 or Stage 3 Billet Camshafts
    • Multi-Angle Valve Job
    • Machined Cam Lobe Clearance
    • Drilled For 14mm Heads Studs
    • Resurface
    • Ultrasonic Cleaning
    • Final Lash
  • Gaskets, Hardware & Accessories:
    • Head Studs - IAG / ARP 14mm Set
    • Head Gaskets - IAG Fire-Lock™
    • Valve Cover Gaskets - OEM
    • Cam Seals - OEM
    • Valve Covers - OEM
    • Wrist Pin Seal, Rear Main Seal & Separator Kit
    • Crankshaft Woodruff Key

Media

Installation Instructions

Please review the PDF document below regarding installation, break-in procedures and warranty information.

PDF After Sale Document - Contains Shipping, Engine Care and Warranty Information

Fitment Table

Fitment Notes

Additional hardware may be required to install this long block to the following vehicles, including but no limited to ECU, Sensors, Ancillaries, Covers, Pumps etc.