CP Piston & Ring Set for Honda R18 - Bore (81.50mm) - Size (+0.5mm) - CR (9.0) - Set of 4

This is a set of four forged pistons and matching rings from CP Pistons, designed for Honda R18 engines. You get the pistons and rings needed to rebuild your engine's top end with an improved component. These pistons are 81.50mm in bore size, which is 0.5mm larger than the factory standard, and feature a 9.0:1 compression ratio. This set is intended for engine builders looking to replace worn pistons or to upgrade their engine's internals.

CP Pistons are known for their well-built construction, using forged aluminum to create a strong and durable piston. Forging the aluminum aligns the grain structure, making the piston more resistant to the stresses of combustion and higher performance applications. The 0.5mm oversize bore is useful when rebuilding an engine that has been bored out to clean up cylinder walls or to increase displacement slightly. The 9.0:1 compression ratio is a common target for naturally aspirated builds or mild forced induction setups, offering a good balance between power and reliability.

When installing these pistons, ensure your engine block has been properly machined to the 81.50mm bore size. It's also important to follow the manufacturer's recommended ring gap and piston-to-wall clearance specifications to ensure proper engine operation and longevity. This set includes the pistons and rings; other engine components like bearings, gaskets, and seals will need to be sourced separately.