I.C.Engine Valve Timing
- 1. NAME ENROLLMENT NO. Varmora Raxit 150763119027 Prepared By :- I.C.ENGINE VALVE TIMING DIAGRAM
- 2. Actual valve timing diagram for 4 stroke petrol engine
- 3. What is Engine Valve Timing? • Firstly, read here about how the engine valves open & close. An automotive engine uses valves for it’s ‘breathing’ (inhale / exhale) process. • The engine's camshaft opens and closes the valves at specific interval. The timing of opening & closing of valves is specified in degrees corresponding to the position of engine's pistons. Engine valve timing is most critical process of IC engines.
- 4. Explanation • IV opens 20˚ before TDC. • IV closes 35۫ after BDC to takethe advantage of momentum of rapidly moving gases (Ram Effect). • Ignition occurs 35˚ before TDC ; this is to allow the time delay between the spark and commencement of combustion. • EV opens at 35˚ before BDC; else pressure will rise enormously, and the work required to expel the gas will increase. • EV closes at 10˚ after TDC; this is to increase the volumetric efficiency.
- 5. Valve timing diagram for 4-stroke diesel engine
- 6. Valve timing diagram angles for 4- stroke diesel engine
- 7. Port timing diagram for 2- stroke petrol engine
- 8. Port timing diagram angle for 2- stroke petrol engine
- 9. Port timing diagram for 2-stroke diesel engine
- 10. Explanation • The theoretical Port Timing Diagram of a Two Stroke Diesel Engine is shown in the diagram. • The actual Port Timing diagram may be a bit different from this theoretical one depending upon the capacity, load, and need of the engine. • The exhaust port gets uncovered 60 degrees and inlet port gets uncovered 45 degrees ahead of the completion of the second stroke and exhaust port gets covered 60 degrees and inlet port gets covered 45 degrees after the compression stroke i.e. second stroke. • The injection port opens 15 degrees before and closes 20 degrees after the compression.