IAG Stage 2.5 EJ25 Subaru Closed Deck Short Block For WRX, STI, LGT, FXT
IAG Stage 2.5 EJ25 Subaru Closed Deck Short Block For WRX, STI, LGT, FXT
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IAG Stage 2.5 EJ25 Subaru Closed Deck Short Block For WRX, STI, LGT, FXT
STAGE 2.5 EJ25 2.5L SHORT BLOCK
THE PROBLEM SOLVER
The IAG Stage 2.5 Short Block is designed to solve the majority of common problems which plague modified EJ25 engines, especially at higher horsepower levels. The IAG Stage 2.5 short block builds off our Stage 2 Tuff block's strengths by adding our proprietary closed deck system. This system strengthens and supports the cylinder walls to prevent cracks which can occur with increased cylinder pressures. (This is the most common issue when increasing horsepower.) The Stage 2.5 also features 99.75mm JE Forged Pistons and IAG Spec H beam connecting rods, along with ACL or King Race bearings. These components also significantly strengthen the common failure points such as cracked ring lands and spun bearings.
BUILT WITH 100% NEW COMPONENTS
The IAG Stage 2.5 Short Block starts with brand new Subaru 2.5L engine case halves. Our machinists machine the assembled case halves in our Haas VF-4SS CNC mill to accept the IAG Closed Deck inserts, transforming the block into a solid deck. Next, a deck pair of deck plates are attached and the short block is bored and honed to 99.75mm in our in-house Sunnen SV-30 computer controlled cylinder hone. IAG's in-house honing process allows us to set custom piston to wall clearances to ensure quiet operation and reduced oil consumption. The modified case halves are then assembled using a new 2017+ Subaru 2.5L nitride treated STI crankshaft and IAG-Spec Tuff H-Beam connecting rods with ARP rod bolts. IAG Short blocks feature ACL or King Race rod and main bearings and are all balanced and blueprinted. Finally, the case halves are sealed with new OEM main/case bolts and sealant.
CLOSED DECK FOR EXTRA STRENGTH
Our unique closed deck system significantly increases the strength of the OEM case halves. This process supports the cylinder walls at the top of the case in order to prevent flexing and possible cracking where the case bolt reliefs are cut into the back of the cylinder wall.
During the installation process we machine the assembled case halves in our Haas VF-4SS CNC mill to accept the IAG Closed Deck inserts. Once the case has been machined we heat it in an oven while freezing the specially machined inserts with liquid nitrogen. The inserts are then pressed into place and then machined to a mirror finish.
The unique inserts feature small passages that allow needed coolant flow to the deck surface. This means that the closed deck system does not affect the block's cooling ability and will not cause overheating, even in daily drivers.
DESIGNED FOR BOOST
Each Stage 2.5 Short Block features IAG Spec JE FSR 99.75mm Forged Pistons. These 2618 T6 Alloy high-strength pistons have been specifically designed to support increased cylinder pressures which come with more boost. FSR forgings reduce mass and wear caused by friction without sacrificing strength. This is accomplished by using an asymmetrical skirt design instead of the traditional full-round skirt, also this reduces weight significantly. Featuring smooth flowing radii on the domes and dishes, the design promotes excellent flame travel. The pistons are secured to the rods with .905 x 2.250" x .210" wall 9310 steel wrist pins with Tru Arc locks.
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, .210" 9310 Steel 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.
- 8.5:1 on D Cylinder Heads (EJ255)
- 8.2:1 on B, V and W EJ257 Heads with standard thickness gasket.
Power: The IAG Stage 2.5 Short Block has a power output rating of 700 BHP
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.
