Wiseco Mitsu Evo 4-9 4G63 Stroker Asymmetric Skirt Bore 85.25mm - Size +.010 - CR 9.5 Piston Set

These Wiseco pistons start with 2618 aluminum, a well-built material chosen for its improved tensile strength, making them a solid choice for serious engine builds. They are forged and machined right here in the USA, ensuring a high level of control over their construction. Specifically, these are designed for Mitsubishi Evo 4-9 models with the 4G63 engine, featuring a 85.25mm bore and an asymmetric skirt design. This bore size is a +.010 inch over standard, intended for stroker applications where increased displacement is key.

Wiseco has packed these pistons with features aimed at durability and performance under heavy use. You'll find precision ring grooves, anti-detonation grooves, and other features designed to improve ring seal, which is critical for compression and oil control. The crown is fully machined for accuracy, and they include forced pin oiling to keep the wrist pins properly lubricated. A notable feature is the ArmorGlide skirt coating, which helps reduce friction and resist seizure, while also contributing to quieter operation. These are built to handle severe duty in race applications.

This set includes four pistons, each with a 9.5:1 compression ratio, suitable for many performance engine builds. Please note that these pistons are not CARB approved and cannot be shipped to California. It's always a good idea to consult your engine builder or refer to Wiseco's installation instructions for specific assembly details and compatibility with your build.