PETROL ENGINES

PETROL ENGINES Most engines use a fuel as their energy store.The fuel is burnt to produce heat energy,which is then converted into movement What is an engine? It is a device for converting stored energy into useful work or movement .

CLASSIFICATION OF ENGINES Engines can be classified according to the fuel they use PETROL ENGINES DIESEL ENGINES

CLASSIFICATION OF ENGINES Engines can be classified according to the fuel they use PETROL ENGINES DIESEL ENGINES

CLASSIFICATION OF ENGINES Engines can be classified according to the fuel they use PETROL ENGINES DIESEL ENGINES

CLASSIFICATION OF ENGINES (Contd..) Engines can also be classified according to whether the fuel is burnt inside or outside the engine INTERNAL COMBUSTION ENGINES EXTERNALENGINES(Steam Engine)

CLASSIFICATION OF ENGINES (Contd..) Engines can also be classified according to whether the fuel is burnt inside or outside the engine INTERNAL COMBUSTION ENGINES EXTERNALENGINES(Steam Engine)

CLASSIFICATION OF ENGINES (Contd..) Engines can also be classified according to whether the fuel is burnt inside or outside the engine INTERNAL COMBUSTION ENGINES EXTERNALENGINES(Steam Engine)

TYPES OF PETROL ENGINES 7.Number of strokes used . 1.Number of cylinders 2.Cylinder arrangements The Petrol engines may be classified according to 3.Valve arrangements 4.Speed of the engines 5.Cooling system 6.Lubrication system used

HORIZONTAL ENGINE

VERTICAL CYLINDER FOUR STROKE ENGINE

VERTICAL CYLINDER TWO STROKE ENGINE

TWIN CYLINER ENGINE

V TYPE STIRLING ENGINES

SIX CYLINDER ENGINE

ROTARY ENGINE

WANKEL ENGINE/ROTARY ENGINE

FOUR CYLINDER ENGINE

Horizontally opposed engine

RADIAL ENGINE

INLET PORT EXHAUST PORT TRANSFER PORT CYLINDER SPARK PLUG PARTS OF ANTWO STROKE ENGINE

TWO STROKE ENGINES In this type of engines the cycle is completed in two strokes.When the piston moves from B.D.C to T.D.C, the air and fuel mixture is taken inside the crank case. T D C position B D C position

T D C B D C Stroke is the distance of the piston travels from BDC to TDC STROKE This measurements are used to figure the piston displacement stroke

When the piston moves from T.D.C to B.D.C the inlet port is closed, the mixture is compressed and transferred the into the cylinder through transfer port. Inlet port exhaust port piston Transfer port

When the piston moves from T.D.C to B.D.C the inlet port is closed, the mixture is compressed and transferred the into the cylinder through transfer port. Inlet port exhaust port piston Transfer port

When the piston moves from T.D.C to B.D.C the inlet port is closed, the mixture is compressed and transferred the into the cylinder through transfer port. Inlet port exhaust port piston Transfer port

When the piston is moving upward ,the mixture is compressed. At the same time,air and fuel mixture is coming into the crankcase. Inlet port exhaust port Transfer port NO FUEL MIXTURE AVAILABLE

Compressed mixture When the piston is moving upward ,the mixture is compressed. At the same time,air and fuel mixture is coming into the crankcase. Inlet port exhaust port Transfer port

At the end of the compression stroke, a spark is given by a spark plug.The fuel mixture expands rapidly.A high power is produced. This power forces the piston downwards.So the piston moves from T.D.C to B.D.C Burning the fuel mixture Inlet port exhaust port Transfer port

When the piston comes down, the exhaust port opens and exhaust gases are going out.At the same time,the transfer port also opens and the fresh mixture comes inside the cylinder Thus the four strokes are completed in two strokes of the engine Inlet port exhaust port Transfer port

When the piston comes down, the exhaust port opens and exhaust gases are going out.At the same time,the transfer port also opens and the fresh mixture comes inside the cylinder Thus the four strokes are completed in two strokes of the engine Inlet port exhaust port Transfer port exhaust port Transfer port

