奔驰轿车M275发动机技术初级培训手册

Cars ? Gasoline engine

Engine 275

Initial training

Information module

As at 03/03

Contents04.03.2003

Page Title

1Engine 275 - an overview

8Engine mechanics M275 / M285

16ME 2.7.1 fuel-injection and ignition system

26Fuel system

30Exhaust gas turbocharging

49Comparison of exhaust gas turbocharger and mechanical supercharger

53Exhaust-gas system

54ECI ignition system

62Information unit engine 285

Engine 275 - an overview 04.03.2003

P00.00-2256-50P00.00-2821-50P00.00-3081-50

Highlights M275

The new V12 with bi-turbo charging

High-tech perfection is promised by the new 12-cylinder engine, which will be available as of autumn

2002 in the model refined S-Class. This V12-cylinder bi-turbo comes with commanding performance

values: the engine develops a rated output of 368 kW at 5,000 rpm and a rated torque of 800 Nm at

1,800-3,500 rpm.

This power unit has a generously rated surplus in output and, in particular, torque and this is available at

constantly harmonious output and torque development. In keeping with the character of a luxury sedan

the new motorization comes with a perfectly smooth operation and an harmonic noise design.

GT01_00_0016_C71Taking all viewpoints into consideration the technical realization of the goals set called for a V12-concept

with 5.5 l displacement, 60 degree cylinder bank angle and bi-turbo charging.

Engine breathing is supported by a turbocharger with "wastegate-control system" for each cylinder bank.

Exhaust gas turbocharging development mainly focuses on the finest response characteristics in

combination with the achievement of maximum torque at as low as possible engine speed. Apart from

this special emphasis was placed on the acoustic characteristic.

Output and torque in abundance

In comparison to the predecessor engine the rated output and rated torque for the new engine have been

increased by approx. 30 % or 50 %. Because a corresponding increase in displacement was ruled out due

to the wish to keep to moderate fuel consumption and a compact design, a slightly reduced displacement

with two exhaust gas turbochargers and charge air cooling was selected. The model refined S-Class

achieves thus outstanding performance with excellent acoustics, a superb degree of vibrational comfort

and, in view of the performance data, adequate fuel consumption.

Smooth operation and noise emission

On a 12-cylinder engine with a cylinder angle of 60 degrees, all forces and torques of the 2nd order are

completely balanced as a matter of principle. Thus the greatest possible degree of smooth operation

without additional balance shafts is a given factor.

All engine parts are designed using ultramodern calculation and testing methods in terms of rigidity and

vibrational characteristics. The improvement in vibrational characteristics is contributed to in particular

by a bedplate design with gray cast iron inserts on the crankshaft main bearings. The oil pan is

completely decoupled from the crankcase in terms of vibrations. Combustion noise is dampened by the

installed dual ignition, which serves to keep the pressure gradients in the combustion chamber at a low

level and which minimizes cycle scatter for each individual combustion procedure. Noise reduction was

also achieved by the damping through the exhaust gas turbochargers on the air and exhaust-gas sides as

well as the water jacket of the water-cooled generator.

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Weight

Despite the additional exhaust gas turbocharger, engine-side charge air cooler and the reinforced belt

drive the M275 only weighs 270 kg and thus achieves an excellent power/weight ratio of 0.65 kg/kW.

The following lightweight components are used:

?cylinder head cover made of die-cast magnesium

?weight-optimized cracked, forged steel conrod

?die-cast aluminum for upper and lower section of crankcase

?lightweight silitec cylinder liner

?weight-optimized elastoval piston

? a 3-valve design with one camshaft per cylinder bank

?weight-optimized crankshaft and dynamic balancer

?an oil pan made of die-cast aluminum

Technical data comparison

Sales designation CL 600CL 600S 600SL 600 * Vehicle model215.378215.376220.176230.476 Engine model137.970275.950

Cylinder arrangement / number / angle V12 / 60°

Valves / spark plugs per cylinder 3 / 2

Continuous fuel-injection and ignition system ME 2.7ME 2.7.1

Turbocharging with charge air cooler (intercooler)

