- All-new family of downsized turbocharged engines
- CO2 emissions and fuel consumption reduced by 13 percent
- 33 percent higher power and torque
- Class leading refinement
Opel revealed details of its new midsize gasoline engine family at
the Aachen Colloquium in Germany. The all-new 1.6 liter, four cylinder,
SIDI (Spark Ignition Direct Injection)
ECOTEC Turbo engines, which begin Opel’s renewal of its powertrain
portfolio, bring significant benefits to the customer in terms of fuel
consumption, performance and refinement, while affecting the environment
as little as possible. CO2 emissions and fuel consumption
have been cut by 13 percent compared to the predecessor engine, while
peak torque and peak power have been increased by up to 33 percent.
The new engine family comprises a 1.6 liter Eco Turbo with 125 KW/170
hp and 280 Nm peak torque, as well as a Performance Turbo variant
offering 147 kW/200 hp and 300 Nm peak torque. The 170 hp engine has
been developed with fuel economy, high low end torque and elasticity in
mind, while the performance of the 200 hp unit makes it the benchmark in
its class. The roll out of the new engine family – which has been
developed in Ruesselsheim, Germany – will begin in early 2013.
Opel ECOTEC 1.6 SIDI Turbo EURO 6 Engine |
“The new midsize gasoline engine family is the first milestone in the
fundamental renewal of our powertrain portfolio. Not only do these
downsized engines deliver smooth acceleration and strong pulling power,
they are also highly refined and environmentally compatible,” says
Global Assistant Chief Engineer MGE, Marcel Frensch.
At the heart of the new SIDI ECOTEC Turbo family is an all-new
cylinder block able to withstand peak cylinder pressure of 130 bar. Cast
iron was selected as the preferred material for the cylinder block in
combination with an aluminum bedplate.
Class leading refinement and performance
Opel has designed the new midsize gasoline engine family to be a
leader not only in emissions and fuel consumption, but also in terms of
refinement and performance.
Key development objectives for refinement were low overall radiated
noise and vibration levels, and no unusual sounds. Achieving these goals
enabled vehicle integration that can tune primary engine orders in the
induction and exhaust systems to meet specific vehicle objectives. The
excellent acoustic and vibration performance of the engine is crowned by
the cam cover, which is decoupled from the cylinder head via specific
fasteners and a sealing system designed for high temperatures, due to
the nearby turbocharger.
As a result of these “sound engineering” measures, the customer
perceives quiet and smooth idling, no unusual noises throughout the
operating range, and a pleasant sound quality even at high speeds and
loads.
Balance shafts are industry first for 1.6 liter four cylinder engines
Opel’s SIDI ECOTEC is the only engine in its class to offer balance
shafts. The two balance shafts are inserted in tunnels from the rear end
of the cylinder block and are driven by an inverted tooth chain. The
exhaust side shaft features cast iron gears to reverse rotational
direction of the exhaust shaft. The optional system offsets the
vibrations inherent in the design of four cylinder engines and thus
helps to maximize comfort and reduce noise to a minimum.
Turbocharging for high low end torque
The design and sizing of the turbocharging system plays a key role in
enabling downsized engines to deliver excellent performance and
drivability, while meeting CO2 targets.
Smaller displacement engines with high specific torque and boost
levels require fast transient response, especially at low engine speeds,
in order to be a valid replacement for larger displacement engines.
Thanks to its specially designed turbines, the midsize gas engine’s
turbocharger provides response that is usually generated by twin scroll
turbines on larger engines.
The engine retains the proven concept of a turbine integrated exhaust
manifold. This design was chosen instead of a twin scroll concept
because of its packaging and manufacturing advantages. Although the
turbocharger has identical interfaces, each variant of the new SIDI
ECOTEC engine features a dedicated turbo aerodynamic.
The compressors are designed to deliver high low end torque without
generating noticeable aerodynamic sounds. Combined with low and
high pressure resonators, airborne noises effects like hiss, pulsation
and blade pass noise are almost completely suppressed. With additional
aspects like air handling, duct design and control strategies for
let off noise, the new engine benefits from an aggressive boost strategy
without the typically associated turbo related acoustic degradation.
Compared to the predecessor engine the new SIDI ECOTEC turbo delivers
a remarkable improvement in elasticity, for example, reducing the time
for 80 km/h to 120 km/h fifth gear acceleration by about 20 percent.
Direct Injection for High fuel Efficiency and Performance
In addition to refinement and performance, high fuel economy and low
emissions were the main development objectives of the new 1.6 liter
engines. Opel’s engineers therefore selected a central direct-injection
fuel system, for optimum fuel efficiency and minimal emissions.
The central location of spark plug and injector over the combustion
chamber, and their orientation parallel to the crankshaft, forms a
compact package with the capability to support homogeneous and
stratified engine operation.
The valve train is operated by low friction hydraulic roller finger
followers and driven by a timing chain with a maintenance free hydraulic
tensioner. Acoustics are further improved by the inverted teeth of the
cam drive chain. For mass reduction the midsize gasoline engine features
a two piece crankcase design, supported at the lower end by a die cast
aluminum bedplate.
The cylinder block is manufactured using an innovative thin wall
casting method. This allows the integration of different functional
features directly into the raw block and offers potential to reduce
production time.
The engine uses a broached press fit between the cylinder block and
the bedplate instead of dowels, in order to optimize the main bearing
shape as well as its positional accuracy. The structural design
considers the engine’s use in a variety of vehicle applications,
allowing minimum integration effort and consistent part
interchangeability.
The structural benefit derived from the combination of a forged steel
crankshaft, optimized main bearing journal diameters, and iron main
bearing cap inserts results in minimized noise and vibration at mid and
high rpm.
Two different pistons have been designed for the Eco and Performance
Turbo engines. Each has a dedicated top land including a small bowl. A
cast iron ring carrier adapted to the high cylinder pressures is common
to each piston. The PVD coated first piston ring is an additional
friction reduction measure.
“Flex Plant” in Hungary is home to the engine renewal
Production of the new 1.6 liter SIDI ECOTEC Turbo engine alongside
the other new engine families will be at the Szentgotthárd plant in
Hungary and will begin in late 2012. The factory uses the “Flex Plant”
concept which enables gasoline and diesel engines to be built on a
shared assembly line.
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