Audi A4

Since 1994 of release

Repair and car operation

In 1972 model Audi 80 for the first time has been presented. Since then on the market 4 generations of models from Ingolstadt have arrived. All of them could win a strong place in the market thanks to solid technology and unostentatious external shape, it proves also the statistican of the admission of vehicles. А4 in any relation is the proof of it and the worthy successor.

The tradition obliges

In 1972 automobile factory in Ingolstadt, having let out Audi 80 which thanks to the easy design and the compact sizes, comfortableness and spaciousness of salon and a luggage carrier, and also modern engines and an exemplary running gear has established the high standard of the car of middle class. Audi А4, continuing traditions Audi 80, has arrived on the market in November, 1994 In the following model Audi has meaningly refused the large-sized external sizes. Nevertheless thanks to skilful use of space, increase in a track and wheel base it was possible to improve considerably for sitting in salon the relation of internal length of a body to base.

Engines

Along with two new пятиклапанными engines with working volume 1,8 l, in Audi A4 are offered processed four-cylinder двухклапанный the engine with working volume 1,6 l with anew designed for А4 a head of the block of cylinders with cross-section movement of a stream of air. Besides, two engines already known on Audi 80 are used also: V6 with working volume 2,6 l and 2,8 l. Everyone it:

• The four-cylinder engine with working volume 1,6 l capacity of 74 kw
• Four-cylinder пятиклапанный the engine with working volume 1,8 l capacity of 92 kw
• Four-cylinder пятиклапанный the engine with working volume 1,8 l and with a turbo-supercharging capacity of 110 kw
• V6 With working volume 2,6 l and capacity of 110 kw
• V6 With working volume 2,8 l and capacity of 128 kw

At such gradation choice possibility between two power-plants of identical capacity, because as the four-cylinder engine with working volume 1,8 h.p. is of interest. A turbo-supercharging, and V6 with working volume 2,8 l possess identical capacity in 110 kw. At identical capacity there are distinctions in conceptual characteristics: depending on that for the buyer is priority in the engine, the choice between the raised profitability or большей comfortableness and smoothness of a course can be made.

Technology пятиклапанного the engine

Capacity of the engine along with various parametres, for example working volume and number of turns, appreciably depends on that, gas exchange how fast can be carried out. The more fresh gas for the same time unit can get to the combustion chamber, the more intensively a capacity exit. The majority of engines Audi has a long course, it means that a piston stroke more than diameter of the cylinder. Engines with a long course allow to create short designs, they it is easier than engines with a short course, possess smoothness in work, especially idling, and differ, first of all, that already on low turns reach the maximum twisting moment.

Filling of the chamber of combustion depends, first of all, on opening and closed valves and sections through passage in valves and channels of a head of the block of cylinders.

Three inlet and two final valves, i.e. In the sum five on each cylinder, provide the maximum section through passage. It follows from the area of a plate of the valve and size of a course of its opening. In comparison with extended многоклапанными concepts пятиклапанная the technology in engines with a long course offers the greatest possible advantages from the point of view of intensity of filling of cylinders.

Simultaneously the technology пятиклапанного the engine supposes the form of the chamber of combustion with the central arrangement of a spark plug, and at the expense of it the short way of a spark of ignition for maintenance of fast, effective combustion of a working mix is possible. Also danger of a detonation thus decreases, and at the expense of a high compression there is possible a fuel heavy use. Combustion of a working mix in пятиклапанном the engine is carried out "more softly", than in two- and четырехклапанных engines. As because of большего cross-section section of valves the forces putting them in action, much more poorly as a whole at work пятиклапанного the engine pleasant acoustics is created.

Five valves are put in action by two cam-shafts directly by means of hydraulic тарелочных pushers. As for a long time it is accepted in Audi, the backlash of valves is not regulated.

The inlet cam-shaft serves on three valves on each cylinder, a final cam-shaft – on two. Both cam-shafts are connected among themselves by means of a chain, the drive from коленвала is provided with a gear belt.

Philosophy of adjustment of the engine

The high density of traffic in our streets demands other concept of the engine different from those that existed in 80th: the size of the maximum capacity, and equation of the expense of fuel, assortment of offered capacities, character of the fulfilled gases and noise is in demand not. Chosen Audi the design of the engine with a powerful twisting moment in the bottom range of frequency of rotation supposes movement on low turns and, hence, appreciable decrease in the expense of fuel.