Wiseco Mitsu Evo 4-9 HD2 Asymmetric Skirt Gas Ported Bore 85.50mm - Size +.020 - CR 10.5 Piston Set

If you're rebuilding the engine in your Mitsubishi Evo 4-9 for serious performance, you're looking at a set of Wiseco Professional Series pistons. These aren't your average replacement parts; they're built from the ground up for demanding race applications where durability and consistent performance are critical. Wiseco uses 2618 aluminum, a well-known material for its improved tensile strength, which is essential when you're pushing an engine hard.

What sets these pistons apart is the attention to detail in their design. They feature an asymmetric skirt coating called ArmorGlide, which helps reduce friction and resist seizure, all while keeping operation quieter. You'll also find precision ring grooves, anti-detonation grooves, and features designed for additional ring seal, all working together to keep combustion contained and efficient. The crown is fully machined for accuracy, and they incorporate forced pin oiling to ensure the wrist pin stays well-lubricated under high stress. These are designed to handle heavy to severe duty builds, meaning they're ready for the track or extreme street use.

This set is for a 4G63T engine with a 85.50mm bore, which is .020 inches over the standard size. The compression ratio is 10.5:1, a popular choice for a good balance of power and pump gas compatibility. Keep in mind these pistons are not CARB approved and cannot be shipped to California. They are sold as a set of four.