IAG 950 EJ25 Subaru Short Block - Subaru Models (Inc. 2002-2021 Subaru WRX / 2004-2021 STI / 2004-2013 Forester)

Please Note: This item is not eligible for standard ground shipping and must be delivered via freight. To receive a custom invoice that includes all applicable freight charges, kindly contact us by email or phone.

 

 

COMPETE ON SUNDAY, COMMUTE ON MONDAY

The IAG 950 Short Block epitomizes the ultimate "weekend racer" block, engineered to handle up to 950 BHP, making it our most robust "Street" short block offering. Featuring +2mm IAG Spec H-Beam forged connecting rods, IAG-Spec JE Pistons with electroless nickel plated coating, and H13 tool steel wrist pins, along with our trusted "Fire-Lock™" head gasket system for 14mm head studs, the IAG 950 short block is meticulously assembled by hand using ACL or King rod and main bearings. This combination of components renders the IAG 950 Short Block ideal for both drag and road racing applications.

 

CRAFTED WITH 100% NEW COMPONENTS

The IAG 950 Short Block commences with pristine Subaru 2.5L engine case halves. Our skilled machinists meticulously process the assembled case halves using our Haas VF-4SS CNC mill to accommodate the IAG Closed Deck inserts, effectively transforming the block into a solid deck. Subsequently, a set of deck plates is attached, and the short block undergoes precision boring and honing to a diameter of 99.75mm in our in-house Sunnen SV-30 computer-controlled cylinder hone. Leveraging IAG's in-house honing process, we tailor piston-to-wall clearances to ensure smooth operation and minimize oil consumption. Moreover, the Haas mill precisely cuts a groove at the top of each cylinder to accommodate the Fire-Lock™ head gasket rings and drills each head bolt hole for 14mm head studs. The modified case halves are then meticulously assembled using a new 2017+ Subaru 2.5L nitride-treated STI crankshaft and IAG-Spec Tuff H-Beam connecting rods with ARP rod bolts. All IAG Short Blocks are equipped with ACL or King Race rod and main bearings, meticulously balanced and blueprinted. Finally, the case halves are securely sealed using new OEM main/case bolts and sealant, completing the meticulous crafting process.

 

ENSURE HEAD GASKET RELIABILITY WITH CONFIDENCE

With the IAG 950 EJ25 Closed Deck Short Block, you can bid farewell to head gasket concerns thanks to our innovative "Fire-Lock™" Head gasket system. Proven in our record-setting race cars, this system stands as the most robust Subaru head gasket system ever developed. To achieve this level of reliability, our engineers ingeniously separated the combustion chamber sealing from the fluid sealing aspects of the head gaskets. Our skilled machinists meticulously craft a lip at the top of each cylinder to accommodate the "Fire-Lock™" ring. Once the ring is securely in place, it protrudes above the deck, ensuring an unparalleled seal. The distinct gasket bodies effectively manage the sealing of oil and coolant passages, safeguarding them from entering the combustion chamber. Completing the assembly, 14mm Head studs (Not Included) securely hold the components together, delivering ultimate peace of mind.



STRENGTHENED BY CLOSED DECK DESIGN

Our distinctive closed deck system significantly enhances the durability of the OEM case halves. This method reinforces the cylinder walls at the top of the case, preventing flexing and potential cracking where the case bolt reliefs are cut into the back of the cylinder wall. During installation, we machine the assembled case halves in our Haas VF-4SS CNC mill to accommodate the IAG Closed Deck inserts. Subsequently, we heat the case in an oven while freezing the specially machined inserts with liquid nitrogen. Once the case is heated and the inserts are frozen, they are meticulously pressed into place and then machined to achieve a flawless mirror finish. These unique inserts feature small passages that facilitate necessary coolant flow to the deck surface. Consequently, the closed deck system maintains the block's cooling ability and eliminates the risk of overheating, even during daily driving.



CUSTOMIZED PISTONS ENGINEERED FOR PERFORMANCE

The pistons integrated into the IAG 950 Short Blocks are meticulously crafted to withstand the demanding conditions of racing. Developed in collaboration with JE, these specially engineered IAG-Spec pistons boast electroless nickel plating and a 2618 Alloy construction. Their robust design includes extra thick ring lands engineered to resist collapse under pressure. Enhanced with .250" wall H13 tool steel offset wrist pins, these pistons are engineered to withstand forces up to 950 BHP without bending or breaking. Additionally, they feature JE's Perfect Skirt coating for optimal performance and durability.



IAG 950 Closed Deck EJ25 Short Block Includes:

Case Halves -Converted to Closed Deck using brand new Subaru OEM case halves, bored and honed to 99.75mm.
Fire-Lock -IAG Fire-Lock™ receiver groove machining, latest solution to prevent head gasket failure on high horsepower and high boost Subaru's - *IAG Fire-Lock™ head gaskets required
Head Studs -Machine Case for 14mm head studs - *Head studs are sold separately
Pistons -IAG-Spec JE FSR 99.75mm 2618 Forged Pistons, Electroless Nickel Plated Tops & Ring area, Ring Set, .250" / .906" H13 Wrist Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pins)
Connecting Rods -IAG-Spec Tuff H-Beam +2mm / ARP 625+ 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.


Compression Ratio:

8.5:1 on D Cylinder Heads (EJ255)
8.2:1 on B, V and W EJ257 Heads with standard thickness gasket.



Head Gasket Required:

*IAG Fire-Lock™ .051" Head Gaskets with IAG-Spec Alloy Ring Set* PN# IAG-ENG-1740

 

IMPORTANT DELIVERY NOTE:

Your order is shipping Via Truck Freight which requires you to be available at the time of receipt. There is a possibility the trucking company will try to schedule a delivery time with you.

At the time of delivery, the driver will hand you the delivery receipt also referred to as the bill of lading, you will use this to notate any damages to the shipment. It is important that you fully inspect the shipment from all sides and notate any dents, punctures or rips in the outside packaging on the delivery receipt. Once you've inspected your shipment from the outside, you will need to open it and check the product in its entirety for damages and notate them if any.

If there is no damage sign for the package and enjoy!

In the rare case, you do find that your order arrived with damages, it is important you follow these steps.

- Do not refuse the product
- Document the damages in as much detail as possible on the Bill of Lading
- Take numerous photos from all angles (including packaging)
- Keep the product and contact the shipping company to start the damage claim
- Contact us either by phone or email for the next steps

In the situation where the delivery driver is unable to wait for you to open and inspect your product, simply document "driver was unable to wait for inspection." All damage must be noted on the Bill of Lading before signing and initiating a damage claim. If the damage is not notated before signing for the item it is assumed to be in good condition. This will forfeit the ability for a shipping claim and you will not be eligible for refund or replacement.