Culassa Head Motor

The material most used in the manufacture of culassas es aluminum alloys are relatively easy to work, light and good thermal conductivity. The engines used mainly old cast iron.
As aluminum has poor surface quality, it is necessary to provide the culassa several false in order to improve their strength and longevity. The most important are those of the valve seatmade of high strength steel to resist coke out (at the time of closing) in the difficult conditions of high temperature and reactive gases (escape).
With the introduction of unleaded gasoline were lost, the lubricating properties of this element, so that the valve seats projected to run on this fuel had to be even tougher. Other inserts may be the guides of the valves, supports the camshaft and rocker arms and screw the candle, although some of these may be machined directly on the aluminum culassa. The indirect injection diesel engines still have the pre-combustion chamber as fake.
There are engines in the engine block and culassa are merged on the same piece. With this can save up to n'vel production (fewer parts to manufacture and mount), but still has the advantage of providing a lower emission hidrocarbonetosnão burned.
Culassa in the grip of the cylinder can be used screws, but the use of bolts is most common. The force (torque) and the order of tightening is recommended by manufacturers, in order to avoid permanent deformation when the culassa opreração assembly. Before the 80 "run" the engine that allowed the different parts are accommodated each other, which meant that the strain of tightening culassa forced to downsize and tighten their after 500 miles. Currently bolts are manufactured in a material with uni limit lending, with control of its elongation extremely sophisticated. Thus, it becomes unnecessary to tighten, because the settings of several pieces during the filming signitificativamente are lower than the initial elongation of the bolts

The ease in acquiring a car in the Present Day

The ease and convenience that the Internet offers today is impressive. The Internet can do absolutely anything you want with just a few clicks. Viewed as a potential target audience, Internet users are being bombarded every day with new options for classifieds, shopping and leisure in the network.Currently it is also possible to make purchases and sales of cars via the Internet in a few days for your new car is packed and parked in his garage, but this would be the first contact of the Internet with the product you purchased, questions arise around this service: is it so good to be true? Well, if already abroad, this practice is very common here in Brazil, consumers are increasingly confident when making a purchase online, even when it is an expensive product like cars. According to research on the net, the sale of vehicles in the mean turnover of R $ 2.9 billion and the goal is to close this year with about $ 9 billion.

What to do to get along in this? The first thing to do is seek a safe environment for the purchase.Choose electronic stores that are already in operation for years creates a higher crebilidade with the consumer. The more cars advertised more links created. If you have the opportunity to search for cars that you can see before buying it. Every consumer likes to have direct contact with the product, not just one picture to satisfy him, so never make the payment before seeing the car and try to create a bond with the seller fails to make your purchase if you do not trust him, it should become your best friends now. At such times, the user has a huge benefit of being able to search the network. He explores what he wants, with rich details, compare prices, compare products and services, find the best results, get special offers, choose what you like, compares business conditions and finishes your search by deciding what most suits your needs. All this by just moving the fingers. Time to go to the dealership. A curiosity: in only 8% of cases, is that the consumer sees the car at the time of delivery, it happens most often with cars 0 km. For those who are thinking of buying a car in the net, good luck!

Management Of Electronic Pressure Turbo

With the use of electronic management in both gasoline engines and in diesel, the regulatory control of turbo boost pressure is no longer leaves the hands of a valve actuation as a mechanical valve is the wastegate, which is subjected to high temperatures, and components such as spring and membrane deformations suffering and distress that affect a poor control of turbo boost pressure, and not taking into account factors as important for the proper functioning of the engine as the altitude and temperature.
To describe how a system for regulating the pressure of the turbo, we have a diagram (figure below) that belongs to a diesel engine (1.9 TDI) in which one sees all the elements involved in controlling the pressure of the turbo. The electronic management Diesel (EDC Electronic Diesel Control) interposes a pressure control valve (3) between the intake manifold and waste gate valve (4) which controls all the time pressure that reaches the wastegate valve. As seen in the control circuitry of the turbo pressure is similar to a conventional control loop the only difference being the incorporation of the control valve (3).

The main characteristics of this system are:

- Allows the maximum pressure turbo.

