valve timing diagram of two stroke engine
What is the Mercury 3.5 Hp four stroke valve clearance?
In a two-stroke reed valve engine the reed valve is used to seal the fuel air mixture in the crankcase.
While there may be some overlap of valve opening timing, generally speaking, the exhaust valve opens after the power stroke, and the intake valve opens after the exhaust stroke. Recap... We start the combustion cycle of a standard 4-stroke engine with the intake stroke, the intake valve is open and the vacuum created by the downward movement of the piston draws in the air/fuel mixture from the intake manifold. The intake valve closes as the piston rounds bottom dead center and the compression stroke begins on the upward movement of the piston. At or near the top of the compression stroke, the spark plug fires (both valves are closed at this point) and begins the downward power stroke. As the piston rounds bottom dead center again, the exhaust valve opens to allow the piston to push out the exhaust gasses during the upward exhaust stroke. As the piston gets to the top, the exhaust valve closes and the intake valve opens to start the process over again.
for completely entering of fresh charge the inlet valve opens before suction stroke
It relieves the cylinder of exhaust on the 4th stroke of a 4 stroke engine.
Intake valve and exhaust valve.
Is the time when intake and exhaust valve remain oper during the exhaust stroke.
The most obvious difference is that a two stroke has no valves and valve gear.
Is the time when intake and exhaust valve remain oper during the exhaust stroke.
Valve overlap occurs in a four-stroke engine at the end of the Exhaust stroke and at the beginning of the Induction stroke; and is when both the exhaust and inlet valves are open at the same time. At the end of the Exhaust stroke, the Exhaust valve is closing and the Inlet valve is starting to open in preparation for the induction of fuel and air into the cylinder. It is common knowledge that in vehicles that cannot alter the valve timing, the Inlet valve opens approx 6 degrees before top-dead-centre and the Exhaust valve closes at 9 degrees after top-dead-centre
The purpose of butter fly valve is to maintain one way opening during induction stroke and exhaust stroke.