The engine is known as the heart of the car, especially for high-end cars, the importance of engine performance is self-evident. As a mechanic or auto enthusiast, do you know what kind of engine the car is repaired? Come and raise your knowledge!

 

1. SOHC: (single overhead camshaft engine)

 

According to the engine type divided by the number of camshaft positions, SOHC represents single overhead camshaft engine, which is suitable for 2-valve engine.

 

2. DOHC: (DOHC engine)

 

Indicates a double overhead camshaft engine, suitable for multi valve engines. Usually, the engine has two valves per cylinder. In recent years, 4-Valve and 5-Valve engines have appeared continuously, which undoubtedly opens up a way to improve the intake efficiency and power at high engine speed. This kind of engine is suitable for high-speed engines and can appropriately reduce the fuel consumption at high speed.

 

3. Turbo: (turbocharged)

 

That is, turbocharging, which is abbreviated as t, is generally marked with words such as 1.8T and 2.8T at the rear of the vehicle. Turbocharging includes single turbocharging and double turbocharging. We usually refer to exhaust gas turbocharging. Generally, the exhaust gas drives the impeller to drive the pump wheel and send more air to the engine, so as to improve the power of the engine and reduce the fuel consumption of the engine.

 

4. VTEC: (variable valve timing and valve lift Electronic Control System)

 

VTEC developed by Honda is the first valve control system in the world that can control the opening and closing time and lift of valves at the same time. Now it has evolved into i-vtec. The biggest difference between i-vtec engine and ordinary engine is that the cam will be driven by two groups of different valves at medium and low speed and high speed, and can be automatically converted by electronic system. In addition, the engine can automatically change the opening time and lifting degree of the valve according to the driving conditions, that is, change the intake and exhaust volume, so as to increase the power and reduce the fuel consumption.

 

5. I-vtec: (intelligent variable valve timing and lift system)

 

i-vtec. System is the English abbreviation of Honda's intelligent variable valve timing system. I-vtec system has been widely installed in the engine of the latest Honda car. Honda's i-vtec system can continuously adjust valve timing and valve lift. The working principle of the engine is that when the cam or the pinion rotates forward at a certain angle relative to the turbine shaft at a high speed, it will automatically change the working angle of the engine under the action of the oil pressure of the cam 60, so as to change it to the rear under the action of the engine at a certain speed, Achieve the purpose of continuously adjusting valve timing.

 

6. CVVT: (continuously variable valve timing system)

 

South Korea's automobile industry has never been known for its advanced technology, so the technology used is mostly based on the experience of Germany, Japan and other countries, and CVVT is developed on the basis of VVT-i and i-vtec. Taking the CVVT engine of modern automobile as an example, it can control the opening and closing of valves at any time according to the actual working conditions of the engine, so as to make the fuel burn more fully, so as to improve the power and reduce the fuel consumption. However, CVVT will not control the lift of valves, that is to say, this engine only changes the time of suction and exhaust.

 

7. VVT: (continuously variable valve timing engine)

 

The system adjusts the phase of the engine cam through the equipped control and execution system, so that the time of valve opening and closing changes with the change of engine speed, so as to improve the charging efficiency and increase the engine power.

 

8. VVT-i: (intelligent variable valve timing system)

 

VVT-i is Toyota's unique engine technology, which has been very mature. In recent years, most domestic Toyota cars, including the new weichi, have been equipped with VVT-i system. Similar to the VTEC principle of Honda, the biggest feature of the system is that it can control the intake camshaft according to the state of the engine, and optimize the valve timing by adjusting the camshaft angle, so as to obtain the best valve timing, so as to improve the torque in all speed ranges and improve the fuel economy, so as to effectively improve the performance of the vehicle.

 

9. Dual VVT -- I: (dual intelligent variable valve timing engine)

 

Dual VVT-i refers to controlling the intake system and exhaust system of the engine respectively. During rapid acceleration, VVT-i controlling intake will advance intake time and increase valve lift, while VVT-i controlling exhaust will delay exhaust time. This effect is like a smaller turbocharger, which can effectively improve engine power. At the same time, due to the increase of air intake, the combustion of gasoline is more complete and the purpose of low emission is realized.

