Mercedes-Benz M120 engine

The engine type M 120 is a gasoline engine from Mercedes -Benz with twelve cylinders in a V configuration. The engine is in production version 6.0 liters and four valves per cylinder. He was from 1991 to 1998 used in the saloons and coupés of the 140 / C 140 series and later in the SL R 129 series in the model 600 SL and SL 600

The type of engine was replaced in 1999 for the purpose of the S-Class from the slightly smaller and lighter be built Type M 137.

The M 120 is also used in an optimized form as M 297 in some super sports car, for example in the Pagani Zonda, the Mercedes -Benz CLK GTR and the Lotec Sirius.

In addition, the Mercedes -Benz test vehicle Mercedes -Benz C 112 was equipped with the M 120 and used together with a manual six- speed gearbox for test and test drives.

Formation and technology

The mid-1980s stood at Daimler -Benz in the development work for a new S-Class, which then came out in 1991.

In the competition of the luxury sedans Jaguar had only since the 1960s, twelve-cylinder engines on offer, otherwise were twelve-cylinder domain of sports car manufacturers such as Ferrari and Lamborghini.

Even for the current 126 series, a twelve-cylinder engine of a type " 600 SEL" had been developed in the development except the proven V8 engines M 117. This was, however, not released into production after the discussions around the oil crisis in 1974.

BMW introduced in 1987 a twelve-cylinder engine of the first post-war German history. This was the signal for competition to take similar. Daimler -Benz became the third provider of twelve-cylinder sedans.

In 1988, Dr. -Ing. Kurt Obländer commissioned to develop a twelve-cylinder engine for 1991 published new S-Class 140 series, which exceed the Bavarian unit in power and engine capacity by far and at least 294 kW (400 hp) should have. At this time, a new 5.6-liter V8 engine with four-valve technology and nearly 400 horsepower under the Code M117 / 9 was already fully developed, which the tuning company (and later Daimler subsidiary ) AMG alone at first by means of expensive four-valve cylinder heads produced, then together with Daimler -Benz produced in Simplified design and einbaute for solvent customers in coupes and sedans of series 126.

At the same time Obländer had developed series production a V- 16 cylinder engine for an initially planned in the W140 model "800 SEL", before its production launch, Daimler -Benz but then shrank, similar as before the introduction of the V- 12 engine in the predecessor series W126.

Result for the then introduced into the series W140 new six-liter V12 were 300 kW ( 408 hp ) rated power. This engine was not only the first series-produced twelve-cylinder passenger cars from Mercedes- Benz, he was also the hitherto powerful Mercedes -Benz passenger car engine. The rated torque is 580 Nm at 1600 rpm and already exceeds the 500 - Nm - brand. The V12 is equipped with four-valve technology, variable intake camshaft as well as a fully electronic Bosch injection system with hot-wire air mass sensor ( LH- Jetronic).

In the engine development was the minimization of pollutant emissions and fuel consumption in the foreground. Electronic ignition is calculated from the optimum ignition timing 300 ignition, individually for each cylinder and adapted to the knock limit. As the only twelve-cylinder world of the M 120 has this cylinder - selective anti-knock control. Just so necessary for optimum fuel utilization high compression ratio of 10:1 is possible. A new feature was the engine and drive management, in which all control modules on a common data channel ( CAN bus) to communicate. This is used among other things for quick heating of the catalytic converters after a cold start of the engine, also for traction control and the new engine drag torque control that prevents a car breaks on a slippery surface due to the throttle.

Furthermore, the engine has the world's largest catalyst system for passenger cars it was dimensioned with seven liters in volume, so that by the catalyst occurred no increase in fuel consumption and a high long-term stability was assured. A novel concept double- and three-layer insulated exhaust manifold and also double-walled pipes embedded in a thermally insulated swelling mat ceramic catalytic converters reach operating temperature in a short time.

After public criticism arose thereon, Daimler -Benz abandoned in September 1992, three years after completion of M 120, to the enrichment of the mixture at full load, the eindüste more gasoline than was allowed for the conversion of the pollutants. The manufacturers modified the engine controller, thus a power loss of 10 kW (14 hp) to 290 kW ( 394 hp ) and a small reduction of the torque of 570 Nm was associated.

