Diffrence between Nikasil or Alusil
Very important info regarding m60 engines: There were two types of blocks. Nikasil or Alusil engine. Nikasil engines are known to suffer damage to the cylinder bores from the excessive amounts of sulphur in the low quality fuels. Those blocks are made of Nikasil (Aluminum, Nickel and Silicone). The fuel reacted with Nickel , causing damage to the cylinder bore. If it has a Nikasil engine, get a compression check. If the results are within spec on all cylinders, chances are the engine will work since the new fuel quality has improved.The alusil m60 was BMWs answer to the problem. When they recalled the Nikail engines, those blocks were replaced with alusils. To check what block you have there are casting numbers on the right side of the block, near the 3rd cylinder, above the coolant drain.
Nikasil M60B30 1 725 970 or 1 741 212
Nikasil M60B40 1 725 963 or 1 742 998
Alusil M60B30 1 745 871
Alusil M60B40 1 745 872
NOTE: Later M62 engines do not have any of these block issues and were all alusil!