[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:03.48,Default,,0000,0000,0000,,I'm Jake O 'Neill, creator of Animagraffs,
Dialogue: 0,0:00:03.48,0:00:05.70,Default,,0000,0000,0000,,and this is how a car engine works.
Dialogue: 0,0:00:07.28,0:00:08.96,Default,,0000,0000,0000,,Let's start at a single piston,
Dialogue: 0,0:00:09.64,0:00:12.82,Default,,0000,0000,0000,,the powerhouse of the engine, and work our way outwards.
Dialogue: 0,0:00:14.92,0:00:16.20,Default,,0000,0000,0000,,The 4 stroke cycle.
Dialogue: 0,0:00:17.52,0:00:19.82,Default,,0000,0000,0000,,When a piston travels to the end of its range,
Dialogue: 0,0:00:20.46,0:00:23.08,Default,,0000,0000,0000,,whether up or down, that's a stroke.
Dialogue: 0,0:00:24.74,0:00:28.98,Default,,0000,0000,0000,,Car engines use a 4 stroke cycle, and it goes like this.
Dialogue: 0,0:00:30.00,0:00:31.36,Default,,0000,0000,0000,,First, intake.
Dialogue: 0,0:00:32.10,0:00:33.08,Default,,0000,0000,0000,,The piston descends,
Dialogue: 0,0:00:33.92,0:00:37.22,Default,,0000,0000,0000,,sucking an air-fuel mixture into the cylinder through the
Dialogue: 0,0:00:37.22,0:00:40.72,Default,,0000,0000,0000,,intake port, with both intake valves open.
Dialogue: 0,0:00:42.28,0:00:43.74,Default,,0000,0000,0000,,Next, compression.
Dialogue: 0,0:00:45.08,0:00:48.42,Default,,0000,0000,0000,,With all valves closed, the piston comes back up,
Dialogue: 0,0:00:48.88,0:00:51.42,Default,,0000,0000,0000,,compressing the fuel and air mixture for more powerful
Dialogue: 0,0:00:51.42,0:00:51.92,Default,,0000,0000,0000,,combustion.
Dialogue: 0,0:00:54.70,0:00:56.70,Default,,0000,0000,0000,,Then, the power stroke.
Dialogue: 0,0:00:56.70,0:01:00.96,Default,,0000,0000,0000,,An electrical spark ignites the compressed fuel and air
Dialogue: 0,0:01:00.96,0:01:01.38,Default,,0000,0000,0000,,mixture,
Dialogue: 0,0:01:02.22,0:01:04.88,Default,,0000,0000,0000,,and the resulting combustion forces the piston to the
Dialogue: 0,0:01:04.88,0:01:06.10,Default,,0000,0000,0000,,bottom of the cylinder again.
Dialogue: 0,0:01:07.48,0:01:10.66,Default,,0000,0000,0000,,A connecting rod transfers this power to the crankshaft.
Dialogue: 0,0:01:12.96,0:01:14.16,Default,,0000,0000,0000,,Finally, exhaust.
Dialogue: 0,0:01:15.22,0:01:16.94,Default,,0000,0000,0000,,The piston comes back up,
Dialogue: 0,0:01:17.56,0:01:20.30,Default,,0000,0000,0000,,pushing the spent mixture out through open exhaust valves
Dialogue: 0,0:01:20.30,0:01:25.66,Default,,0000,0000,0000,,and the exhaust port connecting multiple pistons.
Dialogue: 0,0:01:26.70,0:01:29.94,Default,,0000,0000,0000,,For smooth power delivery, pistons take turns firing.
Dialogue: 0,0:01:30.82,0:01:35.98,Default,,0000,0000,0000,,The firing order for this engine is one, three, four, two.
Dialogue: 0,0:01:37.34,0:01:39.94,Default,,0000,0000,0000,,Camshafts, with specially shaped cams,
Dialogue: 0,0:01:40.60,0:01:42.98,Default,,0000,0000,0000,,push spring-loaded valves open in turn.
