4 x N18 N13 Engine Piston & Ring Set A C STD Ø77mm 11257601181 for R55 R56 R58 R60 118i 4X Countryman Paceman This piston and ring set is designed for vehicles equipped with the N18 N13 engine.It includes four pistons and corresponding rings, each matching a cylinder bore of 77.00 mm and a compression height of 28.5 mm.The land height measures 5.5 mm, with an overall piston length of 51.2 mm.The bolt hole length is 48 mm and the bolt hole diameter is 20 mm.The recess diameter is 34.7 mm. The components are constructed to support performance demands and are engineered to maintain consistent under typical driving conditions.The design allows for direct replacement in compatible models including R55, R56, R58, R60, Countryman, and Paceman variants with the specified engine type.Installation follows standard procedures and does not require specialized tools. This is a compatible aftermarket part.References to brands or models do not imply OEM association.