EJ257 V4 Ultra Short Block

The Outfront Motorsports Closed Deck EJ257 V4 Ultra Short Block is engineered to withstand extreme boost levels and the resulting high cylinder pressures without the concern of cracking a sleeve. The V4 closed deck process utilizes optimized billet material reinforcements in known weak areas of the combustion chamber, providing a significantly more robust solution than traditional sleeved blocks. This design retains the stock sleeves, thereby eliminating the risk of dropped sleeves and coolant loss common with sleeved configurations. The V4 insert adds critical strength to the bore without compromising cooling efficiency. Furthermore, this block is fully machined to accommodate ½” head studs and includes rear covers, rear seal, and pin plugs. This engine build comprises a carefully selected suite of high-performance components. It features seasoned EJ257 case halves and is rated to handle up to 950 BHP. The internal components include JE Ultra Pistons, which feature advanced technology such as Grain Flow Optimized Forging, Lateral Gas Ports, Ceramic Crown Coating, Perfect Skirt Coating, an Accumulator Groove, Double Broach Pin Oiling, upgraded 9310 Pins and locks, and Carbon Steel Nitride Rings. Complementing the pistons are Wiseco BoostLine Connecting Rods with ARP 625+ Bolts and King Performance Bearings for enhanced durability and performance. A new OEM Subaru Nitride Treated 2017+ STI Crankshaft is also included. Outfront Motorsports emphasizes quality control throughout their assembly process. All builds are conducted in-house within a cleanroom environment to ensure the highest standards. Blocks are meticulously bored and honed using torque plates, with all tolerances double-checked. This short block requires no core exchange, simplifying the purchasing process for customers. For those with even higher power aspirations or specific build requirements, Outfront Motorsports offers complete customization and encourages direct contact to spec the ideal built block for any application.