Solex carburetor tuning

Tuning carburetor Solex 21083

Carburetor engines of front-wheel drive VAZ cars, although they are not the limit of progressive engineering even at the time of their production, still remain the only option for many.

Installing an injector on carburetor eights and nines is an expensive undertaking, and, as practice has shown, it is of extremely little use. We have to work with the carburetor and fight its congenital diseases.

Content:

Briefly about the Solex 21083 carburetor

The carburetor does not cause any glaring problems, it is quite up to date with its time, there are just some reasons to make changes to its settings and calibration to adapt to driving style.

Solex is not very flexible in settings. All that can be done without removing the carburetor is adjusting the idle speed and replacing the jets. Why do tuning the Solex 21083 carburetor, let's figure it out together.

Solex for a one and a half liter engine of eights and nines differs from the same model for a 1.3 liter engine almost only in jets and some calibration dimensions. This is where he doesn’t always show good results. Let’s make a reservation right away - there can be no talk of any fuel savings when making changes to the carburetor design.

Consumption may change for the better, but this will inevitably lead to failures in transient engine operation, unstable idle and inefficient high speeds due to a lean mixture.

In order to save fuel and spend 3 liters per hundred, you need to change the car, not the jets. Therefore, with your permission, we will not talk about savings.

In any case, it will lead to unstable operation of the engine, and we value our eight or nine for stability.

Tuning Solex and its feasibility

There is no need to immediately begin drastic measures to modify the carburetor - it will be enough to perform the simplest operations, and the characteristics of the Solex can be changed beyond recognition and congenital diseases can be eliminated. Minimum things to do:

selection and replacement of fuel jets;
selection and replacement of air jets;
changing the size of the primary chamber diffuser;
polishing and grinding of small diffusers;
adjustment and polishing of throttle valve axles.

His Majesty diffuser

As you can see, the diffuser occupies not the last place in this hierarchy, and here’s why. The main problem with Solex DAAZ 21083 is that the standard mixture is too lean.

The engineers deliberately took this step in order to strangle the engine in favor of efficiency, depriving it of its dynamic potential.

But even without resorting to complex and subtle calculations, it is clear that first of all it is necessary to eliminate aerodynamic errors, which are full of any DAAZ carburetor.

If you pick up a diffuser, large or small, pay attention to the quality of the casting and show all this happiness to an engineer at least from Ford Europe, he will go crazy.

The standard diffuser creates such a quantity of turbulence and parasitic flows in the intake tract that the efficiency of the carburetor is reduced by 20 percent.

What kind of tuning can we talk about with such diffusers! Therefore, first of all, they need to be sanded, removing all the seams that create swirls.

What to do with jets

After the diffusers are brought into human form, the filling of the cylinder with the working mixture is significantly improved, and as a result, the output from the engine, even after such an insignificant alteration at first glance, is visible even to the eye.

Now it makes sense to think about increasing the filling of the combustion chamber. Standard diffusers on 21083 have diameters of 21x23 mm of the primary and secondary chambers, respectively.

Usually the dimensions are adjusted to 24 mm, so the motor will not be pinched at least by air.

Now you can increase the diameters of the fuel jets. “Can” does not mean necessary, and if fuel economy is more important, then the jets are best left alone.

Even after replacing them with jets of increased diameter, the car will not turn into a Maserati, but fuel consumption will definitely increase.

If this doesn’t scare you, then change the standard jets to 107.5 and 115, and the air jets to 155 and 135 in the primary and secondary chambers, respectively. If you are not satisfied with the result, you can always install the standard jets in place.

Finishing and tuning of DAAZ 21083

Now about the little things, if they make sense when working with Solex. In order to avoid failures in transient conditions, the diameters of the accelerator pump nozzles are increased. We strongly do not recommend doing this if there are no spare staff, since the result may be exactly the opposite of what was expected, and fuel consumption will increase.

Therefore, as an escape route, the standard accelerator injectors should be kept in a safe place. The diameter of the nozzle nozzle of the primary chamber is increased to a maximum of 45, it is better to leave the secondary one in the drain.

This minimal and simple tuning of the Solex 21083 carburetor can slightly revive the engine of the eight or nine. Filter your gasoline carefully, and good luck on the road!

Source: http://LadaMaster.com/tyuning-karbyuratora-soleks-21083

Do-it-yourself carburetor tuning, modification of Solex, DAAZ, OZONE, how to remake and improve at home

Carburetor tuning helps get rid of failures when accelerating a car, as well as improve the quality of the mixture supplied to the cylinder. Elimination of factory defects and installation of stock spare parts make it possible to eliminate obstacles to the movement of the fuel-air mixture, which has a beneficial effect on engine operation throughout the entire speed range.

The importance of carburetor modifications

Carburetors produced from the factory are designed to operate the engine on a forced lean mixture, which ensures maximum efficiency and environmental concern.

Because of this, the standard carburetor does not allow the engine's power to be fully realized, and the car does not realize all its dynamic characteristics.

