The IAG Stage 2.5 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. 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. IAG-Spec Tuff H-Beam connecting rods and ARP 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 .180" Chromoly Wrist Pins are added to finish the Stage 2.5 short block.
Stage 2.5 Closed Deck Includes:
- Case Halves - Converted to Closed Deck using brand new Subaru OEM case halves, bored and honed to 99.75mm.
- Pistons - IAG-Spec JE FSR 99.75mm 2618 Forged Pistons, Ring Set, .180" Chromoly Wrist Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pins)
- Connecting Rods - IAG-Spec Tuff H-Beam / ARP2000 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:
Oil Pump - Subaru JDM 12mm High Volume Oil Pump - Part# 15010AA310 [Add $219.00]
or 11mm Subaru Oil Pump - Part# 15010AA360 [Add $199.95]
- Head Gaskets - JE Pro Seal .039 inch Head Gaskets - 1 Pair Part # SB1001-039 [Add $96.00]
- Hardware / Seal Option - (Wrist pin plugs, washers, separator cover, bolts, etc. In case you don’t want to transfer from the original engine). Part # IAG-ENG-1720 [Add $105.99]
- 8.5:1 on D Cylinder Heads (EJ255)
- 8.2:1 on B, V and W EJ257 Heads with standard thickness gasket.
Head Gasket Recommendations:
- *IAG Recommends JE Pro Seal .039 inch head gaskets
Power: The IAG Stage 2.5 Short Block has a power output rating of 675BHP.
*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 cover and seal kit that includes (1) Rear main seal, (3) OEM wrist pin plugs, (3) OEM wrist pin plug washers, (1) OEM separator cover, (6) OEM separator cover bolts, (1) OEM wrist pin service cover, (1) OEM wrist pin service cover O-ring and (2) OEM wrist pin service cover screws. *If you are reusing your original wrist pin service plugs and covers always replace the (3) OEM 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.
2002-05 Subaru WRX (Requires Mods)
2006-14 Subaru WRX
2004+ Subaru STI
2005-09 Subaru Legacy GT
2004-13 Subaru Forester XT
*Pictures used for marketing purposes only, actual product may vary
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.
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
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