Cylinder head / stud nuts — the specialist deviation

Snowbum holds 25 ft-lb for all models and warns against anything above ~26, on the grounds that these studs thread into a fifty-year-old aluminium crankcase that may already have been over-torqued by someone else. That is a considered position about aged hardware, not a reading of the factory figure — and it is a deliberate 4 N·m below BMW's minimum. Both numbers are published here because the choice is yours to make knowingly: the factory value on a known-good crankcase, the conservative value if the thread history is unknown. What you must not do is take 25 as the factory spec, which is what this guide previously implied.