This document provides an overview of internal combustion engines. It begins with an introduction that defines engines and heat engines. It then covers the history and classification of IC engines. The main parts of an IC engine are described along with advancements like direct fuel injection. Performance parameters and the operation of 2-stroke and 4-stroke engines are explained. Emerging technologies like digital triple spark ignition and nano engines are also discussed.

1. IC ENGINES
by
SALEEM MALIK CHILAKALA

2. CONTENTS
 INTRODUCTION
 HISTORY
 CLASSIFICATION
 PARTS OF AN IC ENGINE
 ADVANCEMENTS IN IC ENGINES
 CALIBRATION OF IC ENGINES

3. INTRODUCTION
◦ An Engine is a device which transforms the chemical energy of a
fuel into thermal energy and uses this thermal energy to produce
mechanical work.
◦ Engines normally convert thermal energy into mechanical work
and therefore they are called heat engines.
◦ Heat engines can be broadly classified into :
i) External combustion engines ( EC Engines)
ii) Internal combustion engines ( IC Engines )
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4. HISTORY
◦ Internal combustion engines date back to 1876 when Otto first developed the spark-
ignition engine and 1892 when Rudolf Diesel invented the compression-ignition
engine.
◦ Since that time these engines have continued to develop as our knowledge of engine
processes has increased, as new technologies became available, as demand for new
types of engine arose, and as environmental constraints on engine use changed.
◦ Internal combustion engines, and the industries that develop and manufacture them and
support their use, now play a dominant role in the fields of power, propulsion, and
energy.
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5. CLASSIFICATION OF HEAT ENGINES
Heat Engines
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Open
cyclegas
turbine
Wankel
engine
Gasoline
engine
Diesel
engine
Steam
engine
Stirling
engine
Steam
turbine
Closed
Cycle gas
turbine

6. External combustion engines (EC Engines)
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Figure 1 : External Combustion Engine

7. ◦ Internal combustion engines can be classified as Continuous IC engines and
Intermittent IC engines.
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Continuous IC Engines
• In continuous IC engines products of combustion of the fuel enters into the prime
mover as the working fluid.
INTERNAL COMBUSTION ENGINE

8. ADVANTAGES OF INTERAL COMBUSTION ENGINE
1. Greater mechanical simplicity.
2. Higher power output per unit weight because of absence of auxiliary units like boiler ,
condenser and feed pump.
3. Low initial cost
4. Higher brake thermal efficiency as only a small fraction of heat energy of the fuel is
dissipated to cooling system.
5. These units are compact and requires less space.
6. Easy starting from cold conditions.
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9. DISADVANTAGES OF INTERNAL COMBUSTION ENGINES
1. IC engines cannot use solid fuels which are cheaper.
2. Only liquid or gaseous fuel of given specification can be efficiently used. These fuels are relatively
more expensive.
3. IC engines have reciprocating parts and hence balancing of them is problem and they are also
susceptible to mechanical vibrations.
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11. Crank shaft :-
Backbone of the
engine, operates the
piston through
connecting rod for
operating all tasks.
Cam shaft :-
Receive the drive from crankshaft, operates valve
mechanism.
Connecting rod:-
• Intermediate part of piston
and crank shaft.
• Has one big end connected
to crank shaft and the small
end to the piston.
Piston:-
Made of aluminium alloy,
move in the cylinder liner
in reciprocating manner and
operates suction ,
compression and exhaust.

12. Valves:-
Inlet valve is made of high carbon
steel, and exhaust valve is made of
silicon steel.
Valves are meant for opening and
closing of inlet and exhaust ports
according to requirement.
Block
Body of the engine
containing
cylinders, made of
cast iron or
aluminium
Head :
The piece which closes the end
of the cylinders, usually
containing part of the clearance
volume of the combustion
chamber.
Combustion chamber:
The end of the cylinder
between the head and the
piston face where
combustion occurs.

