BMW N55 User manual

Revision Date:
55 Engine
Introduction ..................................................5
Engine Components/Systems Overview . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Te c h n i c a l Data .................................................8
Full Load Diagram............................................9
CurrentModels ...............................................10
Engine Designation and Engine Identification . . . . . . . . . . . . . . . . . . . . .11
EngineDesignation .........................................11
Breakdown of N55 Engine Designation . . . . . . . . . . . . . . . . . . . . . . . .12
Engine Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
EngineComponents .........................................14
EngineHousing ...............................................14
EngineBlock ...............................................14
Crankcase and Bedplate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Crankshaft....................................................17
Crankshaft Main Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
PistonsandRings .............................................18
Connecting Rod andBearings ..................................19
Oil Pan .......................................................22
Electrionic Volume-controlled Oil Pump ..........................23
Oil Pump and Pressure Control ...............................24
OilSupply ....................................................27
Oil Filtration and Oil Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
OilSprayNozzles ...........................................31
Oil Pressure ................................................31
Oil Level ...................................................31
Oil Return ..................................................31
CylinderHead.................................................32
Cylinder Head Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Crankcase Ventilation ..........................................34
NaturallyAspiratedMode ....................................34
BoostMode ................................................36
Valvetrain .....................................................39
Intake and Exhaust Valves ....................................40
Valve Springs...............................................40
Subject Page
Table of Contents
Initial rint Date: 02/10

Camshafts....................................................41
Valve Timing ...............................................42
VANOS System ...............................................43
Overview...................................................44
VANOS Solenoid Valves .....................................45
CamSensorWheels ........................................45
Valvetronic III ..................................................46
Phasing....................................................46
Masking ...................................................46
Combustion Chamber eometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Valve Lift Adjustment Overview ...............................50
Valvetronic Servomotor ...................................52
Function .................................................52
Belt Drive and Auxiliarly Components ............................53
VibrationDamper..............................................54
Air Intake and Exhaust System ..................................56
Air Intake System ...........................................56
IntakeManifold .............................................59
Fuel Ta n k Ventilation System .................................60
ExhaustManifold ...........................................61
Tu r b o c h a r g e r ...............................................62
Function of the twin scroll turbocharger . . . . . . . . . . . . . . . . . . . .65
Diverter valve ............................................65
CatalyticConverter..........................................66
Exhaust System ............................................67
Vacuum System ...............................................68
Vacuum Pump ..............................................69
Fuel Injection .................................................71
Fuel Pressure Sensor .......................................72
High Pressure Fuel Pump ....................................73
Fuel Injectors ...............................................74
Cooling System ...............................................75
Components ...............................................77
N55, Cooling System Components ...........................77
OilCooler ...............................................79
Coolant Passages ...........................................80
Engine Electrical System .....................................82
CircuitDiagram................................................83
Engine Cooling Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85
Digital Motor Electronics (DME/ECM) . . . . . . . . . . . . . . . . . . . . . . . . . . . .87
Digital Motor Electronics Circuit Diagram . . . . . . . . . . . . . . . . . . . . . .88
N55, MEVD17.2 Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
Functions ..................................................90
Subject Page

Fuel supply system ......................................90
Fuel quantitycontrol .....................................90
Boost pressure control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90
Enginecooling ..........................................91
System Protection .......................................92
CrankshaftSensor ..........................................92
IgnitionCoil ................................................94
Oil Pressure Sensor .........................................95
OxygenSensors ............................................95
Oxygen sensor before catalytic converter . . . . . . . . . . . . . . . . . . .96
Oxygen sensor after catalytic converter . . . . . . . . . . . . . . . . . . . . .96
Hot-film air mass meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97
High Pressure Fuel Injector Valve .............................97
Function .................................................98
ServiceInformation ..........................................99
CylinderHead.................................................99
CylinderHeadCover...........................................99
Fuel Injectors .................................................99
IgnitionCoils.................................................100
Subject Page

55 Engine
Model: All with 55
Production: From Start of Production
After completion of this module you will be able to:
• Describe the features of the N55B30M0 engine
• Describe the specifications of the N55 engine
• Identify the internal and external components of the N55 engine
• Understand the function of the crankcase ventilation on the N55 engine
• Understand the function of the electronic volume control oil pump
4
N55 Engine

The N55 engine is the successor to the N54. Re-engineering and modifications have
made it possible to now use only one exhaust turbocharger. Against the backdrop of
reduced costs and improved quality, the technical data have remained virtually the same.
55 Engine
Introduction
5
N55 Engine

