1. STUDY OF I.C. ENGINES
Prepared By:-
Ved Mandavgane

2. l DEFINITION OF I.C. ENGINES
An internal combustion engine (ICE) is a heat engine
where the combustion of an air-fuel mixture occurs in a
combustion chamber. In an internal combustion engine,
the expansion of the high-temperature and high-pressure
gases produced by combustion applies direct force to
some component of the engine. This force moves the
component over a distance,transforming chemical
energy into useful mechanical energy
l ENGINE NOMENCLATURE
*Internal Combustion Engines-V Ganesan

3. l CLASSIFICATION
1. Cycle Of Operation
(A) Otto cycle
Otto cycle is the typical cycle for most of the cars
internal combustion engines, that work using
gasoline as a fuel. Otto cycle is exactly the same
one that was described for the four-stroke engine.
It consists of the same major steps: Intake, compression,
ignition, expansion and exhaust.

4. (B)Diesel cycle
Most truck and automotive diesel engines use a cycle
reminiscent of a four-stroke cycle, but with compression
heating causing ignition, rather than needing a separate
ignition system. This variation is called the diesel cycle. In
the diesel cycle, diesel fuel is injected directly into the
cylinder so that combustion occurs at constant pressure, as
the piston moves.

5. 2. On The Basis Of Fuel
Gasoline engine:These engines function according to the
Otto cycle. In these engines gasoline(petrol) is used as fuel.
An air-fuel mixture prepared outside the combustion
chamber and an electric spark is used to ignite the charge.
These engines are also known as Spark Ignition/Ignited (SI)
engines.
Diesel engine:These engines function according to the
Diesel cycle. In these engines diesel is used as fuel. In this
case only air is sucked in during the suction stroke instead
of an air-fuel mixture like a traditional SI engine. The fuel
is injected with high pressure with the help of fuel injectors
at the end of the compression stroke thus igniting the charge.
These engines are also known as Compression
Ignition/Ignited (CI) engines.
Gas engine:These engines use either CNG(Compressed
Natural Gas) of LPG(Liquid Petroleum Gas) as fuel.
The most commonly used fuel in these engines is LPG.
Before electric motors, hybrid vehicles used LPG as an
alternative fuel.

6. 3. Methods Of Charging
(a) Turbocharging
(i) Compound/Intake turbos
(ii) Wastegate-Intercooler turbos
*Compound Turbo(Variable Geometry)

7. () Supercharging
(i) Mechanical supercharger
*Roush Stage 2 Root Supercharger

8. (a) Twincharging
(includes one or two turbochargers and a supecharger)
This system was used on only in 5 production cars namely

9. ZENVO TS1 GT

10. LANCIA DELTA S4

11. JAGUAR C-X7

12. VOLVO S-60 POLESTAR

13. NISSAN MARCH SUPERTURBO
*Courtesy-DRIVETRIBE Magazine

14. 1. Ignition
(i) Compression Ignition[C.I.]
(ii) Spark Ignition[S.I.]
2. Cooling Methods
(i) Air cooling: It is a method in which the engine is
cooled with the help of air passages made in the
engine.
*Teardown of an Air-cooled engine of a Porche 930 Turbo.

15. (i) Liquid cooling: This type of engine cooling uses a
coolant liquid (ethylene glycol) and engines using this
method of cooling have waterjackets/passages for cooling
water. Previously these engines also used oil for cooling.

16. 1. Cylinder arrangement
Vertical engine
In this type of cylinder arrangement the pistons are
mounted vertically/ perpendicular to the ground. A common
example of this type of engine is the Royal Enfield
motorcycles

17. Horizontal engine
In this type of cylinder arrangement the pistons are
mounted parallel to the ground and in case of a
multicylinder engine the pistons are mounted in opposite
directions but slightly inclined upwards. A common
example of this type of single cylinder would be the Hero
Splendor.

18. Radial engine
In this type of cylinder arrangement the pistons are
arranged in a radial shape so as to fit in a larger engine in
minimum space without increasing the amount of vertical
space taken up by the engine. (as shown in the above
image).

19. V-engine
In this type of cylinder arrangement the pistons are
mounted on a single crakshaft and opposite to each other.
These are generally used for even number of cylinders.
Eg:2,4,6,8,10,12. A common example of these type of
engines is the Harley-Davidson lineup.

20. Opposed piston
In this type of cylinder arrangement the pistons are
horizontally perpendicular to each other in opposite
directions.
A few examples of this type of engine is the 1963(1st Gen)
VolksWagen Beetle.

21. W engine
In these type of engines the pistons are mouted in the shape
of a W by joining two V shaped engines together. This
arrangement is used only for engines having 12 cylinders or
more, i.e; 12 or 16 (the highest number of cylinders used in
a production car).
The most well known examples of this type of engines will
be the Bugatti Veyron and the Bugatti Chiron and the other
manufacturer bieng; Bentley Motors.

22. 1. Camshaft layout
(A) Sidemounted camshaft
(B) Overhead camhsaft
i. SOHC
ii. DOHC

23. 1. Vertical and Horizontal engines and its Merits and
Demerits

24. 1. Types of engines
(i) Four stroke S.I. engines
These engines use gasoline as fuel.They operate on
the Otto cycle. They are used in most Light Duty
Passenger vehicles. The air-fuel mixture is ignited by
a spark.
(ii) Four stroke C.I. engines
These engines use diesel as fuel. They operate on the
Diesel cycle. They are used in some Light Duty
Passenger vehicles and all Heavy Duty Commercial
vehicles. The air-fuel mixture is ignited by
compressing it.
Two stroke and Four stroke scavenging
Scavenging is the process of removal of exhaust
gases by fresh charge.
This process is commonly found in two stroke
engines. It can be found in four stroke engines only
during valve overlapping.

25. *Scavenging process in 2 stroke engine

26. lEngine specifications & applications
Number of Strokes
Number of Cylinders
Method of Cooling
Number of Valves and Camshaft Arrangement
Displacement
Bore and Stroke
Fuel System
Compression Ratio
Maximum Torque
Maximum Horsepower

27. * Specifications list of Yamaha R15 MotoGP edition.

28. l Applications of I.C. engines
I.C. engines are used in following application.
1. Road vehicles: 2 wheelers, Passenger cars, Light &
heavy commercial vehicles.
2. Small aircrafts, Helicopters & Railway locomotives.
3. Marine applications, Ships.
4. Industrial electric power generation.