Electronically controlled gasoline injection systems provide more precise fuel delivery compared to carbureted systems. They allow for stratified fuel charge combustion for improved efficiency and reduced emissions. Common types include multi-point port injection and direct injection into the combustion chamber. While carbureted systems struggle with uneven fuel distribution among cylinders and icing, fuel injection systems inject exact amounts of fuel directly into each cylinder port or combustion chamber for uniform air-fuel ratios.

1.
UNIT II ENGINE AUXILIARY SYSTEMS
UNIT II ENGINE AUXILIARY SYSTEMS
Syllabus
Syllabus
Ele
Electr
ctroni
onical
cally
ly cont
control
rolled
led gaso
gasolin
line
e inj
inject
ection
ion sys
system
tem for
for SI
SI engi
engines,
nes, Ele
Electr
ctroni
onical
cally
ly
con
contr
trol
olle
led
d di
dies
esel
el in
inje
jecti
ction
on sy
syste
stem
m (U
(Uni
nit
t in
inje
ject
ctor
or sy
syste
stem,
m, Ro
Rota
tary
ry di
dist
stri
ribu
buto
tor
r ty
type
pe an
and
d
com
common
mon rail
rail dir
direct
ect inj
inject
ection
ion sys
system
tem),
), Ele
Electr
ctroni
onic
c ign
igniti
ition
on syst
system
em (Tra
(Transi
nsistor
storize
ized
d coi
coil
l
ign
ignit
ition
ion syst
system
em,
, cap
capaci
acitiv
tive
e disc
discharg
harge
e ign
igniti
ition
on sys
system
tem),
), Turb
Turbo
o cha
charge
rgers
rs (WG
(WGT,
T, VGT
VGT),
),
Engine emission control by three way catalytic converter system, Emission norms (Euro
Engine emission control by three way catalytic converter system, Emission norms (Euro
and BS).
and BS).
Electronically controlled gasoline injection system for SI engines
Electronically controlled gasoline injection system for SI engines
CARBURETION
CARBURETION
Introduction
Introduction
Spark-i
Spark-igniti
gnition
on engine
engines
s normal
normally
ly use
use volati
volatile liquid
le liquid fuels. Preparati
fuels. Preparation
on of
of fuel-ai
fuel-air
r mixtu
mixture
re is
is
done outside the engine cylinder and formation of a homogeneous mixture is normally not
done outside the engine cylinder and formation of a homogeneous mixture is normally not
com
comple
plete
ted
d in
in th
the
e in
inle
let
t ma
manif
nifol
old.
d. Fu
Fuel
el dro
dropl
plet
ets,
s, wh
whic
ich
h rem
remai
ain
n in
in sus
suspe
pensi
nsion
on,
, co
cont
ntin
inue
ue to
to
evaporate and mix with air even during suction and compression processes. The process of
evaporate and mix with air even during suction and compression processes. The process of
mi
mixt
xture
ure pre
prepar
parat
atio
ion
n is
is ext
extrem
remel
ely
y im
impor
porta
tant
nt for
for sp
spark
ark-i
-igni
gniti
tion
on eng
engin
ines
es.
. Th
The
e pur
purpos
pose
e of
of
carburetion is to provide a combustible mixture of fuel and air in the required quantity and
carburetion is to provide a combustible mixture of fuel and air in the required quantity and
quali
quality for
ty for effici
efficient operation of
ent operation of the engine
the engine under all
under all condi
conditions.
tions.
Definition of Carburetion
Definition of Carburetion
The process of formation of a combustible fuel-air mixture by mixing the proper amount
The process of formation of a combustible fuel-air mixture by mixing the proper amount
of fuel with air before admission to engine cylinder is called carburetion and the device which
of fuel with air before admission to engine cylinder is called carburetion and the device which
does this job is called a carburetor.
does this job is called a carburetor.
The Simple
The Simple Carbur
Carburetor
etor
Carburetors are highly complex. Let us first understand the working principle bf a simple
Carburetors are highly complex. Let us first understand the working principle bf a simple
or elementary carburetor that provides an air fuel mixture for cruising or normal range at a
or elementary carburetor that provides an air fuel mixture for cruising or normal range at a
single speed. Later, other mechanisms to provide for the various special requirements like
single speed. Later, other mechanisms to provide for the various special requirements like
starting, idling, variable load and speed operation and acceleration will be included.
starting, idling, variable load and speed operation and acceleration will be included.

2.
Types of Carburetors
Types of Carburetors
Constant Choke Carburetor:
Constant Choke Carburetor:
In the constant choke carburetor, the air and fuel flow areas are always maintained to be
In the constant choke carburetor, the air and fuel flow areas are always maintained to be
constant. But the pressure difference or depression, which causes the flow of fuel and air, is
constant. But the pressure difference or depression, which causes the flow of fuel and air, is
being
being varied
varied as
as per
per the
the demand
demand on
on the
the engine.
engine. Solex
Solex and
and Zenith
Zenith carburetors
carburetors belong
belong to
to this
this
class.
class.
Constant Vacuum Carburetor:
Constant Vacuum Carburetor:
In the
In the consta
constant vacuum carburetor, (sometim
nt vacuum carburetor, (sometimes
es called variabl
called variable
e choke carbureto
choke carburetor)
r) air and
air and
fuel flow areas are being varied as per the demand on the engine, while the vacuum is
fuel flow areas are being varied as per the demand on the engine, while the vacuum is
maintained to be always same. The
maintained to be always same. The S.U. and Carter carburetors
S.U. and Carter carburetors belong to tills class.
belong to tills class.

3.
Multiple Venturi Carburetor:
Multiple Venturi Carburetor:
Mu
Mult
ltip
iple
le ven
ventu
turi
ri sy
syste
stem
m us
uses
es dou
doubl
ble
e or
or tr
trip
iple
le ven
ventu
turi
ri.
. Th
The
e boo
boost
st ven
ventu
turi
ri is
is lo
loca
cate
ted
d
concentrically within the main venturi.The discharge edge of the boost venturi is located at
concentrically within the main venturi.The discharge edge of the boost venturi is located at
the throat of the main venturi. The boost venturi is positioned upstream of the throat of the
the throat of the main venturi. The boost venturi is positioned upstream of the throat of the
larger main venturi. Only a fraction of the total air flows though the boost venturi.
larger main venturi. Only a fraction of the total air flows though the boost venturi.
Now
Now the
the pressure
pressure at
at the
the boost
boost venturi
venturi exit
exit equals
equals the
the pressure
pressure at
at the
the main
main venturi
venturi throat.
throat. The
The
fuel nozzle is located at the throat of the boost venturi.
fuel nozzle is located at the throat of the boost venturi.
GASOLINE INJECTION AND IGNITION SYSTEM
GASOLINE INJECTION AND IGNITION SYSTEM
Introduction
Introduction
In
In in
inte
terna
rnal
l co
comb
mbust
ustio
ion
n eng
engin
ines
es,
, gas
gasol
olin
ine
e di
dire
rect
ct in
inje
ject
ctio
ion
n (G
(GDI
DI),
), is
is a
a var
varia
iant
nt of
of fue
fuel
l
injection employed in modern two-stroke and four-stroke gasoline engines. The gasoline is
injection employed in modern two-stroke and four-stroke gasoline engines. The gasoline is
hi
highl
ghly
y pre
pressu
ssuri
rize
zed
d in
in a
a co
comm
mmon
on rai
rail
l fu
fuel
el li
line
ne and
and in
inje
ject
ctor
ors
s in
inje
ject
cts
s fue
fuel
l di
direc
rectl
tly
y in
into
to th
the
e
combustion chamber of each cylinder.It is opposed to conventional multi-point fuel injection
combustion chamber of each cylinder.It is opposed to conventional multi-point fuel injection
which injects fuel to the intake manifold. Gasoline direct injection enables a stratified fuel
which injects fuel to the intake manifold. Gasoline direct injection enables a stratified fuel
charge (ultra lean burn) combustion for improved fuel efficiency, and reduced emission levels
charge (ultra lean burn) combustion for improved fuel efficiency, and reduced emission levels
at low load.
at low load.
TRANSITION OF FUEL SUPPLY SYSTEM
TRANSITION OF FUEL SUPPLY SYSTEM
The transition of the fuel supply system used in automobiles is graphically shown below.
The transition of the fuel supply system used in automobiles is graphically shown below.
In carburetor the fuel from the fuel chamber is sucked in by the pressure variation caused due
In carburetor the fuel from the fuel chamber is sucked in by the pressure variation caused due
to the incoming air. The fuel then mixes with the air and reaches the cylinder through the inlet
to the incoming air. The fuel then mixes with the air and reaches the cylinder through the inlet
manifold. Where as in a port injection system the fuel to the cylinder is supplied by a separate
manifold. Where as in a port injection system the fuel to the cylinder is supplied by a separate
fuel injector placed near the inlet valve of the cylinder. And in a direct injection system the
fuel injector placed near the inlet valve of the cylinder. And in a direct injection system the
fuel to the cylinder is supplied by a fuel injector placed inside the cylinder.
fuel to the cylinder is supplied by a fuel injector placed inside the cylinder.

