The low cost and availability of gas is the main reason why car owners are massively switching to alternative fuels and installing gas-cylinder equipment. Among them there are also owners of old cars with a carburetor engine, who are also not averse to saving on fuel and increasing the respectable (but also fearsome) resource of a decrepit engine. But the design features of gas equipment on a carburetor, which are usually classified as generations, do not allow the installation of an arbitrarily selected configuration of a gas installation on a vehicle with a carburetor. There are a number of differences here that are worth considering carefully.
HBO for a carburetor car
The engines of any car are divided into carburetor and injection. These are fundamentally different devices: the first sucks in a mixture of fuel and air due to the difference in pressure, all remote adjustment is absent or minimal. An injector, on the contrary, is a high-tech modern means of injecting fuel into the engine through separate nozzles, one for each cylinder. The process at all stages is corrected by an on-board computer, which, with bundles of pressure, temperature, oxygen and other sensors, collects information about the state of affairs, analyzes it and automatically controls the supply of fuel through solenoid valves in units and lines.
Several advantages of installing a spacer on a gasoline engine
The first and main thing is to prevent deformation when the engine body is very hot and to prevent the carburetor from overheating and disrupting the operation of the device. Models from brands such as Solex and Ozone are most susceptible to such “diseases”.
Here are some more benefits of installing a thick gasket when installing on a gasoline carburetor engine:
- If there is no spacer between the carburetor sole and the cylinder head body, the temperature is transferred to the device, strong heating occurs, so on a hot engine you will have to turn the starter for a long time before the engine grabs gasoline and starts. This occurs due to the acceleration of the evaporation of gasoline vapors; in addition, the specific density of the delivered fuel increases due to the high temperature and saturation of the combustion chamber with vapors;
- Having tightly tightened the nuts on the device to ensure a reliable connection and the impossibility of gasoline leaks, at the first heating the sole warms up and the deformation process begins. With subsequent inevitable heating, the deformation increases. Having removed the carburetor for repair, we get a deformed sole. This will cause the engine to run on three cylinders on a cold engine, and subsequently the engine will constantly fire. There will be air leakage along the lower flange and the intake manifold. Such a malfunction will require correction of the deformed sole; if the damage is severe, the sole or the carburetor itself will need to be replaced. Straightening the flange, and in case of severe deformation, milling - these works may involve a fuel supply system that is not equipped with a platform for the combustion chamber. None of even the most trendy sealants can help here;
- With many methods advertised on the Internet, a textolite sole under the carburetor, in the opinion of many car enthusiasts, should be installed on every car. However, you should be wary of fakes. You can often see a textolite spacer with an additional layer of unknown material on display. After a short period of time, it dries out or decomposes even worse, the performance and power of the engine drops due to a malfunction.
Selecting a gas generation system compatible with the carburetor
Since LPG is built into the fuel delivery system to the engine, it is important to take all these features into account. New generations of gas installations (starting from 3) are equipped with their own electronic brains, which fully simulate the necessary settings and form the optimal injection of a gas-air mixture of a suitable composition for a smooth and accurate ride and ensuring the integrity and safety of the mechanism.
To do this, they have their own sets of sensors and lambda probes that measure the level of oxygen content sorted into tubes, valves, injectors, gearboxes and manifolds. At the slightest change in the desired parameter, the sensor will immediately inform the software unit about this, which will properly respond by opening/closing a specific electrovalve. The carburetor circuit is devoid of all these advantages - there is simply not even a simple on-board computer that can diagnose and adjust the operation of the chassis, there are not even sensors, except for the most basic ones. LPG is installed through a special adapter-mixer, or directly - by making inserts directly into the carburetor and bringing out the main pipes for supplying gas there. Only two sensors are connected: to the carburetor throttle valve and an oxygen lambda probe in the intake manifold. Their readings set in motion a single electronic valve that regulates the flow of gas from the reducer. This is the operation scheme of 2nd generation gas equipment, which is optimally suited for carburetor versions of the engine.
Even older car models (for example, old Soviet ones) do not have even that minimal electrification and all adjustments are carried out manually, by rotating two screws on the gearbox housing, and another on the gas supply hose from the cylinder. The valve is the most ordinary mechanical one, without power blocks or sensors. Their functions are performed by a one-sided vacuum membrane in the reducer, which, at a certain value of vacuum, opens for a certain period of time, allowing a portion of gas into the collector. All adjustments are very simple - the portion size depends on the degree of opening/closing of only one dispenser screw, which is once set, then adjusted only together with carburetor maintenance (or if there is a malfunction). The most simple and accessible, but ineffective operating principle of 1st generation LPG is still relevant today, thanks to the significant prevalence of cheap and reliable carburetor engines in old cars.
Equipment adjustment
You can try to adjust the operation of HBO Atiker, Lovato and Tomasetto yourself. To figure out how to set up a 2nd generation LPG on an injector, you should have relevant experience and know the operating principles of the car’s electrical equipment.