- Has cut injection at high speeds.

- Provides a good response to the accelerator throughout the margin of rotations.

- The speed of the turbo-compressor can go up to 110,000 rpm

The solenoid control (AMAL) behaves as a "passkey" that lets through more or less pressure to the wastegate valve. This is controlled by the ECU (control unit) that causes the electrical impulses through the opening or closing. When the engine rotates at low and medium speeds, the valve control misses the pressure that is in the intake manifold through its entrance (a) until the exit (2) and directly to the wastegate valve, whose membrane is pushed to cause its opening, but this does not take effect until the blowing pressure of the turbo is enough to overcome the spring force. When the engine revs are high pressure that reaches the wastegate valve is very high, enough to overcome the force of its spring and open the valve to derive the exhaust gas bypass the (low pressure turbo). When the ECU believes that the pressure in the intake manifold may exceed the normal operating margins, either by circular altitude, high ambient temperature or by a request from the driver of high performance (hard acceleration and sudden), without this jeopardize the smooth operation of the engine, the ECU can modify the value of the pressure that comes with the turbo wastegate valve, cutting off the passing of pressure through the control valve closes the passage (1) and opens the way (2) (3), thus calling into contact with the waste gate valve to atmospheric pressure that will keep closed and thus increases the pressure of the turbo.

To be clear, what does the solenoid control during operation, is to deceive the wastegate valve diverting part of the turbo pressure to prevent it from acting.

The valve control is managed by the ECU (control unit), linking the mass of its electrical terminals with a fixed frequency, where the amplitude of the signal determines when to open the valve to increase pressure of the turbo manifold. The ECU to calculate when to open or close the valve control takes into account the pressure in the intake manifold through the turbo pressure sensor that is embedded in the ECU itself (figure p.9) and that receives the pressure via a tube (7) connected to the intake manifold. Also takes into account the air temperature in the intake manifold through a temperature sensor (6), the number of engine rpm and altitude by means of a sensor that is sometimes embedded in the ECU or outside.

As we outline below the inlet and exhaust of a diesel direct injection (TDi) that uses a turbo-compressor geometry (TGV). As shown in the diagram does not show the wastegate or wastegate and even though the solenoid control pressure turbo (3) is still present and it leaves a tube that goes directly to the turbo-compressor. Still not seeing where it binds specifically, the tube is connected to the valve or actuator. The operation of the turbo pressure control is very similar to previously studied, the difference is that the wastegate valve is replaced by a vacuum valve, both have a similar operation, while an open or close a valve, the other moves a mechanism vane actuator.
In this case the altitude sensor is out of the ECU (control unit).

Lubrication Of Turbo

Since the turbo is subjected to high operating temperatures, the lubrication of moving parts (brackets and shaft) is widely compromised, by being subjected to high temperatures and dynamic imbalances there is a risk of a bad choice or late changes cause the oil emergence of film and remains of coal in the vane shaft joint, which can cause vibrations at distinct frequencies to resonate can damage the turbo. In addition to the spindle is subject at all times to large temperature changes in the heat of the hot zone of the turbo is transmitted to the coldest zone, which accentuate the lubricant requirements, one must therefore use oil approved and take into account the country where you live.
We recommend that after use the engine over long distances and high speeds, do not immediately stop the engine, let it idle for at least 30 sec. to ensure adequate lubrication and cooling. The explanation is simple and pure physics, the side most exposed to heat (turbine) can overheat too if they shut down the engine immediately after intensive use of the engine, taking into account that oil burns to 221 º C may cause charring the turbo.

The lubrication of the turbocharger variable geometry is even more demanding than the normal traditional moving parts of the turbo, you have to lubricate the entire set of levers and rods that are moved by the actuator, to catch dirt (dirt poor quality oil) the guides and gates hold turbo and stops working properly causing the engine power loss.

