Like heart of a car, it can be said that engine determines characteristics of car. In terms of engine, you can usually pay more attention to parameters like maximum power and peak torque, but you don't know much about some relatively unpopular knowledge. Today, I will share with you cold knowledge about car engines - how many engines are there? type?
The difference between an internal combustion engine and an external combustion engine
How many engine types are there? First of all, according to place of fuel combustion, it is divided into an external combustion engine and an internal combustion engine. An external combustion engine is combustion of fuel in an open area (outside cylinder). The heat released during combustion of fuel is transferred to another medium, and piston is driven by another medium. A steam engine is a typical external combustion engine. When fuel is burned, water is burned Open, and then steam pushes piston to generate driving force.
Because external combustion engine burns out of cylinder, heat loss is relatively large and thermal efficiency is low, but it has advantage of not being picky about food. It is not picky about fuel, since as long as this substance can burn (strongly) with release of heat, it can be used as fuel for external combustion engines. In an internal combustion engine, fuel burns directly (in cylinder), generating heat that drives piston. The fuel of an internal combustion engine burns in cylinder, so heat loss is small and thermal efficiency is higher.
What do letters L, V, H, W of engine mean?
After talking about internal combustion engines and external combustion engines, let's focus on types of internal combustion engines. According to different types of fuel, engines can be divided into gasoline, diesel and methanol. If layout has in-line, boxer, V-shaped, H-shaped, W-shaped and other forms of engines, what do letters L, V, H and W mean?
L, V, H and W denote cylinder block layout. L is in-line, which means cylinders are in a straight line, just like we stand in a row at attention. Its cylinder block and crankshaft are simple in structure. The cylinder head has low production cost, good torque performance at low speeds, high stability, compact size and simple layout. Most mainstream family cars on market are L4. The disadvantage of in-line engine is low power.
A V-engine has a defined angle between cylinders that looks like a V from side. Benefits The angled cylinder reduces height and length of engine, leaving more room for cab layout. In addition, since there is a large space between cylinders, it is convenient to increase diameter of cylinders to increase displacement and power of engine. The disadvantage of V-shaped engine is need to use two cylinder heads, more complex design and higher cost.
The H-type engine is a horizontally opposed engine. Its cylinders are divided into left and right sides, with 2 or 3 cylinders symmetrically located on each side. The pistons on left and right sides make opposite 180° movements, like two people pulling a saw. The H-type engine is horizontal, vehicle's center of gravity is very low, and vehicle moves more smoothly. In addition, torques generated by pistons on both sides of engine cancel each other out, reducing engine vibration. and noise. This is engine used by Subaru.
The W-type engine is an exclusive technology of German concern Volkswagen. Strictly speaking, a W-type engine is a variant of a V-type engine. The cylinders on each side are offset at a slight angle based on V-type, and it becomes a W-type engine. It takes up less space and weighs less. The disadvantage is that width is wider, engine compartment is fuller, and construction is complex and expensive.
Regular family cars around us tend to have an inline 4-cylinder engine (L4), mid-range and high-end models can be equipped with an in-line 6-cylinder engine (L6), such as BMW 540/740, luxury brands such as Hongqi H7, Jeep Grand Cherokee use V6 engine, while Bentley and Audi A8 use W12 engine. And what kind of engine? Everyone can add.
This article was originally created by Auto Observer and any plagiarism will be investigated for legal liability under law.