Aluminum engine block alloy contains 17% silicon.(METALS/POLYMERS/CERAMICS)

The cylinder crankcase in this engine block is made in a low-pressure die-casting process from an over-eutectic aluminum-silicon alloy with at least 17% silicon, reports BMW, Greenville, S.C. The cylinder liners are formed by exposing the hard silicon crystals. The iron-coated pistons run directly in these uncoated, honed cylinder bores, and thus do not require any additional lining.

Made of die cast aluminum, the bedplate features cast gray-iron inlays that ensure very precise support of the crankshaft. To form a positive engagement with the aluminum frame, the inlays