Features of the device
The camshaft pig-iron, cast, number of support depends on a design of a head of the block of cylinders (engine type). Working surfaces of cams and a neck under an epiploon are bleached for wear resistance increase.
For an exception of axial moving of a camshaft from its back party the flange is provided.
The camshaft drive (irrespective of engine type) is carried out by a gear belt from the gear pulley established on cranked shaft. For a belt tension the tension roller on which there are no teeths serves. It rotates on an axis,
Established on an arm which fastens to the block of cylinders. Changing position of an arm concerning bolts of its fastening, it is possible to change a belt tension.
Replacement of a belt of a drive of a camshaft
Cars with engines in working volume of 1,1 and 1,3 l
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Fig. 2.52. A drive of a camshaft of the engine in working volume of 1,1 l
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Fig. 2.53. A drive of a camshaft of the engine in working volume of 1,3 l
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The drive of a camshaft of the engine in working volume of 1,1 l is shown on fig. 2.52, the engine in working volume of 1,3 l – on fig. 2.53.
Dismantling of a drive of a camshaft
Turn away a bolt of fastening of a pulley of the pump of a cooling liquid.
Turn away a bolt of fastening of the generator.
Remove a pulley of the pump of a cooling liquid and a drive belt.
Remove a pulley of a cranked shaft.
Uncover a drive газораспределительного the mechanism.
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Fig. 2.54. Adjusting labels on gear to a pulley And a camshaft and a head of the block of cylinders In the engine in working volume of 1,3 l
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Fig. 2.55. Adjusting labels on gear to a pulley of a cranked shaft and the block of cylinders of the engine in working volume of 1,3 l
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Fig. 2.56. Adjusting labels on gear to a pulley of a camshaft and a head of the block of cylinders of the engine in working volume of 1,1 l
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Fig. 2.57. Adjusting labels on gear to a pulley of a cranked shaft and the block of cylinders engine (pin) in working volume of 1,1 l
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Turn of a cranked shaft establish the piston of 1st cylinder in position ВМТ of the end of a step of compression, thus labels on gear pulleys of distributive and cranked shaft should be combined with adjusting labels on the engine (fig. 2.54, 2.55, 2.56, 2.57).
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Fig. 2.58. Easing of an inhaling of a bolt of fastening of a tension roller and roller displacement to the pump of a cooling liquid (the engine in working volume 1,1)
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Fig. 2.59. A tension roller of a drive газораспределительного the engine mechanism in working volume of 1,3 l
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Ослабьте an inhaling of a bolt of fastening of a tension roller also displace a roller to the pump of a cooling liquid. Tighten a bolt of fastening of a roller (fig. 2.58 and 2.59).
Remove a gear belt of a drive газораспределительного the mechanism.
THE PREVENTION
The gear belt should not be bent. It is necessary to replace the bent gear belt, as it can burst while in service that will lead to serious damages of the engine.
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Fig. 2.60. By arrows the direction of rotation of a gear belt is shown
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If the belt which was in operation is established, necessarily it is necessary to consider a direction of its rotation (fig. 2.60). Installation of a belt for work "in the opposite direction" can lead to its rupture and thereof to serious damages of the engine.
Remove a gear pulley of a camshaft.
Turn away bolts of fastening of a gear pulley of a cranked shaft.
Remove a tension roller of a belt of a drive газораспределительного the mechanism.
Check of a technical condition of a belt of a drive газораспределительного the mechanism
Check up a belt on замасливание and pollution by a dust. If necessary replace a belt. Insignificant замасливание or pollution by a dust remove a dry fabric or a paper. Solvents to clearing do not apply.
At a partition of the engine or adjustment of a tension of a belt carefully check up a belt condition. Replace a belt new at presence at least one of specified below defects.
1. Hardening of an external surface of a belt (the external surface of a belt glossy, not elastic also has hardened to such degree that from pressing by a nail does not remain dents).
2. On an external surface of a belt there are cracks.
3. On an internal surface of a belt of a crack or breakage of teeths.
4. Strong deterioration of teeths (an initial stage). Deterioration of the loaded party of teeths (разлохмачивание cord threads, a wear-out of a rubber layer, whitish colour, an indistinct structure of a cord).
