Repair parts and components
MOTOR. change of pistons
For replacement of worn pistons in parts
embedded sets of pistons with piston pobral them
fingers and, with stop and piston rings in an amount
required per engine.
To ensure proper clearance between the cylinder liner and
piston skirt (0.05-0.07 mm) pistons normal size
after finishing sorted by company
manufacturer of piston skirt diameter D into 5 groups, which
referred to the diameter varies by 0.01 mm. Code letter
groups applied to the surface of the piston. In Fig. 30
described the measurement of piston skirt.
Along with the selection of the pistons to the cylinder liners in diameter
they also picked up by weight. The latter is necessary for
maintain balanced engine. The difference in mass of the
heavy and the lightest pistons this kit (the engine)
should noxtexceed 3 g. Pistons normal size
sorted by the manufacturer to mass into 4 groups
markings are (1,2,3,4) is applied to the piston with
using a metal stamp.
Matched to the cylinders the size of the pistons have to be
labeled (marked) serial number of cylinder liners,
to which they are selected.
After selection of the pistons to the sleeve over, pick up
Piston pin to piston and sleeve of the upper head rods.
In the piston wrist pin bosses installed with interference
or gaps up to 0.0025 mm. The clearance between the piston pin and
hole bushing connecting rod must be within
To facilitate the selection of piston pins, pistons and sleeves
the upper connecting rod heads (after final machining
processing) are sorted into four size groups, in which the diameters
differ by 0.0025 mm.
The dimensions of the parts (diameter), as well as
color notation (marks) of various screening groups
are shown in Table. 2.
In the manufacture of parts marking paint applied in
piston to the bottom surface of one of the bosses, the lower finger
- On the inner surface at one end to
a rod - at the top of the head.
Piston pin belonging to a particular group,
Pick prisborke to the piston rod and sleeve, belonging to
one size group.
In the normal gap between the connecting rod bushing paltsemi finger
oiled engine, should enter smoothly
in the bush under the force of right thumb
(See Fig. 23). Since this requirement to the assembly with your finger
rod must be allowed selection of new pins and connecting rods
manned by two adjacent size groups.
In all cases, try to trim piston rod with your fingers to
Room temperature 20 C. * 3
Matched to the piston connecting rod and piston pin smazhte oil for
engine and insert the piston bosses and connecting rod with the upper head
a mandrel and a hammer. Pre-heat the piston
a water bath to a temperature of 45-75 * C.
It is unacceptable to collect a piston with a piston with your finger, if their combined
obtained increased against the normal tightness.
This is, in some cases dxistort the size of the piston skirt and leads
rise to knock the piston in the cylinder walls during engine operation,
until it receives a normal warm-up.
When assembling pistons with rods to ensure that
that embossed on the bottom of the piston arrow was pointing in the direction of
The mounting tabs on the body of the connecting rod and
It should be borne in mind that the axis of the piston pin is offset
about the axis of the piston at 1.50-1.60 mm.
After assembling the engine, the cylinders were installed and new
pistons, and engine installation on the vehicle follow the rules of running.