Air supply Naturally aspirated

engine

Total displacement cm35,7865,513

Rated output kW (hp) at rpm270 (367) at 5,500368 (500) at 5,000

Rated torque Nm at rpm530 at 4,100800 at 1,800 - 3,500

13.414.7

Fuel consumption (New European Driving Cycle)

Super Plus l/100 km/h

Acceleration 0 - 100 km/h s 6.3 4.8

* Market launch 04/2003

Performance graph M137Performance graph M275

P01.00-2341-73GT01_00_0018_C73

Comparison of M275 / M285 with M137

Engine 137 (ME 2.7)Engine 275 / Engine 285 (ME 2.7.1)Advantage

ECI ignition system (AC voltage ignition system with integrated ionic current measurement), ignition voltage 30 kV, two spark plugs per cylinder ECI ignition system (AC voltage ignition system with

integrated ionic current measurement), ignition

voltage 32 kV, two spark plugs per cylinder

Improve ignition performance and reliability

No knock sensors, recognition of knocking combustion by using the ionic current measurement 4 knock sensors

?A29/1 and A29/2 on left cylinder bank

?A30/1 and A30/2 on right cylinder bank

Recongition of knocking ignition over the knock

sensors offers the availability of an optimally graded

performance map for the monitoring of smooth

operation

Naturally aspirated engine One exhaust gas turbocharger (bi-turbo) made of

steel casting for each cylinder bank.Enormous generation of power for a relatively low fuel consumption

Fuel pump is drived by fixed12V à constant delivery volume Fuel pump (max. delivery rate approx. 245 l/h) is

drived by PWM signal (control by a fuel pump control

module) à deliver according to demand

?Less wear and noise

?Saves energy

A total of 8 O2 sensors for in front of and behind the four firewall catalytic converters respectively A total of 4 O2 sensors, 2 in front of and 2 behind

the firewall catalytic converters respectively

Reduction of the number of components

Fulfillment of Euro 4 and LEV 1

Cylinder Shut Off: the left row of firing cylinders are

shut-off when idling or when running in a low loading situation -----

Priority is given to obtaining a performance

advantage

Camshaft adjustment-----Ditto

Detection of combustion misfires through ionic current signals Detection of combustion misfires through ionic

current signals and through smooth operation

evaluation using crankshaft position sensor (L5)

Optimize the combustion misfiring detection to suit

turbocharged engine

Engine mechanics M275 / M28504.03.2003 Crankcase The crankcase and oil pan for the M137, M275 and M285 engines are designed as follows.

Legend:

1Upper crankcase section made of die-cast

aluminum

2Weight-optimized crankshaft and dynamic

balancer

3Upper crankcase section made of die-cast

aluminum

4Rubber gasket between crankcase bottom

section and upper section of oil pan

5Upper section of oil pan made of die-cast

aluminum

6Oil pan bottom section made of die-cast

aluminum

P01.40-2029-09 The upper section of the oil pan in the S-Class is designed as shown. The front axle design of the various

vehicle models (S-, SL-Class and Maybach) means that the oil sumps have to be located in different places.

Service tip

The following must be noted when removing and installing the upper oil pan:

A copper connecting link is located at one of the screws, which serves to set up the ground connection

between the oil sensor and the crankcase.

Never forget this when assembling!

GT03_00_0001_C71

The oil pan constriction on the M275 consists of two parts. This has a positive effect on the sealing

concept.

The upper part of the oil pan is sealed against the lower part of the oil pan using a silicone sealant

Spare Part No. A 002 989 73 202/50 ml.

The upper part of the oil pan is sealed against the crankcase by means of a rubber seal which is vibration

dampening and also serves to optimize noise generation.

Aluminum crankcase with gray cast-iron insert

A genuine highlight is the particularly innovative design of the crankcase.

The crankcase is of a two piece bedplate design. Massive gray cast iron inserts in the area of the lower

crankcase section's main bearing achieve improved noise generation characteristics.

