Carburettor DAAZ-4178: specifications and adjustments

For more than 100 years, the carburetor has been used on most gasoline vehicles. The work of this device is to prepare a mixture of air and gasoline vapor, which will enter the combustion chambers. Consider how the carburettor DAAZ-4178 works , find out its technical characteristics and learn how to regulate its operation.

DAAZ for UAZ and Volga vehicles

Many owners of UAZ cars, as well as the "Volga" with a 402-m engine are interested in the selection of carburetors for their cars. If we analyze all existing solutions on the market, then the best approach for these engines is from the Dmitrov aggregate plant.

Carburettor DAAZ-4178 for motorists is considered a very popular model. It allows you to significantly improve the dynamics of the engine, as well as with the correct setting leads to a lower fuel consumption.

Carburetor device

These units are designed for the preparation of high-quality fuel mixture. Then the unit feeds it to the combustion chambers. The ratio of fuel in the mixture is directly proportional to the amount of air that passes through the device.

Line 4178 is a two-chamber emulsion system. In general, the entire line, and carburetor DAAZ-4178-1107010-30 including, has the same device. In these carburetors all effective and well-proven technologies are applied. Here you can note the presence of a more balanced float chamber, a system of sequential opening of the dampers and other technologies.

The device is assembled from standard units and assemblies and practically does not differ from other designs. The carburetor consists of a main metering tank, an idling system, transient systems, a pump, an econostat and an EPHC.

Carburettor DAAZ-4178 - technical specifications

Consider the purpose of each of the main systems of this unit. This model is chosen by many motorists. Models with index 30 and 40 are suitable for "Volga" and UAZ. The owners of these cars speak very well about such devices. They have wide options for customization, as well as almost problem-free.

Basic dosing system

This system is designed to supply the required amount of fuel mixture at different operating modes of the motor. It is able to work with all modes, except idling. Thus, at a medium engine load, the dosing system is obliged to provide a lean fuel mixture of constant composition.

If you consider the device of the simplest carburetor, and then look at the technical characteristics of the DAAS-4178 carburetor, in the simplest design, as the throttle opens, the air through the diffuser passes more slowly than the fuel that will be released into the chamber from the nebulizer . So the mixture is enriched. In order to prevent too rich a mixture, engineers have provided the possibility of compensating the ratio of the fuel mixture with the air ratio. The amount and volume of air can be adjusted by means of throttle valves. In carburettor units, such compensation processes are a dosing system.

In most models from DAAZ, these methods of compensating the composition of the fuel mixture operate on the basis of pneumatic braking. So, fuel arrives, and then it is sprayed not from the float chambers, but through a special emulsion channel. This is a special tube. In the walls of the tube there are special technological holes. They facilitate the outlet of air coming from above from the jet. There, in this channel, there is a process of mixing, and the mixture itself can leave these technological holes.

As the throttle opens, the rarefaction and volume of the mixture increase. Also, the volumes of fuel passing through the jets and the amount of air increase. The amount of air is fully proportional to the volume of fuel. So compensation is provided.

In short, the GDS creates all the conditions for the motor to work on small, medium and high loads and modes. This carburetor DAAZ-4178-1107010-30 provides the engine with power stability and operation in all possible modes of operation.

The design and operation principle of CXX

For the engine at idling, only a very small volume of mixture is required at the minimum speed. In such conditions, a fully closed throttle is observed. But the level of rarefaction in the diffuser is not enough now to start the GDS.

Just for this carburettor DAAZ-4178-30 has in its design an idling system. Its task is the preparation of a mixture that allows to ensure stable operation of the engine with a fully closed flap.

The system channels combine a special cavity behind the throttles and the upper part of the chambers. When the engine is running at idle, a sufficiently high vacuum is created under the damper. When it is exposed to the fuel comes from the channel for the emulsion into the channel of the system XX. The ratio of fuel to air in the mixture depends on the capabilities of jets.

Further the mixture gets into the chokes, where it then mixes with air. For this, there is a technological gap between the flap and the walls of the chamber. This gap can be adjusted with a screw, which is installed on the damper lever. This is a quantity screw, with the help of which the adjustment of the carburetor DAAZ-4178-1107010 is carried out.

The amount of the mixture that passes through the channel into the zadrossal space can be adjusted with a special screw with a cone nozzle. This screw is responsible for adjusting the quality of the mixture. If you twist it, the channel cross section is thus reduced.

If the throttle valve opens more smoothly, then the amount of air increases significantly, but the volume of fuel remains the same as it was. GDS still does not enter into this process because of a lack of dilution. The result is a depleted mixture and a failure in the motor's operation.