Subject to adjustment when operating a vehicle on LPG:
- the number of idle speeds at which the engine switches to gas;
- if necessary, adjustment of the gas mixture dispenser is required;
- when operating a car on propane-butane fuel, the air filter quickly becomes dirty, it must be replaced with a new one or blown out;
- the gas line is checked for leaks;
- the presence of gas in the cylinder is monitored;
- It is necessary to ensure that the gas tank is not empty to periodically start the engine on gasoline.
When installing gas equipment, it is sometimes necessary to increase or decrease the number of revolutions at which the injection engine switches to gas. To do this, turn the adjustment resistance on the HBO switch button, achieving the required parameters. In a carburetor car, the delay time for automatically turning off the gas is regulated in the same way.
Step-by-step diagram of installation and connection of a gas installation
The undeniable advantage of 1-2 generation gas equipment is cheap and easy setup, without the need to connect dozens of bundles of cables and injectors.
Anyone with the minimum skills of a car mechanic and the simplest necessary tools can handle the installation. Those who are not even motivated by this to roll up their sleeves and lift the hood to carry out the installation themselves will be pleasantly surprised by the prices in car services for such a service with the help of in-house specialists. Especially when compared with the cost of installing injection systems.
Any LPG model compatible with a carburetor consists of:
- A gas cylinder filled with liquefied propane or methane. There are cylindrical and toroidal varieties, differing from each other in shape and size. Since this is a volumetric unit, it is installed either in the trunk, or if the dimensions allow for a spare wheel. Several small cylinders fit under the hood for cars with high ground clearance.
- Multi-valve (representatives of the 2nd generation also have a ventilation box through which the gas is filtered and released in an emergency), the regulation of the fuel supply from the cylinder is combined with a composition filter, separating large mechanical impurities. The valve is located directly on the cylinder to which it is screwed.
- Line - a copper or plastic tube running from the fuel tank to the gearbox. Equipped with a valve for manually shutting off the gas supply under high pressure. Often there are configurations with an additional filter.
- The evaporator reducer is one of the key points in the operation of gas equipment. Liquefied gas stored in cylinders is completely unsuitable in its raw form for use by a motor, so in the reducer it is transferred into the free gaseous phase (evaporates) and the pressure is normalized to the operating parameter. All these procedures are accompanied by a sharp expansion of the gas and, accordingly, a decrease in temperature. In this regard, a somewhat unexpected problem may arise - an icy gearbox that is not able to function normally (which is why in the cold winter the engine is first started and warmed up on gasoline and only then is gas connected). To avoid regular freezing of the gearbox, it is placed closer to the stove and connected to the cooling system so that it warms it up by circulating liquid.
- The dispenser at the outlet of ready-to-use fuel from the gearbox is filled with a certain portion and only then allows the gas to pass further. Depending on the generation and configuration of the gearbox, it can be mechanical (the dispenser is adjusted only by a screw), vacuum (with an additional tube into the manifold and a membrane, adjustment is carried out by changing the vacuum in the manifold) and electric (2 generations, then it comes with a small power unit).
There are two main options for connecting to the carburetor: with a mixer or directly. The first method for those who do not have any tools is to simply screw the ready-made adapter to the mounting connectors on the carburetor body. In the second case, a hole is drilled into both chambers, a corresponding thread is cut into them with a special tool, onto which the fittings are screwed.
Operating principle of HBO2
The principle of operation of 2nd generation HBO on a carburetor engine is as follows.
The gas is contained in a cylinder equipped with a multi-valve. Fuel is supplied to the valve using the main pipeline. Gas filtration systems are installed there. This is where it can be cleaned of dirt, debris and other foreign elements. Then comes the gearbox. It is connected to a system that is needed to cool the engine. In it, the gas changes form from water to steam. This is achieved through temperature and pressure. The gas is supplied as steam to the engine to be mixed with air.
Now the fuel enters the mixer. There, gasoline and air are mixed to create a mixture. A power regulator is installed on the sleeve. It is needed to regulate the amount of gasoline in the engine. If the mode operates on gas, the gasoline supply will intersect with the valve located on the fuel line.
Note. To prevent the pump from constantly breaking down, a gasoline valve should be placed between the gasoline pump and the carburetor. This is necessary so that the first one contains gasoline necessary for lubrication.
The HBO button is responsible for controlling the system. If the ignition is turned off, the switch is de-energized and the fuel is shut off.
The connection diagram consists of three modes:
- Gaza. When the ignition is turned on, the switch receives energy, opening access to the fuel supply. This is necessary to improve the launch. Pulses will appear on the ignition coil. The switch will see them and open access to the valve. Fuel will flow until the wire stops receiving signals.
- Gasoline. No fuel will be supplied here. Power will be supplied to the gas valve, which will open the flow of gasoline to the engine.
- Transition. Here the supply of both fuel options will be turned off.
Connection
The installation diagram for the gas equipment has been completed, all that remains is the connection: the only element requiring electrical wiring and power supply in the first generation is the gas/gasoline switching valve.
To do this, you will need to install the solenoid valve on the gasoline line and combine its wiring with the gas supply switch cable.
