Part Number: FCPPA810085 Manufacturer: FCP Engineering Forged high performance pistons for a variety of applications in almost all types of racing and street engines. Manufactured from 4032-T6 aluminum, molybdenum coated piston bottom. Each piston kit also includes HD series rings and pins. Cylinder diameter : 81.00 mm Compression ratio (CR): 8.5:1 Compression height: 33.00 mm Pin diameter: 20 mm Stroke: 86.40 mm Audi 200, S2, RS2, S4, S6 - 2.2 2.5 20V Turbo