The IAG Trojan 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. The case halves are then CNC machined with O-ring receiver grooves around the bore surface as well as drilled and tapped to accept 1/2" head studs that greatly reduce head gasket failure during high cylinder pressure scenarios. 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 625+ 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. Finally, IAG-Spec 99.75mm JE FSR 2618 Forged Pistons and electroless nickel plated tops and ring area as well as upgraded .250" / .906" H13 wrist pins are added to finish the Trojan short block. Additionally, all IAG-Spec piston skirts utilize the JE Perfect Skirt coating.
IAG Trojan Closed Deck Includes:
- Case Halves - Converted to Closed Deck using brand new Subaru OEM case halves, bored and honed to 99.75mm.
- O-Ringing - Machine and O-Ring Deck Surface
- Head Studs - Machine Case to 1/2" 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 / 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.
- 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 Trojan Short Block has a power output rating of 750BHP.
*All IAG short blocks are balanced and blueprinted.
These blocks are built to order and have a lead time of 2-4 weeks. Free shipping includes the 48 continental states only and will be shipped in a reinforced triple wall cardboard box. We are an authorized IAG dealer and an OEM Subaru parts dealership.