5. Strong deterioration of teeths (a final stage). Deterioration of a cord on the loaded party of teeths to an exposure of a rubber layer (reduction of width of teeths).
6. Cracks in the basis of teeths.
7. A separation of teeths.
8. Strong deterioration of edges of a belt (the serviceable belt should have accurately cut off edges).
9. Cracks on belt edges.
Check of a technical condition of gear pulleys and tension roller
Check up gear pulleys of distributive and cranked shaft, a tension roller on presence of excessive deterioration, cracks or damages. If necessary replace defective details.
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Fig. 2.61. Check of ease and smoothness of rotation of a tension roller
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Check up ease and smoothness of rotation of a tension roller (fig. 2.61), be convinced of absence люфта and extraneous noise.
If necessary replace a roller.
Assemblage of a drive of a camshaft
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Fig. 2.62. Installation of a flange and a gear pulley of a cranked shaft of the engine in working volume of 1,1 l: 1 – a cranked shaft; 2 – a gear pulley of a cranked shaft
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Fig. 2.63. Installation of a flange and a gear pulley of a cranked shaft of the engine in working volume of 1,3 l: 1 – a facet; 2 – a cranked shaft; 3 – a flange; 4 – a gear pulley of a cranked shaft; 5 – a special washer
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Establish a flange and a gear pulley of a cranked shaft, as is shown in fig. 2.62 and 2.63. Will pay special attention on their mutual position at installation.
The moment of an inhaling of a bolt of fastening of a gear pulley of a cranked shaft, Н·м:
Engines in working volume of 1,3 l..... 140–150
Engines in working volume of 1,1 l..... 70–100
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Fig. 2.64. Installation of a gear pulley of a camshaft of the engine in working volume of 1,3 l: And, In – adjusting labels
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Fig. 2.65. Installation of a gear pulley of a cranked shaft of the engine in working volume of 1,3 l (on выноске – adjusting labels)
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Fig. 2.66. Installation of a gear pulley of a camshaft of the engine in working volume of 1,1 l
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Fig. 2.67. Installation of a gear pulley of a cranked shaft of the engine in working volume of 1,1 l
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Establish a gear pulley of a camshaft (fig. 2.64, 2.65, 2.66, 2.67) and tighten a fastening bolt the specified moment.
The moment of an inhaling of a bolt of fastening of a gear pulley of a camshaft of engines in working volume makes of 1,3 and 1,1 l 80–100 Н·м.
At position of the piston of 1st cylinder in ВМТ the end of a step of compression be convinced of combination of labels on gear pulleys of distributive and cranked shaft with adjusting labels on the engine.
THE NOTE
At installation of a gear pulley of a cranked shaft track that the pin of a gear pulley has entered into a small aperture of a flange of a shaft.
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Take away a tension roller of a belt of a drive газораспределительного the mechanism as it is possible more close to the pump of a cooling liquid and tighten a bolt of its fastening.
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Fig. 2.68. Installation of a spring of a tension roller of the engine in working volume of 1,1 l
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Fig. 2.69. Installation of a spring of a tension roller of the engine in working volume of 1,3 l
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Get the end of a spring of a tension roller in an aperture of an arm of a roller and by means of a screw-driver get other end of a spring for a forward cover of the block of cylinders (fig. 2.68 and 2.69).
THE NOTE
Gear belt establish so that its leading branch has been a little weakened.
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THE PREVENTION
At a lining of a gear belt position of distributive, cranked or intermediate shaft should not change. Otherwise there can be serious damages of the engine or it will cease to give the maximum capacity. After a tension of a gear belt once again check up position of distributive, intermediate shaft and a belt pulley: if the label on gear to a camshaft pulley coincides with a label on a head of the block of cylinders simultaneously should coincide a label on a pulley of a cranked shaft and a label on the block of cylinders. Otherwise it is necessary to repeat installation of a gear pulley of a camshaft and a pulley of a cranked shaft at the removed gear belt.
Densely put on a gear belt pulleys in a following order:
– A pulley of a cranked shaft;
– A camshaft pulley;
– A tension roller.
