4.2.10. Service of conrod and piston assemblies and mirrors of cylinders
|
|
Implementation of the procedures described below will require the following special equipment: a vertical drill for removal of step wear of cylinders; a micrometer and a telescopic nutromer (for check of a condition of cylinders); хон (for restoration of mirrors of cylinders) and tools for expansion and compression of piston rings (for installation and installation of conrod and piston assemblies). |
Removal of conrod and piston assemblies
|
|
In principle extraction of conrod and piston assemblies can be made without removal of the engine from the car though if to take into account to difficulty, connected with a detachment of the pallet of a case and work under the car, such approach does not seem expedient at all. Authors of this manual recommend to perform this work on the engine removed from the car. |
Components of conrod and piston assembly
|
|
- Remove the engine from the car.
- Install the engine on the assembly stand or a strong workbench and remove from it a head of cylinders, the pallet of a case and a maslozabornik of the oil pump.
- Make sure available identification tags on the lower heads of rods and covers of conrod bearings of a bent shaft. Try to remember an order of installation of assemblies.
- By means of the measuring probe of lezviyny type check the size of an axial side play of rods. At excess by a side play of admissible value (see size tables and adjustments at the end of the Management), replace a worn-out rod.
- Having brought the piston of the first cylinder into the lower point of its course, give nuts of fastening of a cover of the lower head of a rod (the conrod bearing). Uncover.
- Wipe a bearing insert in a cover and an open part of a conrod neck of a shaft pure неворсящейся with rags, then lay along a neck a piece of the calibrated plastic wire from the measuring Plastigage set. Put on a cover a rod and tighten nuts of its fastening with the required effort.
- Turn off nuts, uncover and, having measured on a scale on set packing width of the flattened-out calibrated wire, determine the size of a gap of the conrod bearing. Compare result of measurement to standard requirements (see size tables and adjustments at the end of the Management), at excess of an admissible limit replace the bearing assembled.
- Repeat the procedure for the remained rods. Remember the size of a gap of each of bearings.
- Serially uncover the lower heads of all rods, then the wooden handle of the hammer push out assemblies from cylinders at the top then at once establish on rods of their cover with the enclosed inserts. In case of need, before starting extraction of conrod and piston assemblies it is necessary to remove by means of a special vertical drill step wear in the top part of cylinders.
|
|
For protection of necks of a bent shaft and mirrors of cylinders against damage to process of extraction of conrod and piston assemblies put on pieces of a plastic tube bolts of fastening of covers of bearings. |
- Remove from pistons (at the top) piston rings and you will throw out them.
|
|
Check of a condition of pistons
|
|
- Examine pistons on existence of traces of operation, scratches, zadir and progar.
- Remove all traces of coal deposits from the bottom of the piston and from ring flutes.
- Estimate degree of wear of ring flutes of pistons. For this purpose, having taken new measure, check the size of their side gap in the corresponding flutes of each of pistons. Compare result of measurement to standard requirements (see size tables and adjustments at the end of the Management).
- Examine inserts of bearings of rods of all pistons on identification of signs of wear. At detection of development of the outer edges of inserts it is necessary to check the corresponding rod for a bend.
|
|
|
|
As the rikhtovka of rods requires the special equipment, authors of this manual recommend to make this check and recovery repair in a workshop of car service. |
Check of a condition of the block and mirrors of cylinders
|
|
- Check mirrors of cylinders for existence of cracks, zadir, scratches and traces of operation.
- By means of a special nutromer complete with a micrometer measure diameters of cylinders for the purpose of assessment of degree of their wear and detection of ovality and conicity. You perform measurements in two directions (up and down the block) and at three levels on height of cylinders - on the upper bound of a piston stroke, in the middle and below. The difference between distances And yes In, measured determines ovality of the cylinder, a difference between measurements by the top and lower borders of a piston stroke And in the top and lower planes of the working site of the cylinder defines its conicity.
- Choose the maximum and minimum indications from results of six measurements of each of cylinders. The difference of these indications can be considered as criterion of degree of wear of the cylinder.
- If wear any of cylinders exceeds admissible value (see size tables and adjustments at the end of the Management), it is necessary to pierce all cylinders to the standard repair size (with excess) with the subsequent their honingovaniye.
|
|
The choice of the necessary repair size from among provided by the standard is defined by the sizes of the most strongly worn-out cylinder. |
- By means of the measuring instrument of planeness and the probe of lezviyny type check planeness of the top interfaced surface of the block (act as when checking planeness of a head of cylinders). If not planeness of the block exceeds admissible value (see size tables and adjustments at the end of the Management), execute a block pro-point.
- Carefully wash out the block suitable solvent and dry it compressed air, paying special attention to a purge of maslotok and remote cavities.
