Wiseco Mitsu Evo 4-9 4G63 Asymmetric Skirt Bore 85.50mm - Size +.020 - CR 9.5 Piston Set

These Wiseco pistons are forged from 2618 aluminum, a material chosen for its improved tensile strength, making them well-suited for the demands of a performance 4G63 engine build. The bore size is 85.50mm, and this set is +.020 inches over, meaning they are sized to account for a specific machining operation on the engine block. The compression ratio is a 9.5:1, which is a common target for builds seeking a balance between pump gas drivability and boosted performance.

Wiseco has incorporated several features into these pistons for serious builders. The asymmetric skirt design helps manage piston rock and reduce noise, while the ArmorGlide skirt coating further reduces friction and resists seizure. You'll also find precision ring grooves, anti-detonation grooves, and features designed to improve ring seal, all contributing to better combustion efficiency and durability under heavy loads. The crown is fully machined for accuracy, and forced pin oiling ensures the wrist pin receives adequate lubrication.

This set includes four pistons, ready for installation in your Mitsubishi Evo 4-9 with the 4G63 engine. Remember 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 procedures.