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After that create a tension of a leading branch of a belt, having turned a gear pulley of a camshaft in a direction, the return to a normal direction of rotation; check up combination of adjusting labels.
Release a spring of a tension roller, having weakened an inhaling of a bolt of its fastening.
Turn a camshaft in a normal direction of rotation (clockwise if to look from a forward end face of the engine) at two teeth of a gear pulley (on 15 °).
Will make additional effort a tension roller in a normal direction of rotation (to provide dense прилегание belt teeths to teeths of pulleys without a backlash).
Having convinced of density прилегания a belt, tighten a bolt of fastening of a tension roller in this position so that its spring had possibility to move.
Turn a gear pulley of a cranked shaft on two-four turns counter-clockwise for maintenance of dense landing of a belt on pulleys.
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Fig. 2.70. Check of a tension of a gear belt of the engine in working volume of 1,3 l
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Check up a tension of a gear belt. For this purpose undertake a hand a tension roller and with moderate effort (approximately 5) compress a tension branch of a belt (fig. 2.70). Thus belt teeths should reach approximately half of radius of a head of a bolt of fastening of the tension device (on head sides) (engines in working volume 1,3).
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Fig. 2.71. The scheme of check of a tension of a gear belt of the engine in working volume of 1,1 l
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Be convinced that by pressing an average part of a leading branch of a belt big and index fingers the distance between an underside of a belt and the aperture centre under a bolt of fastening of a cover of a drive газораспределительного the mechanism in the block of cylinders makes about 20 mm (engines in working volume 1,1) (fig. 2.71). Check of a tension of a belt see on fig. 2.72.
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Fig. 2.72. Check of a tension of a gear belt of the engine in working volume of 1,1 l
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Establish a drive cover газораспределительного the mechanism.
Establish a pulley of a cranked shaft.
Establish a belt of a drive of the compressor of the conditioner and adjust a belt tension.
Establish a pulley of the pump of a cooling liquid.
Establish поликлиновой a belt of a drive of auxiliary units and adjust its tension.
Cars with engines in working volume of 1,5 and 1,6 l
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Fig. 2.73. A camshaft drive
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The drive of a camshaft of engines in working volume of 1,5 and 1,6 l is shown on fig. 2.73.
Dismantling of a drive of a camshaft
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Fig. 2.74. A jack Installation site under the engine
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Fig. 2.75. Removal of an arm of an engine mount
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Having turned away a bolt of fastening of an arm to the block of cylinders of the engine and three nuts of fastening of an arm, remove an engine mount arm (fig. 2.75).
Turn away a bolt of fastening of a pulley of the pump of a cooling liquid.
Turn away a bolt generator fastening.
Remove a pulley of the pump of a cooling liquid and a drive belt.
Remove a pulley of a cranked shaft.
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Fig. 2.76. A drive cover газораспределительного the engine mechanism
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Uncover a drive газораспределительного the mechanism (fig. 2.76).
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Fig. 2.77. Displacement of a tension roller of a belt of a drive газораспределительного the mechanism to the pump of a cooling liquid
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Displace a tension roller of a belt of a drive газораспределительного the mechanism in a direction to the pump of a cooling liquid and temporarily fix it in this position (fig. 2.77).
Remove a drive belt газораспределительного the mechanism.
THE PREVENTION
If the belt which was in operation is established, necessarily it is necessary to consider a direction of its rotation. Installation of a belt for work "in the opposite direction" can lead to its rupture and thereof to serious damages of the engine.
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THE NOTE
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Fig. 2.78. Arrows specify a direction of rotation of a gear belt
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If the drive belt газораспределительного the mechanism is supposed to be used again, put on it a label of a direction of rotation in the form of an arrow (fig. 2.78) to establish it in former position.
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Remove a belt from a gear pulley of a camshaft.
Remove a gear pulley of a camshaft.
Turn away bolts of fastening of a gear pulley of a cranked shaft. Remove a gear pulley of a cranked shaft and a flange.
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Fig. 2.79. A tension roller of a belt of a drive газораспределительного the mechanism
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Remove a tension roller of a belt of a drive газораспределительного the mechanism (fig. 2.79).