4.
OPERATING DIFFICULTIES FOR A CARBURETOR.
OPERATING DIFFICULTIES FOR A CARBURETOR.
Some problems associat
Some problems associated with
ed with comfor
comfortable running of
table running of the carburetor are
the carburetor are discus
discussed here.
sed here.
1. Ice formation:
1. Ice formation: The vaporisation of the fuel injected in the current of the air requires latent
The vaporisation of the fuel injected in the current of the air requires latent
heat and the taken mainly from the incoming air. As a result of this, the temperature of the air
heat and the taken mainly from the incoming air. As a result of this, the temperature of the air
drops below the dew point of the water vapour in the air and it condenses and many times
drops below the dew point of the water vapour in the air and it condenses and many times
freeze into ice if the temperature falls below dew point temperature.
freeze into ice if the temperature falls below dew point temperature.
2. Vapour Lock:
2. Vapour Lock: The improved volatility of modern fuels and the necessity of providing heat
The improved volatility of modern fuels and the necessity of providing heat
to prevent the ice formation, has created carburetion difficulties due to vaporisation of fuel in
to prevent the ice formation, has created carburetion difficulties due to vaporisation of fuel in
pipes
pipes and
and float
float chamber.
chamber. The
The heating
heating may
may also
also occur
occur due
due to
to petrol
petrol pipes
pipes being
being near
near the
the engine.
engine.
If the fuel supply is large and supply is small, a high velocity will result causing high vacuum.
If the fuel supply is large and supply is small, a high velocity will result causing high vacuum.
This causes considerable drop which may also cause the formation of vapour bubbles. If these
This causes considerable drop which may also cause the formation of vapour bubbles. If these
bubbles
bubbles formed
formed accumulate
accumulate at
at the
the tube
tube bend,
bend, then
then they
they may
may interrupt
interrupt the
the fuel
fuel flow
flow from
from the
the
tank or the fuel pump and engine will stop because of lack of fuel. Vapour lock is formed
tank or the fuel pump and engine will stop because of lack of fuel. Vapour lock is formed
because
because of
of rapid
rapid bubbling
bubbling of
of fuel
fuel and
and usually
usually happens
happens in
in hot
hot summer.
summer.
3. Back Firing:
3. Back Firing: During the starting of an engine under cold working conditions, the usual
During the starting of an engine under cold working conditions, the usual
manipulation of the choke varies the mixture from too lean to too rich. A very lean mixture
manipulation of the choke varies the mixture from too lean to too rich. A very lean mixture
will burn very slowly and the flame may still exist in cylinder when the exhaust valve is about
will burn very slowly and the flame may still exist in cylinder when the exhaust valve is about
to open. The fresh charge in the intake manifold is about to open. The fresh charge in the
to open. The fresh charge in the intake manifold is about to open. The fresh charge in the
intake manifold is not so diluted as when inducted into the cylinder and mixed with the
intake manifold is not so diluted as when inducted into the cylinder and mixed with the
clearance gases and consequently burn more rapidly than the charge in the cylinder. If lean
clearance gases and consequently burn more rapidly than the charge in the cylinder. If lean
charge comes in contact with flames existing in the cylinder, there will be flash of flame back
charge comes in contact with flames existing in the cylinder, there will be flash of flame back
through the intake manifold, burning the charge therein and causing the customary back firing
through the intake manifold, burning the charge therein and causing the customary back firing
in the carburetor.
in the carburetor.
ADVANTAGES OF FUEL INJECTION OVER CARBURETOR
ADVANTAGES OF FUEL INJECTION OVER CARBURETOR
The fuel injection eliminates several intake manifold distribution problems. One of the
The fuel injection eliminates several intake manifold distribution problems. One of the
most difficult problems in a carbureted system is to get the same amount and richness of
most difficult problems in a carbureted system is to get the same amount and richness of
air-fuel mixture to each cylinder. The problem is that the intake manifold acts as a storing
air-fuel mixture to each cylinder. The problem is that the intake manifold acts as a storing
device, sending a richer air fuel mixture to the end cylinders. The air flows readily around the
device, sending a richer air fuel mixture to the end cylinders. The air flows readily around the

5.
corners and through various shaped passages. However the fuel, because it is heavier is unable
corners and through various shaped passages. However the fuel, because it is heavier is unable
to travel as easily around the bends in the intake manifold. As a result, some of fuel particles
to travel as easily around the bends in the intake manifold. As a result, some of fuel particles
continue to move to the end of the intake manifold, accumulating there. This enriches the
continue to move to the end of the intake manifold, accumulating there. This enriches the
mixture going the end cylinder. The center cylinder closest to the carburetor gets the leanest
mixture going the end cylinder. The center cylinder closest to the carburetor gets the leanest
mixture. The port injection solves this problem because the same amount of fuel is injected at
mixture. The port injection solves this problem because the same amount of fuel is injected at
each intake valve port. Each cylinder gets the same amount of air-fuel mixture of the same
each intake valve port. Each cylinder gets the same amount of air-fuel mixture of the same
mixture richness.
mixture richness.
Another advantage of the fuel injection system is that the intake manifold can be designed
Another advantage of the fuel injection system is that the intake manifold can be designed
for the most efficient flow of air only. It does not have to handle fuel. Also, because only a
for the most efficient flow of air only. It does not have to handle fuel. Also, because only a
throttle body is used, instead of a complete carburetor.
throttle body is used, instead of a complete carburetor.
With fuel injection, fuel mixture requires no extra heating during warm up. No manifold
With fuel injection, fuel mixture requires no extra heating during warm up. No manifold
heat control valve or heated air system is required. Throttle response is faster because the fuel
heat control valve or heated air system is required. Throttle response is faster because the fuel
is
is un
unde
der
r pre
pressu
ssure
re at
at th
the
e in
inje
ject
ctio
ion
n va
valv
lves
es at
at al
all
l ti
time
mes.
s. An
An el
elec
ectr
tric
ic fue
fuel
l pu
pump
mp su
supp
ppli
lies
es th
the
e
pressure.
pressure. The
The carburetor
carburetor will
will depend
depend on
on differences
differences in
in air
air pressure
pressure as
as the
the force
force that
that causes
causes the
the
fuel to feed into the air passing through.
fuel to feed into the air passing through.
Fu
Fuel
el in
inje
ject
ctio
ion
n ha
has
s no
no ch
choke
oke,
, bu
but
t spr
spray
ays
s at
atom
omiz
ized
ed fue
fuel
l di
direc
rectl
tly
y in
into
to th
the
e en
engi
gine
ne.
. Thi
This
s
eliminates most of the cold start problems associated with carburetors.
eliminates most of the cold start problems associated with carburetors.
Ele
Electr
ctroni
onic
c fuel
fuel inj
inject
ection
ion als
also
o int
integra
egrates
tes mor
more
e eas
easily
ily wit
with
h com
comput
puteri
erized
zed eng
engine
ine cont
control
rol
systems because the injectors are more easily controlled than a mechanical carburetor with
systems because the injectors are more easily controlled than a mechanical carburetor with
electronic add-ons.
electronic add-ons.
Multi port fuel injection (where each cylinder has its own injector) delivers a more evenly
Multi port fuel injection (where each cylinder has its own injector) delivers a more evenly
distributed mixture of air and fuel to each of the engine's cylinders, which improves power
distributed mixture of air and fuel to each of the engine's cylinders, which improves power
and performance.
and performance.

6.
ELECTRONIC FUEL INJECTION
ELECTRONIC FUEL INJECTION
Engine Sensors: In order to provide the correct amount of fuel for every operating condition,
Engine Sensors: In order to provide the correct amount of fuel for every operating condition,
the engine control unit (ECU) has to monitor a huge number of input sensors.
the engine control unit (ECU) has to monitor a huge number of input sensors.
Various Sensors used in a GDI system
Various Sensors used in a GDI system
Mass airflow sensor
Mass airflow sensor -
- Tells the ECU the mass of air entering the engine
Tells the ECU the mass of air entering the engine
Oxygen sensor - The device measures the amount of oxygen in the exhaust gas and sends
Oxygen sensor - The device measures the amount of oxygen in the exhaust gas and sends
this information to the electronic control unit. If there is too much oxygen, the mixture is too
this information to the electronic control unit. If there is too much oxygen, the mixture is too
lean. If there is too little, the mixture is too rich. In either case, the electronic control unit
lean. If there is too little, the mixture is too rich. In either case, the electronic control unit
adjusts the air fuel ratio by changing the fuel injected. It is usually used with closed loop
adjusts the air fuel ratio by changing the fuel injected. It is usually used with closed loop
mode of the ECU.
mode of the ECU.
Thr
Throttl
ottle
e pos
positio
ition
n sens
sensor
or -
- Monitors the throttle valve position (which determines how
Monitors the throttle valve position (which determines how
much air goes into the engine) so the ECU can respond quickly to changes, increasing or
much air goes into the engine) so the ECU can respond quickly to changes, increasing or
decreasing the fuel rate as necessary
decreasing the fuel rate as necessary
Coolant temperature sensor -
Coolant temperature sensor - Allows the ECU to determine when the engine has reached
Allows the ECU to determine when the engine has reached
its proper operating temperature
its proper operating temperature
Voltage sensor -
Voltage sensor - Monitors the system voltage in the car so the ECU can raise the idle
Monitors the system voltage in the car so the ECU can raise the idle
speed if voltage is dropping (which would indicate a high electrical load)
speed if voltage is dropping (which would indicate a high electrical load)
Manifo
Manifold
ld absolute
absolute pressure
pressure sensor
sensor -
- Mo
Moni
nito
tors
rs th
the
e pr
pres
essu
sure
re of
of th
the
e ai
air
r in
in th
the
e in
inta
take
ke
manifold. The amount of air being drawn into the engine is a good indication of how much
manifold. The amount of air being drawn into the engine is a good indication of how much

