Outfront Motorsports Closed Deck EJ257 V4 Ultra Short Block | OUT-SB-V4-ULTRA

Built for extreme boost and high-cylinder-pressure applications, the Outfront Motorsports V4 Ultra Short Block uses a reinforced closed-deck EJ257 design engineered to improve cylinder strength while retaining the factory sleeves.

The V4 closed-deck process uses a thicker billet insert in known weak areas of the cylinder, increasing bore support without unnecessarily compromising cooling. Because the OEM sleeves remain in place, this design avoids the sleeve movement and coolant-sealing concerns associated with some sleeved-block configurations. The block is also machined for 1/2-inch head studs for high-output applications.

Features

• Seasoned EJ257 case halves

• Rated up to 950 BHP

• Outfront V4 closed-deck process

• Reinforced high-stress cylinder areas

• Retains factory cylinder sleeves

• Machined for 1/2-inch head studs

• Torque-plate bored and honed

• Assembled in-house by Outfront Motorsports

• Components cleaned, inspected, and tolerances double-checked before assembly

• No core required

Internal Components

• JE Ultra Pistons

  • Grain Flow Optimized Forging

  • Lateral gas ports

  • Ceramic crown coating

  • Perfect Skirt coating

  • Accumulator groove

  • Double-broach pin oiling

  • Upgraded 9310 wrist pins and locks

  • Carbon steel nitride rings

• Wiseco BoostLine connecting rods

• ARP 625+ rod bolts

• King Performance bearings

• New OEM Subaru nitride-treated 2017+ STI crankshaft

What's Included

• Complete assembled EJ257 V4 Ultra Short Block

• Rear covers

• Rear main seal

• Pin plugs

Applications

• Subaru EJ257 engine applications

• High-horsepower turbocharged Subaru builds