Check of a technical condition of a belt of a drive газораспределительного the mechanism
Check up a belt on замасливание and pollution by a dust. If necessary replace a belt. Insignificant замасливание or pollution by a dust remove a dry fabric or a paper. Solvents to clearing do not apply.
At repair of the engine or adjustment of a tension of a belt carefully check up a belt condition. Replace a belt new at presence at least one of specified below defects.
1. Hardening of an external surface of a belt (the external surface of a belt glossy, not elastic also has hardened to such degree that from pressing by a nail does not remain dents).
2. Cracks on an external surface of a belt.
3. On an internal surface of a belt of a crack or breakage of teeths.
4. Strong deterioration of teeths (an initial stage). Deterioration of the loaded party of teeths (разлохмачивание cord threads, a wear-out of a rubber layer, whitish colour, an indistinct structure of a cord).
5. Strong deterioration of teeths (a final stage) Deterioration of a cord on the loaded party of teeths to an exposure of a rubber layer (reduction of width of teeths).
6. Cracks in the basis of teeths.
7. A separation of teeths.
8. Strong deterioration of edges of a belt (the serviceable belt should have accurately cut off edges).
9. Cracks on belt edges.
Check of a technical condition of gear pulleys, tension and bypass rollers
Check up gear pulleys of distributive and cranked shaft, tension and bypass rollers on presence of excessive deterioration, cracks or damages.
If necessary replace defective details.
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Fig. 2.80. Check of ease and smoothness of rotation of tension and bypass rollers
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Check up ease and smoothness of rotation of tension and bypass rollers (fig. 2.80), be convinced of absence люфта and extraneous noise.
If necessary replace rollers.
Replace rollers in the presence of traces of leak of greasing from bearings.
Assemblage of a drive of a camshaft
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Fig. 2.81. Installation of a flange and a gear pulley of a cranked shaft: 1 – a facet; 2 – a cranked shaft; 3 – a flange; 4 – a gear pulley of a cranked shaft; 5 – a special washer
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Establish a flange and a gear pulley of a cranked shaft, as is shown in fig. 2.81. At installation will pay special attention on their mutual position.
Establish a gear pulley of a camshaft and tighten a bolt of its fastening by the moment 80–100 Н·м.
Establish bypass a roller and tighten a bolt of its fastening by the moment 43–55 Н·м.
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Fig. 2.82. Installation of a gear pulley of a camshaft: And, In – adjusting labels
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Combine a label And on gear to a pulley of a camshaft with a label In on a cover of the bearing of a shaft (fig. 2.82).
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Fig. 2.83. Installation of a gear pulley of a cranked shaft (on выноске adjusting labels are shown)
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After that establish the piston of 1st cylinder in ВМТ the end of a step of compression and combine a label on gear to a pulley of a cranked shaft with a label on a forward cover of the block of cylinders, as is shown in fig. 2.83.
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Fig. 2.84. Installation of a spring of a tension roller
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Establish a tension roller, springs (fig. 2.84) and the remote plug, temporarily tighten fastening bolts. Then tighten a bolt with a washer in an oval aperture of an arm of a tension roller.
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Fig. 2.85. Installation of the bottom end of a spring of a tension roller
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Get the bottom end of a spring for a forward cover of the block of cylinders, as is shown in fig. 2.85.
Fix a tension roller in this position (displaced to the pump of a cooling liquid).
Establish a gear belt on a pulley of a cranked shaft.
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Fig. 2.86. Installation of a gear belt: 1 – a gear pulley of a cranked shaft; 2 – bypass a roller; 3 – a gear pulley of a camshaft; 4 – a tension roller
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THE PREVENTION
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Fig. 2.87. Check of a tension of a gear belt
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At a lining of a gear belt position of distributive, cranked or intermediate shaft should not change. Otherwise there can be serious damages of the engine or it will cease to give the maximum capacity. After a tension of a gear belt once again check up position of distributive, intermediate shaft and a belt pulley: if the label on gear to a camshaft pulley coincides with a label on a head of the block of cylinders simultaneously should coincide a label on a pulley of a cranked shaft and a label on the block of cylinders (fig. 2.87). Otherwise it is necessary to repeat installation of a gear pulley of a camshaft and a pulley of a cranked shaft at the removed gear belt.