Engine Components/Systems Overview
The following provides an overview of the features of the N55 engine:
Crankcase:
• Large longitudinal ventilation holes inter-connect the crankcase lower chambers
and relieve unwanted crankcase pressure between cylinders.
• Modified oil galleries enhance the supply of oil to vacuum pump.
Crankshaft: Is light weight design and has an asymmetric counterweight arrangement.
istons and connecting rods:
• A specially formed bushing/bore in small end of the connecting rods evenly
distributes the force of the pistons on the power stroke.
•Lead-free bearing shells are installed on the big-end of the connecting rods.
Cylinder head:
• Specially designed water passages intergraded into the cylinder head enhance
injector cooling.
• The combustion chambers are machined to work in conjuction with the Valvetronic
III system with regard to promoting air turbulence and mixture formation.
Crankcase ventilation:
• In contrast to the N54, the N55 crankcase ventilation does not use cyclone
separators.
• The cylinder and head cover have integrated blow-by passages that connect the
crankcase ventilation directly to the intake ports.
VANOS:
• The N55 VANOS oil passages are simplified compared to the N54 engine.
• The solenoid valves have integrated non-return valve and 3 screen filters.
• The VANOS units are of a lightweight design for increased adjustment speed
and have a reduced susceptibility to soiling.
Valvetrain:
• The N55 is the first BMW turbo engine to incorporate Valvetronic.
• The valvetrain is a new designed that combines Valvetronic III with Double VANOS.
• With Valvetronic III the 3rd generation brushless servomotor is introduced.
• The position detection sensor of eccentric shaft is now integrated in the servomotor.
6
N55 Engine

Oil supply:
• An enhanced and simplified oil circuit design is used.
• The inlet pipe, oil deflector, and oil collector are combined in one component.
• Oil pump uses a Duroplast slide valve and it is electronically controlled based on
a characteristic map within the engine management.
Forced induction:
• The N55 uses a single twin scroll turbocharger with vacuum operated,
electronically controlled wastegate valve.
• The electric diverter valve is intergraded into the turbocharger compressor housing.
Air intake and exhaust system:
• Air intake system is similar in configuration as the N54 with the exception of the
intake manifold and the use of a single turbo.
• The intercooler is an air to air type mounted in the lower area of the front bumper
cover.
• The exhaust system uses no underbody catalytic converter.
Vacuum system:
• The N55 engine has a two-stage vacuum pump as on the N54.
• The vacuum system has the vacuum reservoir built into the cylinder head cover.
Fuel injection:
• HDE (high pressure fuel injection) system is installed on the N55.
• The HDE system uses solenoid valve fuel injectors instead of the piezoelectric
type used on HPI.
• The high pressure pump and pressure sensors are similar in design and function
in both the HDE and HPI systems.
Digital Motor Electronics (DME):
• The DME is mounted on the intake manifold and cooled by intake air.
• The location of the DME facilitates the installation of the N55 engine in several
current BMW platforms/models.
7
N55 Engine

Te c h n i c a l Data
Unit N54B30O0 (E71/X6
xDrive35i)
N55B30M0
(F07/535i)
Configuration 6 inline 6 inline
Cylinder capacity [cm³] 2979 2979
Bore/stroke [mm] 84.0/89.6 84.0/89.6
ower output at
engine speed [kW/bhp] [rpm] 225/306 5800 - 6250 225/306 5800 - 6400
ower output per liter [kW/l] 75.53 75.53
Tor qu e at engine speed [Nm] [rpm] 400 1300 - 5000 400 1200 - 5000
Compression ratio [ε]10.2 10.2
Valves/cylinder 4 4
Fuel consumption,
EU combined [l/100 km] 10.9 8.9
CO2 emission g/km 262 209
Digital Motor Electronics MSD81 MEVD17.2
Exhaust emission
legislation, US ULEV ULEV II
Engine oil specification
BMW Longlife-01 BMW
Longlife-01 FE BMW
Longlife-04
-
Top speed [km/h] 240 250
Acceleration
0 - 100 km/h/62mph [s] 6.7 6.3
Vehicle curb weight DIN/EU [kg] 2070/2145 1940/2015
* = Electronically governed
8
N55 Engine

Full Load Diagram
Compared to its predecessor, the N55 engine is characterized by lower fuel consumption
with the same power output and torque data.
Full load diagram E90 335i with 54B30O0 engine
compared to the F07 535i with 55B30M0 engine
9
N55 Engine

