| Questions | 5 |
| Topics | Air-Fuel Mixture, Engine Block, Exhaust Stroke, Lighting, Oil Pump |
The stoichiometric ratio defines the proper ratio of air to fuel necessary so that an engine burns all fuel with no excess air. For gasoline fuel, the stoichiometric ratio is about 14.7:1 or for every one gram of fuel, 14.7 grams of air are required. Too much air results in a lean air-fuel mixture that burns more slowly and hotter while too much fuel results in a rich mixture that burns quicker and cooler.
The engine (or cylinder) block is the large casing that contains the cylinders and many of the internal components of the engine.
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.
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.
The oil pump is driven by the camshaft and is responsible for pumping oil through the oil galleries (passages) that run throughout the engine. It also contains the oil filter and a pressure relief valve which prevents excessive pressure from building up in the lubrication system.