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Establish a gear belt on a camshaft pulley. After belt installation on a camshaft pulley be convinced of a tension of a leading branch of a belt. Then, turning a camshaft pulley in the opposite direction, be convinced that the tension branch stretches also all adjusting labels are combined.
Tighten bolts of fastening of the tension device.
Turn a cranked shaft on two turns in a rotation direction (clockwise) so that to establish the piston of 1st cylinder in ВМТ the end of a step of compression, thus labels on gear to a pulley and a cover of bearings of a camshaft should be combined.
The moment of an inhaling of a bolt of fastening of a tension roller 20–27 Н·м.
Check up a belt tension (fig. 2.87). For this purpose, undertaken a hand for a tension roller with moderate effort (approximately 50), press to it a leading branch of a belt. Belt teeths should reach approximately half of radius of a head of a bolt of fastening of a tension roller (on head sides).
Establish a drive cover газораспределительного the mechanism.
The moment of an inhaling of bolts of fastening of a cover of a drive газораспределительного the mechanism 8–10 Н·м.
Establish a pulley of a cranked shaft, watching that the pin of a gear pulley of a cranked shaft has entered into an aperture of a pulley of a cranked shaft.
The moment of an inhaling of a bolt of fastening of a pulley of a cranked shaft 140–150 Н·м.
Establish a belt of a drive of the fan of system of cooling and adjust a belt tension.
Establish a pulley of the pump of a cooling liquid.
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Fig. 2.88. A belt of a drive of auxiliary units of the engine
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Establish поликлиновой a belt of a drive of auxiliary units (fig. 2.88) and adjust its tension.
Check of a technical condition
Camshaft
Surfaces of basic necks of a camshaft and cams should be well polished and without damages. If on surfaces of necks there are traces of jamming or deep risks, it is necessary to replace a shaft.
Establish a camshaft extreme necks on two prisms placed on a testing plate, and measure the indicator of hour type radial palpation of basic necks. Radial palpation should not exceed 0,02 mm.
Корпусы camshaft bearings should not have cracks. On basic surfaces of bearings under camshaft necks teases and scratches are not supposed.
Check up a backlash between necks of a camshaft and apertures of support. The backlash is defined by calculation after a measurement of necks and apertures in support on a head of the block of cylinders with the established cases of bearings.
For backlash definition it is possible to take advantage of the special calibrated plastic wire. For this purpose execute the following:
– Carefully clear necks of a camshaft and basic surfaces of a head of the block of cylinders and cases of bearings;
– Remove pushers of valves;
– Lay a camshaft in support of a head of the block of cylinders and place on necks of a shaft pieces of a plastic wire;
– Establish cases of bearings and tighten nuts of their fastening in two steps the moment 20 Н·м;
– Remove cases of bearings and depending on size of flattening of a wire on a scale put on packing of a wire, define a backlash.
Forward epiploon of a camshaft
Check up working edges of an epiploon on deterioration presence. At deterioration of working edges replace an epiploon.
Check up the surface of a camshaft interfaced to working edges of an epiploon. At presence on this surface of steps of deterioration replace a camshaft.
Gear belt
The surface of a gear part of a belt should have an accurate profile of teeths. On teeths there should not be a deterioration, folds, cracks, подрезов and отслоений fibres of a fabric from rubber.
On any surfaces of a belt there should not be traces of hit of engine oil.
On face surfaces of a belt there should not be a stratification or разлохмачивания; it is supposed, however, insignificant выступание fringes of a fabric basis of a belt.
The surface of an external flat part of a belt should be equal, without cambers, folds, cracks and deepenings.
Useful data and councils
Gear belt of a drive of the mechanism газораспределения
Today gear belts have found «the second breath». Almost all motor-car manufacturers equip the cars with an elastic drive. German designers have gone further away. They widely apply a double gear belt (Duplex) as reliable connection of a camshaft with krivoshipno-shatunnym the mechanism.
