8pcs N63 Engine Pistons & Rings Set 11:1 for 550i 750i X5 F01 F02 F03 E70 E71 N63 4.4L V8 11257613626 11257576475 8907510000 Material: Aluminum Engine Model: Designed for N63B44 4.4L (4395cc) V8 Twin Turbo Engine Engine Compression Ratio: 11:1 Cylinder Bore Diameter: 89mm Piston & Ring Set: Includes 8 pistons, rings, pins, and bolts for a complete engine rebuild Compression Height: 32.1mm Pin and Bolt Length: 60mm This piston and ring set is engineered to match the specifications of the N63B44 4.4L V8 engine, proper fitment and.The 11:1 compression ratio supports enhanced performance output and improved throttle response.Constructed from aluminum, the pistons are designed to handle increased stress under performance conditions.The 89mm bore diameter provides precise cylinder fitment, contributing to efficient combustion and engine.All components are included for full installation, allowing for a complete overhaul.This set meets or exceeds OEM standards with compatibility for part numbers 11257576475, 11257556955, 11257574822, 11257574823, 11257617547, 11257613626, and 8907510000.Not compatible with N63.11 engine model.