The very compact design of the crankcase does not lead to any increase in the size of the engine

compared to previous models despite turbocharging. This, together with the light-weight construction

technology used, leads to a total engine weight of just 270 kg which represents an increase in weight of

just 50 kg compared to the basic M137 engine.

The increase in weight is due to the additional coolant compressor and the extraordinarily powerful 350 A

alternator.

GT03_20_0005_C01

In order to meet the demands of higher heat and pressure loads, the wall between the cylinders of the

upper crankcase section have been widened compared with the M137 by 2 mm to 8 mm and in each

case 3 water cooling bores (1 and 2) have been integrated into the walls.

The cylinder bore has been reduced compared with the M137 from 84.0 mm to 82.0 mm. By contrast the

cylinder spacing of 90 mm and the stroke of 87 mm have not been altered.

Water-cooling bores (1 and 2) for cooling walls

GT03_20_0006_C01

1

The cylinder liners are made up of an alloy of aluminum-silicon (silitec). They have a wall thickness of

2.5 mm.

Advantage:

?lower cylinder thermal distortion

?lower noise and less pollutant emissions

?lower weight and greater dimensional stability.

GT03_20_0007_C01

Piston The cast pistons and piston ring are designed to cope with the extremely high pressures and

temperatures. For the realization of the smallest, noise-relevant plays and for the purpose of improving

the emergency running characteristics, the gravity die-cast pistons have been galvanically coated with

iron.

The piston pins have been optimized in accordance with the acting loads both in terms of outer diameter

and wall thickness.

Piston cooling is supported by oil spray nozzles.

2

Connecting rod

Forged steel conrods made of crack-capable forged steel are used. To protect the extremely high loads

DaimlerChrysler is using a high-strength forged material for the first time.

As previously with the 137 engine for reasons of higher dimensional accuracy in the M275 and M285

engines the lower connecting rod eye is cracked (broken) and bolted to the crankshaft's main bearing.

GT_03_10_0003_C01

Cylinder head

The aluminum cylinder heads come with the 3-valves-per-cylinder technology familiar from the M137.

Each cylinder bank contains a camshaft, which actuates both the inlet and exhaust valves by means of

cam followers.

The M275 and M285 engines do not need camshaft adjustment, as their torque increasing function in

combination with turbocharging is rendered superfluous.

Chain drive

Camshaft drive ensues from the crankshaft by means of a twin roller chain. A sprocket wheel is used in

the V-center for deflection purposes. Otherwise the chain is routed through slightly bent slide rails.

The chain tensioning force is achieved over a tensioning rail by means of a hydraulic chain tensioner.

In order to improve the noise characteristic of the chain drive, the sprocket wheel of the crankshaft, the

guide wheel and the camshaft are rubberized.

To optimize the overall length the oil pump drive has been located downstream of the timing chain. The

oil pump chain drive is designed as a single roller chain.

GT_01_30_0016_C01

Engine control How is the engine control's basic adjustment made?

The basic adjustment is 30° ATDC. At 30° ATDC the groove (6) of the camshaft at left and right is

centered relative to the separating surface for the cylinder head cover towards the inner-V. To fasten the

camshafts, the special tool familiar from the M137 can be used. The groove on the crankshaft gear (2)

points to the mark on the crankcase. The guide wheel (3) without a mark need not be considered.

1Copper plated connecting link, two each for camshaft sprocket adjustment

2Groove in crankshaft

3Guide wheel without mark

4Mark on camshaft sprocket at right R

5Mark on camshaft sprocket at left L

6Groove in camshaft

P05.10-2144-06

Crankcase ventilation of M275/M285

The blow-by gas is aspirated by the vacuum in the charge air distribution pipe, or turbocharger intake pipe.

It is routed from the timing-chain compartment to the centrifugal oil separator where the oil is separated from the blow-by gas.

Following this, the blow-by gas is routed to the pressure regulating valve. The separated oil is fed back to the oil pan over the timing-chain compartment.