7.
power
power it
it is
is producing;
producing; and
and the
the more
more air
air that
that goes
goes into
into the
the engine,
engine, the
the lower
lower the
the manifold
manifold
pressure,
pressure, so
so this
this reading
reading is
is used
used to
to gauge
gauge how
how much
much power
power is
is being
being produced.
produced.
Engine
Engine speed
speed sensor
sensor -
- Mo
Moni
nito
tors
rs en
engi
gine
ne sp
spee
eed,
d, wh
whic
ich
h is
is on
one
e of
of th
the
e fa
fact
ctor
ors
s us
used
ed to
to
calculate the pulse width.
calculate the pulse width.
Crank Angle sensor -
Crank Angle sensor - Monitors the position of the piston and gives the information to the
Monitors the position of the piston and gives the information to the
ECU. Accordingly the ECU adjusts the valve timing.
ECU. Accordingly the ECU adjusts the valve timing.
Fuel Injectors:
Fuel Injectors:
The solenoid-operated fuel injector is shown in the figure above. It consists of a valve
The solenoid-operated fuel injector is shown in the figure above. It consists of a valve
body
body and
and needle
needle valve
valve to
to which
which the
the solenoid
solenoid plunger
plunger is
is rigidly
rigidly attached.
attached. The
The fuel
fuel is
is supplied
supplied
to the injector under pressure from the electric fuel pump passing through the filter. The
to the injector under pressure from the electric fuel pump passing through the filter. The
needle valve is pressed against a seat in the valve body by a helical spring to keep it closed
needle valve is pressed against a seat in the valve body by a helical spring to keep it closed
until the solenoid winding is energized. When the current pulse is received from the electronic
until the solenoid winding is energized. When the current pulse is received from the electronic
control unit, a magnetic field builds up in the solenoid which attracts a plunger and lifts the
control unit, a magnetic field builds up in the solenoid which attracts a plunger and lifts the
needle valve from its seat. This opens the path to pressurised fuel to emerge as a finely
needle valve from its seat. This opens the path to pressurised fuel to emerge as a finely
atomised spray.
atomised spray.

8.
ELECTRONIC FUEL INJECTION
ELECTRONIC FUEL INJECTION
There are two types of electronic fuel injection. They are,
There are two types of electronic fuel injection. They are,
1. Multipoint Fuel Injection (MPFI)
1. Multipoint Fuel Injection (MPFI)
2. Gasoline Direct Injection (GDI)
2. Gasoline Direct Injection (GDI)
MULTI POINT FUEL INJECTION (MPFI)
MULTI POINT FUEL INJECTION (MPFI)
Engines with multi port injection have a separate fuel injector for each cylinder, mounted
Engines with multi port injection have a separate fuel injector for each cylinder, mounted
in the intake manifold or head just above the intake port.
in the intake manifold or head just above the intake port.
Thus, a four-cylinder engine would have four injectors, a V6 would have six injectors and
Thus, a four-cylinder engine would have four injectors, a V6 would have six injectors and
a V8 would have eight injectors. Multi port injection systems are more expensive because of
a V8 would have eight injectors. Multi port injection systems are more expensive because of
the added number of injectors. But having a separate injector for each cylinder makes a big
the added number of injectors. But having a separate injector for each cylinder makes a big
difference in performance. The same engine with multi port injection will typically produce
difference in performance. The same engine with multi port injection will typically produce
10 to 40 more horsepower than one with carburetor because of better cylinder-to-cylinder fuel
10 to 40 more horsepower than one with carburetor because of better cylinder-to-cylinder fuel
distribution. Injecting fuel directly into the intake ports also eliminates the need to preheat the
distribution. Injecting fuel directly into the intake ports also eliminates the need to preheat the
in
inta
take
ke ma
mani
nifol
fold
d si
sinc
nce
e on
only
ly ai
air
r flo
flows
ws th
throu
rough
gh th
the
e ma
manif
nifol
old.
d. Th
This
is,
, in
in tu
turn
rn,
, pro
provi
vide
des
s mo
more
re
freedom for tuning the intake plumbing to produce maximum torque.
freedom for tuning the intake plumbing to produce maximum torque.

9.
GASOLINE DIRECT INJECTION (GDI)
GASOLINE DIRECT INJECTION (GDI)
In conventional engines, fuel and air are mixed outside the cylinder. This ensures waste
In conventional engines, fuel and air are mixed outside the cylinder. This ensures waste
between
between the
the mixing
mixing point
point and
and the
the cylinder,
cylinder, as
as well
well as
as imperfect
imperfect injection
injection timing.
timing. But
But in
in the
the
GDI engine, petrol is injected directly into the cylinder with precise timing, eliminating waste
GDI engine, petrol is injected directly into the cylinder with precise timing, eliminating waste
and inefficiency. By operating in two modes, Ultra-Lean Combustion Mode and Superior
and inefficiency. By operating in two modes, Ultra-Lean Combustion Mode and Superior
Output Mode, the GDI engine delivers both unsurpassed fuel efficiency and superior power
Output Mode, the GDI engine delivers both unsurpassed fuel efficiency and superior power
and torque. The GDI engine switches automatically between modes with no noticeable shift in
and torque. The GDI engine switches automatically between modes with no noticeable shift in
performance.
performance.
MAJOR OBJECTIVES OF THE GDI ENGINE
MAJOR OBJECTIVES OF THE GDI ENGINE
Ultra-low fuel consumption.
Ultra-low fuel consumption.
Superior power to conventional MPI engines
Superior power to conventional MPI engines
Two Combustion Modes:
Two Combustion Modes: In response to driving conditions, the GDI engine changes the
In response to driving conditions, the GDI engine changes the
tim
timing
ing of
of the
the fue
fuel
l spra
spray
y inj
inject
ection
ion,
, alt
altern
ernati
ating
ng bet
betwee
ween
n two
two dis
disti
tinct
nctive
ive com
combust
bustion
ion mod
modes-
es-
st
stra
rati
tifi
fied
ed cha
charge
rge (U
(Ult
ltra-
ra-Le
Lean
an com
combus
busti
tion
on),
), and
and hom
homoge
ogeno
nous
us cha
charge
rge (Su
(Supe
perio
rior
r Ou
Outp
tput
ut
combustion).
combustion).

10.
DIESEL INJECTION SYSTEMS
DIESEL INJECTION SYSTEMS
Fuel injection in diesel engines
Fuel injection in diesel engines
Mechanical and electronic injection
Mechanical and electronic injection
Older engines make use of a mechanical fuel pump and valve assembly which is driven by
Older engines make use of a mechanical fuel pump and valve assembly which is driven by
the engine crankshaft, usually via the timing belt or chain. These engines use simple injectors
the engine crankshaft, usually via the timing belt or chain. These engines use simple injectors
which are basically very precise spring-loaded valves which will open and close at a specific
which are basically very precise spring-loaded valves which will open and close at a specific
fue
fuel
l pre
press
ssur
ure.
e. Th
The
e pum
pump
p ass
assem
embl
bly
y con
consi
sist
sts
s of
of a
a pum
pump
p wh
whic
ich
h pre
press
ssur
urize
izes
s th
the
e fue
fuel,
l, and
and a
a
disc-shaped valve which rotates at half crankshaft speed. The valve has a single aperture to
disc-shaped valve which rotates at half crankshaft speed. The valve has a single aperture to
the pressurized fuel on one side, and one aperture for each injector on the other. As the engine
the pressurized fuel on one side, and one aperture for each injector on the other. As the engine
turns the valve discs will line up and deliver a burst of pressurized fuel to the injector at the
turns the valve discs will line up and deliver a burst of pressurized fuel to the injector at the
cylinder about to enter its power stroke. The injector valve is forced open by the fuel pressure
cylinder about to enter its power stroke. The injector valve is forced open by the fuel pressure
and the diesel is injected until the valve rotates out of alignment and the fuel pressure to that
and the diesel is injected until the valve rotates out of alignment and the fuel pressure to that
injector is cut off. Engine speed is controlled by a third disc, which rotates only a few degrees
injector is cut off. Engine speed is controlled by a third disc, which rotates only a few degrees
and is controlled by the throttle lever. This disc alters the width of the aperture through which
and is controlled by the throttle lever. This disc alters the width of the aperture through which
the fuel passes, and therefore how long the injectors are held open before the fuel supply is cut,
the fuel passes, and therefore how long the injectors are held open before the fuel supply is cut,
con
contr
trol
olli
ling
ng th
the
e am
amoun
ount
t of
of fue
fuel
l in
inje
ject
cted
ed.
. Th
This
is con
contr
trast
asts
s wi
with
th th
the
e mo
more
re mo
moder
dern
n me
metho
thod
d of
of
having a separate fuel pump (or set of pumps) which supplies fuel constantly at high pressure
having a separate fuel pump (or set of pumps) which supplies fuel constantly at high pressure
to each injector. Each injector then has a solenoid which is operated by an electronic control
to each injector. Each injector then has a solenoid which is operated by an electronic control
un
unit
it,
, wh
whic
ich
h ena
enabl
bles
es mo
more
re ac
accu
curat
rate
e con
contr
trol
ol of
of in
inje
ject
ctor
or ope
openi
ning
ng ti
time
mes
s dep
depen
endi
ding
ng on
on ot
othe
her
r

