How to insert the piston into the trimmer cylinder

Power units MeMZ-966V, 966G (27, 28 hp)

A long cylinder without bore, pistons of the nominal size, mainly of group B, should be installed.The difference in the mass of the heaviest and lightest pistons for one engine should not exceed 3 g.

It is recommended to assemble the piston with the connecting rod in the following sequence:

insert the retaining ring into one of the bosses so that it fits snugly into the groove;

heat the piston to a temperature of 80.85 C and align it with the connecting rod, directing the arrow to the piston bottom and the number on the connecting rod in one direction;

lubricate the piston pin with engine oil and insert it into the bore of the piston bosses and into the bushing of the upper connecting rod head. the finger enters the heated piston under light hand pressure. When your finger rests-

Groups Skirt diameter Diameter Gap,

and the pistons of the cylinder after mm

ABC 72.18. 72.19 72.2. 0,

72.19. 72.20 72.20. 4. 72.25. 05.0.07

72.21 72.25. 72.26. 0.05.

in the retaining ring, insert the second ring. After the piston has cooled down, the pin should be stationary in the holes of the piston bosses, but movable in the connecting rod bushing;

install the piston rings as shown in fig. 7. Checking the condition and replacing the piston rings. When checked, the piston rings must be thoroughly cleaned of carbon deposits and sticky deposits and rinsed. The main check consists in determining the thermal clearance in the lock of the piston ring inserted into the cylinder (Fig. 54). In this case, the piston rings are inserted into the cylinder, pushing it with the bottom of the piston to a depth of 8.10 mm. The gap in the joint of the operating ring should not exceed 1.5 mm.

They also check the running-in of the piston ring along the cylinder. If there is a trace of gas breakthrough, the piston ring must be replaced.

Installing a piston into a cylinder

Piston rings are supplied as spare parts of nominal and one overhaul size in sets for one engine. Rings of repair size differ from rings of nominal size with an outer diameter increased by 0.25 mm. They are installed only on repair pistons when the cylinders are grinded to the appropriate size. Before installation, the piston rings should be cleaned from preservation and washed thoroughly, then select them for each cylinder. After selecting the kits for each cylinder, you need to check the clearance at the joint of the piston rings. When installed in a new cylinder, it should be 0.21. 0.55 mm for compression and 0.9. 1.5 mm for oil scraper discs (saw off if necessary). The gap at the junction of new compression piston rings installed in working cylinders should not exceed 0.93 mm.

Before installing the piston rings on the pistons, check the ease of movement of the piston rings by rolling the ring in the piston grooves (Fig. 55) in order to make sure that the grooves are clean, there are no nicks, etc. Rings are put on the pistons using a mandrel (Fig. 56), observing be careful not to break or deform them. The installation of the rings starts from the lower oil scraper ring; into the bottom groove

install the radial expander 5 (see Fig. 7), the lower disc 3, the axial expander 4 and the upper disc, then install the lower and upper compression rings. When installing compression rings, the rectangular chamfer made on the inner surface must face up. After installing the rings, you need to lubricate the pistons and piston rings with oil and once again check the ease of movement of the rings in the grooves and place the joints of the rings, as shown in Fig. 7.

Selection and replacement of piston pins. Piston pins are rarely replaced without replacing the pistons, as their wear is usually very low. Therefore, the spare parts are supplied with pistons complete with piston pins, matched to the color marking on the piston boss and the inner surface of the pin (the kit also includes retaining rings). The marking designates one of four size groups, differing from each other by 0.0025 mm. The dimensions of the piston pin and the diameter of the piston pin boss for each of the size groups are indicated in Appendix. 2.

It is forbidden to install the piston pin into a new piston of a different size group, as this leads to deformation of the piston and its possible seizure.

insert, piston, trimmer, cylinder

When replacing the piston pin on a working piston, it is selected according to the measurement of the diameter of the bosses to ensure an interference fit of up to 0.005 mm. After selecting the piston pin on the piston, it is checked against the bushing of the upper connecting rod head. The mounting clearance between bushing and pin should be 0.002. 0.007 mm for new parts and no more than 0.025 mm for those who worked; the maximum allowable gap is 0.05 mm. The new piston pin is color-coded to match the connecting rod bushing in four different size groups. On the connecting rod, the marking is applied with paint at the upper head (see Appendix 2).

The mating of the new piston pins with the connecting rod bushings is checked by pushing a carefully wiped piston pin into the dry wiped bushing of the upper connecting rod head with a snob (Fig. 57). At the same time, there should be no perceptible backlash. To achieve such a conjugation, it is allowed to install parts of adjacent size groups.