13. Piston rings:
Metal rings that fit
into circumferential
grooves around the
piston and form a
sliding surface
against the cylinder
walls.
Fuel injector :
A pressurized nozzle that
sprays fuel into the incoming
air (SI engines )or into the
cylinder (CI engines).
Fuel pump : Electrically or
mechanically driven pump to
supply fuel from the fuel tank
(reservoir) to the engine.
Main moving parts of engine
1)Crank shaft
2)Cam shaft
3)Connecting rod
4)Piston
5)Valves
6)Rocker arm
7)Pushrod
8)Cam follower(tapet)
9)Fly wheel
10)Fan
Main stationary parts
1)Crank case
2)Cylinder block
3)Cylinder head
4)Inlet and exhaust manifold

14. CARBURETOR
 A carburetor is a part in an
internal combustion petrol
engine that controls the mixture
of air with the gasoline,
 A carburetor atomizes gasoline.
 In automobiles, carburetors have
mostly been replaced by fuel
injection systems due to the
introduction of catalytic
converters in order to alleviate
air pollution.
 Carburetors are still commonly
used in small engines like those
used in lawn movers.

15. SPARK PLUG
• The spark plug is a seemingly
simple device, although it is
tasked with a couple of different
but critical jobs.
• First and foremost, it creates
(literally) an artificial bolt of
lightning within the combustion
chamber (cylinder head) of the
engine. The electrical energy
(voltage) it transmits is
extremely high in order to create
a spark and to “light the fire”
within the controlled chaos of the
combustion chamber.
• Here, the voltage at the spark
plug can be anywhere from
20,000 to more than 100,000
volts.

16. 2. Power / Exhaust
a. ignition
b. piston moves downward
compressing fuel-air mixture in
the crankcase
c. exhaust port opens
1. Intake / Compression
a. inlet port opens
b. compressed fuel-air mixture
rushes into the cylinder
c. piston upward movement
provides further compression
Internal Combustion Engines
– two stroke -

17. Internal Combustion Engine four stroke
starting position 1. intake 2. compression
ignition 3. power 4. exhaust

19. Valve timing diagram of 4- stroke single
cylinder diesel engine.
◦IVO - 25 before TDC
◦IVC - 30 after BDC
◦EVO - 45 before BDC
◦EVC - 15 after TDC
◦FVO - 15 before TDC
◦FVC - 25 after TDC
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20. Valve timing diagram of 4- stroke single cylinder petrol engine.(low speed)
◦ IVO - 10 before TDC
◦ IVC - 20after BDC
◦ EVO - 25 before BDC
◦ EVC - 5 after TDC
Valve timing diagram of 4- stroke single cylinder petrol engine.(high speed)
◦ IVO - 10 before TDC
◦ IVC - 50 after BDC
◦ EVO - 45before BDC
◦ EVC - 20 after TDC
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21. Performance Parameters
(a) Power and Mechanical Efficiency.
(b) Mean Effective Pressure and Torque.
(c) Specific Output.
(d) Volumetric Efficiency.
(e) Fuel-air Ratio.
(f) Specific Fuel Consumption.
(g) Thermal Efficiency and Heat Balance.
(h) Exhaust Smoke and Other Emissions.
(i) Specific Weight.
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22. ●The first four strokes are the same as four stroke internal combustion engine.
●After exhaust stroke, instead of air/fuel mixture – fresh air/water is sucked into the cylinder from the filter and
is removed during sixth stroke.
SIX STROKE ENGINES

23. Direct fuel Injection
◦ In direct fuel injection, first the air is
filled in the cylinder. Then half way
through the compression stroke, a
small amount of fuel is injected to the
cylinder to create a lean mixture.
◦ At the end of compression, just before
the spark the rest of fuel is injected to
the head of spark plug.
◦ The burning of fuel occurs in a
stratified pattern near the spark plug.