 

10. D-cvvt: (dual variable valve timing, variable intake system engine)

 

According to the basic configuration of Rohens, the V-6 lambda engine adopts double variable valve timing (d-cvvt) technology on the intake and exhaust camshafts, and is equipped with a new variable intake system (VIS), which improves the intake volume of the cylinder and thus improves the fuel efficiency. Equipped with a 3.8-liter V-6 engine, the power is 290 HP. Although the output power is strong, it does not affect its environmental protection and ultra-low emission control (ULEV) characteristics. Among them, the Aisin 6-speed automatic transmission with overdrive has made great contributions. Its smooth transmission performance and wide transmission ratio ensure the strong power and excellent fuel economy of Rohens.

 

11. TDI: (turbodirect injection supercharged engine)

 

TDI technology allows fuel to be injected directly into the cylinder through a high-pressure injector, because the shape of the piston crown is a concave bowl design, and the fuel will form a spiral mixture in the cylinder. The technology of direct injection turbocharged diesel engine (TDI) pioneered by Volkswagen Group equipped with Bora TDI is very advanced, and a number of advanced technologies are adopted, such as pump injection system and adjustable vane turbocharger, which are applied to domestic cars for the first time. Bora TDI adopts the latest high-pressure fuel injection technology - pump injection system. This system makes diesel oil and air mix more fully and burn more thoroughly; At the same time, the oxidation catalytic reactor is adopted to greatly reduce the emissions of CO, HC and particles, in which the CO2 emission can be reduced by 30% compared with gasoline vehicles with the same displacement. In addition, the use of EGR system greatly reduces the generation of NOx, and its emission index meets the Euro 3 standard. The "TDI logo" of Volkswagen diesel engine is the most successful diesel engine recognized in the world.

 

12. Gdf-p: (diesel engine)

 

The hydraulic timing device of the distribution pump drives the roller frame to move by the timing piston to adjust the injection timing. The high-pressure chamber of the timing piston is connected with the pump chamber. The pressure in the pump chamber increases with the increase of the speed. The pressure in the high-pressure chamber of the piston increases with the increase of the speed, and the injection timing is advanced. Jetta electronic control system connects the electric valve n108 in series between the high and low pressure chambers of the piston. The duty cycle controls the pressure difference between the high and low pressure chambers. The injection timing changes. The duty cycle is large, the pressure difference is small, and the timing is late. The needle valve lift sensor g80 detects the injection timing and carries out closed-loop control of the injection timing. Volkswagen's gdf-p diesel engine is more popular.

 

13. FSI: (in cylinder direct injection stratified combustion engine)

 

FSI is a new technology in the field of gasoline engine, which means stratified fuel injection. Some are similar to the high-pressure fuel supply technology of diesel engines. It is equipped with a fuel supply system controlled on demand, and then provides the required pressure through a piston pump. Finally, the fuel injection nozzle injects the fuel directly into the combustion chamber at the most appropriate time. Through the design of the shape of the combustion chamber, there will be a thicker mixture around the spark plug and a thinner mixture in other areas, which ensures that the lean combustion can be realized as much as possible under the condition of smooth ignition, which is also the essence of stratified combustion. FSI significantly improves the power performance of engines at the same level, but the fuel consumption can be reduced by about 15%.

 

14. TFSI: (turbocharged Fuel Stratified Injection Engine)

 

The t-word more than FSI represents turbocharger, and the engine itself does add a turbocharger on the basis of FSI engine. Turbocharging uses the high temperature and high pressure of the exhaust gas to drive the exhaust gas turbine to rotate at high speed. It drives the intake turbine to compress the intake air and improve the air density. At the same time, the computer controls to increase the fuel injection volume and cooperate with the high-density intake air. Therefore, the working efficiency of the engine can be improved under the condition of constant displacement. FAW Volkswagen and Shanghai Volkswagen call their 1.4tfsi and 1.8tfsi engines 1.4TSI and 1.8TSI, which are extremely irresponsible. At the same time, in order to avoid people's objection to TFSI or TSI, the manufacturer explained: "because we generally use three words as the title of engine specific technology in the consistent system, we call TFSI TSI for short this time, in which t stands for turbocharging and Si stands for direct injection technology". The latest TSI engines of domestic maiteng, Suteng and other models are actually different from the TSI mentioned earlier. Maiteng 1.8TSI and the 1.4TSI engine to be mounted on Sagitar actually castrate the supercharging and fuel stratification technology. Of course, this is also the consideration of oil products and cost after localization. Because a supercharging kit costs at least 15000 yuan. It needs to be replaced every 50000 kilometers, and more expensive turbochargers need to be replaced for more than 100000 kilometers.