Partial load ventilation

During partial load ventilation the air is routed across the check valve into the charge air distribution pipe.Full load ventilation

During full load ventilation the partial load ventilation line is closed by the boost pressure applied to the check valve. The air separated from the oil is then routed to the Turbocharger intake pipe downstream of the air cleaner.

GT18000003C81

Pressure regulating valve

Charge air distribution pipe

Turbocharger intake pipe Check valve,

full load ventilation

Centrifugal oil separator

Check valve,

partial load ventillation

Oil separator/Pressure regulating valve

A centrifugal oil separator integrated into the ventilation system of the engine on the left-hand camshaft

achieves excellent removal of oil under all operating conditions.

An additional pressure regulating valve ensures that there is adequate vacuum in the crankcase during

the air inlet suction and turbocharging processes as well as under conditions of partial loading and full

loading.

At a specific vacuum (> 50 mbar) in the turbocharger intake pipe the connection to the crankcase is

sealed by means of a diaphragm in the pressure regulator valve.

If the pressure in the crankcase rises above a specific value, the diaphragm is opened and thus the

connection to the turbocharger intake pipe set up again.

GT_01_30_0017_C71

ME2.7.1 fuel-injection and ignition system04.03.2003

Motor electronics control module 2.7.1

The electronic engine management is an advanced development of the ME 2.7 of the M137. It includes

the engine control function including all diagnoses and is networked over the CAN-C databus with further

electronics. The control module is housed in a ventilated electronic module box along with other

electronics.

The engine control function has been adapted to the bi-turbo engine:

?The pressure in the charge air distribution pipe and the corresponding temperature are recorded for

calculation of the aspirated air mass using separate pressure and temperature sensors.

?The boost pressure is recorded by a second pressure sensor upstream of the throttle valve and serves

the boost pressure control.

?Boost pressure is regulated by the wastegate valve in the exhaust gas turbocharger.

P07.08-2017-01?Torque momentum coordination and the engine's emergency (limp-home) function have been adapted

to the turbocharger-specific requirements.

?The diagnosis has been extended by the charger protection feature, which serves to prevent any

impermissibly high turbine wheel speed.

?The signals from 4 knock sensors are evaluated for knock identification.

?The ionic current misfiring detection familiar from the 137 engine has been adapted to suit the

requirements of a highly-supercharged engine. The detection quality was able to be improved by

continuously comparing it with a speed uniformity analysis on the crankshaft.

?In order to safeguard the exhaust gas turbocharger and the three way catalytic converters against too

high exhaust gas temperatures, a model-based exhaust gas temperature control has been introduced.

?The communication of ME control module with the alternator via a bi-serial communication interface.

E ngine fuse and relay box (K40/8)

I n the engine compartment the S and CL 600 models have had an additional relay box installed. The following components are contained in this relay box:

K40/8kW Charge air cooler recirculation

pump

K40/8kV

Motronic relay

K40/8kX Intank fuel pump relay

(only for S 55 AMG, CL 55 AMG)

F use 87Motronic 1

F use 88Motronic 2

F use 89reserve P20.00-2118-04 F use 90Charge air cooler recirculation

pump

F use 91reserve

K40/8

C ontinuous fuel injection system (overview)

B OSCH M E 1.0M119

M120

?Control through hot film mass air flow sensor

M E 2.0M112

M113

?Control through hot film mass air flow sensor

M E 2.1M111?Control through hot film mass air flow sensor

M E 2.7 M E 2.7.1 M E 2.7.1M137

M285

M275

?Control through hot film mass air flow sensor

?Pressure motor control

?Pressure motor control

M E 2.8M112

M113?Control through hot film mass air flow sensor M anifold air pressure sensor for monitoring

M E 2.8.1M112 ML

M113 ML

?Pressure motor control

V DO M SM M166?To 08/2001 control through hot film mass air flow sensor

?As of 09/2001 pressure motor control

S iemens S IM4M111 EVO?To speed 2,000 rpm control through hot film mass air flow sensor

?As of speed 2,000 rpm manifold air pressure control