Combustion Engine

1.0

INTRODUCTION OF ENGINE In our life, vehicle is very important thing because vehicle will make us easily

to going anywhere we want. It’s can make our journey short and not take too long time. So, we use engine to make vehicle function. We separate engine with 3 part, on air use, on water use and on land use. 1.1

Separation on engine :1)

Petrol engine

•

2-stroke

•

4-stroke

2)

Diesel engine

•

2-stroke

•

4-stroke

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2.0

OPERATIONAL 2.1

4-STROKE ENGINE

1)

Intake stroke •

Moving piston from TDC (Top Dead Center) to BDC (Bottom Dead Center)

•

Intake valve open and exhaust valve close.

•

Draws a air into the combustion chamber.

2)

Compression stroke •

Moving piston from BDC (Bottom Dead Center) to TDC (Top Dead Center).

•

Both valve are close

•

The air is compressed by piston.

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3)

Power stroke •

Before TDC ( Top Dead Center), temperature air inside combustion chamber increase until 500oC – 700oC.

•

Injector nozzle sprayed a fuel into combustion chamber.

•

Explosion is happen and pressure inside combustion chamber increase and pushing piston from TDC (Top Dead Center) to BDC (Bottom Dead Center).

3)

Exhaust stroke •

Intake valve is close and exhaust valve is open.

•

Piston moving from BDC (Bottom Dead Center) to TDC (Top Dead Center).

•

Piston will push out a gas from combustion chamber.

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2.2

ENGINE 2-STROKE 1)

Intake stroke and Compression stroke •

The air/fuel mixture has entered the cylinder.

•

The piston begins to move up. This compresses the charge in the cylinder and draws a vacuum in the crankcase, pulling in more air, fuel, and oil from the carburetor.

•

The compressed charge is ignited by the spark plug, and the cycle begins again.

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2)

Power stroke and Exhaust stroke •

This stroke occurs immediately after the ignition of the charge.

•

The piston is forced down.

•

After a certain point, the top of the piston passes the exhaust port, and most of the pressurized exhaust gases escape.

•

As the piston continues down, it compresses the air/fuel/ mixture in the crankcase.

•

Once the top of the piston passes the transfer port, the compressed charge enters the cylinder from the crankcase and any remaining exhaust is forced out.

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3.0

CIRCULATION DIAGRAM FOR MOTOR DIESEL AND PETROL 3.1

Motor Petrol C

P (pressure)

D

B A

V (volume)

•

A-B

: Compression

•

B

: Ignition plug

•

B-C

: Combustion/ pressure increase

•

C-D

: Power

•

D-A

: Exhaust

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3.2

Motor Diesel P (pressure)

B

C

D

A

V (volume)

•

A-B

: Compression

•

B

: Fuel Injection

•

B-C

: Pembakaran / tekanan constant

•

C-D

: Power

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•

4.0

D-A

: Ekzos / pembuangan sisa gas

DIFFERENTIATION MOTOR DIESEL 2-STROKE VS 4-STROKE

4-STROKE

2-STROKE

•

Medium construction

•

Construction- complicated

•

Use valve

•

For general not use a valve

•

Rotation sound is long

•

Rotation sound is short

•

Used fuel by the common way

•

Using a pump blower

5.0

ADVANTAGE AND DISADVANTAGE OF MOTOR DIESEL 5.1

Advantage motor diesel •

Price of fuel is generous than petrol

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•

Dangerous of explosion is less

•

Exhaust gases not poisonous

•

The energy from diesel engine was power than petrol engine

5.2

Disadvantage motor petrol •

Price of injection pump is very expensive.

•

Injection nozzle needed the regular maintenance

•

Machine vibration is bigger

•

Bigger energy starter is required

•

Price of maintenance is expensive.

6.0

ADVANTAGE AND DISADVANTAGE OF MOTOR PETROL 6.1

Advantage motor petrol

•

Operational in high speed engine rotation.

•

Engine sound is more silence

•

Regular maintenance schedule

6.2

Disadvantage motor petrol

•

Price of diesel fuel expensive than petrol.

•

Not suitable for heavy vehicle such as lorry, ship and etc.

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