The efficiency of the engine cooling system depends not only on the power of the external heat exchanger (radiator with fan) and the coolant circulation rate (pump performance), but also on the properties of the coolant itself.

Under extreme loads, this factor becomes very significant, if not predominant. The boiling of the coolant in the hottest zones of the engine, cavitation on the pump blades, change the structure of the coolant, saturating it with bubbles. The presence of a vapor-gas phase in the coolant leads to a sharp decrease in the heat transfer coefficient in the wall-coolant system. This equally applies to the deterioration of heat transfer inside the radiator channels and in the engine cooling jacket. The latter, in turn, threatens local overheating of the engine, especially the 5th and 6th cylinders of in-line sixes, which are problematic from the point of view of heat dissipation.

You can help the engine by increasing the circulation rate (coolant flow rate) by replacing the standard pump with a high-performance pump or an electric pump. It is very useful to raise the boiling point of the coolant by installing a radiator cap that maintains higher pressure in the cooling system, for example 1.3 bar.

This article is about how to make a breathing tank (Briefer tank) on your own and implement a coolant circulation scheme with separation of the vapor-gas phase and its subsequent removal into the expansion tank.

As always, it all starts with a flea market. Having obtained the necessary piece of “luminium”, you can begin. All work is divided into actual turning and welding and other work. Turning and welding is clearly visible in the pictures and is performed by turners and argon workers. There is no need for great skill here; the main thing is to properly puzzle the specialists and interest them financially.

Other: making a seat on the neck of the tank for the radiator cap. The work is not difficult, but requires accuracy. I’ll say right away that the drill I had stocked up in advance was not useful. Everything was removed with a metal file, needle files and a small chisel. Fortunately, aluminum is a malleable material.

The connection diagram for the tank is shown. The pressure in the system will be equal to the pressure of the cap valve on our tank. The cap on the radiator no longer plays a piano; it can simply be replaced with a plug.

Product budget:

Blank - 50 hryvnia (khokhlobaks), turner 100 gr., argon operator 10 gr. I bought myself a chocolate bar for my troubles. Total 30 American hryvnia.

That's all, ride and have fun.

I wish you all creative success.
Sincerely, Victor(SOARA).

PS: I completely forgot how articles in serious tuning magazines end: This device will be a wonderful decoration under the hood of your car!

In this article we will try to improve engine cooling with little cost, that is, without changing the design. To do this, it is enough to replace individual elements of the system, starting with the radiator - the main cooling element of the engine. Aluminum non-assembled radiators are characterized by increased heat transfer, both when the engine is idling and when driving at low speed.

At the same time, the reserve is over 25 percent compared to the standards. It is often the radiators that “leak” on domestic cars, and corrosion is the culprit. Many car enthusiasts consider coolant to last forever, so they don’t change it on time. But when hot coolant circulates in the aluminum radiator tubes, the corrosion process begins.

We've dealt with the radiator, it's time to take the next step to improve the temperature balance - choose a new electric fan for the car. No matter how good the radiator is, it will not cope with its task without a fan, especially in difficult conditions. We select a fan whose impeller has the highest air flow rates. We also note the presence of balancing; this eliminates imbalance during rotation, which in turn significantly reduces the noise level and extends the service life of the electric motor bearings.

In passing, we note that no less important than the fan itself is the sensor for turning it on. It would seem that it is difficult to come up with something new here; the design is extremely simple. And yet there are manufacturers who have increased the reliability and service life of the sensor. This is achieved by eliminating sparking and a spring-loaded lever, which completely eliminates operation defects.

What else will help us improve the temperature balance of the engine? Well, of course the pump. Once again, we are looking for a solution that leads to both improved reliability and increased performance. The pump must have a double-row ball-roller bearing, a ceramic oil seal, and additional sealing of the housing-oil seal and shaft-oil seal interface - all this to prevent coolant leaks. The new pump will move fluid through the heater radiator more efficiently.

This is the time to remember about the stove faucet. The classic VAZ design is still alive and, by the way, works well, but every owner of a Zhiguli has probably experienced the drawback of this faucet - hot antifreeze suddenly begins to leak into the interior of the car. Choosing a ceramic faucet.

Next up is the thermostat. We cannot but agree that this is a very important element of the cooling system. We are looking for a thermostat with a modified bypass valve, due to which the engine temperature remains unchanged under all operating conditions.

We emphasize that it is best to use a set of measures, that is, not only change the thermostat, but also the radiator, pump, and fan. Finally, let’s look at such a seemingly insignificant detail as the cap, in our case, of the radiator and expansion tank. This is actually a very important element.

