What is a Mercedes Benz V8 Kompressor Engine?

This article will answer the following questions: what is a Mercedes Benz V8 Kompressor engine?  Which models have Mercedes V8 Kompressor engines? And what are the differences between Mercedes Benz V8 engines with a supercharger and a Turbocharger? 

What is a Mercedes Benz V8 Kompressor Engine?

A Mercedes Benz V8 Kompressor is a supercharged petrol engine with 8 cylinders in V configuration. The Kompressor logo located on the back of the car represents the vehicle has a  Mercedes Benz supercharged engine. Supercharging is a type of forced induction method usually implemented on propeller aircraft. Since air gets thinner at high altitudes, an air compressor is used to compress the air before going into the intake manifold.

The Kompressor logo is exclusively used by Mercedes Benz; it means there is an air compressor also known as a supercharger installed on the engine. The M113 V8 petrol engine is the only 8 cylinder engine produced by Mercedes Benz with a supercharger.

The M113 engine was mainly used in the 2000s in the Mercedes Benz passenger cars, it was similar to the M112 V6 engine with additional two cylinders. M112 and M113 both had the same 90 degrees V angle and twin spark plugs per cylinder. M113 had two spark plugs and 3 valves per cylinder, 2 valves for the intake and 1 valve for the exhaust which allowed for a better scavenging effect and improved cylinder charging. 

M 113 was available in 4.3, 5.0 and 5.4 litres displacement depending on the models. Mercedes Benz models with V8 engines were really popular in the early 2000s as the engines produced more than 300 bhp.

 Mercedes Benz AMG which is the high-performance division of Mercedes Benz decided to further develop the M113 and install a twin-scroll supercharger with twin liquid cooler intercoolers. The V8 engine with Kompressors was named M113K where K represents the supercharged version of the M113.

The M113K was hand-built in the Affalterbach manufacturing plant. The engine block was made with aluminium-silicon alloy and aluminium single overhead camshafts. It was very reliable and used iron coating on the piston skirts, forged steel connecting rods and reinforced pistons pins to handle the extra output.

The stroke was increased from 86 to 92 mm and a magnesium intake manifold with a sequential fuel injection system was installed on the M113K. The fuel is injected into the air intake manifold with the help of eight fuel injectors at a pressure of 4-5 bars.

The power output of the M113 K was from 350 bhp to 400 bhp depending on the capacity of the supercharger and the state of tune of the engine.

Which models have the Mercedes Benz V8 Kompressor engine?

Mercedes Benz is the first automotive car manufacturer that started using supercharged engines in production vehicles. Although the latest models no longer use this technology, Mercedes Benz produced really good cars with M113K engines. Following are the models with V8 Kompressor:

The most expensive Mercedes Benz sports car, the Mercedes Benz SLR Mclaren 722 produced in 2007 also used the M155 which is an AMG version of the M113K engine.

The overall power produced by the engine in the 722 editions was 641 bhp and 820 Nm of torque which was 30 horsepower more than the standard edition. Mercedes Benz decided to go with the rotary air compressor instead of a turbocharger.

The M155 was exclusively available in the AMG 55 models and used up to 5.5 litres displacement of the twin-scroll supercharger.

What is the difference between the Mercedes Benz V8 engines with superchargers and turbochargers?

  • V8 engine with superchargers

The M113K and M155 are V8 engines with a twin-scroll supercharger installed on top of the intake manifold. The compressed air is cooled by the twin liquid-cooled intercoolers.

An Air compressor unlike Turbocharger, works with a belt drive and since it is directly driven by the crankshaft, the boost pressure produced by an air compressor is immediate. There is no lag in the power like in the case of turbocharged vehicles.

The compressor pulley has a magnetic clutch which is controlled by the engine control unit. The supercharger can be engaged or disengaged from the drive belt according to the driving conditions.

An air recirculation valve is also present in the air induction system to compensate for the flow of air in different driving circumstances. Mercedes Benz predominantly used roots or the twin-scroll supercharger which are positive displacement and have a linear output, unlike the centrifugal types.

An electric air pump is mounted on the engine for the secondary air injection system which injects air into the exhaust system and brings the catalytic converter to operating temperatures.

The exhaust manifold can be designed in a simpler structure and compact form on supercharged engines and optimised for maximum airflow.

  • V8 engines with turbochargers

The M278 and M177/M176 V8 petrol engines found on the latest Mercedes Benz models on the other hand use two turbochargers for each cylinder bank. Air is still Cooled by a liquid-cooled intercooler, however, as the turbochargers mounted on the exhaust side are used to compress the air and produce the boost pressure.

Mercedes Benz uses waste-get type turbochargers with a turbine wheel on the exhaust side and compressor wheel on the intake side. There are non-friction bearings in turbos but the engine oil lubrication circuit is connected as the rpm of the turbochargers can reach 200000 revolutions per minute. 

The boost pressure is controlled by electro-pneumatic transducers that can control the wastegate linkage connected to a vacuum cell. The boost pressure transducers are controlled by the signal from the engine control unit.

There is no need for an air bypass valve as the sheer size of the intercooler and intake manifold can compensate for the airflow under different driving circumstances.

Because the turbochargers are driven by exhaust gases, the boost is not available at the lower engine speeds and the construction of the exhaust manifold is much more complex.

Mercedes Benz uses town scroll turbochargers to reduce the turbo lag and mount the turbochargers closer to the exhaust ports so maximum gases can flow over the turbine wheel spool the turbos more quickly.

Conclusion

Mercedes Benz no longer uses V8 Kompressors on the latest production cars as Turbochargers can function as effectively and help in achieving greater power output with smaller displacement in the engines. Turbochargers are also cheaper to manufacture and improve the thermodynamic efficiency of the petrol engine by recovering the energy lost in the exhaust gases. Despite the advantages of Turbocharging the engines, many car collectors and enthusiasts still prefer the M113k Kompressor engine for its immediate power delivery and distinctive sound of the supercharger.

FAQs: what is a Mercedes Benz V8 Kompressore engine?

What is a V8 Kompressor?

A V8 compressor is an 8 cylinder engine with forced air injection. The intake air is compressed by a turbine driven by the crankshaft of the internal combustion engine.

What does Kompressor mean on a Mercedes?

If there is Kompressor written on the back of the Mercedes means, the car has a supercharger used to compress the intake air.

Is Mercedes Kompressor a turbo or supercharger?

Mercedes Kompressor is a supercharger. Mercedes Benz uses a roots blower or a twin-scroll compressor with its inline 4 and V8 engines.

Which Mercedes-Benz has a V8 engine?

Mercedes Benz V8 engine is present in all models after C class. It is also used in the Mercedes Benz high-performance versions of the standard model. The V8 engine is hand-built by AMG.

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