 

15. TSI: (mechanical turbocharging and direct fuel injection engine)

 

The design of TSI (turbocharged Fuel Stratified Injection Engine) is very ingenious. It actually installs a turbocharger and a supercharger into an engine. T in TSI does not mean turbocharger, but twincharger. As mentioned above, the turbocharged engine has a power neutral gear at lower and higher speeds. In order to further improve the efficiency of the engine, add a supercharger and let it increase the intake pressure at low speeds. The size of the turbocharger can be larger to make up for the power neutral at high speed, so as to achieve an excellent power performance from low to high speed.

 

16. Continuously variable valve phase engine

 

An engine continuously variable valve phase driving device of Volkswagen includes a valve sleeved with a valve spring, a rocker arm driving the valve to move back and forth, and a rotating cam driving the rocker arm to swing. The cam is a multi working condition cam that can change the valve lift and opening and closing time. The profile of the multi working condition cam is: one end is a low-speed and small load cam profile, The other end is a high-speed and large load cam profile, between the low-speed and small load cam profile and the high-speed and large load cam profile is a smooth transition medium speed load cam profile, and the multi working condition cam is connected with a servo motor that can move the multi working condition cam along its axial direction; Because the profile of the multi working condition cam is continuous and smooth, stepless regulation can be carried out according to the needs to realize continuous variable valve phase. In addition, the profile of the multi working condition cam covers various working conditions of the engine. Therefore, the utility model can well meet the needs of variable working conditions of the engine.

 

17. AVS: (variable valve lift system)

 

AVS refers to the variable valve lift system, also known as the two-stage variable timing control system. Generally speaking, the engine equipped with such equipment will save fuel and energy to a great extent, and increase horsepower at the same time. This technology is widely used in Audi cars.

 

18. VAD: (variable inlet system)

 

Under the control of PCM, the VAD airway can be opened in time when the engine has high power output (opening more than one airway is equivalent to increasing the airway diameter), which can ensure the demand of engine air volume to the greatest extent and give full play to the dynamic performance of the engine. This technology is widely used in Mazda car series.

 

19. VIS (variable intake manifold system)

 

Under the control of PCM, keep high torque from low speed under small load to high speed under large load. Working principle: change the length of the effective intake manifold, effectively control the flow inertia of the intake air flow in the intake port, make the frequency of the flow pressure wave of the air flow coincide with the frequency of the intake valve under different working conditions, and then ensure the intake volume of the engine under any working conditions to the greatest extent. The essence is to realize the maximum intake of the engine by using the principle of medium inertia harmonic supercharging. When the engine speed is lower than 4400 rpm, VIS does not work, the VIS valve is closed, and the air flow path is long; When the engine speed is greater than 4400 rpm, VIS works, the VIS valve is open and the air flow path is short; This can meet the demand of air volume under different working conditions.

 

20. VTCS: (variable eddy current control system)

 

Open the intake manifold at different opening under different water temperature and speed to meet the air demand of the engine under various working conditions. Principle: under the same working condition, different VTCS valve opening changes the air flow rate into the engine and forms a vortex. Vortex is what we often call vortex, which makes the oil-gas mixing of the engine more sufficient. Especially when the engine is cold started at low temperature and the engine is under low load, the mixture atomization is not good, the combustion is not sufficient and the emission is poor. In order to improve the atomization level of gasoline at low temperature and the emission level of the engine, the emission level of Mazda 6 can reach and exceed the Euro III standard. Working process: when the water temperature is lower than about 62 ℃ and the engine speed is lower than 3750 rpm, the channel area of the intake pipe is reduced; With the further increase of water temperature, the speed increases further, the opening of VTCS valve is fully opened, and the area of intake pipe reaches the maximum.