Bore: Ø67mm Stroke: 47mm Displacement: 166 Compression ratio 12:1 Material: primary aluminum alloy with high silicon content and hardened and tempered, barrel with silicon carbide coating in a galvanic nickel matrix and crossed polishing with two passages of diamonds with extremely tight tolerances. Processing: on high precision numerical control machine tools. Piston cylinder fits in selection of 0.05 mm. Heat exchange surfaces recalculated and increased.