Dialogue: 0,0:01:46.02,0:01:49.82,Default,,0000,0000,0000,,Cam gears and a timing belt or chain links everything to
Dialogue: 0,0:01:49.82,0:01:52.60,Default,,0000,0000,0000,,the crankshaft, and it all spins together.
Dialogue: 0,0:01:56.70,0:01:59.96,Default,,0000,0000,0000,,The crankshaft translates piston power out of the engine.
Dialogue: 0,0:02:00.60,0:02:04.24,Default,,0000,0000,0000,,It has counterweights to balance against the pistons for
Dialogue: 0,0:02:04.24,0:02:05.50,Default,,0000,0000,0000,,perfectly smooth revolutions.
Dialogue: 0,0:02:07.92,0:02:09.46,Default,,0000,0000,0000,,This is what RPM means.
Dialogue: 0,0:02:10.18,0:02:12.70,Default,,0000,0000,0000,,We're counting the number of full crankshaft revolutions
Dialogue: 0,0:02:12.70,0:02:13.30,Default,,0000,0000,0000,,per minute.
Dialogue: 0,0:02:16.30,0:02:20.90,Default,,0000,0000,0000,,The engine block holds the crankshaft and cylinders and the
Dialogue: 0,0:02:20.90,0:02:24.70,Default,,0000,0000,0000,,cylinder head holds valves, ports, cams, etc.
Dialogue: 0,0:02:25.70,0:02:29.72,Default,,0000,0000,0000,,The geared flywheel sits at one side of the crankshaft for
Dialogue: 0,0:02:29.72,0:02:30.84,Default,,0000,0000,0000,,connection to a transmission.
Dialogue: 0,0:02:32.00,0:02:34.28,Default,,0000,0000,0000,,It's also where the starter connects to the system.
Dialogue: 0,0:02:35.82,0:02:39.40,Default,,0000,0000,0000,,This engine has four cylinders arranged in a single row,
Dialogue: 0,0:02:40.22,0:02:42.58,Default,,0000,0000,0000,,but there are many other possible configurations,
Dialogue: 0,0:02:43.46,0:02:45.98,Default,,0000,0000,0000,,like six cylinders with three on each side,
Dialogue: 0,0:02:46.54,0:02:48.54,Default,,0000,0000,0000,,angled in a v-shape, or eight.
Dialogue: 0,0:02:49.90,0:02:51.28,Default,,0000,0000,0000,,Despite different design goals,
Dialogue: 0,0:02:51.52,0:02:53.56,Default,,0000,0000,0000,,the basic engine parts are all there.
Dialogue: 0,0:02:55.22,0:02:57.50,Default,,0000,0000,0000,,Now let's look at other systems that support this
Dialogue: 0,0:02:57.50,0:02:58.44,Default,,0000,0000,0000,,combustion process.
Dialogue: 0,0:03:02.70,0:03:03.94,Default,,0000,0000,0000,,Air intake.
Dialogue: 0,0:03:05.96,0:03:11.72,Default,,0000,0000,0000,,Air comes in through the air filter and then into the
Dialogue: 0,0:03:11.72,0:03:15.02,Default,,0000,0000,0000,,intake manifold where it mixes with fuel before being
Dialogue: 0,0:03:15.02,0:03:18.26,Default,,0000,0000,0000,,sucked into individual cylinders through intake ports.
Dialogue: 0,0:03:25.00,0:03:25.74,Default,,0000,0000,0000,,Fuel.
Dialogue: 0,0:03:29.86,0:03:36.82,Default,,0000,0000,0000,,The fuel pump carries gas from the tank through a fuel
Dialogue: 0,0:03:36.82,0:03:42.20,Default,,0000,0000,0000,,filter to the engine where fuel injectors emit a precisely
Dialogue: 0,0:03:42.20,0:03:45.50,Default,,0000,0000,0000,,timed spray of gas into the intake port.
