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 pieces for a complete engine overhaul 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 Twin Turbo Engine, proper fitment and.The 11:1 compression ratio supports enhanced performance characteristics, suitable for applications requiring increased power output and throttle response.Constructed from aluminum, the pistons are designed to handle elevated stress levels associated with performance use.The 89mm bore diameter provides a precise fit within the cylinder block, contributing to efficient combustion and engine longevity.Each set includes all necessary components such as pins and bolts to support a full rebuild.OEM part numbers include 11257576475, 11257556955, 11257574822, 11257574823, 11257617547, 11257613626, and 8907510000.This set is not compatible with the N63.11 engine model.