The gear belt has a number of advantages before приводной a chain. Last obviously is more expensive. To make a belt is much easier, than a chain. In essence the gear belt is the closed tape from маслобензостойкой the rubbers, reinforced by a kapron cord with привулканизированными to it teeths. If to compare a belt to a chain comparison will appear not in favour of last. The belt is much easier than a chain that, naturally, should affect weight of the engine. Besides, the engine supplied with a belt, is much more silent than the colleague equipped with a chain. Also "elastic band" out of an engine casing that affects time of its installation or replacement is mounted. For example, on replacement of a belt of a drive газораспределительного the mechanism four-cylinder восьмиклапанного the engine with its subsequent installation on labels such focus leaves about 25–30 minutes With a chain will not pass.
At correct service the gear belt goes long. Home producers, we will remind, give a guarantee on run of 60 thousand in km, foreign – and that it is more. Rover has managed to remove term of replacement of a belt to 160 thousand in km of run.
In what correct service of a belt drive consists? Not less often than each 15-30 thousand in km the belt tension should be checked. However it does not mean that it is necessary to unbend only a casing and to check up, whether on a place a belt. Is better to examine it, having removed from the engine. At times it is difficult to notice that one of teeths is cut. If it has already occurred, be assured that long he will not stretch. Therefore, having removed a belt, make on it a mark a chalk, and further a tooth behind a tooth examine it. After installation also it is necessary to check position of directing and tension rollers. All these elements should be in one plane, otherwise the belt will work with a warp that considerably will reduce its resource.
The important factor for belt work – absence on its surface of oil. Whatever there was маслобензостойкая a rubber from which the belt is executed, nevertheless it not that case when «porridge oil you will not spoil». Here oil just to the detriment. Therefore it is periodically necessary to pay attention to a condition of epiploons of distributive and cranked shaft. And if you have noticed an oil leak, try to eliminate it somewhat quicker. As practice shows, stay of a belt in oil cuts its resource by half, and even three times.
If this control to ignore, consequences will not keep itself waiting long. Through 40-50 thousand in km for the account вытягивания a belt its tension will weaken also it will start to "whip". As a result of it "the heavy" camshaft rotates not synchronously with cranked shaft, and with backlog. This "asynchronous" work leads still большему to weakening of a tension of a belt. As a result there is an excessive loading on teeths.
Breakage of several teeths can lead to that once the camshaft remains motionless whereas the cranked shaft will rotate successively. During this moment open valves of cylinders "will meet" pistons. Result – breakage of a core or the valve bend, the broken directing plugs, camshaft breakage. Is, the truth, and exceptions when breakage passes almost without serious consequences. However such it is possible only on those cars in which engines specially are for such a case executed проточки in pistons. Our VAZs, namely cars, for example, concern them VAZ-2105 with the engine of 1300 sm 3 and VAZ-2108 with the engine of 1500 sm 3.
In most cases belt breakage manages to the owner of the car in a round sum connected with capital repairs of the engine. For example, cost of a belt for car BMW engine makes $40, engine repair will manage in $2500. The belt for вазовской can be bought "nine" for $25. And here motor repair will pull on $400.
Valves
It is possible to reanimate any "tired" car. However technical difficulties are thus great. Without spare parts, machine tools, the welding equipment and other technological support here not to manage. The main thing – factory repair manuals (and they are accessible now) speak nothing about possible alternative decisions, especially about a problem of a choice among details, materials and tools which are in the domestic market. Such is a circle of questions in which both the enthusiast-single, and mechanics of small automobile repair shop lack the information.
Sooner or later any engine becomes a source of troubles: глохнет in a way, it does not wish to be started up in the mornings, pulls is worse, "eats" superfluous fuel and oil. It is quite probable that the reason of its whimsical behaviour is plain: to clean the carburettor or atomizers of system of injection enough, to adjust ignition and to replace маслосъемные caps that all has entered into norm. But happens that traditional approaches do not help restoration of working capacity of the engine, and at compression gaugings is found out that in one or several cylinders it below the admissible.
Then first of all specify character of malfunction: deterioration цилиндропоршневой groups, подгорание plates or deterioration of cores and directing plugs of valves. The technics of diagnosing is simple enough and described in many grants on repair of engines.
