BMW N73B60 Workbook
Subject Page
N73B60 Engine
Objectives of the Module........................................................................2
Purpose of the System............................................................................3
Technical Data........................................................................................ 4
Disassembly - Components
Intake Manifold....................................................................................... 6
Cylinder Head Cover...............................................................................8
Ancillary Components and Drive Belts.................................................... 9
Cylinder Heads......................................................................................10
Valvetronic.............................................................................................11
Fuel Injectors.........................................................................................14
Lubrication Components.......................................................................15
Crankshaft and Bearings.......................................................................17
Pistons and Connecting Rods...............................................................17
Crankcase.............................................................................................19
Lubrication System................................................................................19
Cooling System.....................................................................................21
Table of Contents
N73B60 Engine - Workbook
2
N73B60 Engine - Diagnosis
N73B60 Engine
Model: E66 - 760Li
Production: MY 2003
This intent of this workbook is to assist you with key components for disassembly/reassembly in addition to the detailed information found in the Repair Instructions, Technical Data
and Tightening Torques from the latest TIS information.
This section will be instructor led for a brief review of the N73 engine. You are encouraged
to use this workbook with the latest TIS information to make notes during disassembly/
reassembly of the engine. This will be valuable to you as supplementary information or a
memory refresher when performing repairs in the future.
NNoottee::
For more in depth and detailed information about the N73 engine, refer to the ST047
2003 Systems Diagnosis training manual.
For additional and updated information, always refer to:
www.bmwcenternet.com
- TIS information/updates
- Service Information Bulletins
- DCS messages
Objectives:
After completion of this module you will be able to:
• Disassemble the N73 engine.
• Perform critical measurements and observations to determine engine condition.
• Correctly reassemble (including valve gear timing) the N73 engine.
3
N73B60 Engine - Diagnosis
N73B60 Engine
Purpose of the System
The N73 engine is a complete new BMW development from the NG Series (New
Generation) as a B60 (6 liter). The N73B60 will be used in the E66 as a 760Li (USA).
The BMW 760Li will set new standards in terms of performance and driving dynamics in
the 12-cylinder market segment as well as significantly reduce fuel consumption.
For the first time at BMW, Valvetronic technology (combination of Bi-VANOS and variable
intake valve lift) is supplemented by direct injection (DI).
In addition, the N73 cylinder heads use 4 valve technology.
The combination of these cutting edge technologies provides low fuel consumption and
maximum power output and torque, making the N73 the best engine in its class.
KT-9765
4
N73B60 Engine - Diagnosis
Technical Data
Technical Data Comparison N73B60 M73B54
V-angle configuration 12 cyl. V / 60º 12 cyl. V / 60º
Displacement (cm 3) 5972 5379
Bore / Stroke (mm) 89 / 80 79 / 85
Cylinder spacing (mm) 98 91
Crankshaft main bearing diam. (mm) 70 75
Conrod big end diam. (mm) 54 48
Power output (kW/HP)
at engine speed (rpm)
320 / 438
6000
240 / 326
5000
Torque (Nm)
at engine speed (rpm)
600
3950
490
3900
Idle speed (rpm)
Maximum engine speed (rpm)
550
6500
600
6500
Compression ratio 11.3 : 1 10 : 1
Valves per cylinder 4 2
Intake valve diam. (mm) 35 42
Exhaust valve diam. (mm) 29 36
Intake valve lift (mm) 0.3 - 9.85 10.3
Exhaust valve lift (mm) 9.7 10.3
Engine weight (kg) 280 -
Fuel requirement Premium unleaded Premium unleaded
Knock control Ye s Ye s
Injection pressure (bar) 50 - 120 3.5
Digital Motor Electronics (ECM) 2x MED 9.2.1 & Valvetronic ECU
with 2x HDEV ECU
2x ME 5.2 & EML IIIs
Emission compliance level LEV LEV
Firing order 1-7-5-11-3-9-6-12-2-8-4-10 1-7-5-11-3-9-6-12-2-8-4-10
Fuel consumption savings compared
with M73
12 % -
Maxmimum regulated vehicle speed
(km/h / mph)
250 / 155 250 / 155
5
N73B60 Engine - Diagnosis
Power and Torque Output - N73B60 / M73B54
N73B60
M73B54
Engine RPM
6
N73B60 Engine - Diagnosis
Intake Manifold
The intake system is a complete component constructed of magnesium in a shell type
design and has separate manifold chambers for each cylinder bank.
1. Intake manifold pressure sensors
2. Captured gaskets
3. Pressure control valves for crankcase
ventilation
4. Throttle valves
The individual parts of the intake system are bonded and bolted to each other, providing
considerable weight reduction (separating the shell halves is not permitted).
The entire intake system is protected against corrosion by a dip coating procedure. The
fastening bolts of the add on parts are also coated and must be replaced in the event of
damage, to prevent corrosion and pitting.
All of the gaskets (2) are secured by retainers (captured) to provide ease of installation. The
intake system is isolated from the engine by rubber elements on the fastening bolts.
An intake manifold pressure sensor (1) is used for each cylinder bank. Recording the manifold differential pressure is necessary for the correct throttle position (synchronization) so
that a manifold differential pressure of 50 mbar can be balanced on each bank.
Both sides of the induction system are fitted with a pressure control valve (3) for crankcase
ventilation which is distributed to both banks.
NNoottee::
When replacing the spark plugs, it is necessary to remove the entire intake system to
avoid damaging the spark plugs during installation. The spark plugs must be replaced
every 100,000 miles in US vehicles.
KT-9589
7
N73B60 Engine - Diagnosis
Intake Manifold - Removal
Top Diagram
• Remove plug connections on the throttle
assemblies (1).
• Detach engine vent hoses from pressure control valves (2).
• Detach oustide braces for intake manifold
(3 L/R).
Lower Diagram
• Remove plug connections on the intake manifold pressure sensors (1 L/R).
• Remove bolts (2) along sections (3).
• Lift intake manifold up to remove.
Questions
HHooww mmaannyy aattttaacchhiinngg bboollttss aarree tthheerree??
WWhhaatt iiss tthhee ttiigghhtteenniinngg ttoorrqquuee?? NNmm
HHooww aarree tthhee iinnttaakkee mmaanniiffoolldd ggaasskkeettss hheelldd iinn ppllaaccee??
CCaann tthhee ggaasskkeettss bbee rreeuusseedd??
NNootteess::
001
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