ADVANTAGES OF TWO STROKE ENGINES 1.Simple in construction 2.Easy to manufacture 3.Low cost 4.Simple lubrication system 5.Uniform power production (one power stroke for every revolution of the crank shaft) 6.There is no separate valve operating mechanism 7.More power is produced

DISADVANTAGES OF TWO STROKE PETROL ENGINES 1.It consumes more lubrication oil 2.Wear and tear more 3 Not suitable for heavy duty engines 4.More wastage (unburnt fuel may escape through port) 5.The dead gases can not be removed completely

FOUR STROKE ENGINES FIRST STROKE –SUCTION STROKE While the inlet valve is open ,the descending piston draws fresh petrol and air mixture into the cylinder. Fig.

Fig. IN LET VALVE OPEN POSITION EXHAUST VALVE CLOSE POSITION FOUR STROKE ENGINES FIRST STROKE –SUCTION STROKE While the inlet valve is open ,the descending piston draws fresh petrol and air mixture into the cylinder.

Fig. IN LET VALVE OPEN POSITION EXHAUST VALVE CLOSE POSITION FOUR STROKE ENGINES FIRST STROKE –SUCTION STROKE While the inlet valve is open ,the descending piston draws fresh petrol and air mixture into the cylinder.

Fig. IN LET VALVE OPEN POSITION EXHAUST VALVE CLOSE POSITION FOUR STROKE ENGINES FIRST STROKE –SUCTION STROKE While the inlet valve is open ,the descending piston draws fresh petrol and air mixture into the cylinder.

Fig. IN LET VALVE OPEN POSITION EXHAUST VALVE CLOSE POSITION FOUR STROKE ENGINES FIRST STROKE –SUCTION STROKE While the inlet valve is open ,the descending piston draws fresh petrol and air mixture into the cylinder.

SECOND STROKE-COMPRESSION STROKE While the valves are closed,the rising piston compresses the mixture to a pressure about 7-8atm; the mixture is then ignited by the spark plug. Fig. IN LET VALVE CLOSE POSITION EXHAUST VALVE CLOSE POSITION

Fig. IN LET VALVE CLOSE POSITION EXHAUST VALVE CLOSE POSITION SECOND STROKE-COMPRESSION STROKE While the valves are closed,the rising piston compresses the mixture to a pressure about 7-8atm; the mixture is then ignited by the spark plug.

Fig. IN LET VALVE CLOSE POSITION EXHAUST VALVE CLOSE POSITION SECOND STROKE-COMPRESSION STROKE While the valves are closed,the rising piston compresses the mixture to a pressure about 7-8atm; the mixture is then ignited by the spark plug.

Fig. IN LET VALVE CLOSE POSITION EXHAUST VALVE CLOSE POSITION SECOND STROKE-COMPRESSION STROKE While the valves are closed,the rising piston compresses the mixture to a pressure about 7-8atm; the mixture is then ignited by the spark plug.

THIRD STROKE-POWER STROKE While the valves are closed the pressure of the burned gases of the combustion forces push the piston downwards. Fig. IN LET VALVE CLOSE POSITION EXHAUST VALVE OPEN POSITION

FOURTH STROKE-EXHAUST STROKE The exhaust valve is open and the rising piston discharges the spent gases from the cylinder. Fig.

SUCTION STROKE

COMPRESSION STROKE

POWER STROKE

EXHAUST STROKE

1.Less fuel consumption 2.Thermal efficiency is more ADVANTAGES OF FOUR STROKE ENGINES 3.More volumetric efficiency 4.Less wear and tear.

DISADVANTAGES OF FOUR STROKE ENGINES 4.More complicated design. 1.More components 2.Separate valve operating mechanism is required. 3.More cost

PISTON ARRANGEMENT IN TWIN CYLINDER ENGINE CRANK SHAFT CONNECTING ROD

PISTON ARRANGEMENT IN FOUR CYLINDER ENGINE

PISTON ARRANGEMENT IN FIVE CYLINDER ENGINE

PISTON PISTON RINGS PISTON PIN BOSS PISTON SKIRT PISTON TOP RING GROOVES FIRE RING

CYLINDER,PISTON, SPARK PLUG AND VALVES ARRANGEMENT