Engine - Block

One of BMW's core competencies is manufacturing the engines. In particular they create their own engine blocks.

The engine block of the S63top is made from a die-cast aluminum alloy called Alusil. Alusil (Al17Si4CuMg) is an aluminum-silicon alloy which contains approximately 78% aluminum and 17% silicon. These aluminum-silicon alloys, when etched, will expose a very hard silicon precipitate. The silicon surface is porous enough to hold oil, and is an excellent bearing surface (i.e., for tightening things down onto).

The block weighs 220 lb, it has 8 cylinders longitudinally arranged in a 90 degree V. Each cylinder has a bore (diameter) of 8.83cm and a stroke (piston travel) of 8.90cm, having an overall effective displacement of 4.4L.

The cylinder heads (labelled 3 below) is a new M development that contains integrated air ducts for crankcase ventilation (clearing out the exhaust gasses that blow past the pistons into the crankcase).

The parts of the block are as follows.

1. Cylinder head covers of very light heat-resistant plastic.
2. Cylinder head cover gaskets help to keep the seal between the cylinder head covers and cylinder heads air tight.
3. Cylinder heads into which the valves, camshafts, spark plugs, and fuel injectors are installed.
4. Cylinder head gaskets to keep the seal between the block and the heads air tight.
5. Crankcase that holds the crankshaft and cylinders.
6. Upper oil pan gasket.
7. Upper oil pan where the oil pump is located.
8. Lower oil pan gaset.
9. Lower oil pan that seals the bottom of the oil pan.
10. Timing chain guides for guiding the two independent timing chains that connect the crankshaft to the camshafts.
11. Crankcase cover.