Checking the condition of the connecting rods and replacing them. The connecting rods are checked for nicks, cracks, dents, the condition of the surfaces, the dimensions of the bearings of the lower and upper connecting rod heads, the parallelism of the axes

How to insert rings on the piston correctly

Replacing the piston rings of the YaMZ diesel engine of the MAZ car

Install the piston rings in the reverse order.

Carefully clean the piston from carbon deposits, protecting it from damage (especially the end surfaces of the piston ring grooves).

Before assembly, thoroughly rinse all parts, and blow out the oil channels with compressed air. Assemble the piston with the finger by lightly pressing the hand, while it is necessary to abundantly lubricate the hole in the piston and the finger with engine oil. It is not allowed to press the finger into the piston.

In order to install a piston assembly with piston rings and a connecting rod into the cylinder liner, pre-compress the rings by sinking them into the piston grooves. To compress the rings, use a mandrel (Fig. 3) with a tapered inner surface and a shoulder that allows you to correctly center the mandrel on the cylinder liner. After installing the piston in the mandrel, settle it in the cylinder liner.

When assembling the piston with the connecting rod and installing them on the engine, comply with the following requirements:

The piston and liner must be of the same size group.

Set the compression rings with the stamp to the top of the piston crown.

H. Pull the locks of adjacent piston rings in opposite directions into the plane of the piston pin.

Install the piston so that the offset combustion chamber in the piston is directed towards the inside of the engine, towards the fuel pump.

On YaMZ-2Z6NE2, BE2 engines with individual cylinder heads, pistons with a central combustion chamber are used. Install the piston in the sleeve so that the arrow on the piston points to the camber of the engine. towards the fuel pump. In this case, the grooves on the piston bottom for the valves will be displaced relative to the center of the cylinder towards the exhaust manifolds.

5 Marks of pairing on the connecting rod and on the cover must be the same.

Dirt, burrs and nicks on the connecting rod and cover splines are not allowed.

Lubricate the threads and bearing ends of the heads, bolts of the connecting rod caps with engine oil and tighten in two steps, starting with the long bolt, first with a torque of 100 Nm (10 kgcm), finally with a torque of 200. 220 Nm (20. 22 kgcm).

Connecting rod and piston group of the ZMZ-406 engine

Remove the connecting rod bearing shell from the connecting rod.

Remove the piston with a connecting rod from the cylinder carefully so as not to damage the cylinder mirror.

Check marks on connecting rod and connecting rod cover.

If the marks are not visible, mark the connecting rod and cover with the cylinder number.

Remove the remaining pistons with connecting rods in the same way.

Remove the piston rings with a puller.

Remove circlip from both sides of the piston.

If there is no device, you can knock out the piston pins with light hammer blows through the mandrel 1.

Remove connecting rod 2 from piston 3.

Remove the remaining pistons from the connecting rods in the same way.

After disassembly, rinse all parts in gasoline. Remove carbon deposits from pistons.

READ  What Kind Of Oil Is Poured Into The Trimmer

Clean the piston ring grooves with an old piston ring or ring fragment.

Dimensional groups of pistons, connecting rods and pins

Add a comment

Inspection, inspection and repair

Inspect the pistons. If they have seizures, traces of burnout, deep scratches, replace the pistons. Measure the piston diameter. If it is less than 91.9 mm, replace the piston. The piston diameter is measured in a plane perpendicular to the piston pin axis, 8.0 mm below the piston pin axis. The piston is installed in the cylinder with a clearance of 0.024–0.048 mm. In order to ensure the size of the clearance, the pistons are divided by diameter into five size groups A, B, C, D and D. The letter markings are knocked out on the piston crown. When matching the piston to the cylinder, the above clearance must be ensured. The maximum permissible clearance between the piston and the cylinder is 0.25 mm. The clearance between the piston and the cylinder can be determined by measuring the piston and cylinder. The spare parts are supplied with pistons of two overhaul sizes: with a diameter increased by 0.5 mm and by 1.0 mm. On one of the bosses under the piston pin, the inscription 406 (piston of nominal size), 406AP (piston increased by 0.5 mm), 406BR (piston increased by 1.0 mm) are cast.

The gap should be between 0.05. 0.087 mm for compression rings and 0.115. 0.365 mm for the oil scraper ring.

If the clearances exceed those specified, the rings or pistons must be replaced.

To do this, insert the ring into the cylinder and push it with the piston like a mandrel so that the ring fits in the cylinder evenly, without distortion.

Measure the gap in the ring lock with a feeler gauge, it should be within 0.3-0.6 mm for compression rings and 0.5-1.0 mm for oil scraper disks.

If the clearance exceeds the specified, replace the ring.

If the gap is less, you can cut the ends of the ring with a file clamped in a vice. In this case, the ring is moved up and down the file.

