WHEELSPIN 2k17 Bapurao Deshmukh College Of Engineering Sevagrma (Wardha) Title – WORKING OF FOUR STROKE PETROL ENGINE Author – Abhijit kumar Date 28TH February 2017

CONTENTS HEAT ENGINE. MAIN PARTS PETROL ENGINE CLASSIFICATION OF ENGINE WORKING OF A PETROL ENGINE SUCTION STROKE COMPRESSION STROKE POWER STROKE EXHAUST STROKE CONSTANT VOLUME OR OTTO CYCLE

1. HEAT ENGINE HEAT ENGINE :- An heat engine is a power generating machine, which converts potential energy of the fuel into heat energy and then into motion. It is a combination of various mechanism which avails to do various work according to its purpose. FIG-1.1 HEAT ENGINE

2. MAIN PARTS PETROL ENGINE Cylinder Head Camshaft Cam Push Rod Valves Spark Plug Injector Gaskets Cylinder block Piston Piston Rings Gudgeon Pin (Piston Pin) Connecting Rod Crank Shaft Engine Bearing Manifold Oil Sump Flywheel FIG NO-2.1 MAIN PARTS OF ENGINE

Rotary type e.g.-gas turbines 3. Heat engine Internal combustion External combustion Steam engine Reciprocating type Rotary type e.g.-gas turbines Spark ignition Compression ignition Oil engine/diesel engine Petrol engine Gas engine/CNG/LPG 2 stroke 4 stroke 2 stroke 4 stroke

4. WORKING OF A PETROL ENGINE A Four Stroke Internal Combustion Engine is an engine whose working cycle consists of an intake stroke, a compression stroke, a power stroke and an exhaust stroke. FIG NO-4.1 FOUR STROKE ENGINE

5. Suction Stroke – with pistons moving downwards and opening of the inlet valve creates suction of the air-fuel mixture. Fig-5.1 Petrol Suction Stroke

6. Compression Stroke – With closing of Inlet valve, the area above the piston gets closed. The piston moves up resulting in compression of the air-fuel mixture in a confined space. Fig-6.1 Petrol Compression Stroke

6.1 Combustion Process – At this stage a spark is fired by the spark-plug resulting in instantaneous burning of petrol resulting in an explosion. This causes heat to release resulting in generation of expanding forces known as power. Fig-6.2 Petrol Combustion process diagram

7. Power Stroke – These forces again push the pistons downwards resulting in their reciprocating motion. Fig-7.1 Petrol Power Stroke

8. Exhaust Stroke – On their way up, the pistons push the exhaust gases above them thru’ the exhaust valve which opens during the exhaust stroke. Fig-8.1 Petrol Power Stroke

9. CONSTANT VOLUME OR OTTO CYCLE Otto Cycle is also known as Four-Stroke Spark-Ignition Cycle. It was named after German engineer Nikolaus Otto, who invented, developed and patented first Four-Stroke petrol engine. The Four-Stroke petrol engine works on the following cycle. The cycle is so called constant volume because heat is supplied constant volume petrol gas and light oil work on this cycle. In this case petrol engine the proper mixing of petrol and air take place in the carburetor which is situated outside the engine cylinder. Piston Displacement Fig-9.1 Ideal Otto Cycle