

IAG Stage 2.5 EJ25 Subaru Closed Deck Short Block
Subaru Models (inc. 2002-2014 WRX / 2004+ STI)

Features & Product Details
RallySport Direct carries the highly sought-after high-performance upgrades and accessories brought to you by IAG Performance. Whether you’re building a mild street car, or an all out rally car, or just looking for dead reliable power from your Overlander build, look no further than IAG!
The IAG Performance Stage 2.5 Hybrid Closed-Deck Short Block has been designed for power-hungry enthusiasts who want to increase the displacement and low-end torque of their Subaru that was originally equipped with the EJ20 2.0 engine. The Hybrid 2.5 features pistons that are designed to lower the compression and math the EJ20 cylinder heads without the need to modify the cylinder head chamber.
Each 2.5L Hybrid Shortblock will start with a brand new Subaru 2.5L engine case halves in which IAG machines them, and they are assembled together in-house and are CNC milled 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. The short block is then deck plate bored and honed to 99.75mm in IAG's in-house cylinder hone. The modified case halves are then assembled using a brand new 2017+ 2.5L nitride-treated STI crankshaft that is matched to ACL rod and main bearings. The rest of the blueprinted engine features IAG-Spec JE FSR 99.75mm 2618 forged pistons w/ skirt coating, and IAG Spec Tuff H-Beam connecting rods that are assembled with ARP 2000 rod bolts.
This is a great rebuild option for those of you who want an assembled short block built by one of the best industry-leading performance shops available and is rated to 700 BHP.
SPECS:
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Specifications
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REVIEWS & CUSTOMER MEDIA


Went closed-deck after my cylinder 4 piston cracked. Much better engine overall, and you might even get a warranty out of it depending on who installs it. IAG as always making excellent products and they stand behind their work!
Oem block spun a bearing @60k miles while on FBO and e85. Went with this block and have been impressed by it so far. And also while knowing I no longer have oem cast pistons lol. RSD supplied the block with fast shipping, expedited shipping when I didn't even pay for that kind of shipping which is a plus for me. Block arrived with other parts I ordered accurately and no mistakes on my order. TY RSD and IAG. Hoping for this break-in period to go by fast now.
QUESTIONS & ANSWERS
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Q: Heads and head studs Swerve.and.Destroy1 year ago
Could I machine stock heads to +1mm and re surface the deck or would I need to do more to make the heads handle more power. I’m aiming for 390 on pump and 420-450 on e85. I was also wondering what size head studs I would need. For this build.
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Q: Head studs Swerve.and.Destroy1 year ago
What size head studs does this block take?
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A: This will use 11mm head studs still.
Lane H. @ RallySport Direct 1 year ago
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Q: Would there be any short blocks that fit in a 2.5i Premium Sedan Impreza? daGi1 year ago
I wanna build my impreza but there is no fit for my car
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A: In theory anything is possible, however the cost of an IAG block and necessary mods would quickly out weigh the cost of buying a WRX.
Lane H. @ RallySport Direct 1 year ago
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Q: Fitment R Car2 years ago
Title Says: "Subaru Models (inc. 2002-2014 WRX / 2004+ STI)" but fitment chart lists no 2002 or 2003 models. Please clarify and correct fitment info. Thanks.
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A: The reason this is not listed on the fitment chart for 02-03 WRX is because they have the EJ205, so it is not a direct fitment. It can be used in the 02-03 WRX but you'll need additional parts for it to work properly.
Jesse F. @ RallySport Direct 2 years ago
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Q: Rev Limit Neuspeed2 years ago
What is the rev limit for this engine?
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A: That's more so dependent on what head work you have done. ie Valves, springs, retainers, seals and cams. You would also need the JDM 12mm oil pump on this block to support the power levels it is rated for, especially if you decide to run the engine above the factory rev limit/ fuel cut.
Maverick
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