2. Bharat Stage 6 Introduction - Comparison
of BS 4 and BS 6
Legislative Limits – Diesel Heavy
Duty engines
Stage Test NOx PM CO HC PN
cycle g/kWh Numbers/ Per
kWh
BS4 ETC 3.5 0.03 4 0.55 --
BS6 WHTC 0.46 0.01 4 0.16 600 X 10 11
BS4 ESC 3.5 0.02 1.5 0.46 --
BS6 WHSC 0.40 0.01 1.5 0.13 800 X 10 11
% change from
BS4 to BS6
(Steady state
cycle)
89 % 50 % 0 % 72 %
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3. Introduction to 5L
BS6 engine
• 5L BS4 engine is already in production for ILCV and MHCV trucks manufactured in
Pune, Lucknow and Jamshedpur.
• To meet stringent BS6 emission norms, engine has been upgraded to enhance its performance and emission
capability by suitable hardware and software changes/additions including after treatment system.
• 5L BS6 engine is equipped
with following :
Better thermal management system and in cylinder
combustion capability Better fuel injection system
Closed loop control after
treatment system.
Improved closed loop air
management system
• To enhance value proposition being offered to the customer, following
improvements are done.
Higher low end torque and
peak torque.
Flatter peak
torques
Higher oil change
intervals
Improved software capabilities
including diagnostics.
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4. Specifications / Comparison with
BS4 engine
• 5L BS6 engine Power and torque
specifications
Power rating Max Torque Lead vehicle Applications
180 Ps@2200
rpm
590 Nm@ 1000 to
2000 rpm 700 Nm
@ 1000 to 1700
rpm
Ultra 1518 Truck , LP / LPO 1618
Bus
Ultra 1918, LPT 1918 Cowl
200 Ps@2200
rpm
850 Nm @ 1100 to
1600 rpm
2820.T /3520.T Signa Truck
• 5L BS6 engine Performance comparison
with BS4 engine
Power
rating
BS4 Engine BS6 engine Improvements over
BS4
Max
torque
590 Nm @ 1000 to
2000 rpm
804 Nm @ 1350 to
1800 rpm
590 Nm@ 1000 to
2000 rpm 700 Nm
@ 1000 to 1700
rpm 850 Nm @
1100 to 1600 rpm
Higher torques
Enhanced flat torque
speed range
180 Ps @ Rated engine speed
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5. pressures
• Improved strength for
compatible to
2000
bar
Changes in
Aggregate
BS 4 BS 6 Reason for change
Fuel Pump Assembly
Pump/Rail -
Suitable for
1800-2000 bar)
Pump/ Rail - Suitable
for 2000+ bar (with
TPTF function)
• Required for BS6
compliance
• Finer atomization with
increased
Injector Assembly Solenoid operated
Solenoid operated
(With structural
improvements)
Common Rail Assembly 2000 bar (DFR 4.2) 2000 bar (DFR 4.2)
Turbocharger Pneumatic WG Electronic WG For better transient
performance
Exhaust Throttle Valve Exhaust Brake assy. Electronic ETV For better thermal
management and after
treatment system
performance
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6. 5L BS6 Engine
changes
Changes in
Aggregate
BS 4 BS 6 Reason for change
Piston
Combustion bowl: Re-
entrant toroidal type
(gallery
and non gallery
cooled)
Combustion bowl: Re-
entrant
toroidal type
(gallery cooled
only) with change
in bowl geometry
Bowl geometry optimized
to achieve better
combustion
characteristics
Main bearing lower A 370 material A 280 material Higher unit load carrying
capability
EGR valve Light duty Medium duty Better robustness and life
EGR temperature
sensor
Not present
Present (fitted on EGR
pipe- cold side)
For EGR temperature
measurement to provide
closed loop EGR control
Air Temperature
sensor and Not present Present (fitted in air
intake system and
For closed loop air
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7. Changes in
Aggregate
BS 4 BS 6 Reason for change
After treatment
system
sensors
DP sensor
DP sensor + Exhaust
gas temperatures
sensors (3 Nos-
T4/T5/T6)+ NOx
sensors ( 2 nos)
For closed loop control
After treatment
system
DOC +DPF (non
catalyzed)
DOC +
DPF(catalyzed) +
Urea mixer with
injector + SCR
Stringent BS6 emissions
Urea supply and
dosing
module Not present Present
To supply and dose urea in
mixer before SCR
Engine oil 15W 40 CI4+ 15W40 CK4 (Low Ash BS
VI)
Low ash content
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9. 5L BS6 Engine
changes
New injectors with low
back leak
Fuel pump with TPTF
function
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10. 5L BS6 Engine
changes
- Casting and machining Modifications in
cylinder head, bedplate, flywheel
housing and intake manifold
- Piston
change
c
- New 25L Oil sump (For
MHCV vehicles)
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11. 5 lit FIE Improvements from BS
IV to BS VI
0
1
0
4
0
2
0
3
S.
No
Part BS4
Improvement in BS6
Image Details
1
Injector
Quill
Edge
Filter
Prevents large external
contamination
to enter injectors that
causes valve seat wear,
orifice wear, avoid injector
valve
stuck open/ close
2 Injector
Control Valve
assembly
Sleeve Valve assembly
Sleeve valve assembly has
a sleeve to maintain
reduced back leak at
higher pressures.
Valve assembly has double
stem cone angle
preventing erosion points
and increasing contact
point for seat.