Carburetor tuning is especially important when boosting the engine, since the need for a sufficient amount of prepared air-fuel mixture increases even more.

Standard carburetor adjustments can affect idle speed, but set it up for optimal performance in the midrange. and even more so at high speeds it is not possible.

At speeds above 4500, engine starvation occurs, since an unfinished carburetor is not able to cope with an air flow at a speed of about 120 m/s.

As a result, a situation arises that an untuned carburetor strangles both forced and conventional engines.

Grinding the diffuser

It is recommended to start tuning a Solex carburetor by reducing the resistance to air flow in the intake tract. The factory-made diffuser has a lot of sagging and protrusions caused by poor casting quality and subsequent surface treatment. Because of this, parasitic air flows and turbulence arise, which interfere with the flow of the mixture into the combustion chamber.

To correct the situation, you should disassemble the carburetor and visually inspect the diffuser. It usually looks like the one shown in the figure below.

Solex carburetor diffuser with obvious casting defects

Initially, it is necessary to sand all seams and protrusions that have arisen due to imperfect production technology. As a result of the modification, you should get a result as in the figure below.

Diffuser with polished surface

At this stage, it is possible to complete the improvement of the passage of the fuel-air mixture, but as you know, there is no limit to perfection.

Experienced car enthusiasts recommend not stopping only at polishing manufacturing defects, but giving the diffuser maximum aerodynamic characteristics.

You can achieve good streamlining of the surface by giving it a shape similar to an oval or wing, as shown below.

Diffuser with maximum streamlining

Pump booster drive

The greatest controversy in carburetor tuning is replacing the pump amplifier drive cam. Some car owners recommend replacing it with No. 4, but many are against it, citing the following arguments:

a significant increase in fuel consumption in urban and mixed driving modes;
dips in dynamics when the accelerator pedal is pressed sharply;
poor acceleration at low speeds, which is especially noticeable when trying to make a sharp start at a traffic light.

Tuning and standard cams for pump amplifier drives

Upgrading the carburetor by replacing the cam should be done with the possibility of going back, so you should not throw away the standard spare parts left after tuning.

The result for each car is individual, so after replacement you should check the gas mileage and improvement in dynamic performance.

If the ratio of these parameters suits the car owner, then you can leave the tuning spare part, otherwise you should return to the standard part.

Features of the selection of jets

When doing carburetor tuning with your own hands, the car enthusiast should modify the existing jets or purchase new ones of the appropriate size. To refine the jets, metal drills with a diameter of 1 mm to 2.5 mm are used.

With their help, a standard jet is drilled out to the required size. In this case, the throughput increases. To reduce it, instead of drilling, soldering with tin is used.

Next, a hole of the required size is made in the solder.

Location of jets in a Solex carburetor

Tuning the Ozone and Solex carburetors is not fundamentally different, since they are structurally similar, which can be seen in the images.

Jets in the Ozone carburetor

We remake the carburetor according to plan:

Initially, you need to decide on the size of the jets. Depending on the goals pursued, a jet of increased or decreased size is installed;
It is recommended to check the carburetor settings. If necessary, they should be adjusted;
The vehicle is being tested. At the same time, dynamic characteristics and fuel consumption are controlled;
We gradually increase or decrease the size of the jets until we achieve failures in engine operation and unstable operation;
We return to the penultimate installed jet;
If desired, you can replace the jets in both chambers;
Check the result. An increase in diameter should lead to an increase of 5-10% power, and a decrease should lead to a reduction in fuel consumption to 1 liter per 100 km.

Boring large diffusers

One of the drastic ways to remake a carburetor is to increase the air flow by boring the diffuser. The car gains improved dynamics under heavy and medium loads. This method is not without its drawback - at low speeds, failures in engine operation appear.

Boring of diffusers should be part of a comprehensive carburetor tuning. After this, the selection of new jets is mandatory. If the required diameter is not available, they will need to be drilled out. This operation is especially relevant for forced engines of 1.7 and 1.8 liters, since nozzles of increased diameter are not available for sale for them.

Not all car owners agree to put up with dips at the bottom. To improve dynamics at low speeds and at light loads, use:

Fuel nozzle, which has a larger diameter compared to the standard one. Installed in the EPHH valve;
Enlarged spray nozzle. It is usually installed in the first chamber, and in the second, at the discretion of the car enthusiast, you can put the same spout;
Cam UN, with an increased size.

For boring you can use:

special scan;
feather drills for wood.

To improve the aerodynamic properties after boring, the roughness on the surface of the diffuser should be removed. For this, sandpaper with a gradual reduction in abrasiveness is used. It is recommended to do the final treatment with zero-grit sandpaper. For more thorough processing, you can use Goya paste or a woolen rag.

How to remake a carburetor completely depends on the skills and financial capabilities of the car owner. Tuning should be done with a reasonable approach, so that instead of increasing power, you do not end up with increased fuel consumption and unstable engine operation.

