Part Number: FCPPB845090M50 Manufacturer: FCP Engineering Forged high performance pistons for a variety of applications in almost all engine types for racing and street use. Made of 4032-T6, the bottom of the piston is molybdenum coated. Each piston kit also includes HD series rings and shafts. Cylinder diameter: 84.50 mm Compression Ratio (CR): 9.0:1 Compression height: 32.50 mm Shaft diameter: 22 mm Stroke: 84.00 mm BMW 328 528 Turbo (M50B28, M52B28) Connecting rod length must be 135 mm These pistons are intended for the BMW 2.8 M50B25 engine with a modified M52B28 crankshaft!