Skoda Felicia

Since 1994 of release

Repair and car operation

Pistons are issued only the nominal sizes and share on diameter on three dimensional groups (And, In and).

For the purpose of maintenance of stable work of the engine all four pistons should have the same weight. Weighing of pistons is made for observance of this condition in the course of manufacturing. The disorder of weights is corrected by removal of metal from a skirt.

Piston fingers

The piston finger provides шарнирное connection of the piston with a rod. The finger is executed from a high-quality steel, ground and polished. On an average part of a finger the top head of a rod sits down. The finger ends are passed in apertures in piston lugs. For fixing of the finger filled in assemblage lock rings are used.

The new finger is established in the piston with a small tightness, without a backlash or with the minimum backlash. In the plug of the top head of a rod the finger is put with a backlash. At excessive люфта fingers at loading increase on the engine start to knock.

Before installation of a finger from one of the piston parties the lock ring (use for ring landing by the special adaptation) is established. Then, from an opposite side in the piston piston finger slightly greased with impellent oil refuels. The finger refuels so that its end acted in the piston on size 1 ч 1.5 mm. Further in the piston the top head of a rod also slightly greased with impellent oil refuels (track that the aperture маслотока in the top part of a rod has appeared it is directed aside, opposite, the specified arrow put on the bottom of the piston). Further fill a finger against the stop with its end face in the lock ring filled in the piston and establish the second lock ring on the other hand a finger.

Piston rings

Each of pistons is equipped with three piston rings established in specially done in top part of walls of the piston of a flute. The form and an order of landing of rings in flutes are shown on an illustration.

Top компрессионное the ring is made of a steel and chromeplated outside for the purpose of decrease in a component of a friction, and also protection of metal against aggressive influence of the hot fulfilled gases. The ring has the correct round form and symmetric section in the form of a rectangle with the truncated corners.

The second (bottom) компрессионное the ring is executed from pig-iron and has asymmetrical cross-section section in the form of a rectangle with an inclined outer side. The angle of slope of an external side of a ring makes nearby 1 ° thanks to what the ring clip to a cylinder mirror is necessary on very insignificant area. Deterioration of a contact platform provides density прилегания rings.
On one of face surfaces of this ring there is a label in the form of an inscription of "TORAHS". The ring should be established on the piston this label upwards.

The maslosemnoe ring consists of three separate sections: two narrow lateral rings and the wavy dilator placed between them. The general thickness of assemblage makes 3 mm.

The oil removed by a ring from a mirror of the cylinder is taken away through apertures in a flute in the piston and, further, in the pallet картера the engine.

All piston rings have a cutting design. Cuts of rings are called as locks, provide possibility of installation of rings on pistons, and, besides, serve for indemnification of thermal expansion.

The new ring most densely nestles on a mirror of the cylinder around the lock. In the course of further extra earnings the clamping effort is gradually levelled on ring perimetre, providing the maximum hermetic sealing of assemblage.

Replacement of piston rings by the worn out engine which cylinders have got out of the initial shape, leads to only short-term restoration of a compression as the ring cannot take the form of the worn out cylinder and its density прилегания is distributed non-uniformly.

Rods

Rods are forged from a special steel. The rod consists of the top head, a connecting core and the bottom, cutting head. In the top head of a rod запрессована the bronze plug which is carrying out a role of the bearing under landing of a piston finger. The connecting core has двутавровое section. The bottom head is cut in a plane, a perpendicular longitudinal axis of assemblage.

The surface of beds under installation of loose leaves шатунных bearings in a cutting bottom head of a rod is carefully processed. As a result of such processing interchangeability of covers шатунных bearings in view of what on covers and the bottom heads special adjusting labels are provided is lost. At factory assemblage of a label usually there correspond numberings of cylinders.

The cover fastens to a rod by means of special bolts of the raised durability and two nuts with carving М9х1.

In the top head of a rod the through aperture is provided, through which oil in an engine operating time moves on cylinder walls. At rod installation it is necessary to track, that this aperture has been directed aside from a camshaft.

On weight rods share on two groups. Easier (with weight 590 ч 598) are marked by the yellow label put on a head. On heavier rods (600 ч 609) the label has blue colour. All rods in the engine should have identical weight at what at updating the weight of heavier rods is led to weight of easier, rather the reverse.

The scheme of procedure of measurement of a workshop of car-care centre of a rod is shown on an illustration. During weighing the rod should settle down horizontally. The difference of weights of the rods weighed both from outside bottom, and from outside top heads should make no more than 2 ч 6 weight Updating is made by removal of a material from the top head and a cover of the bottom head in the places designated by arrows on an illustration. The maximum admissible thickness of a layer removed from the top head is limited to distance from a plane remaining after processing to an axis of an aperture under installation of a piston finger. The given distance should make of durability reasons not less than 15 mm. In case of the bottom head the distance is measured from the processed plane to an axis шатунного the bearing and should make not less than 35 mm.

The diesel engine and the petrol engine of 1.6 l

As a whole the design of shatunno-piston assemblages is similar 1.3 l described for engines, with that difference that possibility of installation of rods of the repair sizes (see Specifications) is provided. Besides, in diesel engines rods are equipped маслораспылителями coolings of pistons.

REMOVAL