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ShiftCam
Functional principle of
ShiftCam
The vehicle features BMW Shift-
Cam technology for varying valve
timing and valve lift on the in-
take side. The heart of this tech-
nology is a one-piece shifting
intake camshaft that has two
lobes for each valve: a partial-
load cam and a full-load cam.
The partial-load cam is fine-
tuned for consumption optim-
isation and engine smoothness.
As well as adapting valve timing,
the partial-load cam also reduces
intake-valve lift. With the partial-
load cams activated, moreover,
the lobes for the cylinder's left
and right intake valves produce
staggered valve lift and offset
angles of rotation. Consequently
the two intake valves open at
very slightly different times and
the distance to which they open
also differs. The advantage: The
fuel/air mixture flowing into the
combustion chamber is swirled
more thoroughly and combusted
effectively - so all in all the fuel
is utilised more efficiently and
engine operation is perceptibly
smoother. The full-load cam is
designed for optimised engine
power and it maximises intake
valve lift. The intake camshaft is
shifted axially to vary valve tim-
ing and valve lift. The pins of an
electromechanical actuator en-
gage a shift gate on the intake
camshaft. This permits load-de-
pendent and speed-dependent
actuation of the intake valves
and, consequently, a no-com-
promises combination of per-
formance and low fuel consump-
tion.
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