Quote:
The Compression Stroke
1 The piston moves back up, compressing the fuel/air mixture into a tiny space between the top of the piston and the top of the cylinder. This space is called the combustion chamber. It also happens to be where the spark-plug electrode end enters the cylinder. The fuel/air mixture is compressed into about 1/10 the space it occupied before the piston moved up, and this 10:1 compression ratio increases the pressure in the combustion chamber to about 200 psi (pounds per square inch). Normal air pressure is 15 psi. The reason this is necessary is that compression will make the explosion much more intense than it would have been if the fuel/air mixture had been allowed to spread out. So, when the compressed mixture is ignited, the pressure will increase another four times, creating a heck of a lot of power when it explodes!
2 At this point, the intake valve has closed, so the compressed mixture can't go out. Both the intake and exhaust valves have seals to ensure that nothing can get past them when they are closed.
The Power Stroke
1 The spark plug produces a spark across the gap between its electrodes, which ignites the compressed fuel/air mixture.
2 The burning fuel/air mixture explodes, creating intense pressure that forces the piston down again. The power that pushed the piston down is transmitted, via the connecting rod, to the crankshaft. It then travels, via the drive train, through the clutch, the transmission, the driveshaft, to the differential, and so on to the wheels.
The Exhaust Stroke
1 The piston moves up again, pushing the burned gases up with it.
2 The exhaust valve opens and lets the burned gases out into the exhaust manifold.
3 From there, they travel through the exhaust system (which, on newer cars, includes antipollution devices), through the muffler and out the tail pipe into the air.
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This is the last of the homeworks I have on Engines. I've been working on such texts for three weeks and I still get mixed up between the crankshaft and the camshaft. (first stoke missing from the clipboard because I already translated it)
Ya'll lucky the homework for my other class was not on there... Constitutional Law (cue scary music)
