It is also made of titanium but the cost for this little high. Crank is made of steel. It is revolving inside the cylinder. One end of it connects with a crankshaft and another end is connected with a piston. It is the house of a crank, crankshaft, lubricating oil, and other fastened engine parts.
The Crankcase is made of cast iron or cast aluminum via sand casting. The crankshaft is made of cast iron or forged steel, steels are generally used for high loading situations in diesel engines.
Ports are generally used in Two-stroke engines such as two-stroke petrol engines. These are the openings for inlet charge and exhaust gases. A spark plug is used for igniting the charge inside the cylinder. The spark plug is only used in Petrol engines.
When it comes to diesel engines, the fuel is sprayed with the help of a fuel pump inside the engine cylinder. In the two-stroke engine, there is 1 power stroke for every 1 revolution of the flywheel.
There are two strokes in a two-stroke engine. Meanwhile, it closes all the three ports name inlet port, transfer port, and exhaust port. Then the charge above the piston is compressed adiabatically. And in the meantime spark plug gives the spark and the charge are ignited and produces a power stroke. The power is transferred to the crankshaft with the help of connecting rod.
During this stroke when the piston moves downward it uncovers the inlet port. During the second stroke, the piston moves down from the top dead center TDC and the inlet port is closed. Since the exhaust port is open, the exhaust gas leaves the cylinder through it but some exhaust gas remains inside the cylinder.
The special shape of the piston head deflects the fresh charge inside the cylinder. This process is called scavenging where with the help of fresh charge, the exhaust gas is pushed out. When the flywheel completes one revolution, then the cycle of operation is repeated.
Generally, a two-stroke petrol engine works in this principle, also for a two-stroke diesel engine the working principle is the same, but there is one little change and that is, a two-stroke diesel engine has a fuel injector instead of the spark plug.
The fuel is sprayed inside the cylinder, due to the high temperature compressed air inside the cylinder, the fuel is ignited. In this system, a certain amount of lubrication oil is mixed with the petrol itself. If it is less it can damage the engine or even if it is more there will be excessive carbon deposits in the cylinder head and the engine will also give dark smoke.
When the petrol mixture is entered into the cylinder due to the high temperature it evolves and leaves a thin film of lubricant over the cylinder wall, crankcase, crankshaft, bearings. Firstly discuss the advantages of 2-stroke engines then go to the disadvantages. Actually recently we are not using these types of engines in Bikes and Cars for the above-mentioned disadvantages.
Also, Two-stroke engines polluted air much more than Four-stroke engines. The construction of four stroke engine is complex than two stroke engines. It is consist of the following components:. The piston moves inside of the cylinder. The intake and exhaust manifold are connected to the cylinder head. The other end of the piston is connected to the connecting rod.
It is generally made up of aluminum alloy. The main purpose of the intake manifold is to supply the charge equally in multi-cylinder engines. It opens only at a suction stroke and remains closed in other strokes.
The movement of the inlet valve is controlled by the camshaft. It opens only at exhaust stroke and remains closed in others strokes. The movement of the outlet valve is also controlled by the camshaft. It avoids leakage of gases from the combustion chamber to the crankcase. As per the working cycle and number of cylinders , the classification of four stroke engine is as follows The four stroke petrol engine is based on the Otto cycle invented by Nicholas auto in The Otto cycle consists of the following cycles,.
Piston sucks the fresh charge from the intake manifold. The pressure in the cylinder increases and it pushes the piston to the bottom dead centre. The four stroke diesel engine is based on the diesel cycle invented by Rudolf diesel auto in The diesel cycle consists of the following cycles,. Piston sucks the fresh air from the intake manifold. Due to the high temperature of Compressed air the fuel ignited automatically.
The pressure in the cylinder increases and it pushes the piston to the bottom dead center. The engine can be cooled by surrounding air by providing fins.
Hence the weight of the engine is less as compared to water-cooled engines. But due to the single cylinder, the engine provides only one power stroke in two complete revolutions of the shaft.
The multi-cylinder engines are used to smooth the power fluctuations and vibrations that occur in single cylinder engine. Depending on the arrangement of cylinders, the multi-cylinder engines are classified as follows :. The four stroke engine has a wide range of applications because of its higher thermal efficiency and higher RPM. It is used in applications where the efficiency requirement is higher.
What is the working principle of 4 stroke petrol engine? The basic working principle of the 4 stroke petrol engine is on the otto cycle. Otto cycle was invented by Nicholas auto in
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