The BMW N62 is a naturally aspirated V8 petrol engine which was used in BMW cars from 2001–2010. It also remained in small-scale production for the Morgan Aero until 2019. The N62 is the world's first engine to use a continuously variable-length intake manifold, and BMW's first V8 to feature variable valve lift.
N62B48 in a E65 750i
Variable-length intake manifold
In internal combustion engines, a variable-length intake manifold (VLIM),variable intake manifold (VIM), or variable intake system (VIS) is an automobile internal combustion engine manifold technology. As the name implies, VLIM/VIM/VIS can vary the length of the intake tract in order to optimise power and torque across the range of engine speed operation, as well as to help provide better fuel efficiency. This effect is often achieved by having two separate intake ports, each controlled by a valve, that open two different manifolds – one with a short path that operates at full engine load, and another with a significantly longer path that operates at lower load. The first patent issued for a variable length intake manifold was published in 1958, US Patent US2835235 by Daimler Benz AG.
Lower intake manifold on a 1999 Mazda Miata engine, showing components of a variable-length intake system.