Name: IAG 550 2.5L Subaru Short Block for WRX, STI, Legacy GT, Forester XT - 550 BHP
Brand: IAG Performance
SKU: IAG-ENG-S550
Price: 3999.99 USD
Availability: InStock

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Description
Vehicles
Shipping & Returns
Warranty

Description

IAG 550 EJ25 2.5L SUBARU SHORT BLOCK

Stage 2 Short Block H-Beam Connecting Rods

DESIGNED FOR STRENGTH

The IAG 550 Short Block is designed for modified EJ25 Subarus that need a stronger short block to support increased cylinder pressures created by additional boost pressure. The IAG 550 short block features IAG Spec H-Beam forged connecting rods. The upgraded connecting rods and race bearings are able to support additional engine load produced by larger turbochargers or increased boost which the OEM STI rods found in the Stock short blocks cannot support reliably.

BUILT WITH 100% NEW COMPONENTS

Each IAG 550 Short Block starts with brand new EJ25 Subaru 2.5L, 99.5mm stock bore engine case halves as standard. The case haves are carefullly measured and assembled using a new 2017+ Subaru 2.5L nitride treated STI crankshaft, which is matched to ACL or King race main bearings. The IAG 550 Short Block features IAG Spec H-Beam Connecting Rods with ARP2000 rod bolts, along with ACL or King race rod bearings. The case halves are sealed with new OEM main case bolts and sealant. Finally, IAG Spec JE 99.5mm Forged Pistons are carefully selected, measured, and installed to finish off the short block.

FORGED PISTONS, DESIGNED FOR BOOST

Each IAG 550 Short Block features IAG Spec JE 99.5mm Forged Pistons. These 2618 T6 Alloy high-strength pistons have been specifically designed to support increased cylinder pressures which come with more boost. 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 .180" wall carbon steel wrist pins with Tru Arc locks.

What's Inside:

IAG 550 Short Block Includes:

Case Halves - Brand new Subaru OEM case halves 99.5mm stock bore
Pistons - IAG-Spec JE 99.5mm Forged Pistons, Ring Set, .180" Chromoly Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pin)
Connecting Rods - IAG-Spec H-Beam Rods with 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 bolt

Compression Ratio:

9.3:1 on D Cylinder Heads (EJ255) w/ OEM Head Gasket
8.8:1 on B, V, and W EJ257 Heads w/ OEM Head Gasket
9.4:1 on S20 Cylinder Heads without Combustion Mod and with OEM Head Gasket
9.0:1 on D Cylinder Heads (EJ255) w/ .039" JE Proseal Head Gasket
8.5:1 on B, V, and W EJ257 Heads w/ .039" JE Proseal Head Gasket
9.1:1 on S20 Cylinder Heads without Combustion Mod and with .039" JE Proseal Head Gasket

Power Rating:

Power: The IAG 550 Short Block has a power output rating of 550 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:

IAG Oil Pickup, Baffle and 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" 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.

Graph 1

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

Graph 2

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.

Installation Instructions:

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

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.

Quality Guaranteed

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.

LEARN MORE

Vehicles

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

Shipping & Returns

SHIPPING

FREE 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

RETURNS

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 support@iagperformance.com. 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.

Warranty

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.