Educational Revolution

        Valve Timing Diagram for a Four Stroke Cycle Petrol Engine -The petrol engines is also known as spark ignition engines.The valve timing diagram for a four stroke cycle petrol engine is shown in Figure: The following particulars are important for a four stroke cycle petrol engine regarding valve timing diagram: (a)           The inlet valve opens (IVO) at 10 °- 20 ° before top dead center (TDC) and closes 30 ° - 40 ° after bottom dead center (BDC). (b)          The compression of charge starts at 30 ° - 40 ° after BDC and ends at 20 ° - 30 ° before TDC. (c)            The ignition (IGN) of charge takes place at 20 ° - 30 ° before TDC. (d)          The expansion starts at 20 ° - 30 ° before TDC and ends at 30 ° - 50 ° before BDC. (e)           The exhaust valve opens (EVO) at 30 ° - 50 ° before BDC and closes at 10 ° - 15 ° after TDC. Note:- (i)                          The inlet valve of a four stroke I.C. engine remains open for 230 °. (ii)            

Each stroke in IC(internal combustion) engines forms a sequence of operations in one cycle of IC Engines. These are the name of four strokes.   Ø Suction stroke   Ø Compression stroke   Ø Expansion stroke   Ø Exhaust stroke Strictly speaking, when an engine is working continuously, we may consider a cycle starting from any stroke. We know that when the engine returns back to the stroke where it started, we say that one cycle has completed. The following sequence of operation in a cycle is widely used. 1.   Suction stroke In this stroke, the fuel vapor in correct proportion is supplied to the engine cylinder. 2.   Compression stroke In this stroke, the fuel vapor is compressed in the engine cylinder. 3.   Expansion or working stroke In this stroke, the fuel vapor is fired just before the compression is complete. It results in the sudden rise of pressure, due to expansion of the combustion products in the engine cylind

Two Stroke vs Four Stroke Enigne – Advantages and Disadvantages of Two Stroke over Four Stroke Cycle Engines. In a two stroke engine, the working cycle is completed in two strokes of the piston or one revolution of the crankshaft. In a four stroke engine, the working cycle is completed in four strokes of the piston or two revolutions of the crankshaft. The following are the advantages and disadvantages of two stroke over four stroke cycle engines: Advantages: 1.   A two stroke cycle engine gives twice the number of power strokes than the four stroke cycle engine at the same engine speed. Theoretically, a two stroke cycle engine should develop twice the power as that of a four stroke cycle engine. 2.    For the same power developed, a two stroke cycle engine is lighter, less bulky and occupies less floor area. 3.    A two stroke cycle engine has a lighter flywheel and gives higher mechanical efficiency than a four stroke cycle engine. Disadvantages: 1.   The thermal

    Mechanical Engineers are multi-skilled One might refer to a qualified mechanical engineer as a jack-of-all-trades, and those in the engineering sector often do. Mechanical engineers have a working knowledge of computer applications, electricity, structures, mathematics, and physics, plus they’re required to have some understanding of social, environmental, and economic factors. Global opportunities for Mechanical Engineer There isn’t a country in the world that doesn’t need its engineers and there are a number of mechanical engineering courses which can testify to that. Mechanical Engineer provide affiance solutions to the development of process and product ranging small components design to large machinery.Mechanical Engineer create and develop mechanical systems for all of humankind. Concerned with the principles of force, energy and motion, mechanical engineer use knowledge of design manufacture and operational processes to advance world around us-Enhan

          A spark plug is a device which provides initial current to ignite the fuel it takes power from battery when we kick or turn the starter pedal. Spark plug is used only in patrol engines because in diesel engine due to high compression ratio the diesel ignite itself but it is not happened with patrol engine due to low compression ratio. It has following major parts.   Ø Insulator   Ø Ground Electrode   Ø Central Electrode   Ø Terminal   Ø Tip