2. Read and translate the text.

WНАТ IS AN INTERNAL COMBUSTION ENGINE?

The gasoline engine is that type of machine where power generated within the cylinders. The engine is set in motion by the explosions of a mixture of gasoline and air.

Combustion takes place above the pistons. The detachable head is secured to the top of the cylinder block. It encloses the cylinder block and forms the combustion chamber. When the fuel is burnt within the cylinders the expansion of gases is used for producing piston movement. Such a type of engine is called theinternal combustion engine.

In any internal combustion engine the gas charge is drawn into the cylinder.

The internal combustion engine converts heat into mechanical energy by burning a mixture of oil fuel and air within its cylinder or cylinders. The internal combustion engine consists of the following: 1. A cylinder (there may be several). 2. A piston which moves up and down inside cylinder. 3. A crankshaft connected to the piston by a rod known as a connecting rod. The connecting rod turns the up-and-down motion of the piston into a rotary motion of the crankshaft. 4. A flywheel which keeps the crankshaft moving when the pressure is exerted upon the top of the piston. 5. Two valves known as the inlet valve and the exhaust valve. 6. A camshaft which is used to open and close the valves. 'Combustion engines may be divided into types according to the duration of the cycle on which they operate. By a cycle is meant the succession of operations in the engine cylinder which constantly repeats itself. The great majority of modern automobile engines operate on the four-stroke cycle.

It is completed in four strokes of the piston, or during two revolutions of the crankshaft. Engines are also being built to operate on a cycle which is completed in two piston strokes. The four-stroke cycle comprises the following four phases or operations, which succeed one another in the order in which they are given: Admission of the charge to the cylinder. Compression of the charge. Combustion of the charge. Expulsion of the products of combustion.