One other thing we used to do for final assembly on any motor that had machine work was to fill the water jacket/water passage in the heads with shaving cream. This prevents any metal, glass bead, etc from falling into the motor during assembly. Initially fill the motor with water. Then drain after you get it running and fill with anti-freeze.

This is old school stuff. I doubt it will cause a problem with BMW water pumps; but, may be worth asking your buddy.

And yes, I am giving away my age a bit.


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