How to improve snowmobile cooling and reduce cylinder temperatures

Many users will answer without thinking, citing well-known requirements: oil proportions, carburetor and ignition adjustments, engine cleanliness and correct driving style. These facts are undeniable. But what if following these basics does not provide the necessary parameters? The answer is simple as always - modify the engine cooling system on your own. What steps can be taken in this direction will become clear as you read the article. The simplest step is to insulate the exhaust system with thermal insulation materials. The idea behind this modernization is to ensure that the air sucked in by the forced cooling system is not warmed up due to heating by the exhaust manifold. Additionally, this method reduces operating noise. Imported snowmobile mufflers, initially in their design, have internal packing made of high-temperature materials with a high degree of sound absorption

Such modernization should be approached carefully, since exhaust system loses the ability to transfer heat to the external environment and its internal parts begin to experience temperature loads for which they were not designed. As a result, segments inside the muffler begin to burn out, which subsequently move freely and create metallic sounds that are not typical for the operation of a snowmobile. However, in each individual case, the duration of destruction of the muffler is individual and can last for years.

A more correct solution should be considered a separate air supply to the air intake or the use of a heat shield from the influence of the muffler. There is no need to talk about this; all the photographs presented below give a clear idea of ​​how this can be accomplished. There are snowmobiles that normally have air intake through a special channel - a casing - from the external environment. It is undeniable that the possibility of direct air intake from the street helps improve engine cooling and reduce cylinder temperatures

The next effective step to improved engine cooling And reduction in cylinder temperature in general - installing a screen between the exhaust manifold and the engine cylinders. This idea has been used on imported snowmobiles almost since the founding of snowmobile construction in Russia

The purpose of such a screen is to cut off the air flow passing through the cylinders and prevent it from heating up further by coming into contact with the hot exhaust manifold. On the assembled engine it looks something like this. Moreover, as can be seen from the photograph, the cooling casing is practically absent at the exit point of the exhaust pipe

Since about 2001, a similar solution began to be used on Buran snowmobile engines, installing on the internal part cooling jacket air flow divider

If you do not have such a solution on your snowmobile, we strongly recommend that you adopt this method, make a plate and install it, regardless of the brand of the snowmobile. Moreover, recently a similar design began to be used at the plant when assembling Taiga snowmobile engines. The effect of the design is very noticeable even without the use of electronic engine temperature sensors. The thermal stress of the left cylinder is especially greatly reduced, and the temperature difference between the left and right cylinders is also minimized. An example of using this method yourself is the photo below, where the part of the cooling shroud highlighted in yellow has been removed

There are craftsmen who install two fan impellers on a snowmobile. The method is very controversial, since in theory, the operation of two impellers of unidirectional rotation will be accompanied by excessive air turbulence - interfering with each other. In practice, no one has conducted research and it is impossible to say whether the air flow increases or decreases

The cooling system is an indispensable attribute of any car. Too much energy when the car moves is forced to be converted into heat. The engine and transmission require active cooling, as do the braking system, powerful electrical components and the air conditioning system. How are supercar cooling systems different from “regular” ones? After all, these cars are at the same time powerful, compact and extremely lightweight. What interesting technical solutions are found in their designs?

Maintain the temperature of an engine with a power of over 300 hp. With. not an easy task at all, especially when it is running at full power and the speeds are low. And the dynamic capabilities of modern supercars are very dependent on the outside temperature.

Often, increasing engine power is prevented by the so-called “thermal package” - an indicator of the power dissipation of the engine and transmission cooling systems, and not the capabilities of the power units. It would seem that at high speed the cooling problem should not be so acute: the radiators are purged with air. But here, too, the design features of a high-speed car introduce their own nuances. The aerodynamic properties of a car largely depend on the ability to create a ground effect, and safe movement also depends on the operation of the braking mechanisms. Last but not least is banal aerodynamic drag, as well as general streamlining; they also have to be taken into account. How can stable operation of all systems be ensured under such conditions?

For a supercar, aerodynamic bodywork is the basis of everything. Including the quality of the cooling system. And “classic” solutions with radiators located under the hood, in the front of the car, are not honored. Even the models front engine The radiator design and aerodynamic design are significantly different from the standard ones.

Thus, the front part of the Mercedes SLR McLaren W199 is standard only at first glance. There is a main radiator, a liquid intercooler radiator with two electric pumps, a large transmission radiator and an engine oil tank - a dry sump system is used, and the oil is first cooled in the main radiator section, and then further reduces the temperature in the tank housing, which is made with a large finned surface.

For better performance of the underbody, some of the air from the radiators is diverted upward through the hood, and the radiator package is arranged in such a way as to “correctly” distribute the flow. The engine is located within the wheelbase, and the volume occupied by the cooling system is several times greater than that of typical passenger cars. The design of radiators is not fundamentally different from the usual one. The aluminum "core" and plastic reservoirs can be seen on most production supercars. All-aluminum parts are widely offered only as tuning and on cars of almost one-off assembly. The electric fans of the system are also quite standard, except that they are noticeably more powerful than usual, have better aerodynamics and are lighter in weight.