Source: https://SwapMotor.ru/ustrojstvo-dvigatelya/tyuning-karbyuratora.html

Solex carburetor tuning

A significant part of our country's vehicle fleet is represented by cars with carburetors. And although the carburetor has a lot of disadvantages, there are also advantages: it is maintainable and unpretentious to fuel.

It is these qualities that make it possible to improve the carburetor and adjust it to increase the elasticity of the engine while maintaining its efficiency.

Important: before you start tuning the carburetor, make sure that the engine and fuel system of the car are in good condition. There should be no problems with compression, fuel pump and oil filter. You can start tuning the Solex carburetor only after these problems have been eliminated.

It is necessary to carry out a full inspection and adjustment of the main systems and mechanisms of the engine, check the serviceability of high-voltage wires, ignition coils, operability of air filters, drive traction, spark plugs.

After this, the carburetor needs to be thoroughly washed and the strainer cleaned. Then it is advisable to measure fuel consumption during a test drive of about 100 km - such a distance will give the most accurate measurement.

Even better - 100 km there and back, maintaining the same driving mode, so that the result is not affected by weather conditions and road terrain.

Cleaning and care

Car owners often encounter Solex carburetors becoming clogged, which requires constant cleaning as the jets become clogged. Dust mixes with oil and turns into deposits on the carburetor. Gradually, the layer of this plaque thickens, particles fall off from it, falling into the float chamber, resulting in clogged nozzles.

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Obviously, constantly cleaning the carburetor is not good for it, since you have to disassemble it every now and then. The most appropriate solution may be to change the height of balancing holes that are too low.

One way to raise them higher is to insert tubes to prevent dirt from getting into the holes. You can experiment with gel pen refills - their diameter (5 mm) is well suited for these purposes. The tubes must be secured well; alternatively, they can be heated with a soldering iron.

Instead of a pen rod, you can use a fragment of a suitable diameter from a conventional antenna.

Improved vehicle dynamics

The easiest way to speed up the car is to take a suitable Solex carburetor from the Niva and replace it with the one on the VAZ.

But you can also improve the carburetor by replacing some parts with others. For example, choose jets with a higher throughput. But here it is important not to overdo it, because...

a mixture that is too rich will cause the car to deteriorate its speed characteristics.

One of the tested options for the VAZ 21099 is to use an air jet marked “150” in the second fuel chamber and bore the fuel jet marked “117” (instead of “107.5”).

Just replacing the jets allows you to increase the speed of the car, the elasticity of the engine, and as a result, the speed is gained better from low speeds. The disadvantage of this method is that fuel consumption increases, especially in urban driving conditions. At this stage, you can make another test drive and compare with the initial measurements.

Manufacturing defects

Sometimes Solex tuning involves simply eliminating factory defects. Despite mass production, significant variation in the quality of carburetors and their parts is a common occurrence. Most often there are under-twisted or, conversely, twisted parts.

It is very easy to correct such a defect with your own hands. Burrs and scuffs on the product are also common - these are casting defects and poor subsequent processing. If there are a lot of such burrs on the working surface, then the air flow decreases.

How to eliminate such a marriage? Here are the step-by-step instructions:

Remove the carburetor from the car.
Clean it thoroughly so that dirt does not get into the fuel channels. If cleaning is not thorough enough, dirt particles can get into the fuel channels, and then into the cylinders. And then the car won’t go anywhere at all.
Separate the top of the carburetor from the bottom.
Unscrew the jets. Pulling out the fuel nozzles can be quite difficult; it is best to use something thin like a toothpick, a pin, or you can pick it up with tweezers.
Blow out the fuel channels. A regular foot pump will work well for this purpose, but you will need the help of another person.
Use a file or sandpaper to smooth out any burrs. To increase the force of the air flow, it is better to process the screws of the air damper axis, removing the metal layer. Inspect the choke control lever; it may be touching burrs on the carburetor body when rotating. It is necessary to remove the lever and smooth the surface of the body casting. In addition to the screws, the throttle valve axles can also be machined; as a rule, they are thick and interfere with the air flow.

Eliminating air leaks

One of the most common problems is excess air sucking under the carburetor. You can also handle this on your own.

To do this, it is necessary to increase the pressing area of the carburetor flange (provided that there is no deformation of the carburetor cover).

You will need corner pads (VAZ 2101–2107), in which we drill holes up to 8.2 mm in diameter. Now all that remains is to replace the factory washers with these pads and tighten the nuts.

If the cause of air leaks is a deformed cover, you can replace the factory gasket by making a new one yourself.

It can be made from thicker cardboard or other suitable material. Lay a fabric thread along the contour of the gasket and along the contour of the holes and secure it with any gasoline-resistant glue.

Grinding the bottom plane of the carburetor cover can also give a good result.

Source: http://CarExtra.ru/tyuning/karbyurator-soleks.html

Personal tuning of the Solex 21083 carburetor

Correct tuning of the Solex 21083 carburetor with your own hands

If carburetor tuning is done correctly, the car's dynamics and engine torque will improve.

