JE Pistons SUB STI EJ257 Block w/ EJ20 Head 100mm Bore 0.25 Oversize CR 9.5 KIT Set of 4 Pistons

This JE Pistons kit gives you a complete set of four forged pistons, designed specifically for your Subaru EJ257 block with an EJ20 head. You'll get the pistons themselves, along with high-quality wrist pins, locks, and JE Pro Seal premium piston rings, all made in the USA. These pistons feature a 100mm bore, which is 0.25 inches oversize from stock, and a 9.5:1 compression ratio, making them a solid choice for performance builds where increased displacement and power are the goal.

JE Pistons uses a proprietary 2618 aluminum forging for these pistons, which offers the high tensile strength needed for demanding performance applications. They've also incorporated their Forged Side Relief (FSR) design, which helps minimize friction and power loss by reducing skirt width and saving weight. Depending on your specific application, these pistons may also feature an accumulator groove to help reduce combustion gas pressure, improving ring seal and consistent power delivery. A skirt coating, if included for your application, further reduces friction and wear on the cylinder walls, contributing to a quieter operation and longer component life.

Because these pistons are engineered specifically for your engine and intended use, they're built to provide a great balance of durability and performance. They are manufactured and machined 100% in the USA, ensuring a high level of quality control. Please note that these pistons are not CARB approved and cannot be shipped to California. Always refer to the manufacturer's installation instructions for proper fitment and assembly details.