Intake valve and exhaust valve.
NO! definitely a 2 stroke and requires oil in gas.
Jason
valves are use in four stroke engine, and ports are use in two stroke engine.
In a four-stroke engine, the intake valve opens in the intake stroke, allowing air-fuel mixture to enter, while the exhaust valve remains closed. During the compression stroke, both valves stay closed to build pressure. In the power stroke, the fuel ignites, pushing the piston down, with both valves still closed to retain pressure. Finally, in the exhaust stroke, the exhaust valve opens, allowing gases to escape, while the intake valve stays shut. This cycle repeats continuously, ensuring efficient engine operation.
Tappet
Tappet
According to the Gates website ( they make timing belts etcetera ) the 1.8 and the 1.9 liter four cylinder engines used in a 1995 Mercury Tracer are ( NON - INTERFERENCE engines )
4 stroke enngines firstly take four strokes until a full four stroke rotation has occured. (SUCK) fuel is sucked in through the inlet valve. (SQUEEZE) piston compresses fuel air mixture. (BANG) fuel explodes from electromagnetic field created by the coil. (BLOW) outlet valve opens and gases are released out. This is one full power stroke.
There is only one intake stroke in a four-stroke engine. The other three strokes are compression, power, and exhaust. The intake stroke is a down stroke of the piston in which fuel is drawn into the cylinder while the fuel intake valve is open. The next stroke is the compression stroke in which the valves are closed and the fuel is compressed for combustion. The following stroke is the power stroke - a downward stroke of the piston after fuel combustion that drives the crankshaft. The final stroke is the exhaust stroke, an upward stroke of the piston as the exhaust valve opens to relieve the exhaust fuel fumes.
Could be another name for the four stroke cylinder head, which contains the inlet / exhaust valves.
Some two stroke engines have 4 valves, Detroit Diesel 71 series and 53 series engines for example. Most small 2 stroke engines have no "Valves" at all in the sense of the "POP" valve used in four stroke engines. Some people feel these engine has one valve because the piston acts as the valve covering the ports cut into the cylinder walls.