At the cars with rear and central location of the power unit in most cases, a fairly compact cooling system is used with side and rear radiators for cooling the engine and charge air. This is done, for example, by Audi on the R8 model, McLaren on the P12 model, and this is how almost all Ferrari models with a mid-engine engine are designed.

But the creators of the Porsche 911 made the cooling system much more extensive and placed the engine radiators in the front part of the body. It is characteristic that the system usually uses not one large, but several small radiators. There are three of them in the 911, three in the R8, and the McLaren has noticeably more radiators, since a hybrid drive is used and the cooling system also has a cooling circuit for batteries and inverters.

An interesting technical solution is used by Porsche. On the 911 GT3, the radiator fan motor has its own individual monitoring and control unit, allowing smooth control of its performance and greater tuning and diagnostic capabilities. And the side radiators with electric fans are made of single quick-release models, and concern for aerodynamics is manifested even in such a small thing as the electric motor cap.

With long cooling routes and a large number of radiators, engine pumps are an important component. Mercedes and Porsche make do with the standard reinforced design, but with a blade profile optimized to prevent cavitation. At engine speeds of more than 7 thousand, a drop in performance can be fatal.

The Audi R8 with a V10 engine has a very interesting design: the oil pump with a pump and thermostat are combined into a single module with a reduced rotation speed, which is driven by a chain. And in any case, it cannot do without additional electric pumps - they make it possible to ensure stable circulation of fluid in large cylinder blocks and pump coolant through the radiators at low crankshaft speeds.

Another important function is to prevent a large, complex and very heat-intensive engine from boiling after switching off, and if there are turbines, the pumps also cool them. Liquid charge air cooling systems on Mercedes SLR and McLaren P12 engines use multi-circuit cooling systems with a dedicated low-temperature circuit. Moreover, the Mercedes cooling system is dual-circuit, while the McLaren already has three circuits - one more is needed for cooling and heating the electronic systems and the hybrid battery.

Oil coolers engine and transmission are an indispensable attribute of a supercar. These parts are also present on the engines of conventional cars, but the difference is in scale. The oil cooler of the automatic transmission of the 722.6 Mercedes SLR series is comparable in size to the main radiator of a small car, and in the oil cooling system of the Audi R8 there are several radiators, including a water-oil heat exchanger and conventional air ones. Not only automatic transmissions require cooling, but also conventional “mechanics”, and even gearboxes often have their own oil radiators or built-in liquid heat exchangers.

An important component of the cooling system is its working fluid, in other words, antifreeze. Extreme machines often use very non-standard compounds. The goal is one - to make the cooling system work as efficiently as possible with the least power consumption, but in addition to this there are several more factors. Firstly, the most advanced motors often use complex alloys based on magnesium and other active metals. In this case, preventing corrosion is a very important task and standard antifreeze formulations may not cope. And “supercar” antifreeze is supposed to be a little more fluid and provide better heat transfer. Improving these parameters by a fraction of a percent already promises a serious gain in work, but it will be very expensive. However, Mercedes, Audi and Porsche are satisfied with quite standard, albeit not the cheapest, antifreeze. But if you have a Ferrari or McLaren, then the recommendations, as befits exclusive cars, will be exotic.

Among the characteristic features of supercar cooling systems are also extremely low weight, widespread use of light alloys and plastics, as well as non-standard technologies and almost one-piece production. Thus, Porsche uses glued-in cooling system pipes on engines to reduce the weight of the cylinder block. And such exotic things as magnesium, titanium and ceramics in structures are almost more common than traditional cast iron and steel. The high density and small thickness of the radiator tubes is also a characteristic detail; it’s not for nothing that many cars have radiator protective meshes installed at the factory.

The photo shows a diagram of the Nissan Almera G15 engine cooling system

The standard engine cooling system cools its heated parts. In modern car systems it also performs other functions:

• cools the lubrication system oil;
• cools the air circulating in the turbocharging system;
• cools exhaust gases in the gas recirculation system;
• cools the automatic transmission fluid;
• heats the air circulating in ventilation, heating and air conditioning systems.

There are several ways to cool an engine, depending on the type of cooling system used. There are liquid, air and combined systems. Liquid - removes heat from the engine using a flow of liquid, and air - a flow of air. In a combined system, both of these methods are combined.

Most often in cars, a liquid cooling system is used. It cools engine parts evenly and quite efficiently and operates with less noise than air. Based on the popularity of the liquid system, it is on its example that the principle of operation of car engine cooling systems as a whole will be considered.

Engine cooling system diagram

The photograph shows a diagram of the engine cooling system of a VAZ 2110 with a carburetor and a VAZ 2111 with an injector (fuel injection equipment).

