Why inlet valve opens early and closes late?
IVC (Inlet valve closing) Intake valve closes (IVC) quite late (40°-80°after BDC), to provide more time for fresh charge to enter the cylinder, when the pressure level in the inlet pipe is higher than inside the cylinder.
Why is it so important for inlet & exhaust valves to open and close at exactly the right time?
The valve which allows mixture into the cylinder is the inlet valve; the one through which the spent gases escape is the exhaust valve. They are designed to open and close at precise moments, to allow the engine to run efficiently at all speeds.
When should intake valve open?
The valves are timed so the intake valve opens slightly before the piston reaches top dead center (TDC) on the exhaust stroke. Likewise, the exhaust valve is timed to close just after the piston starts down on the intake stroke.
What is ignition advance?
Ignition advance is the condition when ignition of fuel occurs earlier than the correct ignition timing. Ignition of mixture takes place near the end of compression stroke. Spark advance may also cause the fuel to explode suddenly under certain operating conditions.
When does the inlet valve open and close in an engine?
The inlet valve usually opens few degrees before the piston reaches TDC in its exhaust stroke. It closes after quite a few degrees of piston reaching the BDC, i.e. when the piston starts to move up the cylinder in the compression stroke.
Why inlet Value opens for sometime after completion of suction stroke?
If you open the inlet valve for some more time after the suction stroke,you tend to fill the swept volume nearly complete (say around 85 to 90\%) and hence you increase the volumetric efficiency. Originally Answered: In IC engines, why inlet value opens for sometime after completion of suction stroke?
How does a four stroke IC engine work?
The inlet valve of a four stroke IC engine remains open for 230°. The charge is compressed when both the valves (i.e, inlet valve and exhaust valve) are closed. The charge is ignited with the help of a spark plug. The pressure inside the engine cylinder is above the atmospheric pressure during the exhaust stroke.
What is valve timing in an IC engine?
The timing of the opening & closing of valves is specified in degrees corresponding to the position of engine’s pistons. Engine valve timing is the most critical process of IC engines. The inlet valve usually opens few degrees before the piston reaches TDC in its exhaust stroke.
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