Features of the Solex 21083 carburetor

Solex is an emulsion-type carburetor. With its help, models with a non-contact ignition system for the combustible mixture were improved.

Its structure is as follows: 2 chambers with sequential opening of the remote control, 2 chamber dosing systems, an idle system for the 1st chamber with transition systems intended for the first and second chambers.

In addition, Solex includes a semi-automatic starting device and a power mode economizer.

Self-tuning of the Solex 21083 carburetor

Next we will talk about grinding, boring, smoothing corners.

https://www.youtube.com/watch?v=8DapaNbs2lc

Disassembling the Solex 21083 carburetor

Divide it into 2 parts, disconnecting the lower part from the upper. All parts must be washed and then blown out with compressed air.

Correct tuning of the Solex 21083 carburetor with your own hands

Using a file or sandpaper, smooth the screws located on the air damper axis. This will eliminate the resistance to the incoming air flow.
Remove the axle and air damper (it is better to sharpen it).

DIY tuning Solex 21083

Disassemble the lower part in the same way as the upper one.
Remove the throttle valves and axles.

Correct tuning of the Solex 21083 carburetor with your own hands

Use a file to round off the axis of the remote control. Remove the screw heads from the axle (you can use screws with a tapered head). Alternatively, you can use a drill and a “10” drill bit.

DIY carburetor tuning

Also check out

DIY carburetor tuning

Assemble the throttle mechanism.

Self-tuning Solex

In small diffusers, eliminate the errors that arose during the casting of the carburetor body (sagging, sharp corners are removed, the legs of the small diffuser also need to be given a wing shape). This shape is more aerodynamic.

Correct tuning of the Solex 21083 carburetor with your own hands

In the accelerator pump, it is better to install 2 tubes in 2 chambers. It is important to position them exactly in the gap between the wall of the mixing chamber and the remote control.
Instead of the amplifier drive cam, install No. 4.

Correct tuning of the Solex 21083 carburetor with your own hands

You need to try to smooth out the unevenness of the mixing chamber as much as possible, because the speed of the air that passes through it is about 120 m/s. If they are not eliminated, air turbulence will occur, which will impede the flow of fresh air.

Thanks to this tuning of the Solex carburetor , the dynamics of the VAZ will improve and the engine will become more responsive.

A lot of information about tuning VAZs can be found at the link.

Source: http://prostovaz.ru/tyuning-vaz/sobstvennoruchnyy-tyuning-karbyuratora-soleks-21083.html

VAZ 2109: tuning Solex carburetors

VAZ 2109 carburetor tuning

VAZ 2109 carburetor tuning is a popular topic and very in demand lately. From the article we will learn how to do this. On a VAZ 2109, tuning a Solex carburetor or a carburetor from another manufacturer is carried out for only one main reason - to increase the power and dynamic characteristics of the car.

To increase power, experts will disagree, it is necessary first of all to refine the power unit itself. Yes, this is true, but if you don't have enough budget, you have to take risks.

Modifying the carburetor without improving other important elements is, of course, a risk, but in some cases it is justified.

Device

VAZ 2109 tuning Solex carburetor

Before tuning, you need to know how the Solex carburetor works. It was produced in several modifications and on the VAZ 2109 it was installed either DAAZ-2108 or DAAZ-2183. The first of the carburetor modifications was installed on a 1.3 liter engine, the second on a 1.5 liter engine. These carburetors are devices that are designed to accurately meter fuel into the air stream.

The Solex carburetor also has the following features:

It is in the carburetor that the process of forming a combustible mixture from fuel and air takes place, with its subsequent supply to the engine cylinders (see When replacing a VAZ cylinder is not necessary);
Note that the Solex carburetor has two vertical channels called chambers.

Solex carburetor design

Due to the fact that there are two chambers, and the damper drive is designed in such a way that as you press the gas pedal, one and then another channel opens, such a carburetor is called a two-chamber carburetor.

Among the main features of the carburetor, we also note cone-shaped narrowings, called diffusers. They are needed to create the vacuum necessary to suck fuel from the float chamber (a special container in the carburetor body).

The Solex carburetor consists of two main parts: upper and lower. The body with a flange, air filter fixing studs and fuel fittings are what the upper part consists of. The lower part consists of the body, diffusers, float chamber and throttle valves.

VAZ 2109 carburetor tuning

Technical parameters of DAAZ-2108/2183 carburetors

Diffuser and its diameter, mm	21-23
Performance of the main fuel jet TZh	97,5-97,5/95-97,5
Performance of the main air jet or VJ	165-125/165-125
Mixing chamber diameter, mm	32
Diameter of pump nozzles, cubic cm for 10 strokes	14,5/14,5

VAZ 21093 carburetor tuning

To tune a Solex carburetor, you need to carry out the following operations:

Remove the carburetor itself from the car;
It is good to clean it from dirt;
Remove the jets and throttle valves (this is done to bore the diffusers);
Both chambers must be enlarged in size using a special machine;
Grind the carburetor to reduce incoming air resistance;
We select the ones needed for the now modernized carburetor.

