PECM Issue 41 2019 | Page 27

"We already set the benchmark in the segment with the
preceding engine. This fundamentally new four-cylinder
presented us with the challenge of doing even better. And we
succeeded with a number of sometimes revolutionary solutions.
With the M 139, we have once again impressively demonstrated
the engine expertise of Mercedes-AMG. Not only is the output
per litre unrivalled for a turbocharged engine, the high level
of efficiency also demonstrates that the internal combustion
engine still has further potential," says Tobias Moers, Chairman of
Mercedes-AMG GmbH.
Why "One Man, One Engine" was reinvented
The new engine is entirely assembled by hand. On the first
floor of the AMG engine manufactory in Affalterbach, a
completely newly designed production line was installed in
which Mercedes-AMG has brought the "One Man, One Engine"
principle to a new level together with Industry 4.0 methods that
incorporate the latest findings in ergonomics, materials handling,
quality assurance, sustainability and efficiency. On the road to
implementing Industry 4.0, AMG's hand assembly operation
likewise follows the vision of "smart production". This excels
with maximum flexibility, and is transparent and highly efficient.
It safeguards and improves the quality of the engines and
production processes using innovative and digital technologies.
"We have completely revised the principle of "One Man, One
Engine" for assembly of the M 139. The result is an ultra-modern
production process that places the focus on people. To achieve
this, we created the ideal working conditions in a bright,
precisely organised and clean environment for our employees.
This provides the best basis for continuing to ensure our high
quality level even as the technology becomes more complex,"
says Emmerich Schiller, COO and member of the Board of
Management at Mercedes-AMG GmbH.
Why a 180-degree rotation brings many advantages
The new engine excels with numerous intelligent design
features. Compared to the likewise transversely installed M 260
four-cylinder in the "35" models or the preceding M 133 engine,
the new Mercedes-AMG M 139 is rotated around its vertical axis
by 180 degrees.
This means that the turbocharger and the exhaust manifold
are now positioned at the rear, on the side of the firewall when
viewed from behind. The intake system is therefore positioned
at the front. This configuration allows the flattest possible
and aerodynamically advantageous front section design.
Furthermore, the new arrangement allows much improved air
ducting with shorter distances and fewer diversions - both on
the intake and exhaust side.
How roller bearings improve the responsiveness of the
turbocharger
The new twinscroll turbocharger combines optimum
responsiveness at low engine speeds with a high power in
the upper rpm range. In addition to this, the turbine housing
is divided into two flow passages which run parallel to one
another. Together with the likewise divided ducts in the exhaust
manifold, this makes it possible to feed the exhaust flow to the
turbine separately.
The aim is to prevent the individual cylinders from influencing
each other negatively during load cycles, and to improve the gas
cycle. The result is higher torque at lower engine speeds, and
extremely good responsiveness. Furthermore, the shafts of the
compressor and turbine have roller bearings for the first time as
in the top output variant of the AMG 4.0-litre V8 engine in the
AMG GT 4-door Coupé.
Issue 41 PECM
27