CP Piston & Ring Set for Mitsubishi 4B11 Evo X - Bore (89.5mm) - Size (+4.0mm) - CR (8.8) - Set of 4

CP Pistons is well-known for building strong, reliable internal engine components for high-performance applications. This set of four forged pistons and rings is specifically made for the Mitsubishi 4B11 engine found in the Evo X. These aren't just stock replacements; they're designed to handle more power and stress than factory parts.

These pistons are forged from a strong aluminum alloy, which makes them more durable and resistant to detonation compared to cast pistons. They are sized at 89.5mm, which is a +4.0mm oversize from the stock bore. This larger bore is often used when rebuilding an engine that has been damaged or to increase displacement. The compression ratio is set at 8.8:1, a common target for modified engines that will be tuned for increased horsepower and torque, especially when using forced induction. This specific compression ratio is a good balance for power and reliability.

This set includes the pistons and the necessary rings to complete the installation. It's important to note that these pistons are not CARB approved and cannot be shipped to California. When rebuilding your engine, always refer to the manufacturer's installation instructions for proper assembly and break-in procedures to ensure optimal performance and longevity.