Selection of jets

VAZ 21093 carburetor tuning

Selecting jets is the most difficult process. They must be selected taking into account not only coincidence, but also high accuracy. Thus, the VJ must be selected so as to allow a certain amount of air to pass through, which would be equal to the amount of fuel passed through the TJ. Otherwise, the fuel mixture will not be properly balanced, which will inevitably lead to poor acceleration and other problems.

In addition, the jets must be properly balanced. This issue must be approached with all responsibility, understanding that instability of the fuel level will lead to a lean mixture.

Carburetor jets

In the process of tuning the carburetor, it is also recommended by experts to install a rubber shut-off needle, which ensures a more reliable level during heavy loads. In addition, such a needle is durable and can eliminate freezes when the accelerator pedal is pressed sharply.

Rubber locking needle

Two carburetors instead of one

This approach is also considered as effective tuning. This idea has quite sound grounds. It would seem why the engineers themselves didn’t think of this at the design stage of the VAZ 2109, but that’s another conversation.

This error can, of course, be corrected by polishing the collectors and both chambers from the inside.
This procedure will allow more mixture to enter the chambers, as a result of which the flow resistance will drop, the quality will improve and everything will become much more efficient. But, still, this is not an ideal option - installing two carburetors instead of one looks much more attractive.

Important points

Here are the important points to consider during installation:

Both carburetors must be the same model (in this case Solex);
You also need to install two filters and prepare the appropriate number of fasteners, tees, hoses, and so on;
After installation, which in itself is not so complicated, you need to start tuning both carburetors, which is considered a more difficult operation.

Do-it-yourself installation algorithm

VAZ 21093 carburetor tuning

Here's what to do:

Take two Solex carburetors;
Bring them into proper condition and equip them with a repair kit;
Purchase two manifolds from the Oka car, which will serve as the basis for the intake tract (you also need to make an adapter manifold yourself).

Next, you need to synchronize the operation of the carburetors by opening the dampers on both of them.

After installing the carburetors, we connect the fuel hoses and two return lines through tees;
Be sure to plug the fitting on one of the collectors;
We start the car (half a turn) and check everything.

The best tuning of the Solex carburetor for VAZ 21093

Pros and cons of a double carburetor on the “nine”

Instant effect	High price for both carburetors and associated components
Increased acceleration from standstill to 100 km/h	Risk of engine damage (applies mainly to older VAZ 2109 models)
Stable operation at high and low speeds
Increasing the maximum speed to 160 km/h (read more about increasing the maximum speed in the article on our website)

Tuning carburetors on a VAZ 2109 is a responsible but entertaining process.
Before carrying out it, it is recommended to study useful photos - materials, diagrams and drawings, watch a video review, and leaf through the instructions. As a result, we carry out modernization with our own hands, which will definitely come in handy.

Source: http://MasteraVaza.ru/sistema-pitaniya-dvigatelya/karbyurator/vaz-2109-tyuning-karbyuratorov-999

Tuning a Solex carburetor on a VAZ 2107 – Lessons from VAZ and Lada!

If you feel that after a little modification of the carburetor your VAZ 2107 can do more, then this article is for you.

A regular “Seven” is equipped with a standard “Ozone” carburetor:

Carburetion translated from French means “mixing”; the main task of the carburetor is to prepare a mixture of air and gasoline in the required proportion.

To do this, the carburetor has its own devices responsible for its functions, such as:

maintaining a constant level of gasoline in the float chamber;
engine starting and warming up system;
idle system;
accelerator pump to ensure acceleration;
main dosing system, including a diffuser, mixture sprayer, air and fuel nozzles;
enrichment econostat.

It should be recalled that if your VAZ 2107 has a 2103 or 2106 engine with a vacuum ignition corrector, then the carburetor is installed 2107 - 1107010-20.

There is an opinion, which many agree with, that the Ozone carburetor does not provide power to the engine at frequencies above 4.5 thousand revolutions per minute. The entire acceleration dynamics of this zone in the VAZ 2107 is reduced to almost zero, and not every engine can reach the legal maximum 5500-5600.

On the series after the “classics” there is a Solex carburetor.

Its main difference from Ozone is the presence of an economizer for power modes, EMR, which further enriches the mixture under heavy load, and leans it in other modes. In Ozone, there is one approach to all modes.

Either the mixture is enriched or depleted. But that is precisely why EMR is good on engines up to 1.5 liters. And on a VAZ 21074 with a volume of 1.6 liters there will be a slight, but “stifling” feeling.

How can you tune a VAZ 2107 carburetor to improve engine traction characteristics?

