Porsche 911 - Manual (Page 22)

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Integrated dry-sump
lubrication.
The purpose of integrated dry-sump
lubrication is to guarantee a
reliable oil supply while reducing
engine temperatures, even in
sportily driven cars.
The oil reservoir is located
inside the engine, making an
external tank unnecessary. Four
oil pumps remove the oil from
the cylinder heads directly into
the oil sump. A fifth pump in the
oil sump directly supplies the
lubricating points in the engine.
To prevent foaming, the oil is
channelled through cylinders
known as swirlpots. In this way,
optimum lubrication is guaranteed
at all times and the oil pressure is
always maintained at the neces-
sary level in order to ensure, for
example, that hydraulic valve
· 47 ·
The new 911 | Engine
911 Carrera 4
clearance compensation remains
fully functional – a condition
that is crucial to the power and
emission characteristics of the
engine.
To reduce power losses and in-
crease efficiency, an electronically
controlled oil pump supplies the
lubricating points inside the engine
as and when required. This means
that the oil pump does not work
so hard when there is less demand
for lubrication. The benefits of an
on-demand oil supply system are
optimum efficiency, reduced fuel
consumption and lower exhaust
emissions.
Single-jet spray nozzles cool the
piston crowns with oil from the
main lubrication circuit – another
detailed solution that helps to
reduce the thermal load on the
engine.
For the engine, all of these
detailed solutions mean a consis-
tent supply of oil regardless of
gravitational loads, even in the
most demanding track conditions.
Engine cooling system.
DFI and VarioCam Plus enable a
tremendous amount of power
to be produced with reduced
emissions, fuel consumption and
noise. The same applies to our
efficient cross-flow cooling
system, as used in motorsport,
where each engine cylinder is
uniformly supplied with coolant.
In the 3.8-litre engine, the higher
output demands a corresponding
increase in cooling. The solution
is a more powerful coolant pump
and a more efficient oil/coolant
heat exchanger expanded by two
additional fins.
Ignition.
The ignition system is designed
for static high-voltage distribution.
Individual ignition coils on each
of the spark plugs ensure perfect
ignition every time.