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IAG / Crest CNC Billet Aluminum EJ25 Subaru Case Halves - Subaru WRX 2006-2014 / STi 2004-2021 / LGT 2005-2009 / FXT 2004-2013
Lease for as low as $/week
IAG / CREST CNC BILLET ALUMINUM EJ25 SUBARU CASE HALVES FOR WRX, STI, FORESTER XT & LEGACY GT
CNC BILLET ALUMINUM EJ25 CASE HALVES
The IAG Performance / Crest CNC Billet Aluminum EJ25 Case Halves are the same premium-grade case halves used in our cutting-edge Stage X Billet Short Block, which has revolutionized the Subaru performance tuning market by reinventing the EJ and addressing virtually every weakness that exists in max-power builds. The EJ25 Case Halves are engineered to eliminate case flex in high-power EJ builds, making it possible to reliably run at a power output rating of 1150+BHP. With features like radiused coolant and oil galleries to improve flow, a 4-bolt bottom end for added strength, and replaceable iron sleeves that make rebuilds easier, these case halves offer a rock-solid foundation to build upon.
SOLID FOUNDATION BY CREST CNC
The IAG Performance / Crest CNC Billet Aluminum EJ25 Case Halves are machined by Crest CNC (formerly Willall), renowned for their precision-machined billet aluminum engine blocks and components. With Crest’s proven track record of producing blocks that endure the rigors of high-output engines, these case halves provide an unbeatable foundation for those pushing the limits of performance.
NEXT-LEVEL INNOVATION
The IAG Performance / Crest CNC Billet Aluminum EJ25 Case Halves are engineered with numerous advanced features that enhance strength and reliability. The halves are precision machined from solid 6061-T6 aerospace aluminum billet and reinforced with Darton Ductile Iron Sleeves. An advanced hard anodized coating protects against marking and staining, while their enhanced strength and stiffness far surpass the stock case, making them an excellent choice for high-power builds. Additionally, increased material thickness has been strategically added in all known weak points, particularly around the head studs and bottom end location, enhancing the block's resilience.
Additional innovations featured in the IAG / Crest CNC Billet Aluminum EJ25 Case Halves include a unique 4-bolt bottom end design that provides extra strength and stability. The case's bolt threads are rolled, rather than conventionally cut, ensuring a solid grip on hardware. The halves also maintain full cooling system operations, while incorporating the use of radiused coolant and oil galleries for improved flow and less foaming and/or turbulence. Finally, the Case Halves feature compatibility with all factory engine bay ancillaries (i.e., AC/PS/etc.).
OPTIONAL IAG FIRE-LOCK SYSTEM: NO MORE HEAD GASKET WORRIES
The IAG Performance / Crest CNC Billet Aluminum EJ25 Case Halves can be machined to accommodate the optional IAG Fire-Lock system. Our proprietary "Fire-Lock" receiver groove machining is designed for compatibility with our IAG "Fire-Lock" Head Gaskets. 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 firmly above the deck, providing a superior seal. The separate gasket bodies take care of sealing oil and coolant passages, while keeping them out of the combustion chamber. 14mm Head studs hold the assembly together. (IAG "Fire-Lock" System, Head Gaskets and Head Studs Sold Separately).
What's Inside:
IAG / Crest CNC Billet Aluminum EJ25 Subaru Case Includes:
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(x2) Crest Billet / Sleeved Case Halves
IAG / Crest CNC Billet Aluminum EJ25 Subaru Case Features:
- Machined from solid billet 6061-T6 Aerospace grade aluminum
- Darton Ductile iron sleeves
- Increased material thickness in all known weak points (around head studs, bottom end location)
- Unique 4 bolt bottom end strengthening
- Threads are rolled into the block rather than conventionally cut for much greater strength
- Full cooling system operation
- Radiused coolant and oil galleries for improved flow and less foaming/turbulence
- Fits all factory engine bay ancillaries (i.e. AC/PS/etc.)
- Multiple Times stiffer and stronger than the stock case
- Precision machined for a superior surface finish
- Hard anodized to avoid marking or straining
- ARP Case Bolts & Crest Hardware
Additional Options:
- Bore & Hone:Bore & Hone to customer specification
- Fire-Lock:Fire-Lock machine the deck surface
- Head Studs:IAG / ARP 14mm Head Studs, nuts, and washers - *14mm head studs are required for this block
- Machining Deck:Machine head gasket deck surface
Minimum Requirements To Build & Assemble:
- 14mm Head Studs (Sold separately)
- Internal components (Pistons, Rods, Bearings, Crank, All sold separately).
- Decking head gasket surface required
*Attention: Special note about using ARP Case Bolts- IAG uses specific torque specs and procedures please refer to the guide provided.
Power Rating: The IAG / Crest Billet Aluminum Closed Deck Case has a power output rating of 1150+ BHP
Please Note: Overbore must be performed (99.75mm is the preferred bore) before assembly!
Head Gasket Required:
- *IAG Fire-Lock .051" Head Gaskets with IAG-Spec Alloy Ring Set* PN# IAG-ENG-1741
*Attention: Special note about using ARP Case Bolts- IAG uses specific torque specs and procedures please refer to the guide provided.
PDF Instructions for Crest CNC (Formerly Willall) Case
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
Quality Guaranteed
Available 24 Month/24,000 Mile Warranty*
IAG stands behind every hand-built engine they produce. IAG's Standard Short Block Workmanship Warranty covers your short block for 12 months or 12,000 miles. They have also teamed up with a selection of IAG Certified Installation Facilities which offer up to a 24 month/24,000 mile workmanship warranty when the engine is purchased, installed, and tuned by that IAG Certified Installer.
Returns may be accepted within 14 days of purchase pending Return Merchandise Authorization (RMA). No returns or cancellations on special order items. All returns will be charged a 20% restocking fee, no exceptions.
To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging. Item must be able to be resold as new.
Several types of goods are exempt from being returned. Hazardous materials, fluids, greases, chemicals, and clothing are not able to return.
Free shipping is available within the lower 48 states for most orders totaling $199 or more. A free shipping option will be available during checkout. This offer is for delivery address in the continental United States and excludes shipments going to Alaska, Hawaii, Military Boxes, and items that require freight shipping.
Processing Time
Patterson Performance stocks a large quantity of items at any given time. Some items may require drop shipping from one of our various distributors. In stock items will ship within 1-2 business days. If you're needing your product quickly, please contact us to verify product availability before placing your order. Orders requiring additional verification (security concerns, incorrect information, etc.) may need additional processing time. Estimated shipping dates are not guaranteed and are subject to change based on inventory levels and manufacturer lead times. Backordered items are shipped immediately once available.
Items ship daily, If the item you ordered is not in stock, a member of our team will contact you via email / phone.
Patterson Performance will only ship to an address that varies from your billing address if payment is made via Paypal or a financing partner.
Patterson Performance ships from multiple warehouses throughout the United States, and sometimes from manufacturers overseas.
You can simply contact us via email / telephone for a live inventory check
Find more information at www.P65Warnings.ca.gov.