Porsche 911 GT2 Brochure page 11

crankshaft runs in eight main
Lightweight design.
bearings and is driven by forged
The six-cylinder twin-turbo boxer connecting rods. For optimum
engine is a compact unit offering strength and durability, we've used
excellent cylinder charging and forged aluminium pistons running
torque-curve characteristics in Nikasil-coated aluminium liners
as well as first-rate balance with and cooled via individual oil-spray
minimal vibration. The flat-six jets. The results: lower frictional
design allows a low centre of resistance and a lengthy service
gravity with resulting advantages life – even when subjected to
for traction and driving dynamics. heavy use.
The alloy crankcase consists of
two main sections, each contain- The cylinder heads are made
ing one bank of cylinders. The from an extremely heat-resistant
lightweight alloy. Each cylinder
bank has two overhead camshafts
driving a set of four valves (two
inlet and two exhaust) on each
individual cylinder. The valves are
arranged in a 'V' formation and
have a highly efficient dual-spring
closing action enabling higher
engine speeds. Performance is
enhanced with the aid of both
Variable Turbine Geometry (VTG,
see page 28) and VarioCam Plus
(variable valve timing and lift on
the inlet side). The benefits are
· 24 ·
not only greater power and of oil is returned directly to the
torque, but also better fuel econ- external reservoir. The flow is dri-
omy and lower emissions. ven by two scavenge pumps in
each cylinder head and a further
two pumps in the crankcase. Gas
Dry-sump lubrication. is removed from the returning
oil via a defoaming device in the
This racing technology uses a reservoir. The oil is returned
separate oil reservoir to ensure to the lubrication points in the
consistent oil pressures through- engine by means of a dedicated
out the engine, even during pro- oil-feed pump. With a further
longed periods of lateral and longi- scavenge pump in each of the
tudinal loads. After passing twin turbocharger units, the
through the engine, every drop 911 GT2 has a total of nine
The 911 GT2 |
separate pumps driving the lubri-
cation system. The oil level can be
checked from inside the car via
the standard on-board computer.
The 911 GT2 is factory-filled with
Mobil 1 high-performance fully
synthetic oil. The exceptional
properties of this premium-quality
lubricant ensure reliable starting
even in the coldest conditions. It
also reduces wear and contributes
to the long-term durability of the
engine.
· 25 ·
Drive