24. Advantages:
• No need of carburettor
• Easy design of manifold
• Better compression is achievable
• No case of knocking in engine
• Due to stratified combustion leaner
mixture can be used which reduces
the fuel consumption.
disadvantages:
• More cost and complexity
• More expensive to build

25. DIGITAL TRIPLE SPARK IGNITION
 4-valve Triple Spark engine controlled by an advanced Electronic
Control Unit for an absolutely unmatched performance.
 To support this exhilarating heart-pumping performance the bike
comes with liquid cooling and a six speed gear box.
 To make use of 3 spark plugs, the engine houses a pent roof
combustion chamber which in turn allows housing 3 spark plugs in
the engine chamber.
 The secondary plugs fires a bit after the primary one has fired and
the timings are controlled by the ECU depending on various
parameters like throttle position, engine revs, load on engine and
many other stuffs.
 These plugs gain a advantage in low-rev riding condition where it
extracts the best economy.
 Presently used in pulsar 200 NS

26.  From back plate to drive washer is less than 1
inch.
 There are no exotic materials required.
 It has high precision ,cost effective, high speed
IDEAL OF SIZE OF NANO
 Also, the fuel for mini diesels needs a lot of ether - as
high as 50% by volume.
 With high ether fuel and a spring starter, the little
Nano will burst into life.
 Richard Gordon claims it will turn 40,000 rpm.

27. EXPLODED VIEW OF NANO ENGINE

28. PISTON CROWN AND VENTURI
 The crown of the piston is conical to assist transfer.
 The contra piston has a matching concave conical depression.

29. APPLICATIONS
 Nano ic engine has various applications ranging from race cars to
space crafts.
 In case of a mine tragedy where harmful gases are emitted ,these
Nano ic engines can be employed as powerful blowers to blow out
these gases is a time saving & the lives of trapped miners .
 Agriculture pumps sets.
 Every field of industry

30. ALIGNMENTS OF PISTONS AND
CYLINDERS

31. A New 5 Stroke Internal Combustion Engine
 The patented 5-stroke concept, which was invented
by Gerhard Schmitz, utilizes two fired cylinders
operating on a conventional 4-stroke cycle, which
alternately exhaust into a central expansion
cylinder, where the hot exhaust gases act on a third
cylinder. The third cylinder is an additional low-
pressure expansion cylinder decoupled from the
expansion and compression processes of the 4-stoke
pair, and enables the optimum expansion ratio to be
selected independently of the compression ratio.
 The advantage to following the expansion ratio in
the design is the compression ratio can be reduced
to delay knock (pre ignition, where the conditions
inside the combustion chamber ignite the air fuel
mixture) onset without a reduction in performance.

32. On-board Engine Computers
 The ECU makes sure processes like ignition timing, the air/fuel mixture, fuel injection, idle speed, and others
operate the way they're supposed to.
 It monitors what's going on in the engine using an array of sensors and performs millions of calculations each
second in order to keep everything operating correctly.
 Other computers in the car control things like electrical systems, airbags, interior temperature, traction
control, anti-lock brakes and the automatic transmission.

33. Hybrid Engines
 One of the biggest engine improvements used to boost
efficiency in recent years is the hybrid engine.
 An electric motor is partnered with a
traditional gasoline engine in order to achieve high fuel
economy numbers, but without the "range anxiety" of
an electric engine
 At low speeds, the electric engine acts alone, meaning the car does not use gas at all. At other times, it assists the
gasoline engine. The whole package gets about 50 miles per gallon (21.3 kilometers per liter) in both the city and
the highway

34. TURBO CHARGER
 The turbocharger uses the exhaust air energy from the
engine
 Turbo-charging is providing pressurized air by using
engine's exhaust.

35. SUPER CHARGER
 Supercharger is driven mechanically with the help of
belts and gears attached to the engine's crankshaft.
 Super-charging is a process by which pressurized
forced air is provided with the help of an external
charging pump

36. Cylinder Deactivation
 The name says it all. ICEs with this feature can simply deactivate some cylinders when less power is required,
temporarily reducing the total volume of the engine cylinders and so burning less fuel.
 This feature is found on V6 and V8 engines.
Variable Valve Timing and Lift
 Valves open and close to allow air and fuel to enter cylinders and for the products of combustion to exit.
 Different valve timings produce different results (more power, better fuel economy).
 Traditionally, you couldn't vary that timing, so the choice had to be made once when the engine was designed.
 But many modern engines can vary valve timing, allowing for example the default low RPM range of the engine
to have more economical timing, and the higher RPM range to go for max power.
 This allows a smaller displacement engine to produce more peak power, so it allows for downsizing and fuel
savings.