The Future Of Turbo-Compressor

The turbo-compressor has not yet reached the peak of its power or development. Some of the improvements that are already under study and testing.
- Manufacture of housing (housing) of the turbine and exhaust manifold in one piece. With this you can save the seals and fasteners (which are expensive) between the turbine housing and exhaust manifold.At the same time also reduces weight and improves engine response since there is less material to heat.The first turbo to make use of this technology was our known KKK16

- Reducing the thickness of the walls of the housing of the turbine. The consequence is a lower weight and improve their behavior in response.
- The turbines of titanium alloy and aluminum are lighter than steel wheels of high quality. This also favors the response behavior of the engine, because the turbocharger accelerate more quickly.
- The geometry of the turbine casing improves the performance of a turbo-compressor and, therefore, the engine with respect to any engine speed. In the diesel engine turbo compressors since they are used with good results in gasoline engines yet, there is still perfecting the best thermal characteristics of materials with which they are built.
- The placement of two small turbochargers (rather than a large one) especially in engines with "V" or motors that have six or more cylinders. Also, the use of bi-turbo engines that use a small turbo for when the engine runs at low rpm and a bigger turbo for when the engine runs at high rpm

Variable Geometry Turbo-Compressor

The turbo "TGV (Variable Geometry Turbo) differs from the conventional turbo for the use of a crown or dish on which are mounted one movable vanes that can be targeted (all together) at an angle determined by a lever mechanism and a push rod A valve vacuum system similar to that used in the Wastegate valve.

For maximum air compression at low rpm shall close the vanes as decreasing the section between them, increases the speed of the exhaust that focus more strongly on the turbine blades (smaller section = higher speed). When the engine rpm increases and increases pressure in the intake manifold, the valve detects it through a tube directly connected to the intake manifold and turn it into a movement that pushes the control system of vanes so that they move for an open position which decreases the speed of the exhaust that focus on the turbine (higher = less speed section).
The fins are mounted on a crown (as shown in the picture below), connected by a shaft which is screwed on the valve shaft vacuum.

The key positions that can take the fins can be described in the text and image as follows:

In the left figure: see how fins adopt a closed position that only leaves room for the passage of exhaust gases. This position is adopted by the turbo when the engine rotates at low rpm and the speed of the exhaust gas is low. With this is done to speed the exhaust gas, while passing through the narrow space left between the fins, which is focusing more strongly on the gas turbine. Also adopts this position when the engine requires the maximum benefits starting from a low speed or relatively low, which causes the engine to accelerate as quickly as required by the driver, for example in a crossing or an abrupt acceleration vehicle.
In figure center: the fin take a more open position which corresponds to an engine operating with an average engine speed and normal speed, in this case the variable geometry turbo would behave like a conventional turbo. Fins take an intermediate position that does not interfere with the passage of exhaust gases which affect and without varying the speed of the turbine.
In the right figure: the vanes adopt a very open due to high speeds at which the engine rotates, the exhaust enters the great speed at the turbo spinning the turbine very quickly. The open position very fins acts as a brake on the exhaust which is limited by the speed of the turbine. In this case, the position of vane performs the function it performed in the valve wastegate turbos conventional means, limits the speed of the turbine when the motor rotates at high speeds and there is a very high pressure in the intake manifold, this explains why the variable geometry turbos have no wastegate valve.

The operation that we saw for the variable geometry turbo is theoretical since the control valve, vacuum in the same way as in conventional modern turbos, is done through an electronic management in charge of regulating the pressure reaches the valve vacuum GV turbos and wastegate valve in the conventional turbos at all engine operating margins and taking into account other factors such as intake air temperature, atmospheric pressure (altitude above sea level) and the requirements of the driver.

The advantages of the turbo-compressor GV are working to achieve a more progressive motor powered on. The difference of the first motors used with conventional turbo-compressor where there was a big jump in power from low revs to high, the behavior ceased to be blunt to get a very progressive power curve with a large amount of air from low speeds and for maintaining a wide area of number of motor revolutions.

The drawback is that this system presents its greater complexity, and therefore the price when compared with a conventional turbo-compressor. As the lubricating system that need to use oils of higher quality and more frequent cuttings.
Until now, the turbo-compressor GV can only be used in diesel engines (except porsche 911 carrera 997 turbo), since the gas temperature of the exhaust gas is too high (200-300 ° C higher) to allow systems like these.