| Questions | 5 |
| Topics | Air-Fuel Mixture, Battery, Connecting Rod, Oil Viscosity, Water 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 battery supplies the power necessary to start the engine when the ignition switch is is turned on.
A connecting rod employs a wrist pin to link each piston to the engine's crankshaft.
The primary component of the lubrication system is engine oil. Engines require oil blends with different thickness (viscosity) and additives depending on their operating conditions. Viscosity is rated using the format XW-XX with the number preceding the W (winter) rating the oil’s viscosity at 0 ℉ (-17.8 ℃) and the XX indicating viscosity at 100 ℃.
The water pump is driven by a belt connected to the crankshaft and ensures that coolant moves through the engine and radiator.