11.
control conditions such as engine speed and loading, resulting in better engine performance
control conditions such as engine speed and loading, resulting in better engine performance
and fuel economy. This design is also mechanically simpler than the combined pump and
and fuel economy. This design is also mechanically simpler than the combined pump and
va
valv
lve
e de
desi
sign
gn,
, m
mak
akin
ing
g it
it ge
gene
nera
rall
lly
y mo
more
re re
reli
liab
able
le,
, an
and
d le
less
ss no
nois
isy,
y, th
than
an it
its
s me
mech
chan
anic
ical
al
counterpart. Both mechanical and electronic injection systems can be used in either direct or
counterpart. Both mechanical and electronic injection systems can be used in either direct or
indirect injection configurations.
indirect injection configurations.
Indirec
Indirect
t injection
injection
Mai
Main
n art
articl
icle:
e: Indi
Indirect
rect inj
injecti
ection
on An
An ind
indire
irect
ct inj
injecti
ection
on die
diesel
sel engi
engine
ne del
delive
ivers
rs fue
fuel
l int
into
o a
a
chamber off the combustion chamber, called a prechamber, where combustion begins and
chamber off the combustion chamber, called a prechamber, where combustion begins and
then spreads into the main combustion chamber.
then spreads into the main combustion chamber.
Direct injection
Direct injection
Modern diesel engines make use of one of the following direct injection methods:
Modern diesel engines make use of one of the following direct injection methods:
Distrib
Distributor pump
utor pump direct injection
direct injection
The first incarnations of direct injection diesels used a rotary pump much like indirect
The first incarnations of direct injection diesels used a rotary pump much like indirect
injection diesels, however the injectors were mounted directly in the top of the combustion
injection diesels, however the injectors were mounted directly in the top of the combustion
chamber rather than in a separate pre-combustion chamber. Examples are vehicles such as the
chamber rather than in a separate pre-combustion chamber. Examples are vehicles such as the
Ford Transit and the Austin Rover Maestro and Montego with their Perkins Prima engine. The
Ford Transit and the Austin Rover Maestro and Montego with their Perkins Prima engine. The
problem
problem with
with these
these vehicles
vehicles was
was the
the harsh
harsh noise
noise that
that they
they made
made and
and particulate
particulate (smoke)
(smoke)
emissions. This is the reason that in the main this type of engine was limited to commercial
emissions. This is the reason that in the main this type of engine was limited to commercial
vehicles (the notable exceptions being the Maestro, Montego and Fiat Croma passenger cars).
vehicles (the notable exceptions being the Maestro, Montego and Fiat Croma passenger cars).
Fuel consumption was about 15% to 20% lower than indirect injection diesels which for some
Fuel consumption was about 15% to 20% lower than indirect injection diesels which for some
buyers
buyers was
was enough
enough to
to compensate
compensate for
for the
the extra
extra noise.
noise. This
This type
type of
of engine
engine was
was transformed
transformed by
by

12.
electronic control of the injection pump, pioneered by Volkswagen Audi group with the Audi
electronic control of the injection pump, pioneered by Volkswagen Audi group with the Audi
100 TDI introduced in 1989. The injection pressure was still only around 300 bar, but the
100 TDI introduced in 1989. The injection pressure was still only around 300 bar, but the
in
inj
jec
ecti
tion
on ti
tim
min
ing,
g, fu
fuel
el qu
quan
anti
tity
ty,
, ex
exha
haus
ust
t ga
gas
s re
reci
circ
rcul
ula
ati
tion
on an
and
d tu
turb
rbo
o bo
boos
ost
t w
wer
ere
e al
all
l
ele
electro
ctronic
nicall
ally
y cont
control
rolled
led.
. Thi
This
s gave
gave muc
much
h mor
more
e pre
precise
cise cont
control
rol of
of the
these
se par
parame
ameters
ters whi
which
ch
mad
made
e refi
refinem
nement
ent muc
much
h mor
more
e acce
accept
ptabl
able
e and
and emi
emissio
ssions
ns acc
accept
eptabl
ably
y low
low.
. Fai
Fairly
rly qui
quickl
ckly
y the
the
technology trickled down to more mass market vehicles such as the Mark 3 Golf TDI where it
technology trickled down to more mass market vehicles such as the Mark 3 Golf TDI where it
proved
proved to
to be
be very
very popular.
popular. These
These cars
cars were
were both
both more
more economical
economical and
and more
more powerful
powerful than
than
indirect injection competitors of their day.
indirect injection competitors of their day.

13.
Common rail direct injection
Common rail direct injection
Mai
Main
n arti
article
cle:
: Com
Common
mon rail
rail In
In old
older
er die
diesel
sel engi
engines,
nes, a
a dist
distrib
ributo
utor-t
r-type
ype inj
injecti
ection
on pum
pump,
p,
regulated by the engine, supplies bursts of fuel to injectors which are simply nozzles through
regulated by the engine, supplies bursts of fuel to injectors which are simply nozzles through
which the diesel is sprayed into the engine's combustion chamber.
which the diesel is sprayed into the engine's combustion chamber.
In common rail systems, the distributor injection pump is eliminated. Instead an extremely
In common rail systems, the distributor injection pump is eliminated. Instead an extremely
high pressure pump stores a reservoir of fuel at high pressure - up to 1,800 bar (180MPa) - in
high pressure pump stores a reservoir of fuel at high pressure - up to 1,800 bar (180MPa) - in
a "common rail", basically a tube which in turn branches off to computer-controlled injector
a "common rail", basically a tube which in turn branches off to computer-controlled injector
val
valve
ves,
s, eac
each
h of
of wh
whic
ich
h con
conta
tain
ins
s a
a pre
preci
cisi
sion-
on-ma
mach
chin
ined
ed noz
nozzl
zle
e and
and a
a pl
plun
unge
ger
r dri
drive
ven
n by
by a
a
solenoid. Most European automakers have common rail diesels in their model lineups, even
solenoid. Most European automakers have common rail diesels in their model lineups, even
for commercial vehicles. Some Japanese manufacturers, such as Toyota, Nissan and recently
for commercial vehicles. Some Japanese manufacturers, such as Toyota, Nissan and recently
Honda, have also developed common rail diesel engines. Different car makers refer to their
Honda, have also developed common rail diesel engines. Different car makers refer to their
common rail engines by different names, e.g. DaimlerChrysler's CDI, Ford Motor Company's
common rail engines by different names, e.g. DaimlerChrysler's CDI, Ford Motor Company's
TDCi (most of these engines are manufactured by PSA), Fiat Group's (Fiat, Alfa Romeo and
TDCi (most of these engines are manufactured by PSA), Fiat Group's (Fiat, Alfa Romeo and
Lancia) JTD, Renault's DCi, GM/Opel's CDTi (most of these engines are manufactured by
Lancia) JTD, Renault's DCi, GM/Opel's CDTi (most of these engines are manufactured by
Fi
Fiat
at,
, ot
othe
her
r by
by Isu
Isuzu
zu),
), Hy
Hyund
undai
ai's
's CR
CRDI
DI,
, Mi
Mits
tsubi
ubish
shi'
i's
s D-
D-ID
ID,
, PS
PSA
A Pe
Peuge
ugeot
ot Ci
Citr
troe
oen'
n's
s HD
HDI,
I,
Toyota's D-4D, Volkswagen's TDi, and so on.
Toyota's D-4D, Volkswagen's TDi, and so on.

14.
Unit direct injection
Unit direct injection
This also injects fuel directly into the cylinder of the engine. However, in this system the
This also injects fuel directly into the cylinder of the engine. However, in this system the
injector and the pump are combined into one unit positioned over each cylinder. Each cylinder
injector and the pump are combined into one unit positioned over each cylinder. Each cylinder
thus has its own pump, feeding its own injector, which prevents pressure fluctuations and
thus has its own pump, feeding its own injector, which prevents pressure fluctuations and
allows more consistent injection to be achieved. This type of injection system, also developed
allows more consistent injection to be achieved. This type of injection system, also developed
by
by Bosch,
Bosch, is
is used
used by
by Volkswagen
Volkswagen AG
AG in
in cars
cars (where
(where it
it is
is called
called Pumpe
Pumpe Düse
Düse -
- literally
literally "pump
"pump
noz
nozzle
zle"),
"), and
and most
most maj
major
or die
diesel
sel engi
engine
ne man
manufa
ufactu
cturers
rers,
, in
in lar
large
ge com
commerc
mercial
ial eng
engine
ines
s (Cat
(Cat,
,
Cummins, Detroit Diesel). With recent advancements, the pump pressure has been raised to
Cummins, Detroit Diesel). With recent advancements, the pump pressure has been raised to
2,050 bar (205 MPa), allowing injection parameters similar to common rail systems.
2,050 bar (205 MPa), allowing injection parameters similar to common rail systems.
Introduction of Ignition System
Introduction of Ignition System
For petrol
For petrol engin
engine
e -
- Batte
Battery
ry ignit
ignition system ,
ion system , Magne
Magneto ignition system Injection system
to ignition system Injection system

 For
For diesel
diesel engine
engine -
- Fuel
Fuel supply
supply system
system.
.

