1. IC ENGINE
Group presentation
Daud Rafique (087)
Rana Ahsan Ali (097)
Muhammad Asif (025)
Jazim Hussain (091)
Hamad Ijaz (063)
Muhammad Abdullah (059)
2. INTERNAL
COMBUSTION
ENGINE
An internal combustion engine
(ICE) is a heat engine where
the combustion of a fuel occurs
with an oxidizer (usually air) in
a combustion chamber that is an
integral part of the working fluid
flow circuit.
3. PRINCIPLE
Internal
combustion heat engines work
on the principle of the ideal gas
law: . Raising the temperature
of a gas increases the pressure
that makes the gas want to
expand. An internal
combustion engine has a
chamber, which has fuel added
to it which ignites in order to
raise the temperature of the
gas.
4. MAIN PARTS OF AN
INTERNAL
COMBUSTION
ENGINE:
Cylinder head. The top end of the engine
cylinder is closed by means of removable
cylinder head.
Piston. A piston is fitted to each cylinder as
a face to receive gas pressure and transmit
the thrust to the connecting rod.
Piston rings.
Connecting rod.
Crankshaft.
Engine bearing.
Crankcase.
Valves.
5. Classification of IC Engines
According to the number of cylinder
According to the ignition:
1. Compression-ignition engine
2. Spark-ignition engine
According to number of strokes:
1. Two-stroke engine
2. Four-stroke engine
According to arrangements of cylinders:
1. Incline
2. V-engine
3. W-engine
6. NUMBER OF
CYLINDERS
• Most modern vehicles use an
even numbers of cylinders.
Most common configuration
features 3,4, 6 or 8 cylinders.
• The numbers of cylinder
greatly impact the
performance of the engine.
7. IGNITION TYPES
COMPRESSION
IGNITION
• Used mostly on diesel
engines, compression
ignition makes use of the
high air pressure and
temperature in the cylinder
• When fuel is injected into the
compressed air, it self
ignites.
• Diesel engines also use glow
plugs to aid self ignition
during cold seasons.
8. SPARK IGNITION
• A spark ignition engine uses
an electrical spark to ignite
the compressed air/fuel
mixture
• The spark is usually
generated by the electrode of
a spark plug, synchronized to
the piston movement
9. 4-STROKE ICE
• As the crankshaft rotates the piston creates a reciprocating
motion called a stroke.
• A crankshaft revolution is equal with two strokes of a piston.
• In case of 4-stroke engines, the piston moves 4 times to complete
a cycle.
10. 4-STROKE ICE
- INDUCTION
• During the induction stroke,
the piston moves downwards
creating a vacuum.
• The motion draws a fresh
charge through the intake
valve, which opens slightly
before the piston descents.
11. 4-STROKE ICE
COMPRESSION
• During the compression
stroke, both intake and
exhaust valves are closed.
• The piston moves upwards,
compressing the air or
air/fuel mixture.
12. 4-STROKE ICE
– IGNITION
• Once compressed, the
mixture is ignited, either by
spark (SI) or through self-
ignition (CI).
• The force of explosion pushes
the piston down, generating
the power stroke.
13. 4-STROKE ICE
– EXHAUST
• To eliminate unburnt gases
and combustion residue, the
exhaust valve opens.
• Shortly after, the piston goes
upward again, pushing the
exhaust residue out.
14. 2-STROKE ICE
• The 2-Stroke internal combustion engine uses the same principle
to generate kinetic energy from burning fuel.
• However , it removes the separate induction and exhaust strokes
, thus finishing a cycle with each rotation of the crankshaft.
15. 2-STROKE ICE-
COMPRESSION
• The Piston travels up from BDC
(bottom dead center),compressing
the trapped charge.
• If the charge is not pre-mixed,fuel
is injected towards thr end of the
stroke.
• Ignition should occur slightly
before TDC (top dead center).
• During compression, the
underside of the piston draws a
fresh charge through a non-return
valve.
16. 2-STROKE ICE-
POWER
• During the power stroke , the
piston moves downwards ,
compressing the charges in the
crankcase.
• Near the end of the stroke , the
exhaust port opens ,allowing
gases to exit the cylinder.
• When the piston reaches
BDC(bottom dead center),the
transfer port opens ,allowing the
compressed charge into the
cylinder.
