| Questions | 5 |
| Topics | Cylinders, Exhaust Stroke, Half Shaft, Lighting, Power Brakes |
Cylinders act as a guide for the pistons that translate the heat energy of combustion into the mechanical energy necessary to move a vehicle. Piston rings seal the piston to the cylinder to contain combustion gases and also regulate the oil distribution between the piston and cylinder wall. A cylinder head closes in the top of the cylinder forming the combustion chamber which is sealed by a head gasket (head). The head provides space for air and fuel intake valves, exhaust valves, and mounts for spark plugs and fuel injectors.
During the exhaust stroke, just before the piston reaches bottom dead center the exhaust valve opens. The resulting gases from combustion are then pushed out through the exhaust valve as the piston travels up the cylinder to top dead center, completing stroke four of the four-stroke piston cycle.
A half shaft is a drive axle that extends from a transaxle or differential to one of the drive wheels. There are two half shafts per drive axle, one for each wheel, each doing "half" the job.
The lighting system consists of interior lights, instrument panel lighting, headlights, and taillights. Like household electrical circuits, the vehicle's lighting system is protected from current spikes by fuses and circuit breakers.
Power brakes multiply the force a driver applies to the brake pedal using a vacuum booster connected to the engine intake manifold. This provides for much higher hydraulic pressure in the braking system than could be generated by the driver alone. Antilock brakes (ABS) use speed sensors and adjust the brake pressure at each wheel to prevent skidding and allow the driver more steering control in slippery conditions.