For a smoother transition from idle to medium duty, the DAAZ-4178-1107010-40 carburetor is equipped with a special transient system. It connects its channels to the channels responsible for idling. Here there is a special hole, which is designed in such a way that after opening the shutter, it enters the zone of maximum rarefaction. This channel also receives a little mixture into the chambers. Due to this, there is no abrupt transition between the operating modes of the motor.

At idle, when the flap is completely closed, air is added to the mixture. The composition is compensated by the presence of jets. If you screw the screw that is responsible for the amount of the mixture, then the flap will open. The gap between the damper and the chamber increases, the amount of air decreases. At the same time, the crankshaft turns increase. If you unscrew the screw, the frequency will decrease. On such a device as carburetor DAAZ-4178, the adjustment is carried out by rotating the adjusting screws.

Accelerating pump

GDS carburetor is designed to ensure trouble-free operation only with a smooth process of opening the damper. If you open it more sharply, then the process of education is violated. In order that there was no failure, the design has a special pump. It allows you to temporarily enrich the fuel mixture, if the throttle opens sharply.

Start device

At the time the engine starts, the crankshaft rotates at low speed. In the inlet chamber there is a sufficiently low vacuum, and the fuel evaporates very poorly at the same time. Also, if the motor is cold, the fuel vapor condenses in the intake tract.

To make the start-up process more stable, it is necessary that the DAAZ-4178-40 carburetor prepare a richer mixture. So, the air damper closes and the throttle opens.

To facilitate the motor start-up process, carburetors are equipped with a special starting device. According to the principle of operation it is an air damper, as well as an automatic device that opens it.

Econostat

This device is designed to further enrich the mixture when working at maximum loads. This is a nebulizer, which is installed at the very top of the mixing chamber. Fuel in the econostat is fed through the channel where the fuel jet is installed.

Power Saving Economizer

In order for the motor to produce the maximum power, the mixture must be very rich.

To make it, the carburettor DAAZ-4178-1107010 and all other models are equipped with a so-called economizer. This system allows to provide additional amount of fuel, which enters the nebulizer. But it does not pass through the main fuel jet. To activate the economizer, a special drive is used.

Carburetor DAAZ-4178 on UAZ

This design is more complicated, in contrast to the factory carburettor. It is also a two-chamber emulsion type carburettor. It is distinguished by the presence of an improved and more balanced float chamber. To make the mixture of higher quality, the designers created a more improved channel with a swirler.

The stable operation of the motor at start-up and with the load here allows the GDS. Advanced CXX supports more stable operation of the motor at the lowest possible speed of the crankshaft. This carburettor DAAZ-4178-1107010-40 allows for a smoother transition from idle to load.

Installation

To independently install this design on the UAZ, no complicated alterations will be required. However, for installation, a thicker gasket from the 126th carburetor is needed. If you are installing without a gasket, then there is a risk of breaking the pump drive.

Installation

How to install the carburettor DAAZ-4178-1107010 on the car UAZ? First, you need to remove the air filter and the housing. Then the device is removed. For this, it is necessary to unscrew the studs from the collector and replace them with new ones and short ones. The electric valves are removed, and the on-site relay is mounted in their place. Next, a new carburetor is installed in place of the old one. Before this, it is necessary to lay two gaskets. Now, the union must be connected to the distribution hose using a hose. Then it's time to move on to installing the EPHC control circuit.

And at the last stage the carburetor is adjusted DAAZ-4178-1107010. So, with the help of special screws, you can achieve optimum engine performance.

How to adjust the carburettor performance?

Although the design of DAAZ-4178 is slightly different from other models of the Dmitrov plant, the adjustment will not cause any difficulties.

In order to adjust the carburettor, you need to use the adjusting screws that are responsible for the quality and quantity of the fuel mixture. So you can set the engine running at idle. Often, idle operating modes are unstable, and without an appropriate setting the car will not go.

Setting the mechanism

Next, we adjust the carburetor DAAZ-4178. The calibration process is a few simple steps. First you need to warm up the power unit well. The screw, which is responsible for the quality of the mixture on the carburetor, needs to be unscrewed almost completely, and then tighten approximately 2.5 turns.

The screw, which is responsible for the amount of fuel mixture, is necessary in order to set the revolutions. To do this, you need to rotate the screw until the revolutions are around 850-950. Further, with the help of the same quality screw, we find the highest speed, then with another adjusting screw we return 900 turns again. These actions should be repeated until the rotation of the quality screw will increase the crankshaft speed.

If the speed starts to fall, then you find the transition from a richer to a lean mixture. It remains only to tighten the quality screw and leave it at this point.

Now you can no longer touch the carburetor DAAZ-4178. Adjusting it is finished. But this is so, if you sharply click on the accelerator, the transition from maximum speed to idle has passed normally. If this is not the case, then you need to slowly rotate the quality screw.

So, we found out what the carburettor of DAAZ-4178 has technical characteristics.