You can remove the spring from the secondary chamber, which is located inside the vacuum damper drive. The point is that the pneumatic, “soft” drive is converted into a mechanical one. Then, when picking up speed, there will be no characteristic “failure” when the first chamber operates at full power, and the second does not open. As a result of improved dynamics, consumption will increase by an average of 0.5 l/100 km. A compromise solution is to cut off 1-2 turns of the spring, which still reduces the acceleration time.
We take out the diffuser from the primary chamber with the small marking 3.5 and change it to the same small one, but marked 4.5. Since the diffuser creates negative pressure and discharges the air flow, a flow of fuel rushes behind it. Some fans, in order to achieve a sporty driving style and use the Ozone carburetor, additionally grind off the edge of the diffuser with a file at the top and the walls at a small angle so that the air flow additionally “swirls” to create a uniform saturation of the mixture. But this is vandalism, because at high mixture speeds the occurrence of turbulence “rinses” the mixture and causes a pressure difference. It’s better to polish the diffusers to a mirror shine, just like on high-speed planes.
You can replace the nozzle in the accelerator pump, from 30 to 40, this is on the Weber 2103 carburetor. This increases acceleration when starting off.
One of the main modifications to the carburetor is to change the size of the jet holes. Attention! The jet sizes are given for carburetors 2107-1107010 and 2107-1107010-20.
We work in the primary chamber: set the main fuel jet to 125, (usual - 112) the main air jet remains at 150.

After this, the dynamics improved a little more.

To “throw in” more power, we use the jets of the secondary chamber. We change both at once: the main air jet - from 150 to 190 (Fig. 6) and the main fuel jet from the standard 150 to 162 (Fig. 7). You need to look for them on Weber 2106.

As a result of these replacements, we get fairly good throttle response in the second half of the gas pedal stroke, up to 6 thousand rpm and above. Fuel consumption increases by somewhere between 1 and 1.5 t/100 km.

You can use this in a familiar situation: during a long overtaking of a long vehicle, oncoming traffic appears; you need to accelerate, but the gas pedal reserve seems to be insufficient.

It is then that you need to use a more powerful flow of tuned jets, the “pseudo-turbocharging” effect occurs.

Now, when driving on city roads, we get dynamics like the “nine”, and you don’t have to “sink to the floor” at a traffic light if you notice a nervous “cool car” behind you in the rearview mirror.

We expect consumption to be 11-11.5 in urban conditions. We did not touch the idle jets, so the flow rate remained the same.

If we add to this the correct setting of the ignition timing, then the VAZ 2107 will become very fast.

In conclusion, we can summarize the advantages and disadvantages of the old Ozone and recall the Solex carburetor.

In our opinion, it is on the Samara that there is an element of insufficient reliability of this carburetor (Solex), jerks and “holes” in the engine operation,
low-quality solenoid valve that requires frequent repairs.
For maximum tuning of the Solex, boring the second chamber is generally required.
“Ozone” practically does not need adjustment more than once a year.
In addition, it was Solex that was originally designed for a transverse engine with a volume of 1.5 liters.
Installing a Solex carburetor on a VAZ 21074, for example, can “strangle” the engine at high speeds.
In addition, the Solex carburetor does not have an independent idle system, but the Ozone does.

The choice is yours!

Source: https://7vaz.ru/tjuning/karbjurator-soleks.html

Solex carburetor modification

Modification of Solex
carburetor Modification of the carburetor allows solving the following problems:
– improving the parameters of mixture formation, and therefore the process, as well as the completeness of fuel combustion, in a wide range of operating modes of the internal combustion engine;
– improving the filling of the cylinders with fresh charge, reducing the work aimed at overcoming the intake resistance, i.e.
increasing engine efficiency. So, carburetor includes modification of the elements listed below (the material is aimed at the happy owners of carburetors of the Solex family, but much of what is discussed below also applies to carburetors of other models).
Modification of the housing makes it possible to improve the throughput of the chambers and reduce resistance in the engine intake tract. First of all, it is worth paying attention to the large diffusers of the first and second chambers, which are narrowings designed to increase the speed of the air flow and, therefore, to increase the vacuum in the area under the small diffusers in which the nozzles of the main dosing systems are located. However, the side effect in this case is a strong increase in resistance, which is logical: to increase the flow speed, some work must be expended. Therefore, the modification must begin with boring the holes of large diffusers; the resulting loss of vacuum in the area under the small diffusers, leading to a depletion of the working mixture, is compensated by selecting the fuel nozzles of the main metering systems of the first and second chambers. The recommended diameters of the large diffusers of the first and second chambers, respectively, are 23...24 mm and 24...26 mm for VAZ family cars with an engine capacity of 1.5...1.6 liters. The maximum value of the diffuser diameter of the second chamber is limited to a greater extent structurally - due to the thickness of the walls of the carburetor . When boring the diffuser of the first chamber, the process of selecting the optimal size of the fuel nozzle of the main metering system becomes significantly more complicated, and the output from the transition system worsens. After boring the holes of large diffusers, it is necessary to begin manual finishing of the surfaces of the first and second chambers. At the same time, factory burrs and technological protrusions are ground off, corners are rounded (they lead to the formation of turbulence and braking of the air flow), and the protruding parts of the throttle valve mounting screws are sharpened. Then you should begin the final processing of the surfaces of the chambers, i.e. for fine grinding and polishing to a mirror finish. Small diffusers that are pulled out, make the upper part of the legs round and sharpen the lower part, they should have the shape of an airplane wing, don’t overdo it, don’t rub it until there is a hole, then if you remove the float from the top cover of the carb, and remove the gasket, then connect the upper and lower parts of the carb, you will see everything inconsistencies, that is, protrusions of the lower part that need to be removed with a file. Assemble everything, rinse, blow out all membranes, any crack, hole on the membrane, immediately throw it out and don’t think about it, there are two of them on the lower part, lubricate all the gaskets under the carb with lithol, also for ventilation of crankcase gases, the tube that goes to You hang a fuel filter on the carburetor so that less dirt flies there.