Gasoline and diesel engines use similar cooling system designs. Their standard set of elements is as follows:

1. conventional, oil radiator and coolant radiator;
2. radiator fan;
3. centrifugal pump;
4. thermostat;
5. heater heat exchanger;
6. expansion tank;
7. engine cooling jacket;
8. control system.

Let's look at each of these elements separately:

1. Radiators.

1. In a conventional radiator, the heated liquid is cooled by a counter flow of air. To increase its efficiency, the design uses a special tubular device.
2. The oil cooler is designed to reduce the temperature of the oil in the lubrication system.
3. To cool the exhaust gases, their recirculation systems use a third type of radiator. It allows you to cool the fuel-air mixture during its combustion, resulting in less nitrogen oxides being formed. The additional radiator is equipped with a separate pump, which is also included in the cooling system.

2. . To increase the efficiency of the radiator, it uses a fan, which can have a different drive mechanism:

• hydraulic;
• mechanical (permanently connected to the crankshaft of the car engine);
• electric (powered by battery current).

The most common type of fan is electric, which can be controlled within a fairly wide range.

3. Centrifugal pump. Using a pump, the cooling system circulates its liquid. A centrifugal pump can be equipped with various types of drive, for example, belt or gear. For turbocharged engines, in addition to the main one, an additional centrifugal pump can be used to more effectively cool the turbocharger and charge air. The engine control unit is used to control the operation of the pumps.

4. Thermostat. Using a thermostat, the amount of liquid entering the radiator is regulated. The thermostat is installed in the pipe leading to the radiator from the engine cooling jacket. Thanks to the thermostat, you can control the temperature of the cooling system.

In cars with a powerful engine, a slightly different type can be used - with electric heating. It is capable of providing temperature control of the system fluid in a two-stage range in three operating positions.

This thermostat is open during maximum engine operation. At the same time, the temperature of the coolant passing through the radiator drops to 90 ° C, thereby reducing the likelihood of engine detonation. In the other two operating positions of the thermostat (open and half-open), the liquid temperature will be maintained at 105 °C.

5. Heater heat exchanger. The air entering the heat exchanger is heated for subsequent use in the vehicle's heating system. To increase the efficiency of the heat exchanger, it is placed directly at the outlet of the coolant that has passed through the engine and has a high temperature.

6. Expansion tank. Due to changes in the temperature of the coolant, its volume also changes. To compensate for this, an expansion tank is built into the cooling system, maintaining the volume of liquid in the system at the same level.

7. Engine cooling jacket. In design, such a jacket represents channels for fluid passing through the engine block head and cylinder block.

8. Control system. The following devices can be represented as control elements of the engine cooling system:

1. Circulating fluid temperature sensor. The temperature sensor converts the temperature value into the corresponding electrical signal value, which is supplied to the control unit. In cases where the cooling system is used to cool exhaust gases or for other purposes, it may have another temperature sensor installed at the radiator outlet.
2. Electronic based control unit. Receiving electrical signals from the temperature sensor, the control unit automatically reacts and performs appropriate actions on other actuators of the system. Typically, the control unit has software that performs all the functions of automating the process of signal processing and setting up the operation of the cooling system.
3. Also, the following devices and elements may be involved in the control system: engine cooling relay after it stops, auxiliary pump relay, thermostatic heater, radiator fan control unit.

The principle of operation of the engine cooling system in action

The smooth operation of cooling is due to the presence of a control system. In cars with modern engines, its actions are based on a mathematical model that takes into account various indicators of system parameters:

• lubricating oil temperature;
• temperature of the liquid used to cool the engine;
• outside temperature;
• other important indicators affecting the operation of the system.

The control system, assessing various parameters and their impact on the operation of the system, compensates for their influence by regulating the operating conditions of the controlled elements.

Using a centrifugal pump, forced circulation of coolant is carried out in the system. As the liquid passes through the cooling jacket, it heats up, and once it enters the radiator, it cools down. As the fluid heats up, the engine parts themselves cool down. In the cooling jacket, liquid can circulate both longitudinally (along the line of cylinders) and transversely (from one manifold to another).

The circle of its circulation depends on the temperature of the coolant. When the engine starts, the engine itself and the coolant are cold, and in order to speed up its heating, the liquid is directed to a small circulation circle, bypassing the radiator. Subsequently, when the engine heats up, the thermostat heats up and changes its operating position to half-open. As a result, coolant begins to flow through the radiator.

If the counter flow of air from the radiator is not enough to lower the fluid temperature to the required value, the fan turns on, generating an additional air flow. The cooled liquid again enters the cooling jacket and the cycle repeats.

If the car uses turbocharging, it may be equipped with a dual-circuit cooling system. Its first circuit cools the engine itself, and the second circuit cools the charge air flow.

Watch an educational video about the principle of operation of the engine cooling system: