PECM Issue 41 2019 | Page 29

The advantages of the crankcase The all-aluminium crankcase is a chill-cast unit which excels with outstanding material properties. In this process the molten aluminium is poured into the metallic mould using the effect of gravity. Thanks to its good thermal conductivity, the water-cooled mould allows rapid cooling and solidification of the melt. The result is a fine-grained, dense structure that guarantees very high strength. Complex interior geometries can be realised with the help of enclosed sand cores. The so-called closed-deck construction – a design from motor racing ensures outstanding rigidity with low weight, and allows peak combustion pressures of up to 160 bar. The areas around the cylinders are mostly solid, and the cover plate is only penetrated by smaller ducts for the coolant and engine oil. The crank assembly with a lightweight, forged steel crankshaft and forged aluminium pistons with optimised piston rings combines low friction with high strength. The maximum engine speed is 7200 rpm, and peak output is developed at 6750 rpm. The sump features baffle plates so that despite the larger sump, and even under high lateral acceleration forces, there is always sufficient engine oil to lubricate all the relevant components. Why the cylinder liners are coated with NANOSLIDE To reduce friction between the pistons and cylinders, the linings are coated using patented NANOSLIDE technology. This gives the linings a mirror-like surface for minimal friction, is twice as hard as conventional grey cast-iron liners and therefore makes them much more durable. NANOSLIDE was developed by Daimler AG, and is protected by more than 90 patent families and more than 40 patents. The coating was first used for AMG’s M 156 engine, has benefitted further AMG engines for many years and can also be found in the Formula 1 engine of Mercedes AMG Petronas Motorsport. More information about Mercedes-Benz is available online at: www.media.daimler.com, www.media.mercedes-benz.comand www.mercedes-benz.com Issue 41 PECM 29