CP Piston & Ring Set for 4G63 2G-Bore (85.5rmm)-Size (+0.5mm)-CR (10.0 Eclipse / 10.5 Evo 8/9)

This is a set of forged pistons and rings from CP Pistons, specifically designed for the 4G63 engine. These pistons are built to a 2G bore size of 85.5mm, which is an oversize of +0.5mm. They offer a compression ratio of 10.0:1 when used in an Eclipse and 10.5:1 when installed in an Evo 8 or 9. If you're rebuilding the engine in one of these performance vehicles, especially if you're looking to handle more power or refresh a worn-out engine, these pistons are a solid choice.

CP Pistons are well-known in the performance engine building world, and these are forged from high-strength aluminum. This forging process creates a piston that is both strong and relatively lightweight, which is crucial for high-performance applications where stress on engine components is significantly increased. The +0.5mm oversize means these are intended for engines that have been bored out to match this dimension, typically during a rebuild to clean up cylinder walls or increase displacement slightly. The included rings are designed to work with these specific pistons and bore size, ensuring a proper seal.

When installing these pistons, remember they are an oversize part, so the engine block's cylinders must be machined to 85.5mm. It's also important to note that these pistons are not CARB approved and cannot be shipped to California. Always refer to the manufacturer's installation guide for specific details regarding ring gap, piston-to-wall clearance, and assembly procedures to ensure optimal performance and longevity of your engine build.