Functions of different types of engine intake manifolds

The intake manifold is located between the throttle valve and the intake valve of the engine. The reason why it is called manifold is that the air channel branches here after the air enters the throttle valve and is buffered by the manifold. Corresponding to the number of engine cylinders, for example, four for a four-cylinder engine and five for a five-cylinder engine, air is introduced into each cylinder respectively.

The difference between intake pipe, intake pipe and air inlet

Distinguish the intake pipe, intake manifold and air inlet, and identify the intake manifold.

admitting pipe

The intake pipe refers to the pipe part where air enters from the air inlet, passes through the air filter and reaches the front of each cylinder. It is the main intake pipe, which is the main intake pipe of the engine.

Intake manifold

The intake manifold refers to the pipe part where air enters each cylinder from the intake pipe and is distributed to each cylinder. Each cylinder has an intake manifold.

The design of intake manifold ensures the reasonable and uniform intake distribution of each cylinder.

admitting port

The air intake is the passage through which air enters the engine block and leads to the cylinder. It is mainly composed of a passage designed on the cylinder head, and the end of the intake passage is an intake valve that controls intake.

Functions of different types of engine intake pipes

The function of the air intake system is to inhale as much air as possible for gasoline combustion. For carburetor and single-point injection engine, the intake manifold refers to the intake pipe behind the carburetor and in front of the intake passage; For multi-point injection engines, the intake manifold refers to the intake pipe behind the throttle body and in front of the intake pipe. Because of the different oil supply methods, the functions of these two intake manifolds are not exactly the same.

Single point jet engine

For the intake manifold of carburetor and single-point injection engine, its function is to distribute the mixture of air and fuel from carburetor or throttle body to the intake of each cylinder.

The air flowing through the air filter is mixed with gasoline and enters the intake manifold. In the process of flowing through the intake manifold, the fine particles of gasoline and air are further mixed to form a mixed gas, and then enter the intake.

This intake manifold must be preheated to make the mixture have a reasonable temperature, thus forming a combustible mixture. Aluminum alloy intake manifold has good thermal conductivity and light weight, so it is commonly used. In addition, a water jacket should be set on the intake manifold to preheat the gas with engine cooling water.

Multipoint injection engine

For the intake manifold of multi-point injection engine, clean air is distributed to each cylinder inlet near the outlet of the intake manifold, and the gasoline nozzle injects atomized gasoline into the intake manifold or cylinder inlet. Because the injected gasoline particles are very small, preheating is generally not needed.