JE Pistons SUB STI EJ257 Block w/ EJ20 Head 99.75mm Bore Single Piston - Left

This is a single, left-side forged piston from JE Pistons, designed for Subaru EJ257 engines that use an EJ20 block. You get the piston itself, along with high-quality wrist pins, locks, and a set of JE Pro Seal premium piston rings. This piston has a 99.75mm bore and an 8.5:1 compression ratio, featuring an inverted dome or dish design.

JE Pistons uses 2618 aluminum for these pistons, which offers strong tensile strength suitable for high-demand performance builds. They are forged and machined in the USA, with a design specific to the engine application for optimized performance and durability. This particular piston includes JE's proprietary Forged Side Relief (FSR) design, which helps minimize friction and power loss by reducing skirt width and saving weight. Depending on the specific application, it may also feature a skirt coating to further reduce friction and wear, while also cutting down on operating noise. An accumulator groove can also be present to help manage combustion gas pressure, reducing ring flutter and improving seal for consistent power delivery.

This piston is intended for use in Subaru EJ255 and EJ257 engines when paired with an EJ20 block. Please note that this part is not CARB approved and cannot be shipped to California.