The IAG Performance / Crest CNC 2.5L Billet Aluminum Short Block is engineered to redefine Subaru performance tuning by addressing virtually every limitation of the EJ platform in high-power builds. The Stage X Billet Short Block eliminates case flex in high-output EJ engines, allowing reliable operation at power levels exceeding 1,150 BHP. It features radiused coolant and oil galleries for improved flow, a 4-bolt bottom end for added strength, and replaceable iron sleeves for easier rebuilds. For enthusiasts seeking uncompromising power and reliability, the Stage X short block is the ultimate solution.
Built on a Proven Crest CNC Platform
The Stage X Short Block is built on Crest CNC’s billet aluminum platform (formerly Willall), renowned for precision machining and high-output durability. By combining Crest’s expertise with IAG’s experience in high-power Subaru builds, this short block delivers an exceptional foundation for extreme performance applications.
IAG Performance / Crest CNC Stage X 2.5L Billet Aluminum Short Block Includes:
- Case Halves -Crest Billet / Sleeved Case Halves
- 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
- Machining -Machined for 14mm Head Studs *(Studs sold separately / Note the proper head gaskets or head gasket modifications are required for proper fitment with 14mm studs.
- Pistons -JE 99.5mm FSR 2618 custom forged pistons, JE Pro Seal Ring Set, .250" H13 .927" tool steel wrist pins, Clips
- 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 79mm Crankshaft
- Case / Main Bolts -ARP Case Bolts
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-1741