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IAG Stage 4 Tuff EJ25 Closed Deck Short Block
The IAG Stage 4 Tuff Short Block starts with brand new Subaru 2.5L engine case halves. IAG machines the case halves assembled together in our Haas VF-4SS CNC mill 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 Stage 4 Tuff case is then drilled and tapped to accept 14mm head studs that combined with the IAG Fire-Lock head gasket set greatly reduces head gasket failure during high cylinder pressure scenarios.
Next, the short block is Deck Plate bored and honed to 99.75mm in our in-house Sunnen SV-30 the most advanced automotive cylinder hone available. IAG˜s in-house honing process is able to set custom piston to wall clearances to best fit your needs. The modified case halves are then assembled using a new 2017+ Subaru 2.5L nitride treated STI crankshaft that is matched to ACL or King race main bearings. Custom IAG TRI-BEAM +2mm connecting rods by Manley and ARP 625+ rod bolts are utilized along with ACL or King race rod bearings. The case halves are sealed with new OEM main/case bolts and sealant (upgrading to ARP mains requires line honing). Finally, IAG-Spec 99.75mm JE FSR 2618 Forged Pistons with Electro-nickel plated tops and ring area as well as upgraded .250" / .906" H13 wrist pins are added to finish the Stage 4 Plus block. 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 H13 tool steel and the pin piers are profiled to increase pin boss strut. 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.
[ Excluded from Shipping Specials ]
$6,599.99
SKU
IAG-ENG-1452
IAG (Integrity Auto Group) was established in 2004, initially selling high quality used performance cars. Within a year and a half, IAG sold over 200 Subaru WRX / STI’s. Our clients began requesting us to provide performance products and services for their Subaru’s, which we quickly catered to. IAG extended these services and parts nationally by 2007. Fast forward to 2019, IAG Performance is known as a leader in the automotive performance industry (specifically Subaru) and carries an impeccable reputation among our clients and peers.
Stage 4 Tuff 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 to fit 14mm head studs - *Head studs sold separately
- Pistons - IAG-Spec JE FSR 99.75mm 2618 Forged Pistons, Electro-nickel Plated Tops & Ring area, Ring Set, .250" / .906" H13 Wrist Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pins)
- Connecting Rods - IAG-Spec Tri-Beam +2mm w/ 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.
Additional Options Available
- Head Studs - IAG / ARP Spec 14mm head studs, nuts, and washers - $550
- Head Gaskets - IAG Fire-Lock .051" Head Gaskets with IAG-Spec Alloy Ring Set* Required for use with this short block -$249.99
- Oil Pump - Subaru JDM High Volume Oil Pump - $219, or Subaru 11mm Oil Pump - $199.95
- Hardware / Seal Option - $105.99 (Wrist pin plugs, washers, separator cover, bolts, etc. In case you dont want to transfer from the original engine).
Compression Ratio
- 8.5:1 on D Cylinder Heads (EJ255)
- 8.2:1 on B, V and W EJ257 Heads with standard thickness gasket.
Head Gasket Required
- *IAG Fire-Lock .051" Head Gaskets with IAG-Spec Alloy Ring Set* PN# IAG-ENG-1740
Power: The IAG Stage 4 Tuff Short Block has a power output rating of 1000BHP.
*All IAG short blocks are balanced and blueprinted.
*Build time for blocks are 2-3 weeks. During the holidays it can take longer.
WARNING: Operating, servicing and maintaining a passenger vehicle or off-road vehicle can expose you to chemicals including engine exhaust, carbon monoxide, phthalates, and lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. To minimize exposure, avoid breathing exhaust, do not idle the engine except as necessary, service your vehicle in a well-ventilated area and wear gloves or wash your hands frequently when servicing your vehicle. For more information go to https://www.P65Warnings.ca.gov/passenger-vehicle.
| SKU | IAG-ENG-1452 |
|---|---|
| Brand | IAG Performance |
| Product Type | Engine |
| Engine | Shortblocks |