Series vehicles with M 120

From 1991

• In the 600 SE, (from 06 /1993 S 600 ) W 140
• In the 600 SEL, (from 06 /1993 S 600 long) V 140

From 1992

• In the 600 SEC ( from 06 /1993 CL 600) C 140
• In the 600 SL, (from 06 /1993 SL 600) R 129

Performance improvements

AMG developed on the basis of the M 120 various engines with 6.9, 7.0 and 7.3 liters, which were used, inter alia, in the CLK -GTR, the SL 70 AMG and the SL 73 AMG. Today they are installed, for example even in the sports car Pagani Zonda. These engines are referred to as M 297.

In the Super Sport version of the Mercedes CLK GTR brought the M 297 to 488 kW ( 664 hp), 478 kW at least still (650 hp), the engine in the Pagani Zonda F is designed in the Club Sport version.

Also machined tuning companies the M 120 from Brabus, Lorinser, Koenig Specials, Renntech, Carlsson Väth and there was the twelve-cylinder engine with displacements between 7.2 and 7.4 liters. Very famous is the Brabus 7.3S with an output of 428 kW ( 582 hp). The power bandwidth goes up to the lesser-known Carlsson RS74 Le Mans with up to 456 kW ( 620 hp). The torque of the different engine capacity versions range 720-850 Nm.

Recently, a new naturally aspirated version of the M 120 is at the peak power: The built- in Pagani Zonda R, six -liter version of the M 120 reached 750 horsepower, significantly more than the previously largest -capacity versions.

From the M 120 there are also two costly conversion to turbo engine.

The Lotec GmbH Kolbenmoor has left it with the standard 6.0 liter engine, but the engine has two exhaust gas turbochargers ( K 27 ) together with intercooler missed and installed in the Lotec Sirius. This engine has a power output of 735 kW (1000 hp) and develops a torque of 1100 Nm at 0.85 bar boost pressure. With short-term retrievable 1.2 bar boost pressure it is 883 kW (1200 hp) and 1320 Nm. By comparison, the supercar Bugatti Veyron brings it only to 736 kW (1001 hp) and 1250 Nm at eight liters, four turbochargers and 16 cylinders.

Another version of the M 120 with exhaust turbocharger comes from the Russian tuner A-level. This engine produces by twin turbochargers and larger displacement to 6.7 liter 616 kW ( 837 hp), develops 1182 Nm of torque. This engine was installed in a S-Class Coupe C 140.

The Lotec Sirius and the S 600 Coupé A-level are individual pieces.

Today, barely avoided a tuner on compressor or turbocharger to increase performance, since they are much more economical in contrast to the large displacement naturally aspirated versions of a, have a higher efficiency and thus less fuel in proportion to the power consume.

The topics of durability, comfort and delayed power delivery ( turbo lag ) have now been satisfactorily resolved, so these engines found their way into the limousine of Mercedes and Maybach.

Larger motors than the M 120 C 74 of Carlsson ( 7414 cm ³) is one well in the future in Germany for cars hardly develop because increasing public awareness of the discussions about CO2 emissions, fuel price, fuel efficiency and alternative propulsion technologies in the foreground. Since approximately 2008, above the trend towards "downsizing ", smaller, lighter and more fuel efficient engines for Daimler AG. It dispensed with the latest facelift, the S- Class W221 far partly on high displacements and cylinder numbers (including the eight-cylinder diesel set, and it is offered in the S-Class, a four-cylinder ).

Data

• Motor Type: M 120 E 60
• Installation on the vehicle: front, along
• No. of cylinders, arrangement: 12, 60 ° V - shape
• Bore × Stroke: 89.0 × 80.2 mm
• Displacement: 5987 cm ³
• Compression ratio: 10.0: 1
• Valve assembly, number: 2 inlet, 2 outlet, v -shaped hanging
• Valve control: each cylinder bank 2 overhead camshafts ( intake camshaft adjustable)
• Camshaft drive: duplex roller chain
• Ignition: ignition map- control
• Cooling: water pump; 18.5 l of water
• Lubrication: Pressure circulation lubrication, 9.5 l oil
• Mixture formation: injection with hot-wire air mass sensor ( Bosch LH- Jetronic)
• Power: 300 kW/408 hp at 5200 rpm; from 09 /1992: 290 kW/394 hp at 5200 rpm
• Torque: 580 Nm at 3800 rpm; from 09 /1992: 570 Nm at 3800 rpm

• Mercedes- Benz engine