For carburetor or throttle body gasoline injection engines, the intake manifold refers to the intake line from behind the carburetor or throttle body to before the cylinder head intake. Its function is to distribute air and fuel mixture to each cylinder intake port by carburetor or throttle body.
For airway fuel injection engines or diesel engines, the intake manifold simply distributes clean air to each cylinder intake. The intake manifold must distribute air, fuel mixture or clean air as evenly as possible to each cylinder. For this purpose, the length of the gas passage in the intake manifold should be as equal as possible. In order to reduce gas flow resistance and improve intake capacity, the inner wall of the intake manifold should be smooth.
Before we talk about the intake manifold, let's think about how air gets into the engine. In the introduction to the engine, we have mentioned the operation of the piston in the cylinder. When the engine is in the intake stroke, the piston moves down to produce a vacuum in the cylinder (that is, the pressure becomes smaller), so that the pressure difference between the piston and the outside air can be generated, so that the air can enter the cylinder. For example, you've all been given an injection, and you've seen how the nurse sucked the medicine into the syringe. If the needle barrel is the engine, then when the piston inside the needle barrel is drawn out, the potion will be sucked into the needle barrel, and the engine is to draw air into the cylinder.
Due to the low temperature of the intake end, composite material has become a popular intake manifold material. Its light weight is smooth inside, which can effectively reduce the resistance and increase the efficiency of the intake.
