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Q.

What is the Difference Between a Two Stroke and Four Stroke Engine?

Asked by Raghav Handa, 31 May '08 11:36 am
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1.

The basic difference is that in two stoke engine power is produced in every two strokes of movement of piston. In four stroke engines the power is produced only once in four movements of the piston.
Answered by Joseph Chacko, 01 Jun '08 09:52 am

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2.

A 2-stroke engine doesn't have valves, a 4-stroke engine does.

In combustion engines the inner energy set free by combustion (e.g. of gasoline or Diesel fuel ) is changed partly into mechanical energy. There are several varieties of combustion engine. The most common is the four-stroke Otto Engine, which was invented by the German merchant and engineer Nikolaus August Otto in 1876.

The working mechanism of the four-stroke Otto-Cycle: The engine's cylinder has got two valves, the intake valve and the exhaust valve, which are opened and closed by a camshaft mechanism. A crank moves the piston in the cylinder bymeans of a "connecting rod".

The operation of the engine is divided into 4 parts, which are called strokes:
-1st stroke (Intake): The piston sucks in the fuel-air-mixture from the carburetor into the cylinder.
-2nd stroke (Compression): The piston compresses the mixture.
-3rd stroke (Combustion): The spark from the spark plug inflames the mixture. The following explos ...more
Answered by sudesh, 01 Jun '08 09:49 pm

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3.

2-stroke engine doesn't have valves, a 4-stroke engine does.
Answered by rajan, 23 Jun '13 03:46 pm

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4.

To understand the mechanical differences between a two stroke and four stroke engine, lets first consider how the four stroke engine works. The four strokes are:
Intake: The piston travels down the cylinder while the intake valve is opened to allow a mixture of fuel and air to enter the combustion chamber.
Compression: The intake valve is closed and the piston travels back up the cylinder thereby compressing the gasses.
Combustion: The spark plug ignites the compressed gas causing it to explode, which forces the piston down.
Exhaust: The piston rises up the cylinder as the exhaust valve is opened, allowing the piston to clear the chamber to start the process over.
Each time the piston rises and falls it turns the crankshaft that is responsible for turning the wheels. This is how fuel is converted into forward motion.
Of note here is that the spark plug only fires once every other revolution. Also, there is a sophisticated set of mechanisms working in synchronization to create t ...more
Answered by GOPI KUMAR, 31 May '08 11:39 am

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5.

A 2-stroke engine doesn't have valves, a 4-stroke engine does
Answered by basavaraj bm, 31 May '08 11:39 am

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6.

Combustion cycle completed in 2/4 strokes of engine
Answered by dhanendra kumar jain, 31 May '08 11:38 am

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7.

- Two-stroke have simpler construction.
- Two-stroke are more powerful (twice for the same engine size).
- Two-stroke are lighte and cheaper.

- Two-stroke have shorter life (lubrication system).
- Two-stroke oil is expensive/
- Two-stroke consumes and pollutes more.
- Two-stroke engines produce more pollution.
Source: http://www.bigbestlawnmower.com
Answered by Albert Peters, 30 Nov '13 02:51 pm

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8.

The basic difference is that in two stoke engine power is produced in every two strokes of movement of piston. In four stroke engines the power is produced only once in four movements of the piston.
Answered by Quest, 10 Aug '13 11:39 am

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9.

2-stroke engine doesn't have valves, a 4-stroke engine does.
Answered by iqbal seth, 09 Aug '13 03:50 pm

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10.

The BA is detailed enough
Answered by anil garg, 05 May '10 01:58 am

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