8.1. Features of a design

Consists of a final collector, a reception pipe, additional and main mufflers. On cars with system of injection between a reception pipe and the additional muffler converter of the fulfilled gases is established. On these cars in a reception pipe (right after transition of two thin pipes to one) a vvarena the carving plug under the sensor of concentration of oxygen (lambda probe).

Also the additional muffler — its forward pipe shorter differs and it is supplied with a flange for converter fastening. Mufflers and converter — non-demountable knots and at failure have to be replaced with new.

The final collector is cast from cast iron. Between it and a head of cylinders the metalreinforced heat-resistant laying is established. To a collector on four hairpins the reception pipe fastens. Connection is condensed with heat-resistant laying. Fastening nuts – brass or copperplated are also recorded from an otvorachivaniye by lock plates (one on two nuts) which edges are unbent on the verge of nuts. The reception pipe is in addition attached by a collar to an arm on the transmission.

On cars with carburetor engines of a pipe of the muffler are moved each other and are fixed by blooming collars. On the cars equipped with system of injection, compound of converter with the additional muffler and reception pipe – flange, forward – with the spherical hinge (pipes can turn from each other on a small corner without tightness loss), its fixing bolts are sprung.

Converter serves for reduction of emissions in the atmosphere of carbon oxide and nitrogen oxides. It consists of two ceramic blocks with a set of the time covered with so-called catalysts of a dozhig: rhodium, palladium, platinum. Passing through a converter time, toxic carbon oxide (SO) turns into low-toxic dioxide (CO2), and nitrogen oxides are restored to harmless nitrogen. Extent of purification of gases in serviceable converter reaches 90–95%. For normal work of converter the composition of the fulfilled gases (in particular, the content of oxygen in them) has to be in strictly set limits. This function is performed by the controller, changing amount of the given fuel depending on indications of the sensor of oxygen (see the Control system of the vpryskovy engine). Converter and the sensor of oxygen are very sensitive to compounds of lead – "having got poisoned" with them, they cease to work. Therefore if the car is equipped with converter, its operation (even short-term) on ethylated gasoline is strictly forbidden. Other reason of failure of converter – interruptions in system of ignition: not burned down fuel burns down in converter, damaging ceramics. It can lead to obstruction of final system and a stop of the engine (or strong loss of power).

The main muffler is located in a niche in a back part of a body. It is attached to body arms on two rubber pillows. The middle part of final system (with the additional muffler) has no fastening points to a body. For protection of a body floor against excessive heating over the main muffler the filter is fixed.

Service of system of release consists in periodic survey of pipes and mufflers regarding corrosion and in tightening or replacement of the weakened connections.