- Examine the block on existence of cracks and other mechanical damages.
|
|
Honingovaniye of mirrors of cylinders
|
|
Mirrors of the cylinders suitable for use in a set with old pistons, but the piston rings demanding replacement, are subject to a honingovaniye. |
|
|
- For removal of polishing from mirrors of cylinders use the superficial khan with grinding stones granularity 280.
- Move the rotating nozzle of a hon up-down in the cylinder with a speed allowing to achieve a mesh pattern of notches with the angle of crossing рисок in 60 °. Such processing guarantees optimum conditions for extra earnings of piston rings.
|
|
It is not necessary to remove more material from a cylinder mirror, than it is necessary for removal of polishing, otherwise there will be an inadmissible increase in diameter of the cylinder and, respectively, a piston gap. |
- In processing grease a nozzle and walls of the cylinder with special honingovochny oil.
|
|
Use of transmission or motive oils, and also mineral alcohols and kerosene for this purpose inadmissibly! |
- Upon completion of a honingovaniye carefully wipe mirrors of cylinders, having completely removed from them any traces of an abrasive.
- After washing and drying of the block once again wipe mirrors of cylinders pure неворсящейся with rags, then oil their motive in order to avoid corrosion development.
|
|
Check of piston gaps
|
|
- By means of a qualitative nutromer and a micrometer measure as it is described higher than diameters of all cylinders.
- Measure diameters of pistons at distance of 47 mm from the piston bottom.
- Having subtracted diameter of the corresponding piston from diameter of the cylinder, define a piston gap. If results of calculations exceed admissible values (see size tables and adjustments at the end of the Management), replace the piston with the discretion or pierce also to an otkhoninguyta the cylinder.
- After a pro-point of cylinders to the standard repair size and a honingovaniye, them it is necessary to repeat the procedure of definition of piston gaps.
|
|
|
|
If the piston, a piston finger or a rod demand replacement, it should be made in a workshop of car service as for extraction/installation of a finger the piston has to be competently heated-up up to the temperature of 70 °C, or it is necessary to use a hydraulic press. The mandrel is necessary for extraction of plugs of the top heads of rods special. |
Replacement of piston rings
|
|
- Pick up a set of the new piston rings answering on the standard size to cylinders of the engine of your car (according to standard or the repair size).
- Serially fill each ring with the bottom of the turned piston in the least worn-out part of the cylinder for measurement of size of gaps in their locks. Use of the piston for gas station of rings in the cylinder allows to achieve perpendicularity of an arrangement of a ring.
- After extraction of the piston measure a gap in the ring lock by means of the probe of lezviyny type.
|
|
After measurement of a gap in the lock the ring has to be used for a complete set of the piston of this cylinder. |
- According to an accompanying illustration on which sections of piston rings are shown put on new rings the corresponding pistons. Use a dilator of piston rings. Compression rings should be established by stamped tags in the form of letters up (to the piston bottom).
- Oil scraper ring arrange so that locks of sections and a dilator were not opposite to each other.
- Develop rings on the piston locks as it is shown on an illustration where: And = the top compression ring, In = the lower compression ring, With = a dilator of an oil scraper ring, D = the top section of an oil scraper ring, E = the lower section of an oil scraper ring.
|
|
Installation of conrod and piston assemblies
|
|
- Grease assembly of the piston and a wall of the first cylinder with pure motive oil.
- Having turned a bent shaft, bring the first conrod neck of a bent shaft into the provision of NMT. Dry wipe a neck with pure rags, then oil its pure motive.
- Uncover the lower head of a rod and wipe bearing inserts, or replace them as necessary. Oil inserts pure motive.
- Put on bolts of fastening of a cover pieces of a plastic tube for protection of walls of the cylinder and a neck of a shaft.
|
- Squeeze piston rings the special tool, then fill conrod assembly in the first cylinder, tapping with the hammer handle in the bottom of the piston and at the same time directing a rod head to a neck of the conrod bearing of a bent shaft.
|
|
|
The piston has to be brought to the cylinder by a forward tag on the bottom (see an accompanying illustration - figures on cylinders and characterize dimensional parameters (standard or repair)) on the engine forward, the tool mandrel for compression of piston rings has to nestle densely on the block on all perimeter during all installation time of conrod assembly. |
- Remove protective plastic tubes from bolts of fastening of a cover of the lower head of a rod.
- Put on a bearing cover a rod head, monitoring combination of the landing tags put in the course of dismantle. Tighten fixing:
- At the first stage tighten nuts with effort of 14 ÷ 16 Nanometers;
- Then tighten nuts with effort of 38 ÷ 44 Nanometers, or (that it is more preferable) on a goniometer for (60 ° than ÷ 65 °).
- Working in a similar manner, establish conrod and piston assemblies in remained (corresponding to them) cylinders.
- Further installation is made as it should be, the return to a dismantle order.
|
|
