sheshnarayan 155

GREATER NOIDA INSTITUTE OF TECHNOLOGY

(2015-16)

DEPARTMENT OF MECHANICAL ENGG.SEMINAR PRESENTATION

ON

4- stroke petrol engine

Submitted To: Submitted By:

Mr. Syed Qaiser Husain Sheshnarayan Yadav

CONTENTS

INTRODUCTION OF PETROL ENGINE PARTS WORKING VALVE TIMING 2 STROKE V/S 4 STROKE ENGINE PETROL ENGINE V/S DIESEL ENGINE ADVANTAGES & DISADVANTAGES

INTRODUCTION OF PETROL ENGINE

Uses Petrol As A Fuel. Inside The Combustion Of Fuel Produces Hot Gases That Expand

Against Parts Of The Engine The Engine And Cause Them To Move. For This Reason, Petrol Engines Are Called Internal-combustion

Engines. A Petrol Engine Turns Heat Energy Into Mechanical Work. Produces Work Is Usually Measured In Horsepower Or Watts. Nearly All Cars, Lawn Mowers, Motorcycles, Motor Scooters,

Snowmobiles, And Small Tractors Have Petrol Engines. So Do Many Trucks, Buses, Aeroplanes, And Small Boats.

TYPES OF PETROL ENGINE2-STROKE PETROL

ENGINE

4-STROKE PETROL ENGINE

4-STROKE PETROL ENGINE A four-stroke engine:

The first four stroke spark-ignition (S.I.) engine was built in 1876 by Nicolaus August Otto, a self-taught German engineer

it is an internal combustion engine Converts gasoline into motion the piston completes four separate strokes while

turning a crank shafts the most common car engine type Is relatively efficient Is relatively inexpensive

PARTS OF 4-STROKE PETROL ENGINE

CYLINDER BLOCKCYLINDERSCYLINDER HEADCRANKCASEPISTON AND

CONNECTING RODS

LUBRICATION SYSTEM

CRANK SHAFTFLYWHEELVALVESCAMSHAFT FUEL SYSTEMEXHAUST

SYSTEM

WORKING

INTAKE STROKE

COMPRESSION STROKE

POWER STROKE

EXHAUST STROKE

VALVE TIMING

2 STROKE V/S 4 STROKE ENGINE4-STROKE ENGINE

It has one power stroke for every two revolutions of the crankshaft.

Engine is heavy.

Engine design is complicated due to valve mechanism.

More cost.

Less mechanical efficiency.

Engine runs cooler.

Less fuel consumption 

Engine requires more space.

Less noise.

More thermal efficiency.

consumes less lubricating oil.

2-STROKE ENGINE

It has one power stroke for each revolution of the crankshaft.

Engine is light.

Engine design is simple due to absence of valve mechanism.

Less cost.

More mechanical efficiency.

Engine runs hotter.

More fuel consumption.

Engine requires less space.

More noise.

Less thermal efficiency.

consumes more lubricating oil.

PETROL ENGINE V/S DIESEL ENGINEPETROL ENGINE

In a petrol engine, the explosion process is: Intake stroke – fuel is

mixed with air Compression stroke –

piston goes up, mixture of fuel and air is compressed

Ignition stroke – fuel/air is ignited through the use of a spark plug

Exhaust stroke – piston goes up, pushes exhaust through the exhaust valve

DIESEL ENGINEIn a diesel engine, the explosion process is: Intake stroke – intake valve

opens, air in, piston goes down Compression stroke – piston

goes up, air compressed (heated upto 3000k)

Combustion stroke – fuel is injected (right time), ignition, piston goes down

Exhaust – piston goes up, pushes exhaust through the exhaust valve

ADVANTAGES

More TorqueLast LongerRun Much Cleaner Than 2 Strokes

More Efficient Use Of Gas

DISADVANTAGES

ComplicatedHalf As Powerful As Two Stroke Engines

More Expensive Than 2 Stroke

THE END