Oil Pickup / Oil Baffle / Windage Tray Options:
The IAG Performance Subaru WRX / STI oil pickup was designed by Tigwerks to replace the OEM EJ25 oil pickup, which is prone to failure. It's a well-known fact that the OEM oil pickups often crack and fail which, in most cases, destroys your engine from lack of oil pressure. To avoid the cracking failures seen in the OEM oil pickup tubes, the Tigwerks oil pickup is manufactured from heavy-gauge steel tubing that is 3x thicker than OEM. Additionally, it features a flange machined from 3/8"Â 1018 CR steel to mate with the block, sealed with a Viton O-ring. The integrated heavy-duty mounting bracket uses two mounting points rather than the OEM single mounting point. Furthermore, the oil pickup features a formed bottom with an OEM style mesh screen for proper filtration. The TIG-welded oil pickup's increased material thickness, matched with the two-point heavy-duty mounting bracket, helps ensure that it does not fatigue and fail over time like an OEM unit.
The IAG Oil Control Baffle and Windage Tray System is designed to limit potential blow-by and prevent oil starvation in your Subaru's WRX / STI EJ engine during high rpm and high g-force driving. Through the use of Viton one-way flapper valves on our baffle and louvers in our windage tray, oil is prevented from reentering the upper crankcase area and is directed down into the oil pan to ensure plentiful supply to the oil pickup. IAG's integrated two-piece Oil Control Baffle and Windage Tray System is designed to work with our own oil pickup, as well as other oil pickups*. The baffle fits neatly in the engine crankcase area, allowing normal installation of the OEM oil pan and popular aftermarket pans*.
Oil Pickup & Baffle Install Notes
- EJ20 Subaru WRX engines require EJ25 oil pans for fitment
- IAG oil pickup spacer (Part# IAG-ENG-2081SP) is required when using IAG oil pickup with Killer B Oil Pan.
- *Does not work with Moroso oil pans or pickups
Oil Pump Option:
The 11mm Subaru Oil pump is one of the most popular off the shelf pumps to use on EJ25 engines. Originally equipped on the 2008-21 STI Dual AVCS engines, it provides an adequate amount of pressure and flow that fits the needs of many OE and built engines. But, as with almost anything, there is room for improvement.
Increasing oil flow volume and pressure in an EJ25 ensures that the bearings have sufficient oil film under all power levels and driving conditions. Additional oil flow to the engine provides a greater oil reserve to operate the AVCS solenoids and cam gears - giving you more consistent performance results.
The IAG Stage 2 CNC Ported 11mm oil pump was developed over years of servicing street and racing engines. In that time IAG has tested and utilized the majority of the popular Subaru oil pumps available on the market (JDM, Cosworth, ACL etc.) for customer, personal and racing vehicles.
Over the last few years if you wanted an upgraded oil pump over the stock 11mm you would either buy a hand ported model from a trusted source, or often an OEM JDM (Japanese Market) 12mm pump. We believe that we have developed a better alternative. The IAG Stage 2 CNC Ported 11mm oil pumps have shown through lab testing on a Spintron Machine that it will outperform a JDM 12mm.
- Stage 2 flows 11.1% more oil than the OEM 11mm Oil Pump
- Stage 2 flows 9% more oil than the OEM 12mm Oil Pump
- Stage 2 oil pressure is 12.4% higher than the OEM 11mm Oil Pump
- Stage 2 oil pressure is 9.8% higher than the OEM 12mm Oil Pump
The Stage 2 Oil pump is a cost effective solution that outperforms the market standards. This pump has been extensively tested on street cars, track cars, and on our in-house Spintron to ensure consistent and repeatable performance.
Each IAG Stage 2 oil pump starts life as an OEM spec 11mm oil pump, straight from Subaru. IAG completely disassembles the new oil pump including pulling the rotors, backing plate & pressure relief valve. Next, the main body is fixtured in our in-house 5-Axis Centroid CNC machine where the inlet and outlet passageways are CNC ported. This allows for a larger, more consistent pathway for the oil into and out of the gerotor internals and helps to prevent cavitation. The Oil Pump Outlet where it meets the engine block is also CNC “Port Matched”, for a perfect transition into the engine block. The Inlet and Outlet sides of the gerotor are also opened up on the CNC mill to reduce inlet side cavitation, and to reduce outlet side pressure drops.
