8pcs N63 Engine Pistons & Rings Set 11:1 for 550i 750i X5 F01 F02 F03 E70 E71 N63 4.4L V8 11257613626 11257576475 8907510000 Pistons and rings set designed for N63B44 4.4L V8 twin turbo engine with a compression ratio of 11:1.This kit includes 8 pistons with rings, intended for engine rebuilds.Specifications include cylinder bore diameter of 89mm, compression height of 32.1mm, overall length of 52.6mm, pin diameter of 22mm, and pin length of 60mm.Compatible with engine models requiring part numbers 11257613626, 11257576475, 11257556955, 11257574822, 11257574823, 11257617547, and OE equivalents such as 8983550720, 1275100944, 0281006991.Also matches aftermarket identifiers including 40631600, WG1726229, WG1889132, and 8907510000.