Dialogue: 0,0:03:54.20,0:03:54.94,Default,,0000,0000,0000,,Cooling.
Dialogue: 0,0:03:55.92,0:03:59.26,Default,,0000,0000,0000,,Engines get very hot during operation and require a cooling
Dialogue: 0,0:03:59.26,0:03:59.72,Default,,0000,0000,0000,,system.
Dialogue: 0,0:04:02.38,0:04:04.80,Default,,0000,0000,0000,,Coolant channels around the cylinders and through the
Dialogue: 0,0:04:04.80,0:04:09.20,Default,,0000,0000,0000,,cylinder heads carry a special liquid called antifreeze to
Dialogue: 0,0:04:09.20,0:04:11.44,Default,,0000,0000,0000,,keep temperatures within safe operating range.
Dialogue: 0,0:04:12.98,0:04:15.64,Default,,0000,0000,0000,,It's called antifreeze because it won't freeze in icy
Dialogue: 0,0:04:15.64,0:04:15.96,Default,,0000,0000,0000,,weather.
Dialogue: 0,0:04:18.98,0:04:20.52,Default,,0000,0000,0000,,After cooling hot engine parts,
Dialogue: 0,0:04:20.84,0:04:22.26,Default,,0000,0000,0000,,coolant circulates through the radiator.
Dialogue: 0,0:04:23.32,0:04:26.16,Default,,0000,0000,0000,,The radiator has a network of small tubes and fins.
Dialogue: 0,0:04:27.32,0:04:32.22,Default,,0000,0000,0000,,Coolant passes through these channels while air pulled in
Dialogue: 0,0:04:32.22,0:04:35.30,Default,,0000,0000,0000,,by the radiator fan blows by the tubes,
Dialogue: 0,0:04:35.74,0:04:37.96,Default,,0000,0000,0000,,cooling the hot liquid for recirculation.
Dialogue: 0,0:04:44.08,0:04:47.74,Default,,0000,0000,0000,,A water pump keeps the coolant system flowing and properly
Dialogue: 0,0:04:47.74,0:04:48.34,Default,,0000,0000,0000,,pressurized.
Dialogue: 0,0:04:51.58,0:04:54.10,Default,,0000,0000,0000,,The thermostat regulates coolant temperature by either
Dialogue: 0,0:04:54.10,0:04:57.58,Default,,0000,0000,0000,,routing coolant back through the engine or to the radiator
Dialogue: 0,0:04:57.58,0:04:58.72,Default,,0000,0000,0000,,for further cooling.
Dialogue: 0,0:05:02.10,0:05:02.74,Default,,0000,0000,0000,,Electrical.
Dialogue: 0,0:05:05.72,0:05:09.18,Default,,0000,0000,0000,,The spark plug delivers the electrical spark that ignites
Dialogue: 0,0:05:09.18,0:05:10.92,Default,,0000,0000,0000,,the fuel-air mixture for combustion.
Dialogue: 0,0:05:11.72,0:05:14.34,Default,,0000,0000,0000,,The metal core is insulated from the outer metal casing
Dialogue: 0,0:05:14.34,0:05:15.12,Default,,0000,0000,0000,,with porcelain.
Dialogue: 0,0:05:16.12,0:05:18.58,Default,,0000,0000,0000,,The spark jumps between these conductive surfaces.
Dialogue: 0,0:05:25.00,0:05:28.24,Default,,0000,0000,0000,,A coil pack delivers electrical current to the spark plugs
Dialogue: 0,0:05:28.24,0:05:33.30,Default,,0000,0000,0000,,as directed by the ECM, or Engine Control Module.
Dialogue: 0,0:05:34.56,0:05:37.44,Default,,0000,0000,0000,,The ECM is a computer that directs many core engine
Dialogue: 0,0:05:37.44,0:05:41.68,Default,,0000,0000,0000,,functions like spark timing, valve open and close timing,
Dialogue: 0,0:05:42.28,0:05:44.16,Default,,0000,0000,0000,,air to fuel ratio, etc.
