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IAG 900 Long Block Engine w/ Stage 4 Heads - 06-14 WRX / 04-19 STI

IAG 900 EJ25 Closed Deck Long Block w/ Stage 4 Heads:

The IAG Performance Hand-Built Subaru EJ25 Closed Deck Long Block Engine Packages are a complete, valve cover to valve cover, crate engine. These engines offer significant ease of installation for customers seeking a complete “drop-in” engine package for their WRX, STI, Forester XT or Legacy GT. The Long Blocks feature a combination of our proven IAG Performance Closed Deck Short Block and Cylinder Head packages, along with other race-proven components to complete the assembly. When paired with our Long Block Installation Packages, you 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.

The IAG 900 package is ideal for clients looking for an engine package to support up to 900 BHP applications. The IAG 900 Long Block features our Magnum Closed Deck Short Block that utilizes a brand new EJ25 Subaru case that is converted to closed deck and is bored and honed to 99.75mm. The Magnum 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 a Subaru EJ25 turbocharged engine. The Magnum internals includes IAG-Spec JE FSR 2618 forged pistons, .250" / .906" H13 pins, IAG-Spec Tuff H-Beam +2mm connecting rods with ARP 625+ rods bolts and an OEM STI crankshaft. The block is then paired up with our Stage 4 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 and resurfaced. The heads are outfitted with GSC valve train components, consisting of +1mm oversized intake and SuperAlloy exhaust valves, Beehive Springs as well as GSC Billet Stage 3 camshafts. To complete the package, we add an IAG / ARP 14mm head stud set and all the required gaskets for the final valve cover-to-valve cover assembly.

IAG’s Break-in Instructions MUST be followed, and the long block must be professionally installed for the 12 month/12,000 mile workmanship warranty to be applicable. If the previous engine experienced an internal failure then all oiling components (i.e. cooler, pump, pickup, cam gears, and solenoids, etc) as well as other necessary components as per your installer’s recommendations, must be replaced during installation.

IAG 900 Long Block Engine Includes:

IAG Magnum Closed Deck Includes:
  • Case Halves - Converted to Closed Deck using brand new Subaru OEM case halves, bored and honed to 99.75mm.
  • 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 - Machine Case for 14mm head studs - *Head studs are sold separately
  • Pistons - IAG-Spec JE FSR 99.75mm 2618 Forged Pistons, Electroless Nickel Plated Tops & Ring area, Ring Set, .250" / .906" H13 Wrist Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pins)
  • Connecting Rods - IAG-Spec Tuff H-Beam +2mm / ARP 625+ Rod Bolts.
  • Rod / Main Bearings - ACL or King Race bearings.
  • Crankshaft - Standard New Subaru Nitride Treated 2017+ STI Crankshaft.
  • Case / Main Bolts – Standard FHI Subaru case bolts.
Stage 4 Heads:
  • Heads - Brand New Subaru OEM WRX STI Cylinder Head Castings
  • Machine Porting - CNC Ported Intake and Exhaust Runners
  • Intake Valves - GSC 37mm (+1mm) Intake Valves
  • Exhaust Valves - GSC 33mm (+1mm) SuperAlloy Exhaust Valves
  • Springs / Retainers - GSC Beehive Valve Springs & Retainers
  • Guides - GSC Maganese Valve Guides
  • Valve Seals - GSC Valve Stem Seals
  • Lifters - OEM Lifter Buckets
  • Camshafts - GSC 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
Power: The IAG 900 Long Block has a power output rating of 900BHP.

*All IAG short blocks are balanced and blueprinted.



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