After that are defined with repair. Here only it is necessary to take to itself for a rule to be
Far away from any miracle liquids. The effect basically is possible, but is reached seldom; usual result – superfluous expenses and efforts. It is better to be guided by high-grade repair procedure at once.
To find a workshop where treat engines, today it is already simple, and not only in big cities. But here is how there work and what its quality is organised? The life shows that at all importance of experience and qualification of employees good results of work without the special equipment and equipment are unattainable, and in this plan disorder of technical armament of our servicing deports and mechanics, alas, is great. And if told above concerned basically the motorist-ekspluatatsionnika the further is addressed not so much to it, how many to the mechanic, after all it will be a question of technology.
In cases when results of diagnostics specify in malfunction of the mechanism газораспределения, the head of the block of cylinders should be removed. The first that it is necessary to make after removal, dismantling and the general survey, – to estimate backlashes between cores of valves and directing plugs. If they more maximum permissible valves replace with the new. But when this vague measure is insufficient, it is necessary to replace and plugs.
For a small workshop such work presents already known difficulties: pig-iron plugs запрессовывают in the aluminium case with a tightness. Thus to avoid microcracks and смятия, plugs should be cooled preliminary in liquid nitrogen (which temperature–196 °С), and a head of the block to heat up to 160–170 °С (at heating to more heat there can be harmful consequences). All it is difficult enough, is labour-consuming and is frequently simply impracticable in semihandicraft conditions. Therefore in rare workshops do not deviate the conditions ordered by the repair manual that directly pours out in loss of quality of landing and distortion of geometry of connection. It then correct, processing «in a place» saddles of valves, and valves long and tiresomely grind in.
But today there is also other technique, extremely profitable both on labour input, and on an investment of means which thus guarantees high-quality results. It is based on application of the original and almost unknown tool in our practice of American company Neway.
With its help restoration of the worn out directing plugs is spent on a place without выпрессовки. Special knifes-rollers cause plastic deformation of metal, compensating deterioration of an internal surface of the plug, simultaneously forming in it a spiral fillet which improves conditions of greasing of a core of the valve, and also serves original лабиринтным as the consolidation facilitating work маслосъемным to caps.
The complete set includes five knifes and a set of development for finishing processing of the plug. It is characteristic that all operations with tool Neway are conducted manually and not connected with an electrical supply or reception from the outside of other kind of energy.
Now about saddles of valves. At traditional methods of their processing directing шарошки or a vertical drill freely rotates in the valve plug. Mills Neway have a motionless axis which is densely fixed already in the restored plug self-established broad цанговым by a clip. The mill is put on an axis with a precision backlash by 0,5 microns that provides the minimum admission of processing. Mills Neway at the expense of unique sharpening and the form of cutting edges form on a surface of a saddle of the valve a special microrelief of type "comb": extra earnings of the valve and a saddle passes quickly and effectively, and need for grinding in disappears. Their productivity is high: any facet on a valve saddle turns out for 3–4 turns of the tool.
Last stage – restoration of working facets of valves. For this operation firm Neway offers special tool "Тизматик-2". The valve motionlessly fix in the special adaptation which, in turn, establish in a usual metalwork vice. Enough several turns of a mill (axial giving is provided with the microlift) to receive an ideal concentric surface of the valve. We will notice that on its working surface, as well as at saddle processing, the special microrelief also is formed.
Here, actually, and all. It is necessary to wash out and grease only all details then it is possible to collect a head.
And grinding in? We will remind once again: at work as tool Neway in this tiresome, long and tiresome operation there is no necessity. After processing of pair "valve-saddle" interface of both details occurs on very narrow corbel, practically on a line.
It is reached small (to 1 °) by a divergence of corners of processing of working surfaces of a saddle and the valve (between them it is formed so-called интерференционный a corner). In the first seconds of work of the engine the interface area increases for the account смятия superficial ledges of the created microrelief on facets, and then there is a necessary 100 %-s' consolidation.
At cost of a set of equipment about $400 (depending on a complete set) Neway can pay off in the first month of work, and at repair of engines of foreign cars – besides to bring in the appreciable income.