Dialogue: 0,0:05:45.56,0:05:47.88,Default,,0000,0000,0000,,The alternator works like a power generator,
Dialogue: 0,0:05:48.54,0:05:51.64,Default,,0000,0000,0000,,converting the engine's mechanical energy into electricity
Dialogue: 0,0:05:51.64,0:05:55.52,Default,,0000,0000,0000,,to charge the battery or run other electrical systems while
Dialogue: 0,0:05:55.52,0:05:56.28,Default,,0000,0000,0000,,the engine is running.
Dialogue: 0,0:05:59.00,0:06:02.14,Default,,0000,0000,0000,,The battery provides power to the starter for engine start.
Dialogue: 0,0:06:07.78,0:06:08.38,Default,,0000,0000,0000,,Oil.
Dialogue: 0,0:06:08.38,0:06:12.12,Default,,0000,0000,0000,,Motor oil is used to lubricate, clean, prevent corrosion,
Dialogue: 0,0:06:12.38,0:06:12.96,Default,,0000,0000,0000,,improve sealing,
Dialogue: 0,0:06:13.56,0:06:16.40,Default,,0000,0000,0000,,and cool the engine by carrying heat away from moving
Dialogue: 0,0:06:16.40,0:06:16.88,Default,,0000,0000,0000,,parts.
Dialogue: 0,0:06:19.92,0:06:22.72,Default,,0000,0000,0000,,Rings around the top of the piston head keep oil out of the
Dialogue: 0,0:06:22.72,0:06:23.66,Default,,0000,0000,0000,,combustion process,
Dialogue: 0,0:06:24.22,0:06:26.94,Default,,0000,0000,0000,,while otherwise allowing the cylinder to be lubricated.
Dialogue: 0,0:06:28.14,0:06:31.20,Default,,0000,0000,0000,,Oil galleries are channels through the engine block and
Dialogue: 0,0:06:31.20,0:06:34.16,Default,,0000,0000,0000,,cylinder head that carry oil to various engine parts.
Dialogue: 0,0:06:37.68,0:06:40.28,Default,,0000,0000,0000,,Oil flows through the engine and back to the oil pan for
Dialogue: 0,0:06:40.28,0:06:41.08,Default,,0000,0000,0000,,recirculation.
Dialogue: 0,0:06:44.54,0:06:47.44,Default,,0000,0000,0000,,Oil rests in the oil pan when not in circulation.
Dialogue: 0,0:06:49.16,0:06:52.46,Default,,0000,0000,0000,,The oil pump keeps oil properly pressurized and flowing.
Dialogue: 0,0:06:54.88,0:06:58.26,Default,,0000,0000,0000,,And the oil filter keeps oil clean from contaminants.
Dialogue: 0,0:07:03.76,0:07:04.18,Default,,0000,0000,0000,,Exhaust.
Dialogue: 0,0:07:08.92,0:07:12.38,Default,,0000,0000,0000,,The exhaust manifold collects gases from multiple cylinders
Dialogue: 0,0:07:12.38,0:07:13.70,Default,,0000,0000,0000,,into one pipe.
Dialogue: 0,0:07:16.40,0:07:19.56,Default,,0000,0000,0000,,Exhaust flows through the catalytic converter which
Dialogue: 0,0:07:19.56,0:07:23.68,Default,,0000,0000,0000,,captures toxic chemicals in engine exhaust and then out
Dialogue: 0,0:07:23.68,0:07:25.96,Default,,0000,0000,0000,,through a muffler that reduces exhaust noise.
Dialogue: 0,0:07:29.30,0:07:30.18,Default,,0000,0000,0000,,And finally,
Dialogue: 0,0:07:30.80,0:07:33.58,Default,,0000,0000,0000,,here's the full functioning engine with all the basic
Dialogue: 0,0:07:33.58,0:07:34.80,Default,,0000,0000,0000,,systems we've discussed.