37. But what is this BS?
 To start with, the ‘BS’ in BS IV stands for ‘Bharat Stage’ which signifies the emission regulation standards set
by Indian regulatory bodies.
 The ‘IV’ is a roman numeric representation for four (4).
 The higher the number gets, the stricter the Bharat Stage emission norms get which eventually means it
becomes trickier (and costlier) for automakers to meet them.
 These emission standards were set by the central government to keep a check on the pollutant levels emitted by
vehicles that use combustion engines.
 To bring them into force, the Central Pollution Control Board sets timelines and standards which have to be
followed by automakers.
 Also, the BS norms are based on European emission norms which, for example, are referred to in a similar
manner like ‘Euro 4’ and ‘Euro 6’.
 These norms are followed largely by all automakers across the globe and act as a good reference point as to
how much does a vehicle pollute.

38. What should be expected in the future?
 As of now, BS IV will be implemented from April 1, 2017. Those looking to purchase a vehicle will have to spend
a higher amount than before to own one.
 But, the larger aim for the automotive sector as a whole is to implement BS VI emission regulation by the year
2020 in India. Yes, BS VI and yes, BS V will be skipped.
 This will require a huge amount of investments to make the oil refineries capable of producing a better quality of
fuel and also investments in the infrastructure to make that fuel available across the country.
 Then, the automakers will have to make investments on their end too in order to speed up the research and
development process and improve their own infrastructure – like the manufacturing plants – to make their offering
BS VI compliant.
 This, eventually, will make owning an internal combustion engine powered car more expensive to own, and
maintain.

39. BS- VI (BHARATH
STAGE)
 They’ll get more fuel efficient than ever before. Lower
emissions means lower usage of fuel per kilometer.
 You’ll have downsized engines getting a big thrust.
Smaller engines means lower fuel consumption,
especially at lower speeds where most cars spend most
of their times.
 India’s now has 9 of the world’s 15 most polluted
cities
 BS6 will take emission control a step further, by
reducing Nitrous Oxide by 68 %.

40. It looks like this:
1. intake (pulls in fuel and air)
2. compression (compresses the mixture)
3. power/ignition (explosive expansion of the fuel)
4. exhaust (exhaust gasses expelled
5. water intake and 2nd power stroke (pulls in liquid water, which boils and turns
to steam, driving the piston)
6. steam recycle (exhaust steam expelled to steam electrolysis module)
7. hydroxy gas intake and ignition (pulls in hydrogen/oxygen gas mixture from
electrolysis module)
8. exhaust (exhaust water vapor expelled or recycled
8 STROKE ENGINE

41. Engine testing ‘acronyms’ used in automotive industry
–DVT Design Validation Testing
–OCT Oil consumption test
–TDC Top dead center
–BDC Bottom dead center
–LPP Location of peak pressure
–BSFC Brake Specific Fuel Consumption
–BMEP Brake Mean Effective Pressure
–MBT Minimum spark, best torque
–MBTLMBT retarded to clear detonation
–TLA Top limit advance
–BLA Bottom Limit advance
–AFR Air Fuel Ratio
CALIBRATION OF IC ENGINES

42.  Emission equipment
 Thermocouples
 Pressure transducers (in cylinder measurement)
 Turbine flow meters
 Smoke measurement
 Fuel measurement
 Blow-by measurement (blow-by: gas past the rings
into the crankcase)
 Air flow measurement
Test Equipment and Instruments

43. Engine Speed Measurement
 Via ECU, on board speed sensor
 On test bed, normally through TDC sensor Shaft
encoder

44. •Mass Air Flow-rate (MAF) sensor
•Various MAF measurement method on test bed
•Estimate MAF by exhaust gas analysis and fuel rate
Air Flow Rate Measurement

45. Fuel Flow Rate Measurement
On board fuel injection amount correcting: estimate via
MAF sensor and lambda sensor for SI engines; for
diesel engine –knock sensor