70cc high end Alu racing Big Evolution cylinder kit. Sharp timing and single-piece manufacture ensure the cylinder head gives high compression and maximum performance. Suitable for Piaggio, Gilera, Aprilia & Derbi Scooter with water-cooled Piaggio 2-stroke engines (LC). It is supplied as a complete kit including cylinder head and necessary mounting hardware. In addition are several base gaskets better dial in the squish and a 12 mm little end bearing. Caution! The cylinder kit can only be used in conjunction with the evolution crankshaft 210.0020. A larger carburettorand a racing exhaust system is recommended. Bore: 47.6. Material: Aluminium with hard-chromed lining. Diameter of gudgeon pin: 12mm. Stroke: 39.3mm