Read also: Car charger circuit

Modification of the accelerator pump consists of selecting the cam profile and replacing the nozzle. The accelerator pump is designed to enrich the working mixture during acceleration mode.

There are a number of drive cam profiles, with the lower the cam number, the greater the accelerator pump performance. Standard profile No. 7 is installed on VAZ-21083, 93, 99, 10 cars.

Optimal for a dynamic driving style are profile values No. 4 and 5.

The cam profile is modified with a file taking into account the increase in fuel supply at the initial moment of opening the throttle valve of the first chamber.

It is also recommended to grind out a small depression at the point closest to the point of maximum opening of both throttle valves in order to ensure additional enrichment of the air-fuel mixture during engine operation at maximum power due to the operation of the accelerator pump (achieved by slightly rocking the accelerator pedal near the stop point) . It should be noted that the cam profile must be smooth, without sharp angles or changes, otherwise the accelerator pump diaphragm may be damaged. In addition, when you release the accelerator pedal, the accelerator pump should not be activated. The accelerator pump nozzle for Solex carburetors is designed in such a way that fuel is injected simultaneously into the first and second chambers of the carburetor . Note: gasoline from the sprayer should not fall on the walls of the chamber.

The next step in modifying the carburetor is the selection of jets for the main metering system. It is worth noting here that the decisive factor is not so much the size of the air jets and the polishing of the fuel channels, but rather the ratio of the diameters of the air and fuel jets.

If there is a wide range of fuel jets, you can always choose a ratio that ensures optimal mixture formation without changing the diameters of the main air jets. Keep in mind that air jets affect the composition of the mixture as the vacuum in the main carburetor , which occurs as engine speed increases.

Up to medium speeds (~ 2500 rpm) they have little effect on the mixture composition, but with increasing speed their influence on the mixture composition increases. The arithmetic is simple: the lower the throughput of the fluid, the richer the mixture becomes as the engine speed increases. As a rule, replacing the emulsion tubes of the main air jets leads to negative consequences, because

in this case, the formation of a fuel emulsion and, consequently, the combustion of the working mixture deteriorate. An accompanying symptom in this case is often the appearance of black smoke (soot) in the exhaust gases, which indicates incomplete combustion.

The most reliable way is to sequentially select the main fuel jets with a step of 2.5 units (25 microns) in the direction of enriching the mixture (increasing diameter) until signs of over-enrichment of the mixture appear (black smoke, deterioration in acceleration characteristics, popping noises in the exhaust system when over-gassing). In this case, you need to go back a step.

If you need to install a fuel jet with a larger diameter than what is available, you can go in the direction of reducing the size of the air jet. When purchasing jets, special attention should be paid to the roundness of the hole, the absence of scoring, and burrs. A positive result can also be achieved by a slight increase in the diameter of the economizer nozzle for operating and power modes.

The spacer installed under the carburetor is also subject to modification. The lower parts of its holes are made converging in order to improve mixing and ensure uniform filling of the cylinders in all modes (with a standard intake manifold, cylinders 1 and 4 are better filled at low speeds, and cylinders 2 and 3 at high speeds).

When modifying the carburetor on your own, do not forget about such operations as flushing, purging and adjustment. Before fine-tuning and during its process, great attention must be paid to the settings and adjustments of the ignition system.

In addition, it is unlikely that anything will be “squeezed” out of a “dead” carburetor . Signs of a “dying” carburetor : the outside of the body is covered with an oily layer of dirt, at idle, air is sucked in from the second chamber, gasoline oozes along the axes of the throttle valves, etc.

A few words about what is undesirable to do. You should not install a high-performance fuel pump, because... The standard performance is more than enough to power the engine under heavy operating conditions.

For the same reasons, you should not increase the stroke of the float in the float chamber (the above applies to moderately boosted engines with a volume of 1.5...1.6 liters).

A few more words about fuel consumption. Here, the owner of a car equipped with a modified carburetor should decide what is more important: reducing consumption or improving the dynamic characteristics of the car? Of course, fuel consumption is influenced by a large number of factors.

