Best Car Modification

How do alloy wheels?

A method of production of alloy wheels is clear even from their names - these wheels are cast into finished form. For the production of alloy wheels used aluminum-based alloys (which is why in Europe are called aluminum wheels), or (which is much rarer) - alloys based on magnesium

It must be said that the characteristics of the finished disc, including its reliability, impact resistance and strength are highly dependent on many factors, from the quality of the alloy, mold and finishing quality finishing and painting. Therefore categorically should not rush with the purchase of cheap alloy wheels - it is possible that their quality is lame on both his feet.


Than alloy wheels differ from steel?

The main differences from the steel alloy wheels are weight, price and appearance - knows about it all. Cast rim, on average, 30-40% lighter than steel, which significantly affects the car's handling and reduces the load on the suspension. In addition, alloy wheels and much more aesthetically beautiful look at the car, which is the main motivation for their acquisition. But, for all the pleasure you have to pay, so, of course, the cost of a cast disk can exceed the value of its steel counterpart several times.

But there are some fundamental differences that come up during the operation, and to be aware of every car enthusiast, decided to buy these wheels.

The fact is that after the casting process drives are hot, and therefore acquire certain additional properties, particularly hardness and brittleness it. That's right - light alloy wheels - fragile, they do not bend when you hit - they crack and burst.

In the crank mechanism piston performs several functions , including the perception of the gas pressure and the transmission of forces on the rod , sealing the combustion chamber and heat removal from it . The piston is the most characteristic part in an internal combustion engine as is realized with the help of thermodynamic process engine.

Conditions in which it operates piston extreme and characterized by high pressure, temperature and inertial loads. at least from steel. The pistons are made of two ways - by injection molding or by stamping called forged pistons .


Scheme piston engine

The piston is integral structural element , which is conventionally divided into head (some sources call it the bottom) and a skirt. The shape and design of the piston is largely determined by the type of engine , the shape of the combustion chamber and the combustion process occurring in it. Piston gasoline engine has a flat or near- flat surface of the head . It may be provided with grooves for the full valve opening . Pistons with direct fuel injection have a more complex shape. In the top of the piston diesel engine combustion chamber holds a certain form , which provides a nice twist and improves mixture formation .


Below the piston head run grooves for mounting piston rings. The piston skirt has a tapered or curved ( barrel ) form . Such a shape of the skirt of the piston compensates for thermal expansion during heating. When reaching the operating temperature of the engine piston takes a cylindrical shape. To reduce the friction losses on the piston side with a layer of antifriction material ( molybdenum disulfide, graphite) . In the piston skirt has holes with the tides ( the boss ) to secure the piston pin .

Piston cooling is carried out by the internal surface of a variety of ways :

oil mist in the cylinder;
oil splashing through the hole in the rod ;
oil splashes special nozzle ;
injection of oil into a special zone in the annular channel rings;
oil flow through the tubular coil in the piston crown .
Piston rings form a tight connection with the wall of the piston cylinder. They are made of cast iron modified . Piston rings are the main source of friction in the internal combustion engine. Friction losses in the rings reach to 25 % of mechanical loss in the engine.

The number and location of the rings depends upon the type and purpose of the engine . The most common scheme - two compression and one oil ring . Compression rings prevent breakthrough of gas from the combustion chamber into the crankcase . The first compression ring works in the most severe conditions. Therefore, a number of pistons of diesel and gasoline engines forced into the groove of the ring set steel insert that improves durability and allows to realize the maximum compression . Compression rings may have a trapezoidal , a barrel , a conical shape , some are performed with a cut ( notch ) .

Scraper ring removes the excess oil from the surface of the cylinder and prevents the ingress of oil into the combustion chamber . The ring has a plurality of drainage holes . Some designs have a spring ring expander .

Compound piston rod by means of a piston pin which has a tubular shape and is made of steel. There are several way to install the piston pin . The most popular so-called floating finger that has the ability to rotate in bosses and the piston rod head during operation. To prevent displacement of the finger he fixed retainer rings . Much less is applied rigidly fixed ends of the piston pin or rigid fastening pin into the piston rod head .

INTRODUCTION


Many people at some point will have had the opportunity to see the outside of gasoline engine (also called "internal combustion engine" or "internal combustion"), but it is likely that many of these people also unaware of its internal .

When we decided to get a license to drive a car or any other motor vehicle, in some countries require a test or exam answer where, precisely, are some questions related to the working principle of thermal engines of internal combustion either gasoline or diesel.





Petrol engine car or modern automobile.



However, as a mere curiosity, maybe you'll have interested in knowing how a gasoline engine and what parts and pieces that make it up, but between your shorter-term projects is not precisely obtain a license conduction.

A gasoline engine is a thermodynamic machine comprises a set of mechanisms or parts fixed and movable, whose main function is to transform the chemical energy produced by combustion provides a mixture of air and fuel into mechanical energy or motion. When this transformation occurs chemical into mechanical energy can do useful work, for example, move a motor vehicle as a car or a car, or any other mechanism, as it might be an electrical generator.

Similarly, with the mechanical energy that provides a heat engine can move any other appropriate mechanism that engages the same such as an electrical generator, water pump, the blade of a lawnmower, etc.


Small gasoline engine mated to a lawn mower.

In general the internal combustion engines can be of two types, according to the fuel used to run:

    Explosion or gasoline

    Internal combustion diesel

While combustion engines using gasoline (or gas, or even alcohol) as fuel, the diesel internal combustion uses only diesel (diesel).

If you ever compare parts or mechanisms that shape structurally a gasoline engine and a diesel engine, we will see that in many respects are similar, while others are completely different, although in both cases the principle is similar.

Both petrol engines as diesels can be used to perform the same functions, but when it needs to develop great powers, as required to move a locomotive, a ship or an electrical generator generation large capacity are used only diesel internal combustion engines.