 Battery
Battery ignition
ignition system:
system:

 Battery ignition
Battery ignition system has the follow
system has the following elements
ing elements

 Primary
Primary Ignition
Ignition Circuit(low
Circuit(low voltage)
voltage)

 Battery
Battery

 Ignition
Ignition switch
switch

 Prima
Primary
ry windi
windings
ngs of
of coil
coil


Contact
Contact breaker
breaker

15.

 capacitor
capacitor

 Secondary
Secondary Ignition
Ignition Circuit
Circuit (
( high
high voltage)
voltage)

 Seconda
Secondary
ry windi
windings
ngs of
of coil
coil

 Distri
Distributor
butor cap
cap and
and rotor
rotor (if
(if the
the vehicl
vehicle i
e is so
s so equipp
equipped)
ed)

 Spark
Spark plug
plug wires
wires &
&

 Spark
Spark plugs
plugs
IGNITION SYSTEM – Magneto System Ignition Switch Distribution Contact Breaker Coil
IGNITION SYSTEM – Magneto System Ignition Switch Distribution Contact Breaker Coil
Magneto Condenser Power Generation Spark Generation Magneto Unit Rotor Arm
Magneto Condenser Power Generation Spark Generation Magneto Unit Rotor Arm
IGNITION SYSTEM – Dynamo/Alternator System Dynamo/ Alternator Distributor Contact
IGNITION SYSTEM – Dynamo/Alternator System Dynamo/ Alternator Distributor Contact
Breaker Coil Ignition Switch Secondary Windings Primary Windings Condenser Battery
Breaker Coil Ignition Switch Secondary Windings Primary Windings Condenser Battery
Ignition Switch Coil Packs IGNITION SYSTEM – Electronic Systems Control Unit Timing
Ignition Switch Coil Packs IGNITION SYSTEM – Electronic Systems Control Unit Timing
Sensor
Sensor
Timing Disc Engine Speed Sensing Unit Alternator Battery
Timing Disc Engine Speed Sensing Unit Alternator Battery
In all
In all spark ignitio
spark ignition engines which work
n engines which work on the
on the Gasoli
Gasoline either 2-Stroke or
ne either 2-Stroke or 4-Stro
4-Stroke cycle
ke cycle
principle
principle and
and utilize
utilize a
a carburetor
carburetor or
or fuel
fuel injection
injection system,
system, the
the combustion
combustion of
of the
the air-fuel
air-fuel
mixture is initiated by an electric spark.
mixture is initiated by an electric spark.
The term ‘Spark Ignition’ means that a brief electric arc is produced between the electrodes
The term ‘Spark Ignition’ means that a brief electric arc is produced between the electrodes
of a spark plug, the energy for which is derived from an external power source. In most cases
of a spark plug, the energy for which is derived from an external power source. In most cases
th
this
is pow
power
er sou
sourc
rce
e is
is th
the
e veh
vehic
icle
le ba
batt
ttery
ery,
, wh
whic
ich
h is
is con
const
stan
antl
tly
y be
bein
ing
g sup
suppl
plem
ement
ented
ed by
by th
the
e
alternate while the vehicle is mobile.
alternate while the vehicle is mobile.
A different method of ignition is employed in diesel engines. This is called ‘compression
A different method of ignition is employed in diesel engines. This is called ‘compression
ig
igni
niti
tion
on’
’ and
and rel
relie
ies
s on
on th
the
e fa
fact
ct th
that
at wh
when
en ai
air
r com
compre
presse
ssed,
d, it
its
s te
temp
mpera
eratu
ture
re ri
rise
ses.
s. In
In di
dies
esel
el
en
engi
gine
nes,
s, co
com
mpr
pres
essi
sion
on ra
rati
tio
o of
of be
betw
twee
een
n 16
16:1
:1 an
and
d 25
25:1
:1 ar
are
e co
com
mmo
mon,
n, an
and
d at
at th
the
e en
end
d of
of a
a
compression the temperature of the trapped air is sufficiently high to ignite the diesel fuel that
compression the temperature of the trapped air is sufficiently high to ignite the diesel fuel that
is sprayed into the The functions of ignition system
is sprayed into the The functions of ignition system
The functions of the coil ignition systems in general use on motor vehicle may be divided
The functions of the coil ignition systems in general use on motor vehicle may be divided
into three areas. These are:
into three areas. These are:
Production of the high voltage necessary to produce a spark at the plug gap.
Production of the high voltage necessary to produce a spark at the plug gap.
Distribute the spark to all the cylinders at proper time based on the firing order.
Distribute the spark to all the cylinders at proper time based on the firing order.

16.
Varying the timing of the spark depending on the various operating conditions of the
Varying the timing of the spark depending on the various operating conditions of the
engine like cranking time, varying speed and load, so that the best performance is obtained
engine like cranking time, varying speed and load, so that the best performance is obtained
from the
from the engin
engine
e under all
under all operat
operating condition
ing conditions.
s.
Mechanism of Ignition
Mechanism of Ignition
It must be remembered that vehicle battery voltages are usually 12 volt or 24 volt and this
It must be remembered that vehicle battery voltages are usually 12 volt or 24 volt and this
value is too low to produce a heavy spark at the plug gap in a cylinder under compression. For
value is too low to produce a heavy spark at the plug gap in a cylinder under compression. For
this reason one of the major functions of the battery ignition system is to raise the battery
this reason one of the major functions of the battery ignition system is to raise the battery
voltage to the required level and then apply it to spark plugs.
voltage to the required level and then apply it to spark plugs.
This process is
This process is correct
correctly initiat
ly initiated in
ed in the primary circuit and completed in the
the primary circuit and completed in the second
secondary
ary
winding of the ignition coil. Depending on the type of engine and the conditions existing in
winding of the ignition coil. Depending on the type of engine and the conditions existing in
the cylinders, a voltage of between 5,000 to 20,000 volts is required and this is called the
the cylinders, a voltage of between 5,000 to 20,000 volts is required and this is called the
ionizing voltage or firing voltage.
ionizing voltage or firing voltage.
This firing voltage forces the electrons to jump between the electrodes of the spark plug in
This firing voltage forces the electrons to jump between the electrodes of the spark plug in
the gap to produce the required spark. The electric spark has sufficient heat energy to ignite
the gap to produce the required spark. The electric spark has sufficient heat energy to ignite
the air
the air
fuel mixture which later continues to
fuel mixture which later continues to burn itself.
burn itself.
The conventional coil ignition system Inductive ignition systems: that uses an ignition coil to
The conventional coil ignition system Inductive ignition systems: that uses an ignition coil to
perform
perform the
the step
step up
up transformer
transformer action
action and
and to
to increase
increase the
the electrical
electrical voltage.
voltage. The
The ignition
ignition coils
coils
of the inductive ignition systems operate on the principle of electromagnetic induction (EMI)
of the inductive ignition systems operate on the principle of electromagnetic induction (EMI)
irrespective of whether it is triggered by contact breakers or by electronic triggering units.
irrespective of whether it is triggered by contact breakers or by electronic triggering units.
Transis
Transistorize
torized
d coil ignition
coil ignition system
system
When the ignition switch is set to the ON/RUN position, +12 Volts is applied to terminal
When the ignition switch is set to the ON/RUN position, +12 Volts is applied to terminal
15 of the ignition module through the 0.4 Ohm ballast resistor. When the ignition switch is set
15 of the ignition module through the 0.4 Ohm ballast resistor. When the ignition switch is set
to the START position (engine cranking) +12 volts is applied directly to terminal 15 of the
to the START position (engine cranking) +12 volts is applied directly to terminal 15 of the
ignition module from the solenoid on the starter motor. This effectively bypasses the 0.4 ohm
ignition module from the solenoid on the starter motor. This effectively bypasses the 0.4 ohm
ballast r
ballast resistor
esistor and
and offers
offers higher
higher voltage
voltage during
during cranking.
cranking.
When the engine starts and the ignition switch is returned to the ON/RUN position, +12
When the engine starts and the ignition switch is returned to the ON/RUN position, +12
Volts is again supplied to terminal 15 of the ignition module through the 0.4 Ohm ballast
Volts is again supplied to terminal 15 of the ignition module through the 0.4 Ohm ballast
resistor.
resistor.