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12. 5L BS6 Engine
changes
Cooling and Air intake
systems
Ultra
1518
2820.T
Signa
Air Temperature
sensor
Smart core
radiators
with better heat
dissipation
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13. Major Changes for BS 6
on Vehicle
Engine Exhaust system
Electrical units
Electro
nic
interfac
es
Cabin
assembly
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15. Bharat Stage 4 or BS
4
Bharat Stage 6 or BS
6
DOC + DPF +
Silencer
Exhaust Gas Processor
(EGP)
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16. Exhaust After
Treatment
Top view showing Urea storage,
supply & Dosing system layout
After treatment system layout
on vehicle
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17. Exhaust After
Treatment
Major Subassemblies of exhaust after
treatment system
Diesel Oxidation
catalyst
Diesel Particulate
filter Urea
Injector
(Water
cooled)
fitted on
mixer
c
Selective catalyst
reduction (SCR) Copyright,
24. Exhaust After treatment system: Selective
Catalytic Reduction (SCR)
After treatment
components
Diesel
Oxidation
Catalyst
Diesel
Particula
te
Filters
(DPF)
Urea
Tank
Selective
Catalytic
Reduction
(SCR)
Ammoni
a
oxidatio
n
catalyst
(AMOx)
4NO + 4NH3
+ O2
zeoli
te
2N
2
+
3H
2O Reduces NOX to molecular
nitrogen using Urea
(Efficiency 90%)
Urea Hydrolysis
Catalyst
SCR Catalyst Ammonia Oxidation
Catalyst
(NH2)2CO + H2O → CO2 +
2NH3
300°C
4NO + 4NH3 + O2 → 4N2
+ 6H2O
4NH3 + 3O2 → 2N2 +
6H2O
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25. EGP has to be lifted only with given
lifting hooks
Storage and
Handling Care
Remove protection caps only before
sensor assembly
Handle it carefully, as inside ceramic
substrate may get damage
Only 6 EGP (3 rows in 2 columns) are
recommended in single trolley for
transportation
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26. Exhaust After treatment system: Sensors
and Functions
Senso
r 6 Senso
r 5
Senso
r 2
Senso
r 1
Senso
r 3
Senso
r 4
NOx
Sensors
2 Nos: 1
&2
Temperat
ureSensors
3 Nos: 3,4
and 5
Pressure
Sensor
1 No:
6
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27. Downstream NOx
sensor
Senses NOx value of
exhaust gases releasing
to environment
Upstream NOx
sensor
Senses NOx value of
exhaust gases from
engine before
entering to
After Treatment Sensors and
Functions
Senso
r 6 Senso
r 5
Upstream
NOx
sens
or
Downstre
am
NOx
sensor
Senso
r 3
Senso
r 4
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28. T5 - Exhaust
gas
temperature
sensor
Senses
temperature of
exhaust gases
5 - Exhaust
gas
temperature
sensor
Senses
temperature of
exhaust gases
T4 - Exhaust
gas
temperature
sensor
Senses
temperature
of exhaust gases
After Treatment Sensors and
Functions
Senso
r 6
T6 - Exhaust
gas
temperat
ure
sens
or
Downstream
NOxsens
or
Upstream
NOx
sens
or
T4 - Exhaust
gas
temperat
ure
sens
or
T5 - Exhaust
gas
temperat
ure
sens
or
T
4
c
T5 and
T6
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29. DP1 – Inlet pressure
sensor
Senses pressure of
inlet gases
flowing to DPF
DP2 – Outlet pressure
sensor
Senses pressure of
outlet gases flowing
from DPF to mixer
After Treatment Sensors and
Functions
DP
Sensor
T6 - Exhaust
gas
temperat
ure
sens
or
Downstream
NOxsens
or
Upstream
NOx
sens
or
T4 - Exhaust
gas
temperature
sensor
T5 - Exhaust
gas
temperature
sensor
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30. Protection Strategies: DPF
regeneration
• Soot mass based: Regeneration event is triggered on accumulation of 30 grams of soot
based on mathematical model to estimate soot mass accumulated depending upon
engine / vehicle duty cycle.
• Time Based: Currently it is kept as 50 hrs interval and subjected to
increase, based on feedback.
• DP sensor
based :
Based on threshold calibration, indication is given to driver to switch on manually
regeneration (DP sensor lamp ‘ON’ on dashboard).
If driver fails do so, vehicle will go to limp home mode (MIL lamp) and the driver
has to visit TASS to initiate DPF regeneration through diagnostic tool.
The first (soot mass based) is primary strategy and the rest two
are back up strategies.
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31. Protection Strategies: Other
components
• Urea Supply (pump) and Doser
(injector) Unit:
Purging strategy after engine shut down with siphon design in DEF lines to prevent Urea
accumulation in Dosing / supply modules
Wire mesh filters at supply module inlet / return connectors and main DEF filter in supply module.
Wire mesh filters in Urea tank also present.
Overvoltage protection and reverse polarity protection provided by Dosing control unit. In addition
short circuit protection is provided for RVV
Air less (Liquid only) dosing system which ensures no direct contact between DEF and air
thereby eliminating possibility of water vaporization and Urea crystallization.
DEF is injected through nozzles with 6 to 9 bar pressure with no contact with air (i.e. air less system).
This eliminates possibility of injector nozzle clogging due to either crystallization or contamination.
Other protection strategy is place to ensure injector nozzle tip cooling such as injecting certain
quantity of DEF for cooling during events such as DPF regeneration.
Water cooled urea injector ensures Injector tip temperatures
within specified limits.
IPX6K and IPX9K water protection class for Supply
module and dosing module
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32. Protection Strategies: Other
components
• NOx
sensor:
Dew point setting and calibration is done based on enthalpy instead of Hence there is sufficient
time for heater to vaporize the water before it starts sensing.
Other features such as drain hole provided in design to
prevent water accumulation.
In built protection for short circuit and
low/ high voltage
Circuit related fault codes in
case of failure
Sensors fault monitoring and OBD monitoring by OBD monitors calibrated and certified for
components failure and deterioration in performance
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