Cylinder Material: special self-lubricating, wear-resistant, highly refined cast iron alloys, obtained by Shell Moulding gravity die-casting. Machining: on numerically controlled high precision machine tools. Recalculated and increased heat exchange surfaces. Exhaust and transfer ports designed and tuned for maximum thermodynamic performance. Dimensional and surface finish quality control performed according to Malossi's internal specifications. Cylinder and piston selected for a 100% fit of 0.010-0.005 mm. Checking of all the seals carried out. Piston Material: special aluminium alloy with high silicon content and low thermal expansion. Machining: on numerically controlled machine tools. Lightened and strengthened. Heat exchange surfaces increased. Piston rings Piston rings in very strong modular cast iron with ground, wear-resistant, hard chrome metal-spray coating on the contact surface. Head Material: special die-cast aluminium alloy. Geometry of heat exchange surfaces recalculated and increased. Machining: numerically controlled high precision machines with diamond tools. Surface rust prevention treatment. Viton Head Gasket. Hemispheric combustion chamber with centred squish and spark plug. Article 31 8694 Ø 57,5 mm Stroke 43 mm Capacity 111.66 Compression ratio 12,5:1 Piston rings No. 2 rectangular section 1.5 mm No. of transferts 6 Head hemispherical Spark plug central Piston alluminium alloy 21%