The connected cord is led out into a button on the driver's seat; usually they try to position it so that it can be pressed without being distracted from the road - after all, the driver usually switches to the gas while driving, having gained a certain speed.
Adjustment and troubleshooting
Setting up even such simple devices as 1-2 generation HBO is a tedious and painstaking task, requiring patience and accuracy. Most car owners of carburetor cars therefore try to transfer it to a service station. All adjustments are performed manually and are described in detail in the corresponding article step by step:
- Rotating the feed screw on the line
- Adjustment of the gearbox (1 or 2 screws depending on the configuration of the specific equipment) at idle speed and in different load modes, sequential calibration.
In fact, all difficulties with the operation of gas equipment for carburetor engines, which can be correctly identified and solved independently and without special problems, tools or skills, are associated with careless compliance with mandatory maintenance (regular replacement of filters, rubber products) or incorrect settings and are corrected accordingly.
Author: A. Kopylov
Equipment setup
As an example, consider the configuration option for a popular gearbox from Tomasetto (Tomasetto AT-07 electronic). Adjustment of 2nd generation Lovato gearboxes and its full analogues, such as Atiker and Torelli, is performed in a similar manner.
Before starting work, make sure that all engine systems are in good condition. The air filter has been changed, the ignition has been adjusted, and the coolant level is normal. Drain the condensate from the gearbox, if it is not new, make sure it is in good condition.
In order to adjust second-generation gas equipment with your own hands, you need to warm up the engine to operating temperature on gasoline, switch to gas and turn off the engine. From now on, we will separate the tuning options for different types of engines.
Correct adjustment of 2nd generation HBO on a carburetor with your own hands
- Using a flat-head screwdriver, tighten the screws of the gearbox and dispenser until they stop (without much effort), and then unscrew:
- membrane sensitivity 2-3 turns;
- “greed screw” of the first chamber until fully open, the second by 1 turn.
- Start the engine on gas. Gradually tighten the sensitivity screw to find the moment the speed drops at a lean mixture. Attention! A drop may occur when the mixture is enriched. Therefore, if, when unscrewing the screw, the speed increases, and then falls again, it means that this is working on a rich mixture. Now, by screwing the screw back in clockwise, you need to set the peak of increased engine speed - this way the idle speed will be found (800-850 rpm). If higher, adjust the quantity screw on the carburetor itself to the desired readings.
- Use the accelerator to increase engine performance around 3000 rpm. Use the “greed screw” of the first chamber to set the moment when, when it is tightened, the drop begins, and when unscrewed, the speed increases. Release the accelerator and revoke the throttle; if the internal combustion engine develops low speed (there is a dip), unscrew the screw of the first chamber of the power register by 1/8. At the same time, adjust the sensitivity screw as indicated in point No. 2. Check by re-gasping again.
- The second chamber of the carburetor operates at increased engine speeds from 3000 rpm (depending on the engine brand). Therefore, the “greed screw” of the second camera must be set to approximately the same position as the first.
- Next, you need to carry out control tests on the move under different loads (lifts, sudden accelerations).
Fuel switch
Gas/gasoline switch is a device designed to switch the operating mode of a vehicle from one type of fuel to another at the moment when a certain number of vehicle engine revolutions is reached.
Switch K-5 Tamona All switches are divided into three main groups.
1. For injection engines. This type of switch has three positions: petrol, gas and automatic mode. 2. For carburetor engines with the installation of an electronic gearbox. In these switches, the “GAS” position is equipped with an automatic shutdown of power from the shut-off valves. 3. For carburetor engines with the installation of a vacuum reducer. And on this gas-gasoline switch there are two toggle switches. One for switching the type of fuel, the second for pumping gas before starting the engine.
The cost of switches usually does not exceed 1000 rubles.
Switches, options and costs All switches come with a wiring diagram and mounting kit.
Balloon
Made of 3-4mm thick steel to ensure safety even in case of accidents. Currently, cylinders are produced in various sizes depending on the engine size.
A cylindrical cylinder is the most common shape in first-generation LPG installations.
Cylindrical cylinders, options and cost Toroidal cylinder - designed for mounting in a spare wheel storage area. This shape allows you to conveniently place the cylinder in a car while maintaining useful space, for example in a station wagon. Toroidal cylinders, options and cost There is a variation in the cost of cylinders; toroidal options are best for installation.
Mixer
Supply the engine with the required amount of gas and air. This happens in various ways through the carburetor diffuser, or by creating a diffuser in the design of the mixer itself.
For each type of vehicle there is a specific mixer model.
Mixer 300-489 FIAT Punto2 Mixers can also be divided into several groups: 1. Mixers installed in the upper part of the carburetor; 2. Mixers - spacers that are installed in the middle part of the carburetor. 3. Fittings, so-called inserts, inserted into the carburetor using drilling. 4. A fork-shaped system consisting of tubes that are inserted into the carburetor without drilling. 5. Mixers for injection systems of various modifications. Faucets, options and costs