The pressure relief valve piston is REM Polished, which provides a non-directional, low Ra, polished finish. This reduces friction, heat and possibility of the relief valve piston galling and sticking, a common failure point on the OEM pumps.
The piston is reinstalled and confirmed to operate correctly. The rotors are measured and checked to be within the manufacturer's specification - aka Blueprinted, and installed next. The pump is then put together with a light coating of assembly lube to reduce friction and scuffing and aid in priming on first start up.
Finally, the backing plate is installed. Loctite is added to the hardware, and each piece receives a painted mark after it is correctly torqued. The pump ships ready to install, with all hardware and seals required for installation.
Need Help Choosing a Block?
Our Experts Are Here to Help
We made this video to highlight the differences between each of our short blocks and to help you choose the best one for your performance goals and budget. Our Build Advisors and Customer Support staff can also assist you with any questions or concerns. Just click the button below for assistance.
Available 24 Month/24,000 Mile Warranty*
We stand behind every hand-built engine we produce. IAG's Standard Short Block Workmanship Warranty covers your short block for 12 months or 12,000 miles. We 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.
Model Year & Fitment
- 2002 Subaru WRX (Requires Mods)
- 2003 Subaru WRX (Requires Mods)
- 2004 Subaru WRX (Requires Mods)
- 2005 Subaru WRX (Requires Mods)
- 2006 Subaru WRX
- 2007 Subaru WRX
- 2008 Subaru WRX
- 2009 Subaru WRX
- 2010 Subaru WRX
- 2011 Subaru WRX
- 2012 Subaru WRX
- 2013 Subaru WRX
- 2014 Subaru WRX
- 2004 Subaru STI
- 2005 Subaru STI
- 2006 Subaru STI
- 2007 Subaru STI
- 2008 Subaru STI
- 2009 Subaru STI
- 2010 Subaru STI
- 2011 Subaru STI
- 2012 Subaru STI
- 2013 Subaru STI
- 2014 Subaru STI
- 2015 Subaru STI
- 2016 Subaru STI
- 2017 Subaru STI
- 2018 Subaru STI
- 2019 Subaru STI
- 2020 Subaru STI
- 2021 Subaru STI
- 2005 Subaru Legacy GT
- 2006 Subaru Legacy GT
- 2007 Subaru Legacy GT
- 2008 Subaru Legacy GT
- 2009 Subaru Legacy GT
- 2004 Subaru Forester XT
- 2005 Subaru Forester XT
- 2006 Subaru Forester XT
- 2007 Subaru Forester XT
- 2008 Subaru Forester XT
- 2009 Subaru Forester XT
- 2010 Subaru Forester XT
- 2011 Subaru Forester XT
- 2012 Subaru Forester XT
- 2013 Subaru Forester XT
Buen trabajo es un excelente producto y bien hecho
First time buyer, was unsure until took the pistons out and measured the cylinder bores which for a Subaru EJ motor are nothing but a bed of excuses for other machine shops inability to provide straight consistent bores due to the closed nature of the block. Not for the guys at IAG straight as an arrow it's the tough jobs that count..
SHIPPINGFREE SHIPPING on orders of $250 or more* Simply look for the logo to enjoy free shipping on selected items throughout the store. Oversized packages and freight shipments do not qualify for free shipping. If the items in your order which qualify for 'Free Shipping' total $250 or more, your order ships FREE! Free shipping is only available to the continental United States also referred to as the “lower 48 states”.
