Oil Circulation System; Design - Audi 4.2-litre V8 FSI Service Training

Oil circulation system

Design

The oil supply in the basic engine, and likewise in
the high-revving engine, is based on a classic wet
sump concept.
The focal point of development was on significant
reduction of the oil flow rate. As a result, the oil
remains in the sump for longer and is better able to
deaerate.
The oil flow rate of 50 litres per minute (at 7000 rpm
and 120 °C oil temperature) is very low for an eight-
cylinder engine. This has helped to minimise oil
pump drive power and thus improve fuel economy.
Hydraulic
camshaft adjustment
Oil cooler (coolant)
Thermostat
18
Cylinder bank 1
Chain tensioner
Oil cooler (air)
The baffle plate is designed such that it not only
prevents the crankshaft churning the oil in the
sump, but also strengthens the main bearing walls.
In the basic engine the oil is cooled by an oil-water
heat exchanger.
In the more highly stressed high-revving engine,
an additional oil-air heat exchanger is used to mini-
mise the oil temperature even at high engine load.
This additional heat exchanger is operated in
parallel with the heat exchanger via a thermostat.
Oil filter module
Oil pump
(gear)
Cylinder bank 2
Oil pressure
regulator
Features
exclusive
to the Audi RS4
377_028