However, if you do not give in to the temptation and drive slowly, then high costs can be avoided, and you need to drive almost without pressing the accelerator pedal (almost only due to the fuel supply of the accelerator, increased during modification, as well as due to the operation of the transition and main metering systems of the first cameras).

As one of the options for solving the above question, you can select two sets of jets - for economical and dynamic driving.

Recommendations for carburetors and their calibration, obtained experimentally
For an engine of 1200-1300 cm3 :
Carburetors 21051 and 21053 (better) are the best option for normal city driving. The first chamber pulls well and saves fuel, the second allows you to accelerate sharply if necessary.

. Jets: I – 110/155 on an emulsion tube from 83 Solex with a ball at the bottom, II – 115-120/135

The 21083 carburetor has a small (21) diameter primary chamber diffuser, as a result of which the engine will be compressed by air, i.e. The maximum speed will drop to 5000-6000, but it will pull like a tank at the bottom.

It is necessary to install an accelerator sprayer with two spouts instead of one marked 40*40 and direct the streams into the gap that is formed when the damper is opened.

Replace the pusher with 4 or 5.

Jets: I – 100/150 on an emulsion pipe from 83 Solex with a ball at the bottom, II – 117.5-120/135

For an engine of 1500-1600 cm3:
Carburetors 21051 and 21053 (better) are the best option for normal city driving.

The first chamber pulls well and saves fuel, the second allows you to accelerate sharply if necessary.

Jets - 1 chamber: fuel (1tzh) - 110, air (1vzh) - 155 on an emulsion pipe from 83 Solex with a ball at the bottom; Chamber 2: fuel (2tzh) - 115, air (2vzh) - 135. Replace the pusher with No. 4 or 5.

Carburetor 21073 allows you to free the engine through the air, i.e. spin it more due to the increased diameter of the primary chamber, which reduces thrust at low speeds.

It is necessary to install an accelerator sprayer with two spouts instead of one marked 40*40 and direct the streams into the gap that is formed when the damper is opened.

Jets: I – 110/150-155 on an emulsion pipe from 83 Solex with a ball at the bottom, II – 115/135. We change the XX jet to 41.

It is necessary to install an accelerator sprayer with two spouts instead of one marked 40*40 and direct the streams into the gap that is formed when the damper is opened.

Replace the pusher with 4 or 5.

Jets: I – 110/150-155 on an emulsion pipe from 83 Solex with a ball at the bottom, II – 115/135

Carburetor 21041 has large “holes” (24*26) and is installed when it is necessary to turn the engine to the limit, but be prepared for problems with idle speed. Jets: I – 110-115/155 on an emulsion pipe from 83 Solex with a ball at the bottom, II – 120/135 on a thin pipe, push out the ball.

With deep tuning of the engine, it is possible to bore the diffusers to a size of 28*30, followed by replacing the throttle body with an increased diameter of 34 mm.

For an engine 1700-1800 cm3 :
Carburetor 21041. Jets: I – 110-115/155 on an emulsion pipe from 83 Solex with a ball at the bottom, II – 120/135

Carburetor 21073. It is necessary to install an accelerator sprayer with two spouts instead of one marked 40*45 and direct the streams into the gap that is formed when the damper is opened.

Jets: I – 110-115/155 on an emulsion pipe from 83 Solex with a ball at the bottom, II – 117.5-120/135. We change the XX jet to 42.

With deep tuning of the engine, it is possible to bore the diffusers to a size of 28*30, followed by replacing the throttle body with an increased diameter of 34 mm. Or installing two carburetors

General recommendations:
After any modifications to the carburetor, it is necessary to adjust the CO at idle, set to 1.5%, maybe 2 (for large diffusers), and at medium ones it should be 0.3-0.6. Jets sold at retail usually do not correspond to the markings; they need to be checked.

When installing a carburetor from front-wheel drive VAZ modifications that have a fuel return line, the fuel return fitting can be plugged or connected through a check valve into the fuel supply circuit to a fine filter. Following the advice of experts, we chose the second method of modernization, which eliminates overload of the carburetor and disruptions in its operation.

To get the maximum benefit from replacing this main element of the power system, it makes sense to upgrade the ignition system by installing a contactless one. Solex carburetors are initially configured to create a lean mixture.
For its effective ignition, a more powerful spark discharge must be created on the spark plug. This can only be achieved by a contactless ignition system, the coil of which produces a voltage of up to 25,000 V, and the interelectrode gap of the spark plugs is 0.7-0.8 mm. Let me remind you that in a contact-transistor ignition system the above characteristics have values of 17000 V and 0.5-0.6 mm, respectively. The gap in the contact system can be increased, but this will cause accelerated failure of the bearing of the movable plate of the breaker, its contacts and the capacitor. After installing the carburetor and successfully starting the engine, you should definitely contact specialists for final adjustment of the unit for exhaust gas toxicity. Without this operation, in addition to increasing the toxicity of exhaust gases, fuel consumption may increase and dynamics may deteriorate.

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