17.
A typical firing sequence is as follows.
A typical firing sequence is as follows.
+12 Volts is applied to the ignition module through the 0.4Ω ballast resistor
+12 Volts is applied to the ignition module through the 0.4Ω ballast resistor
As
Assu
sumi
ming
ng th
that
at th
the
e po
poin
ints
ts in
in th
the
e di
dist
stri
ribu
buto
tor
r are
are ope
open,
n, tr
tran
ansi
sist
stor
or Q1
Q1 is
is tu
turn
rned
ed off
off be
beca
cause
use
terminal 7 of the ignition module is open (no ground from the points). No voltage is present at
terminal 7 of the ignition module is open (no ground from the points). No voltage is present at
terminal 16 of the ignition module, thus no current flows through the 0.6 Ohm ballast resistor
terminal 16 of the ignition module, thus no current flows through the 0.6 Ohm ballast resistor
or the ignition coil.
or the ignition coil.
As the engine cranks, the hexagonal cam in the distributor begins to turn and the points
As the engine cranks, the hexagonal cam in the distributor begins to turn and the points
close.
close.
Wh
When
en th
the
e po
poin
ints
ts cl
clos
ose,
e, a
a gro
groun
und
d is
is ap
appl
plie
ied
d to
to te
term
rmina
inal
l 7
7 of
of th
the
e ig
igni
niti
tion
on mo
modu
dule
le and
and
transistor Ql turns on. This applies +12 Volts to terminal 15 of the ignition coil through the
transistor Ql turns on. This applies +12 Volts to terminal 15 of the ignition coil through the
0.6Ω ballast resistor. The current through the points is extremely small (thousandths of an
0.6Ω ballast resistor. The current through the points is extremely small (thousandths of an
Ampere or milli-amperes) instead of 4-5 Amperes as seen in a non-transistorized system.
Ampere or milli-amperes) instead of 4-5 Amperes as seen in a non-transistorized system.
When transistor Q1 is turned ON, capacitor C2 is discharged (shorted by Q1).
When transistor Q1 is turned ON, capacitor C2 is discharged (shorted by Q1).
When the points open, capacitor C2 begins to charge. The charge path is: +12 Volts from the
When the points open, capacitor C2 begins to charge. The charge path is: +12 Volts from the
ignition switch - 0.4Ω ballast resistor - C2 - 0.6Ω ballast resistor and the ignition coil to
ignition switch - 0.4Ω ballast resistor - C2 - 0.6Ω ballast resistor and the ignition coil to
ground.
ground.
As capacitor C2 begins to charge, a pulse is created in the ignition coil, which causes a
As capacitor C2 begins to charge, a pulse is created in the ignition coil, which causes a
high voltage to be generated and sent to the appropriate spark plug.
high voltage to be generated and sent to the appropriate spark plug.
When the points close again, transistor Q1 is turned ON and the cycle repeats.
When the points close again, transistor Q1 is turned ON and the cycle repeats.
Po
Poin
int
t we
wear
ar an
and
d st
stres
ress
s is
is si
signi
gnifi
fica
cant
ntly
ly red
reduc
uced
ed si
sinc
nce
e th
the
e tr
tran
ansi
sist
stor
or is
is han
handl
dlin
ing
g th
the
e cur
curre
rent
nt
through the coil (4-5 Amperes). The points were designed to switch high currents repeatedly
through the coil (4-5 Amperes). The points were designed to switch high currents repeatedly
for tens-of-thousands of miles, therefore, when switching a very small current, they should
for tens-of-thousands of miles, therefore, when switching a very small current, they should
la
last
st for
for a
a mu
much
ch lo
long
nger
er ti
time
me.
. Tu
Tune
ne-u
-up
p in
inte
terva
rvals
ls (du
(due
e to
to po
poin
int
t fai
failu
lure)
re) bec
becom
ome
e lo
long
nger
er and
and
vehicle maintenance becomes cheaper.
vehicle maintenance becomes cheaper.
But (yes, there's always a "but"), we still have the points. Points are mechanical, subject to
But (yes, there's always a "but"), we still have the points. Points are mechanical, subject to
bounce
bounce and
and vibration
vibration and
and must
must be
be actuated
actuated -
- mechanically
mechanically -
- by
by the
the camshaft
camshaft in
in the
the distributor.
distributor.
Whereas the wear on the point contacts has been reduced, the fiber pawl, which rides between
Whereas the wear on the point contacts has been reduced, the fiber pawl, which rides between
the points and the distributor camshaft, can still wear out or break.
the points and the distributor camshaft, can still wear out or break.

18.
Capacitor Discharge Ignitio
Capacitor Discharge Ignition(CDI) Wor
n(CDI) Working Principle, Its Advantage and Disadvantage.
king Principle, Its Advantage and Disadvantage.
What is a CDI System? A Capacitor Discharge Ignition is an electronic ignition device
What is a CDI System? A Capacitor Discharge Ignition is an electronic ignition device
that stores an electrical charge and then discharges it through an ignition coil in order to
that stores an electrical charge and then discharges it through an ignition coil in order to
produce
produce a
a powerful
powerful spark
spark from
from the
the spark
spark plugs
plugs in
in a
a petrol
petrol engine.
engine. Here
Here the
the ignition
ignition is
is
provided
provided by
by the
the capacitor
capacitor charge.
charge. The
The capacitor
capacitor simply
simply charges
charges and
and discharges
discharges within
within a
a
fraction of time making it possible to create sparks CDIs are commonly found on motorbikes
fraction of time making it possible to create sparks CDIs are commonly found on motorbikes
and scooters.
and scooters.
Working principle a CDI System
Working principle a CDI System
A capacitor discharge ignition works by passing an electrical current over a capacitor.
A capacitor discharge ignition works by passing an electrical current over a capacitor.
This type of ignition builds up a charge quickly. A CDI ignition starts by generating a charge
This type of ignition builds up a charge quickly. A CDI ignition starts by generating a charge
and storing it up before sending it out to the spark plug in order to ignite the engine.
and storing it up before sending it out to the spark plug in order to ignite the engine.
This power passes throu
This power passes through a capacit
gh a capacitor and is transferred to an ignition coil that helps
or and is transferred to an ignition coil that helps
boost
boost the
the power
power by
by acting
acting as
as a
a transformer
transformer and
and allowing
allowing the
the energy
energy pass
pass through
through it
it instead
instead of
of
catching any of it. The CDI ignition systems, therefore, allow the engine to keep running as
catching any of it. The CDI ignition systems, therefore, allow the engine to keep running as
long as there is a charge in the power source. The block diagram of CDI shown below.
long as there is a charge in the power source. The block diagram of CDI shown below.

19.
Working of Capacitor Discharge Ignition
Working of Capacitor Discharge Ignition
A Capacitor Discharge Ignition consists of several parts and is integrated with the ignition
A Capacitor Discharge Ignition consists of several parts and is integrated with the ignition
system of a vehicle. The foremost parts of a CDI include the stator, charging coil, hall sensor,
system of a vehicle. The foremost parts of a CDI include the stator, charging coil, hall sensor,
flywheel and the timing mark.
flywheel and the timing mark.
Flywheel and Stator
Flywheel and Stator
The flywheel is a large horseshoe permanent magnet rolled into a circle that turns-ON the
The flywheel is a large horseshoe permanent magnet rolled into a circle that turns-ON the
crankshaft. The Stator is the plate holding all of the electrical coils of wire, which is used to
crankshaft. The Stator is the plate holding all of the electrical coils of wire, which is used to
power
power ON
ON the
the ignition c
ignition coil, b
oil, bike’s
ike’s lights,
lights, and
and battery
battery charging
charging circuits.
circuits.
Charging Coil
Charging Coil
The charging coil is one coil in the stator, which is used to produce 6 volts to charge the
The charging coil is one coil in the stator, which is used to produce 6 volts to charge the
capacitor C1. Based on the flywheel’s movement the single pulsed power is produced and is
capacitor C1. Based on the flywheel’s movement the single pulsed power is produced and is
supplied to the sparking plug by the charging coil to ensure the maximum spark.
supplied to the sparking plug by the charging coil to ensure the maximum spark.
Hall Sensor
Hall Sensor
The Hall Sensor measures the Hall effect, the instantaneous point where the flywheel’s
The Hall Sensor measures the Hall effect, the instantaneous point where the flywheel’s
magnet changes from a north to a south pole. When the pole change occurs, the device sends a
magnet changes from a north to a south pole. When the pole change occurs, the device sends a
single, tiny pulse to the CDI box which triggers it to dump the energy from the charging
single, tiny pulse to the CDI box which triggers it to dump the energy from the charging
capacitor into the high voltage transformer.
capacitor into the high voltage transformer.
Timing Mark
Timing Mark

20.
The timing mark is an arbitrary alignment point shared by the engine case and stator plate.
The timing mark is an arbitrary alignment point shared by the engine case and stator plate.
It indicates the point at which the top of the piston’s travel is equivalent to the trigger point on
It indicates the point at which the top of the piston’s travel is equivalent to the trigger point on
the flywheel and
the flywheel and stator.
stator.
Advantages of CDI
Advantages of CDI
The major advantage of CDI is that the capacitor can be fully charged in a very short time
The major advantage of CDI is that the capacitor can be fully charged in a very short time
(typically 1ms). So the CDI is suited to an application where the insufficient dwell time is
(typically 1ms). So the CDI is suited to an application where the insufficient dwell time is
available.
available.
The capacitor discharge ignition system has a short transient response, a fast voltage rise
The capacitor discharge ignition system has a short transient response, a fast voltage rise
(between 3 to 10 kV/ µs) compared to inductive systems (300 to 500 V/ µs) and shorter spark
(between 3 to 10 kV/ µs) compared to inductive systems (300 to 500 V/ µs) and shorter spark
durati
duration (about
on (about 50-80 µs).
50-80 µs).
The fast voltage rising makes CDI systems unaffected to shunt resistance.
The fast voltage rising makes CDI systems unaffected to shunt resistance.
Disadvantages of CDI
Disadvantages of CDI
The capacitor discharge ignition system generates huge electromagnetic noise and this is
The capacitor discharge ignition system generates huge electromagnetic noise and this is
the main reason why CDIs are rarely used by automobile manufacturers.
the main reason why CDIs are rarely used by automobile manufacturers.
The short spark duration is not good for lighting relatively lean mixtures as used at low
The short spark duration is not good for lighting relatively lean mixtures as used at low
power
power levels.
levels. To
To solve
solve this
this problem
problem many
many CDI
CDI ignitions
ignitions release
release multiple
multiple sparks
sparks at
at low
low engine
engine
speeds.
speeds.
Turbochargers
Turbochargers
Th
The
e tu
turb
rboc
ocha
harg
rger
er ha
has
s be
been
en a
a gr
grea
eat
t so
sour
urce
ce of
of ma
maxi
xim
miz
izin
ing
g ef
effi
fici
cien
ency
cy of
of an
an in
inte
tern
rnal
al
combustion engine since the late 1920’s. Alfred Buchi was the engineer that came up with the
combustion engine since the late 1920’s. Alfred Buchi was the engineer that came up with the
idea to utilize the wasted energy that is expelled through the exhaust system. It was in 1915
idea to utilize the wasted energy that is expelled through the exhaust system. It was in 1915
that he created his first prototype, which failed. This however did not stop the persistent
that he created his first prototype, which failed. This however did not stop the persistent
in
inve
vent
ntor
or.
. He
He wo
work
rked
ed on
on it
it fo
for
r an
anot
othe
her
r 10
10 ye
year
ars
s be
befo
fore
re he
he pr
prod
oduc
uced
ed th
the
e fi
firs
rst
t pr
prac
acti
tica
cal,
l,
functi
functioning turbocha
oning turbocharger that
rger that increa
increase
se effici
efficiency of
ency of an engine
an engine by
by 40%.
40%.