10
N55 Engine
Curre t Models
N54B30O0 e gi e varia ts
* The e ha ced e gi e ma ageme t system of the BMW Z4 sDrive35is a d the 335is i clude
a electro ically co trolled overboost fu ctio to briefly i crease torque u der full load by
a other 37 ft-lbs. This temporary torque peak of 369 ft-lbs gives the car a sig ifica t i crease
i acceleratio for approximately 5 seco ds.
Model Version Series
Displace-
ment in
cm³
Stroke/
bore in
mm
Power
output in
kW/bhp at
rpm
To rq u e i n
Nm at rpm
135i US E82, E88 2979 89.6/84.0 300 SAE h
5800 - 6250
407
(300 ft-lbs)
1400 - 5000
335i US E90, E92,
E93 2979 89.6/84.0 300 SAE h 5800 - 6250
407
(300 ft-lbs)
1400 - 5000
335i xDrive US E90, E92 2979 89.6/84.0 300 SAE h
5800 - 6250
407
(300 ft-lbs)
1400 - 5000
335is US E92, E93 2979 89.6/84.0 320 SAE h
5800 - 6250
450
(332 ft-lbs)
1400 - 5000
Z4 sDrive35i US E89 2979 89.6/84.0 300 SAE h
5800 - 6250
407
(300 ft-lbs)
1400 - 5000
Z4
sDrive35is US E89 2979 89.6/84.0 335 SAE h
5800 - 6250
450
(332/369 ft-lbs)
*1400 - 5000
535i US E60 2979 89.6/84.0 300 SAE h
5800 - 6250
407
(300 ft-lbs)
1400 - 5000
535i xDrive US E60, E61 2979 89.6/84.0 300 SAE h
5800 - 6250
407
(300 ft-lbs)
1400 - 5000
X6 xDrive35i US E71 2979 89.6/84.0 300 SAE h
5800 - 6250
407
(300 ft-lbs)
1400 - 5000
740i US F01, F02 2979 89.6/84.0 315 SAE h
5800 - 6250
450
(330 ft-lbs)
1600 - 4500

11
N55 Engine
Engine Designation and Engine Identification
Engine Designation
This training material describes the N55B30M0 in detail.
In the technical documentation, the engine designation is used for unique identification of
the engine. In the technical documentation you will also find the abbreviated engine des-
ignation, i.e. N55, that only indicates the engine type.
Item Meaning Index / explanation
1Engine developer
M, N = BMW roup
P = BMW Motorsport
S = BMW M mbH
W = Non-BMW engines
2Engine type
1 = R4 (e.g. N12)
4 = R4 (e.g. N43)
5 = R6 (e.g. N55)
6 = V8 (e.g. N63)
7 = V12 (e.g. N73)
8 = V10 (e.g. S85)
3Change to the basic engine concept 0 = basic engine
1 – 9 = changes, e.g. combustion process
4Working method or fuel type and
possibly installation position
B = asoline, longitudinal installation
D = Diesel, longitudinal installation
H = Hydrogen
5Displacement in liters 1 = 1 liter (whole number of liters)
6Displacement in 1/10 liter 8 = 0.8 liter (tenth of liter)
7Performance class
K = Smallest
U = Lower
M = Middle
O = Upper (standard)
T=To p
S = Super
8Revision relevant to approval 0 = New development
1–9=Revision

Breakdown of 55 Engine Designation
Engine Identification
The engines are marked on the crankcase with an engine identification code for unique
identification. This engine identifier is also required for approval by the authorities. The
N55 engine further develops this identification system and the code has been reduced
from previously eight to seven characters. The engine serial number can be found under
the engine identifier on the engine. To g e t h e r with the engine identifier, this consecutive
number enables unique identification of each individual engine.
Index Explanation
NBMW roup Development
5Straight 6 engine
5Engine with direct injection, Valvetronic and exhaust turbocharger
Basoline engine, longitudinal
30 3.0-liter capacity
MMedium performance class
0New development
Item Meaning Index / explanation
1Engine developer
M, N = BMW roup
P = BMW Motorsport
S = BMW M mbH
W = Non-BMW engines
2Engine type
1 = R4 (e.g. N12)
4 = R4 (e.g. N43)
5 = R6 (e.g. N55)
6 = V8 (e.g. N63)
7 = V12 (e.g. N73)
8 = V10 (e.g. S85)
3Change to the basic engine concept 0 = basic engine
1 – 9 = changes, e.g. combustion process
4Working method or fuel type and
possibly installation position
B = asoline, longitudinal installation
D = diesel, longitudinal installation
H = hydrogen
5Displacement in liters 1 = 1 liter (whole number of liters)
6Displacement in 1/10 liter 8 = 0.8 liter (tenth of liter)
7Typ e test concerns (changes that
require a new type test)
A = Standard
B – Z = Depending on requirement, e.g. RON 87
12
N55 Engine

