1. spark timing 气缸点火正时
The spark timing refers to the right moment when the spark plug needs to ignite the combustion mixture in a cylinder of an internal combustion engine. By advancing or retarding the timing, the engines performance, fuel economy, and emissions can all be adjusted.
2. compression ratio 压缩比
The compression ratio of an engine describes the ratio between the volume of the cylinder when the piston is at its highest position, and the volume when it is at its lowest position. A higher compression ratio increases the engines efficiency, but can also increase emissions and the likelihood of engine knocking if the fuel octane is too low.
3. torque 扭矩
Torque is a measure of the force a engine exerts to turn its output shaft. Increasing engine torque requires the fuel to burn faster and produces the engines power. The torque curve of an engine is a measure of its output across the whole rpm range.
4. bore and stroke 缸径和行程
The bore and stroke of an internal combustion engine are two measurements that determine the size and power of the engine. Bore is simply the diameter of the cylinder, whereas stroke is the distance the piston travels from top to bottom. Increasing either value will result in an increase in horsepower and torque, but it will also require more fuel and cause more emissions.
5. cooling system 冷却系统
The cooling system of an internal combustion engine works to remove the heat from the engine and keep its components at a safe operating temperature. The flow of coolant is regulated by a thermostat and the majority of modern engines utilize a liquid-to-air heat exchanger to further aid in cooling. Overheating can cause damage to the engine and lead to poor performance, higher fuel consumption and higher emissions.
6. fuel system 燃油系统
The fuel system of an internal combustion engine works to deliver fuel to the engine’s cylinders in an efficient and regulated manner. Fuel is delivered to the engine through a fuel pump and fuel injectors, and the amount and timing of the fuel delivery is regulated by the engine’s computer. Poor fuel delivery can lead to misfires, reduced engine performance and higher emissions.
7. emissions control system 排放控制系统
The emissions control system of an internal combustion engine works to reduce the amount of harmful emissions that the engine produces. Modern emissions control systems involve the use of exhaust gas recirculation (EGR), catalytic converters, and other technologies to reduce the amount of pollutants released into the atmosphere. Failure of the emissions control system could lead to higher emissions and can cause the engine to fail emissions tests.