21.
A turbocharger is composed of 3 basic parts, a compressor, a turbine, and a center housing.
A turbocharger is composed of 3 basic parts, a compressor, a turbine, and a center housing.
The turbine is the section of the turbocharger where the exhaust gases of the engine are forced
The turbine is the section of the turbocharger where the exhaust gases of the engine are forced
through to cause the turbine wheel to spin. This rotation energy is then transferred through the
through to cause the turbine wheel to spin. This rotation energy is then transferred through the
center housing and into the compressor by means of a stainless steel, or sometimes inconel,
center housing and into the compressor by means of a stainless steel, or sometimes inconel,
sh
shaft
aft.
. Th
This
is ce
cent
nter
er ho
hous
usin
ing
g is
is co
comp
mpri
rised
sed of
of jo
jour
urna
nal
l or
or ba
ball
ll bea
beari
ring
ngs,
s, de
depe
pend
ndin
ing
g up
upon
on th
the
e
app
appli
lica
cati
tion
on,
, as
as we
well
ll as
as oi
oil
l lu
lubr
bric
icat
atio
ion
n po
port
rts
s an
and
d dra
drain
ins.
s. Th
This
is al
allo
lows
ws th
the
e bea
bearin
rings
gs to
to we
well
ll
lubricated, as well as cooled, to handle the immense rotational speeds and heat that they have
lubricated, as well as cooled, to handle the immense rotational speeds and heat that they have
to endure. Some center housings have integrated coolant passages to provide supplemental
to endure. Some center housings have integrated coolant passages to provide supplemental
cooling. This is not always required, but it does drastically improve a turbochargers life, as
cooling. This is not always required, but it does drastically improve a turbochargers life, as
well as protect it in circumstances where it is put under high or prolonged demand. The
well as protect it in circumstances where it is put under high or prolonged demand. The
compressor does exactly what it’s named for, it compresses air.
compressor does exactly what it’s named for, it compresses air.
Waste gate Turbochargers
Waste gate Turbochargers
A
A wa
wast
steg
egat
ate
e is
is a
a de
devi
vice
ce in
inte
tegr
grat
ated
ed in
into
to a
a tu
turb
rboc
ocha
harg
rger
er th
that
at co
cont
ntro
rols
ls th
the
e ma
maxi
xim
mum
um
allowable boost pressure. The concept of a wastegate is somewhat simple if you recall that
allowable boost pressure. The concept of a wastegate is somewhat simple if you recall that
tu
turb
rboch
ocharg
arger
er boo
boost
st is
is di
direc
rectl
tly
y rel
relat
ated
ed to
to th
the
e ma
mass
ss flo
flowr
wrat
ate,
e, pre
press
ssur
ure,
e, and
and te
temp
mpera
eratu
ture
re of
of
exhaust gases as they pass through the turbine housing of the turbocharger. It is at this stage
exhaust gases as they pass through the turbine housing of the turbocharger. It is at this stage
that the heat energy (potential energy) of the engine exhaust is translated into mechanical
that the heat energy (potential energy) of the engine exhaust is translated into mechanical
energy by the turbine wheel. If exhaust flow is diverted such that it does not flow across the
energy by the turbine wheel. If exhaust flow is diverted such that it does not flow across the
turbine wheel of a turbocharger, than its potential energy is not converted by the turbine.
turbine wheel of a turbocharger, than its potential energy is not converted by the turbine.

22.
Simply put, reducing exhaust flow across the turbine reduces and/or controls boost pressure.
Simply put, reducing exhaust flow across the turbine reduces and/or controls boost pressure.
In
In a
a nut
nutsh
shel
ell,
l, a
a wa
wast
steg
egat
ate
e si
simp
mply
ly di
dive
vert
rts
s ex
exha
haust
ust gas
gas fl
flow
ow aro
aroun
und
d th
the
e tu
turb
rbin
ine
e wh
wheel
eel and
and
straight into the exhaust downpipe once a predetermined manifold pressure (boost pressure) is
straight into the exhaust downpipe once a predetermined manifold pressure (boost pressure) is
reached.
reached.
Variable-geometry turbocharger
Variable-geometry turbocharger
Variable-geometry turbochargers (VGTs), (also kn
Variable-geometry turbochargers (VGTs), (also known as variable n
own as variable nozzle turbines/V
ozzle turbines/V NTs),
NTs), are
are
a family of turbochargers, usually designed to allow the effective aspect ratio (A:R) of the
a family of turbochargers, usually designed to allow the effective aspect ratio (A:R) of the
turbo to be altered as conditions change. This is done because optimum aspect ratio at low
turbo to be altered as conditions change. This is done because optimum aspect ratio at low
engine speeds is very different from that at high engine speeds. If the aspect ratio is too large,
engine speeds is very different from that at high engine speeds. If the aspect ratio is too large,
the turbo wi
the turbo will fail to creat
ll fail to create boost at low speeds; if the aspect ratio i
e boost at low speeds; if the aspect ratio is too small,
s too small, the turbo will
the turbo will
choke the engine at high speeds, leading to high exhaust manifold pressures, high pumping
choke the engine at high speeds, leading to high exhaust manifold pressures, high pumping
losses, and ultimately lower power output. By altering the geometry of the turbine housing as
losses, and ultimately lower power output. By altering the geometry of the turbine housing as
the engine accelerates, the turbo's aspect ratio can be maintained at its optimum. Because of
the engine accelerates, the turbo's aspect ratio can be maintained at its optimum. Because of
this, VGTs have a minimal amount of lag, have a low boost threshold, and are very efficient at
this, VGTs have a minimal amount of lag, have a low boost threshold, and are very efficient at
higher engine speeds. VGTs do not require a wastegate.
higher engine speeds. VGTs do not require a wastegate.

23.
VGTs tend to be much more common on diesel engines as the lower exhaust temperatures
VGTs tend to be much more common on diesel engines as the lower exhaust temperatures
mean they are less prone to failure. The few early gasoline-engine VGTs required significant
mean they are less prone to failure. The few early gasoline-engine VGTs required significant
pre-charge
pre-charge cooling
cooling to
to extend
extend the
the turbocharger
turbocharger life
life to
to reasonable
reasonable levels,
levels, but
but advances
advances in
in
ma
mate
teri
rial
al te
techn
chnol
olog
ogy
y ha
have
ve im
impro
prove
ved
d th
thei
eir
r re
resi
sist
stan
ance
ce to
to th
the
e hi
high
gh te
temp
mpera
eratu
ture
res
s of
of ga
gaso
soli
line
ne
engine exhaust and they have started to appear increasingly in, e.g., gasoline-engined sports
engine exhaust and they have started to appear increasingly in, e.g., gasoline-engined sports
cars.
cars.
Cat
Catalytic converte
alytic converter
r
Cat
Cataly
alytic
tic conv
convert
erter
er is
is a
a vehi
vehicle
cle emi
emissio
ssions
ns con
control
trol devi
device
ce tha
that
t conv
convert
erts
s tox
toxicp
icpoll
olluta
utants
nts in
in
exhaust gas to less toxic pollutants by catalyzing a redox reaction(oxidation or reduction).
exhaust gas to less toxic pollutants by catalyzing a redox reaction(oxidation or reduction).
Catalytic converters are used in internal combustion engines fueled by either petrol (gasoline)
Catalytic converters are used in internal combustion engines fueled by either petrol (gasoline)
or diesel
or diesel inclu
including lean
ding lean burn engines.
burn engines.
The first widespread introduction of catalytic converters was in the United States automobile
The first widespread introduction of catalytic converters was in the United States automobile
market. Manufacturers of 1975 model year equipped gasoline-powered vehicles with catalytic
market. Manufacturers of 1975 model year equipped gasoline-powered vehicles with catalytic
converters to comply with the U.S. Environmental Protection Agency's stricter regulation of
converters to comply with the U.S. Environmental Protection Agency's stricter regulation of
exh
exhau
aust
st em
emis
issi
sions
ons.
. Th
Thes
ese
e “t
“two
wo-w
-way
ay”
” con
conve
vert
rters
ers co
comb
mbin
ined
ed car
carbon
bon mo
mono
noxi
xide
de (CO
(CO)w
)wit
ith
h
unburned hydrocarbons (HC) to produce carbon dioxide (CO2) and water (H2O). In 1981,
unburned hydrocarbons (HC) to produce carbon dioxide (CO2) and water (H2O). In 1981,
two
two way
way cat
cataly
alytic
tic conv
convert
erters
ers wer
were
e ren
rendere
dered
d obso
obsolet
lete
e by
by “th
“three
ree-wa
-way”
y” con
convert
verters
ers tha
that
t als
also
o

