IAG Stage 2 Tuff "Cosy" 2.5L Subaru Short Block for WRX, STI, Legacy GT, Forester XT

IAG Stage 2 Tuff Cosy 2.5L Subaru Short Block for Subaru WRX, STI, Forester XT and Legacy GT.
IAG Stage 2 Tuff "Cosy" Built 2.5L Subaru Short Block

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MSRP: $5,039.99
Our Price: $4,799.99
Savings: $240.00

Quantity in Stock:(Out of Stock)
Availability: Usually Ships in 2 to 3 Weeks
Part#: IAG-ENG-1212

Seal Kit*:
Wrist Pin / Cover Seals P# IAG-ENG-1720 [Add $105.99]
Not Required

Description Warranty Information Applications

IAG Stage 2 Tuff "Cosy" Short Block

IAG Performance is proud to embrace our partnership with Cosworth Performance by offering a variation of our top-selling Stage 2 TUFF block featuring Cosworth 99.75mm Forged Pistons and connecting rods. The IAG Stage 2 Tuff "Cosy" short block starts with new Subaru 2.5L EJ25 engine case halves that are bored and honed to 99.75 on our in-house Sunnen SV-10. IAG's in-house honing process is able to set piston to wall clearances tighter for a quieter running engine. The short block is measured and assembled using a new 2017+ Subaru 2.5L nitride treated STI crankshaft that is matched to ACL or King race main bearings. Next Cosworth 4340 forged connecting rods with Cosworth H11 tool steel rod bolts (260,000psi) are utilized to increase the power rating slightly at the expense of being heavier. The connecting rods are matched to ACL or King race rod bearings. The case halves are sealed with new OEM main case bolts and sealant. Finally, 99.75mm Cosworth forged pistons finish off the short block.

The IAG Stage 2 Tuff "Cosy" Short Block has a power output rating of 675BHP.

Stage 2 Tuff "Cosy" Short Block Includes:
  • Case Halves - Brand new Subaru OEM case halves, bored and honed to 99.75mm.
  • Pistons - Cosworth 99.75mm Forged Pistons
  • Connecting Rods - Cosworth / Cosworth H11 Rod Bolts (260,000psi).
  • 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:
  • Hardware / Seals - OEM cover and seal kit - $105.99

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

*All IAG short blocks are balanced and blueprinted.

Hardware / Seal Option:

Not planning on reusing your original short block service plugs and covers? IAG offers a simple comprehensive OEM cover and seal kit that includes (1) Rear main seal, (3) wrist pin plugs, (3) wrist pin plug washers, (1) separator cover, (6) separator cover bolts, (1) wrist pin service cover, (1) wrist pin service cover O-ring and (2) wrist pin service cover screws. *If you are reusing your original wrist pin service plugs and covers always replace the (3) wrist pin plug washers and (1) wrist pin service cover O-ring before installing a short block to avoid potential leaks. *Never reuse a rear main seal on a new short block.

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

WARNING: This product can expose you to chemicals which is known to the State of California to cause cancer and reproductive harm. For more information, visit www.P65Warnings.ca.gov.

Features / Specs
Cosworth 99.75mm Forged Pistons, Ring set, Pins and Clips
IAG Spec Bore and Hone (Performed on our in-house Sunnen SV-10)
Tighter piston to wall clearance for quiet operation
New FHI Subaru Case Halves (Bored, Honed and Plateau Brushed)
Cosworth Forged Connecting Rods w/ Cosworth Rod Bolts
New FHI Subaru Nitride Treated 2017+ STI Crankshaft
ACL or King Race Rod Bearings
ACL or King Race Main Bearings
New FHI Main Case Bolts
IAG Spec Blueprint Sheet
Power Output Rating: 675BHP

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