Author: haroonkhan

Valve timing diagram for 4-s CI engine is shown in Figure 6.14 and timings are tabulated in Table 6.5. Figure 6.14 Valve Timing Diagram for Four Strokes CI Engines The timings for valves for 4-s CI engines is summarized in Table 6.5.   Table 6.5 Valve Timing for Four Strokes CI Engines Valve activity Theoretical timing Actual timing Inlet valve opens…

Port timing diagram for 2-s SI engines is shown in Figure 6.13. Figure 6.13 Port Timing Diagram for Two Strokes SI Engines The timings for ports for 2-s SI engines is summarized in Table 6.4.   Table 6.4 Port Timing for Two Strokes SI Engines Position Actual timing Inlet port opens 35° before BDC Inlet port closes 35° after…

Valve Timing Diagram for Four Strokes SI Engines Valve timing diagram is a graphical representation of valves opening and closing time with ignition time in terms of angle of crank revolution. Figure 6.12 shows the valve timing diagram for low speed four strokes SI engines. Practically valve cannot be opened or closed at any sharp points. Therefore,…

Comparison between Otto cycle and diesel cycle is summarized in Table 6.2b. Table 6.2b Comparison Between Otto Cycle and Diesel Cycle Otto cycle Diesel cycle In Otto cycle, heat added and rejected at constant volume.For same compression ratio, Otto cycle is more efficient than that of diesel cycle.Otto cycle is used in S.I engines. In diesel cycle,…

Comparison between SI and CI engines is summarized in Table 6.2a.   Table 6.2a Comparison Between SI and CI Engines SI engines CI engines It is based on Otto cycle or constant volume heat addition and rejection cycle.A high volatile, high self-ignition temperature fuel, gasoline is used.A gaseous mixture of fuel and air is inducted during suction…

The working of two strokes CI engine is very similar to two stroke SI engine. The main difference is that in CI engine supercharged air is used through the inlet port and in place of exhaust ports exhaust valves are used. Pressurized air is inducted through the inlet port which expels the combustion gases through…

In a four stroke SI engine, there is one power stroke in two revolutions of crankshaft and two strokes, viz., suction and exhausts are non-productive. If these two non-productive strokes could be served by an alternative arrangement especially without movement of the piston then there will be one power stroke for each revolution of the…

The four stroke compression ignition (CI) engine is very similar to the four-stroke spark ignition engine as shown in Figure 6.6, but it operates at a much higher compression ratio. The compression ratio of SI engines varies from 6 to 10 whereas in CI engines it ranges from 16 to 20. During the suction stroke, air…

The four stroke compression ignition (CI) engine is very similar to the four-stroke spark ignition engine as shown in Figure 6.6, but it operates at a much higher compression ratio. The compression ratio of SI engines varies from 6 to 10 whereas in CI engines it ranges from 16 to 20. During the suction stroke, air…

Working principle of an IC engine consists of thermodynamic cycle involved to generate the power and thermodynamic processes such as suction, compression, heat addition expansion and heat rejection. In this chapter, we will study the operating principles of four strokes and two strokes of spark ignition engine and compression ignition engine.