24.
reduce oxides of nitrogen (NOx); however, two-way converters are still used for lean burn
reduce oxides of nitrogen (NOx); however, two-way converters are still used for lean burn
engines.
engines.
Al
Alth
thou
ough
gh ca
cata
taly
lyti
tic
c co
conv
nver
erte
ters
rs ar
are
e mo
most
st co
com
mmo
monl
nly
y ap
appl
plie
ied
d to
to ex
exha
haus
ust
t sy
syst
stem
ems
s in
in
automobiles, they are also used on electrical generators, forklifts, mining equipment, trucks,
automobiles, they are also used on electrical generators, forklifts, mining equipment, trucks,
buses,
buses, locomotives,
locomotives, motorcycles,
motorcycles, and
and airplanes.
airplanes. They
They are
are also
also used
used on
on some
some wood
wood stoves
stoves to
to
control emissions. This is usually in response to government regulation, either through direct
control emissions. This is usually in response to government regulation, either through direct
environmental regulation or through health and safety regulations.
environmental regulation or through health and safety regulations.
Construction of a catalytic converter;
Construction of a catalytic converter;
The catalyst support or substrate. For automotive catalytic converters, the core is usually
The catalyst support or substrate. For automotive catalytic converters, the core is usually
a ceramic monolith with a honeycomb structure. Metallic foil monoliths made of Kanthal
a ceramic monolith with a honeycomb structure. Metallic foil monoliths made of Kanthal
(FeCrA
(FeCrAl) are
l) are used in
used in appli
application
cations
s where particul
where particularly high
arly high heat resistance is
heat resistance is requir
required
ed Eithe
Either
r
material is designed to provide a large surface area. The cordierite ceramic substrate used in
material is designed to provide a large surface area. The cordierite ceramic substrate used in
most catalytic converters was invented by Rodney Bagley, Irwin Lachman andRonald Lewis
most catalytic converters was invented by Rodney Bagley, Irwin Lachman andRonald Lewis
at Corning Glass, for which they were inducted into the National Inventors Hall of Fame in
at Corning Glass, for which they were inducted into the National Inventors Hall of Fame in
2002.
2002.
The washcoat. A washcoat is a carrier for the catalytic materials and is used to disperse the
The washcoat. A washcoat is a carrier for the catalytic materials and is used to disperse the
materials over a large surface area. Aluminum oxide, titanium dioxide, silicon dioxide, or a
materials over a large surface area. Aluminum oxide, titanium dioxide, silicon dioxide, or a
mi
mixt
xture
ure of
of si
sili
lica
ca and
and al
alum
umin
ina
a can
can be
be use
used.
d. Th
The
e cat
catal
alyt
ytic
ic ma
mater
teria
ials
ls are
are sus
suspe
pend
nded
ed in
in th
the
e
washcoat prior to applying to the core. Washcoat materials are selected to form a rough,
washcoat prior to applying to the core. Washcoat materials are selected to form a rough,
irregular surface, which greatly increases the surface area compared to the smooth surface of
irregular surface, which greatly increases the surface area compared to the smooth surface of
the bare substrate. This in turn maximizes the catalytically active surface available to react
the bare substrate. This in turn maximizes the catalytically active surface available to react
with the engine exhaust. The coat must retain its surface area and prevent sintering of the
with the engine exhaust. The coat must retain its surface area and prevent sintering of the
catalytic metal particles even at high temperatures The catalyst itself is most often a mix of
catalytic metal particles even at high temperatures The catalyst itself is most often a mix of

25.
precious
precious metals.
metals. Platinum
Platinum is
is the
the most
most active
active catalyst
catalyst and
and is
is widely
widely used,
used, but
but is
is not
not suitable
suitable for
for
al
all
l app
appli
lica
cati
tion
ons
s bec
becaus
ause
e of
of unw
unwant
anted
ed ad
addi
diti
tion
onal
al rea
react
ctio
ions
ns and
and hi
high
gh co
cost
st.
. Pa
Pall
llad
adiu
ium
m an
and
d
rh
rhod
odiu
ium
m ar
are
e tw
two
o ot
othe
her
r pr
prec
ecio
ious
us me
meta
tals
ls us
used
ed.
. Rh
Rhod
odiu
ium
m is
is us
used
ed as
as a
a re
redu
duct
ctio
ion
n ca
cata
taly
lyst
st,
,
palladium
palladium is
is used
used as
as an
an oxidation
oxidation catalyst,
catalyst, and
and platinum
platinum is
is used
used both
both for
for reduction
reduction and
and
oxidation. Cerium, iron, manganese and nickel are also used, although each has limitations.
oxidation. Cerium, iron, manganese and nickel are also used, although each has limitations.
Nickel
Nickel is
is not
not legal
legal for
for use
use in
in the
the European
European Union
Union because
because of
of its
its reaction
reaction with
with carbon
carbon
mon
monoxi
oxide
de int
into
o tox
toxic
ic nic
nickel
kel tetra
tetracarbony
carbonyl.
l. Copp
Copper
er ca
can
n be
be us
used
ed ev
ever
eryw
ywhe
here
re ex
exce
cept
pt No
Nort
rth
h
America, where its use is illegal because of the formation of toxic dioxin .
America, where its use is illegal because of the formation of toxic dioxin .
Emission norms (Euro and BS)
Emission norms (Euro and BS)
Bh
Bhar
arat
at st
stag
age
e em
emis
issi
sion
on st
stan
anda
dard
rds
s (B
(BSE
SES)
S) ar
are
e em
emis
issi
sion
on st
stan
anda
dard
rds
s in
inst
sti
itu
tute
ted
d by
by
the Government of India to regulate the output of air pollutants from internal combustion
the Government of India to regulate the output of air pollutants from internal combustion
engines and Spark-ignition engines equipment, including motor vehicles. The standards and
engines and Spark-ignition engines equipment, including motor vehicles. The standards and
th
the
e ti
tim
mel
elin
ine
e fo
for
r im
impl
plem
emen
enta
tati
tion
on ar
are
e se
set
t by
by th
the
e Ce
Cent
ntra
ral
l Po
Poll
llut
utio
ion
n Co
Cont
ntro
rol
l Bo
Boar
ard
d un
unde
der
r
the Ministry of Environment, Forest and Climate Change.
the Ministry of Environment, Forest and Climate Change.
The standards, based on European regulations were first introduced in 2000. Progressively
The standards, based on European regulations were first introduced in 2000. Progressively
stringent norms have been rolled out since then. All new vehicles manufactured after the
stringent norms have been rolled out since then. All new vehicles manufactured after the
implementation of the norms have to be compliant with the regulations. Since October 2010,
implementation of the norms have to be compliant with the regulations. Since October 2010,
Bharat Stage (BS) III norms have been enforced across the country. In 13 major cities, Bharat
Bharat Stage (BS) III norms have been enforced across the country. In 13 major cities, Bharat

26.
Stage IV emission norms have been in place since April 2010 and it has been enforced for
Stage IV emission norms have been in place since April 2010 and it has been enforced for
entire country since April 2017. In 2016, the Indian government announced that the country
entire country since April 2017. In 2016, the Indian government announced that the country
would skip the BS V norms altogether and adopt BS VI norms by 2020. In its recent judgment,
would skip the BS V norms altogether and adopt BS VI norms by 2020. In its recent judgment,
the Supreme Court has banned the sale and registration of motor vehicles conforming to the
the Supreme Court has banned the sale and registration of motor vehicles conforming to the
emission standard Bharat Stage IV in the entire country from 1 April 2020.
emission standard Bharat Stage IV in the entire country from 1 April 2020.
On 15 November 2017, the Petroleum Ministry of India, in consultation with public oil
On 15 November 2017, the Petroleum Ministry of India, in consultation with public oil
marketing companies, decided to bring forward the date of BS VI grade auto fuels in NCT of
marketing companies, decided to bring forward the date of BS VI grade auto fuels in NCT of
Delhi with effect from 1 April 2018 instead of 1 April 2020. In fact, Petroleum Ministry
Delhi with effect from 1 April 2018 instead of 1 April 2020. In fact, Petroleum Ministry
OMCs were asked to examine the possibility of introduction of BS VI auto fuels in the whole
OMCs were asked to examine the possibility of introduction of BS VI auto fuels in the whole
of NCR area from 1 April 2019. This huge step was taken due the heavy problem of air
of NCR area from 1 April 2019. This huge step was taken due the heavy problem of air
pollution
pollution faced
faced by
by Delhi
Delhi which
which became
became worse
worse around
around 2019.
2019. The
The decision
decision was
was met
met with
with
dis
disarr
array
ay by
by the
the aut
autom
omobi
obile
le com
compani
panies
es as
as the
they
y had
had pla
planne
nned
d the
the deve
develop
lopmen
ment
t acco
accordi
rding
ng to
to
roadmap for 2020.
roadmap for 2020.

27.
The phasing out of 2-stroke engine for two wheelers, the cessation of production of the
The phasing out of 2-stroke engine for two wheelers, the cessation of production of the
Ma
Marut
ruti
i 80
800,
0, and
and th
the
e in
intro
trodu
duct
ctio
ion
n of
of el
elec
ectr
troni
onic
c co
cont
ntro
rols
ls hav
have
e be
been
en due
due to
to th
the
e re
regul
gulat
atio
ions
ns
related to vehicular emissions.
related to vehicular emissions.
While the norms help in bringing down pollution levels, it invariably results in increased
While the norms help in bringing down pollution levels, it invariably results in increased
vehicle cost due to the improved technology and higher fuel prices. However, this increase in
vehicle cost due to the improved technology and higher fuel prices. However, this increase in
private
private cost
cost is
is offset
offset by
by savings
savings in
in health
health costs
costs for
for the
the public,
public, as
as there
there is
is a
a lesser
lesser amount
amount of
of
disease-causing particulate matter and pollution in the air. Exposure to air pollution can lead
disease-causing particulate matter and pollution in the air. Exposure to air pollution can lead
to respiratory and cardiovascular diseases, which is estimated to be the cause for 620,000
to respiratory and cardiovascular diseases, which is estimated to be the cause for 620,000
early deaths in 2010, and the health cost of air pollution in India has been assessed at 3% of its
early deaths in 2010, and the health cost of air pollution in India has been assessed at 3% of its
GDP.
GDP.