Shipping Policy: All products sold on the shopping cart are shipped by UPS or USPS. All packages include shipping insurance in case they are lost or damaged. USPS requires signature confirmation on all insured orders over $200.00. USPS shipping times are estimated and not guaranteed. UPS tracking numbers are automatically generated when a package ships and the number is sent to the email address you provided. If a package contents is damaged during shipping please notify the shipping driver and file a claim with the shipper. You have 14 days to inspect your shipment and contents. After that period of time, IAG is no longer responsible for missing items. You have 30 days to report any damaged or incorrect items, after that period of time IAG is no longer responsible for returns or exchanges. You can contact us by Email or call 410-840-3555 for assistance. *International orders are subject to customs charges, duties or fees. Please check with your local customs office before ordering. IAG is not responsible for international customs charges, duties or brokerage fees.
Drop Shipping: Some items require drop shipping to complete an order. These products are shipped from manufacturer or distributor warehouses across the country. In some cases, this may speed up delivery time. In other cases, it could add 1-3 days to the delivery time. If you have a question regarding an order please contact our sales desk at 410-840-3555.
Order Processing: Orders placed after 3PM EST may not be processed the same day. Order processing may take 24-48 hours. USPS orders placed after 10am EST will ship the following business day if the items are in stock
How do I return an item?
You have 14 days to inspect your shipment and contents. After that period, IAG is no longer responsible for missing items. You have 30 days to report any damaged or incorrect items, after that period IAG is no longer responsible for returns or exchanges. All stocking products are subject to a 30 Day return policy. The item(s), when approved for return, are subject to a 20 percent restocking fee. Canceled orders may be subject to a 20 percent cancellation fee. All product returns require a return authorization number before being shipped back to IAG or the manufacturer. An “RMA” number is obtained by calling the IAG Support Desk at 410-840-3555 or emailing firstname.lastname@example.org. Some products may require shipping back to the manufacturer for inspection before a return or exchange may be processed. Some products may not be able to be returned. Products that have been modified or installed are not eligible for return. There are no returns or cancellations for Special Order/Made to Order items and Electrical Components (including the COBB Accessport). Items returned after the 30 Day return period without an RMA will be refused. Canceled service appointments with deposits are non-refundable.
Refunds take 30 days or less. Payments made by Credit Card or PayPal are returned back to the original account used during the transaction. There are no cash returns; we will issue a business check for the return of funds. Refunds are decided by the management and not by sales staff. Canceled service appointments with deposits are non-refundable.
IAG Performance Product Warranty (Excluding - Short Blocks / Long Blocks)
This limited warranty gives you specific legal rights and you may also have other rights, which vary from state to state. We limit the duration and remedies of all implied warranties, including, without limitation, the warranties of merchantability and fitness for a particular purpose to the duration of this express limited warranty. Some states do not allow limitations on how long an implied warranty lasts. The remedies described below are your sole and exclusive remedies and our entire liability for any breach of this limited warranty. Our liability shall under no circumstances exceed the actual amount paid by you for the product, nor shall we under any circumstances be liable for any consequential, incidental, special or punitive damages or losses, whether direct or indirect.
This warranty covers defects in materials and workmanship of your IAG Performance Product for 12 Months or 12,000 Miles from the date of receipt.
IAG will repair any IAG Manufactured Product that proves to be defective in materials or workmanship within the warranty period. If a repair is not possible, we will either replace your Product with a new Product of similar composition and price, or refund the full purchase price of your Product, at our sole discretion. There is no charge for inspection but the buyer is responsible for shipping charges.
IAG Performance Engine Warranty
For more information concerning our engine warranty please visit IAG Performance Engine Warranty Page
Other Manufacturer Products:
Products not manufactured by IAG are subject to the individual manufacturer warranties which may apply. If you have questions concerning the fitment, appearance, or performance of your item, please contact a member of our customer support team for assistance.
Our customer service team is happy to assist you with the products purchased from IAG Performance. Our support associates can help you with installation support, troubleshooting advice, and help to identify possible manufacturer defects.
For products that are found to have defects, our support department can provide the contact information for the manufacturer to arrange a warranty inspection and, if applicable, any necessary repairs or replacement shipments.
You may also contact the manufacturer directly for information regarding product eligibility and specific terms and conditions of warranty coverage.
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