As per my mk2 bentley (which includes gas engines)
Crankshaft Sprocket to Cracnkshaft (lubricated)
6 sided bolt with washer ..........180 NM (137 ft.lb)
Hex head bolt with washer...... 150 NM (111ft.lb)
12 sided bolt with collar (no washer) 90 NM (66 ft.lb)