Primary/Secondary Drive

PRIMARY DRIVE
Primary drive is provided by a double-roller chain from the crankshaft to the two intake camshafts. The chain is guided by a centrally positioned V-shape deflection rail, a straight rail on cylinder bank 5 - 8 and a curved chain tensioner rail on cylinder bank 1 - 4.

SECONDARY DRIVE
Secondary drive is from the intake camshaft to the exhaust camshaft by a single roller chain. The chains are tightened by a hydro-mechanical tensioner, similar to the M62 engine in design. The oil supply for the chain tensioner also supplies the VANOS hydraulic units through a pressure control valve.