diff between 2stroke & 4stroke engines.?

Question

which is better.

Answer 1

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.

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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 the four strokes. A camshaft must alternately tip a rocker arm attached either to the intake or exhaust valve. The rocker arm returns to its closed position via a spring. The valves must be seated properly in the cylinder head to avoid compression leaks. In other words, a symphony of mechanical events occurs.

In the two stroke engine, all four events are integrated into one simple downward stroke, and one upward stroke. Two strokes. Intake and exhaust are both integrated into the compression and combustion movement of the piston, eliminating the need for valves. This is accomplished by an inlet and exhaust port in the wall of the combustion chamber itself. As the piston travels downward from combustion, the exhaust port is exposed allowing the spent gasses to rush out of the chamber. The downward stroke also creates suction that draws in new air/fuel through an inlet located lower in the chamber. As the piston rises again, it blocks off the inlet and port, compressing the gasses at the top of the chamber. The spark plug fires and the process starts over. Significantly, the engine fires on every revolution, giving the two stroke its power advantage.

Answer 2

I.C.Engines are of two types considering the types of strokes. They are :- 1. 2-stroke 2. 4-stroke.
The working is as follows.-
1.Two stroke:- in this type the four steps of producing power is completed in one revolution of the crank shaft.the first 180 degrees of rotation does the intake of gases and the combustion of the compressed gases which were sucked during the previous rotation. In the next 180 degrees of rotation the compression and exhaust takes place. So when you consider the four steps, they are actually completed in one complete rotation of the crankshaft.Hence one power stroke is developed every rotation of the crank shaft.
2.Four stroke:- Whereas in a four stroke engine every 180 degree rotation of the crankshaft completes only one process of the four steps. Like in the first half rotation the suction of air fuel mixture takes place. In the second compression takes place, third the combustion is done and the final half is for exhaust of burnt gases.So taking into account all the four steps, the total rotations is two.so one power stroke is generated every two rotations of the crank shaft.

Answer 3

2 Stroke engine production is closed.
4 Stroke engine is much smarter and efficient than 2 Stroke.
And only in production in India.

Answer 4

a two stroke engine fires every time the piston goes up to the top of the cylinder. this type of engine requires no valves. a four stroke engine fires every second time the piston goes to the top and this type of engine requires a set of intake and exhaust valves.

Answer 5

2 stroke has no oil pump 4 stroke does, 2 stroke is used in lawm mowers weed eaters dirt bikes chain saws, 4 stroke is used in the automobile motorcycles.

Answer 6

4 strokes have
intake, compression, power, exhaust

2 strokes have
intake and compresson as one, and power and exhaust as one

Answer 7

2 stroke mixes the oil and gas itself
4 stroke has to be premixed

Answer 8

Asked and well answered already:-

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