1. Internal Combustion Engines
UNIT 2
Introduction to
Internal Combustion Engines 1

2. CONTENTS Components of an IC Engine Engine Nomenclature
Classification of IC Engines
4 Stroke and 2 Stroke Engines
Valve timing and Port timing Diagrams

3. COMPONENTS OF AN IC ENGINE

4. ENGINE NOMENCLATURE

5. Classification of IC Engines
(a) Based on number of strokes :
(i) Two stroke engines
(ii) Four stroke engines
(b) Based on thermodynamic cycle :
(i) Engines based on Otto cycle (‘Spark-Ignition engine’)
(ii) Engines based on Diesel (‘Compression-Ignition engine’)
(c) Based on mechanism of ignition:
(i) Spark ignition engines
(ii) Compression ignition engines. 5

6. Classification of IC Engines
(d) Based on type of fuel used:
(i) Petrol engines (petrol being used as fuel)
(ii) Gas engines (gaseous fuel being used)
(iii) Diesel engines (diesel being used as fuel)
(iv) Multi-fuel engines (more than one fuel being used)
(e) Based on fuel admission:
(i) Carburettor type engines (use carburettor fuel metering)
(ii) Injection type engines (use fuel injector & injection system)
(f) Based on type of cooling:
(i) Air cooled engines (Small sized engines)
(ii) Water cooled engines (Large sized engines) 6

7. Classification of IC Engines
(g) Based on type of motion
(i) Reciprocating engines
(ii) Rotary engines
(h) Based on cylinder arrangements
(i) Opposed cylinder engines
(ii) Inclined cylinder engines
(iii) V-shaped cylinder arrangement
(i) Rotary engines
(i) Single rotor engine
(ii) Multi rotor engine 7

8. Single Cylinder Engine
CLASSIFICATION
Single Cylinder Engine
Inline Engine
V - Engine

9. Opposed Cylinder Engine
CLASSIFICATION
Opposed Cylinder Engine
W - Engine

10. CLASSIFICATION
Opposed Piston Engine
Radial Engine

11. 4 STROKE AND 2 STROKE ENGINES

12. 4 STROKE AND 2 STROKE ENGINES

13. 4 STROKE AND 2 STROKE ENGINES
2 stroke Petrol Engine

14. 4 STROKE AND 2 STROKE ENGINES
2 stroke Diesel Engine

15. VALVE TIMING AND PORT TIMING DIAGRAMS Theoritical Valve Timing Diagram

16. VALVE TIMING AND PORT TIMING DIAGRAMS
IVO - 10° to 30° before TDC
IVC - 30° to 60° after BDC
IVO - 20° + 180° + 35° = 235°
EVO - 35° before BDC
EVC - 10° after TDC
EVO - 35° + 180° +10° = 225°
IGN - 30° to 40° before TDC
Valve Timing Diagram of 4 stroke Petrol Engine

17. VALVE TIMING AND PORT TIMING DIAGRAMS
IVO - 10° to 25° before TDC
IVC - 25° to 50° after BDC
EVO - 30° to 50° before BDC
EVC - 10° to 15° after TDC
FVO - 5° to 10° before TDC
FVO - 15° to 25° after TDC
Valve Timing Diagram of 4 stroke Diesel Engine

18. VALVE TIMING AND PORT TIMING DIAGRAMS
Valve Timing Diagram of 2 stroke Petrol Engine

19. VALVE TIMING AND PORT TIMING DIAGRAMS
Valve Timing Diagram of 2 stroke Diesel Engine

20. THANK YOU