55 engine, engine identification and engine serial number
Index Explanation
08027053 Individual consecutive engine serial number
NEngine developer, BMW roup
5Engine type, straight 6
5Change to basic engine concept, turbocharging, Valvetronic, direct fuel injection
BOperating principle or fuel supply and installation position, petrol engine longitudinal
30 Displacement in 1/10 liter, 3 liter
ATyp e approval requirements, standard
13
N55 Engine

Engine Housing
The engine housing consists of the engine block (crankcase and bedplate), cylinder
head, cylinder head cover, oil pan and gaskets.
Engine Block
The engine block is made from an aluminum die-casting and consists of the crankcase
with bedplate.
Crankcase and Bedplate
The crankcase features cast iron cylinder liners (2). A new feature is that the webs
between two cylinders on the deck of the block now have a grooved cooling passage
(3). Coolant can flow along these grooves from one side of the crankcase to the other,
thus enhancing cooling of this area.
Five oil return ducts on the exhaust side (4) now permit oil to return from the cylinder
head into the oil pan. These oil return channels extend into the bedplate up to below the
oil deflector. They help reduce churning losses as the returning engine oil can no longer
reach the crankshaft even at high transverse acceleration.
Five oil return channels on the intake side (5) also ensure that the blow-by gasses can
flow unobstructed from the crankshaft area into the cylinder head and to the crankcase
breather in the cylinder head cover.
The cooling duct (1) in the engine block is split and coolant flows directly through it.
Engine Components
14
N55 Engine

55, crankcase with web cooling
Index Explanation
1Cooling duct
2Cylinder liner
3rooved cooling passage
4Oil return ducts, exhaust side
5Oil return ducts, intake side
15
N55 Engine

The crankcase has large longitudinal ventilation holes bored between the lower chambers
of the cylinders. The longitudinal ventilation holes improve the pressure equalization,
between the oscillating air columns that are created in the crankcase, by the up and down
movement of the pistons.
This enhances power by relieving the unwanted pressure that acts against the downward
movement of the pistons. It also enhances crankcase ventilation and adds to oil service
life by promoting the movement of blow-by gasses within the engine.
55, ventilation holes in crankcase
16
N55 Engine

Crankshaft
The crankshaft of the N55 is of lightweight design, at 20.3 kg it’s approximately 3 kg
lighter than the crankshaft in the N54 engine.
The crankshaft is made from cast iron ( 70). The counterweights are arranged asym-
metrically. There is no incremental wheel installed on the crankshaft. The timing chains
are mounted by means of an M18 central bolt.
55 Crankshaft
Crankshaft Main Bearings
As on the N54 engine, the main bearings on the crankshaft are designed as two
component bearings free of lead. The thrust bearing is mounted at the fourth bearing
position.
Index Explanation
ACounterweights
1Main bearing journal 7
2Oil hole from big-end bearing to main bearing
3Oil hole from main bearing to big-end bearing
4Big-end bearing journal, cylinder 4
17
N55 Engine

Pistons and Rings
A full slipper skirt type piston with a diameter of 82.5 mm is used. The first piston ring is a
plain rectangular compression ring with a chrome-ceramic coating on the contact surface.
The second piston ring is a tapered faced Napier type ring. The oil scrape ring is
designed as a steel band ring with spring that is also known as VF system.
55 piston with piston rings
Index Explanation
1Plain rectangular compression ring
2Ta p e r e d faced Napier ring
3VF system ring
4Steel inlay for first piston ring
5roove for first piston ring
6roove for second piston ring
7roove for oil scraper ring
8Hole for lubricating oil drain
9raphite coating
18
N55 Engine

Connecting Rod and Bearings
The size of the connecting rod of the N55 engine is 144.35 mm. A new feature is the
specially formed hole in the small end of the connecting rod. This formed hole is
machined wider on the lower edges of the wrist pin bushing/bore. This design evenly
distributes the force acting on the wrist pin over the entire surface of the rod bushing and
reduces the load at the edges, as the piston is forced downward on the power stroke.
55, small end of the connecting rod
Index Explanation
1Bushing
2Connecting rod
19
N55 Engine

The following graphic shows the surface load on a standard connecting rod without the
formed hole. Due to combustion pressure, the force exerted by the piston via the wrist
pin is mainly transmitted to the edges of the rod bushing.
54, connecting rod small end without formed hole
Index Explanation
ALow surface load
BHigh surface load
20
N55 Engine