Check the seating of the piston pin in the upper connecting rod head. The gap between the pin and the bushing of the upper connecting rod head should be within the range of 0.0045 –0.0095 mm. Pins, pistons and connecting rods are divided into four size groups and are marked with paint. The pin is marked on the inner surface at one end, the connecting rod. on the rod, the piston. on the lower surface of one of the lugs, or a Roman numeral is knocked out on the piston crown. Dimensional groups of pistons, connecting rods and pins are shown in the table. Lightly lubricate the gudgeon pin with engine oil and insert into the upper connecting rod head. The finger should enter the head from the effort of the thumb evenly, without jamming. The connecting rod should rotate on the pin under its own weight from a horizontal position. The pin should not protrude or fall out of the connecting rod head under its own weight if the connecting rod is rotated so that the pin is vertical. Piston pin and connecting rod must be of the same or adjacent size groups.

Pistons with piston rings, pins and connecting rods are selected by weight. The difference in weight for one engine should be no more than 10 g.

Inspect the connecting rod bearings. If they have seizures, risks, chipping, etc. they need to be replaced.

Install the caps on the connecting rods and measure the diameter of the hole in the lower connecting rod head. The nominal hole diameter is 60 0.019 mm, the maximum permissible diameter is 60.03 mm. If the measured diameter exceeds the maximum permissible, replace the connecting rod with a cap. Measure the diameter of the hole in the bushing of the upper connecting rod. The nominal hole diameters are 22 0.007 and 22 –0.003 mm, the maximum allowable diameter is 22.01 mm. If the measured diameter exceeds the maximum permissible, replace the connecting rod. The dimensions of the connecting rod-piston group are given in the table.

Build and install

Assemble piston 4 with connecting rod 3. Before that, heat the piston to a temperature of 60–80 C. Then quickly insert the connecting rod into the piston so that the inscription: Front on the piston and protrusion A on the connecting rod are on the same side, and press in the piston pin 6. Install the locking rings 5. Push the piston rings onto the piston using a puller. The upper compression ring has an inscription: Top. the ring must be installed on the piston with this inscription to the bottom of the piston. There is a groove on the lower compression ring on the inside, the ring must be installed with this groove up to the bottom of the piston. Insert the insert 7 into the lower head of the connecting rod, while the locking lug on the insert must enter the recess in the lower head of the piston. Insert the insert 1 into the connecting rod cover 2, while the retaining protrusion of the insert must enter the recess in the cover. Lubricate the cylinder, piston 4, crankshaft connecting rod journal and bearings 1 and 7 with engine oil. Rotate the piston rings so that the locks of the compression rings are at an angle of 180 to each other, the locks of the oil scraper ring discs are also at an angle of 180 to each other and 90 to the locks of the compression rings, the lock of the oil scraper ring expander at an angle of 45 to the lock of one of the oil scraper discs. Turn the crankshaft so that the connecting rod journal of the cylinder in which the piston is installed is at Nm. Insert the piston with the connecting rod into the cylinder, with the inscription: Front on the piston boss must face forward of the engine (towards the camshaft drive). In order not to damage the cylinder mirror, it is recommended to put on bushings made of soft material (for example, cut rubber or plastic hoses) on the connecting rod bolts. Using a special crimp, squeeze the piston rings and push the piston into the cylinder with light blows with a hammer handle, while the crimp must be tightly pressed against the block, otherwise the piston rings can break. Move the piston down so that the lower head of the connecting rod sits on the connecting rod journal of the crankshaft, remove the hose cutters from the connecting rod bolts. Install the connecting rod cover 2 on the connecting rod bolts, while the ledge B on the connecting rod cover should be on the same side as the protrusion A on the lower connecting rod head, and the cylinder numbers stamped on the connecting rod and the cover were located on one side.

Install the remaining pistons with connecting rods in the same way.

Turn the crankshaft several times, it should rotate easily, without jamming.

Install the oil pump, oil pan and cylinder head.

Adjustment lever defective

This breakage occurs when the contact surface of the lever wears out.

The abrasion of the contact surface occurs due to the presence of abrasive particles in the gasoline or due to strong vibration of the engine during operation. This defect in the adjusting lever causes problems with the intake, as well as improper idling of the engine.

Fuel pump problems

A common malfunction that “pursues” the fuel pump is the deformation of the pump membrane. For this reason, it does not fit properly and the pump passages are not sealed.

The reasons for membrane deformation can be the following:

  • long work of the trimmer;
  • use of unsuitable fuel;
  • ingress of gases into the impulse channel.

As a result, diaphragm damage reduces pump performance and, as a result:

  • depletion of the combustible mixture occurs;
  • it is difficult to start the engine;
  • there are interruptions in the operation of the motor;
  • the piston is damaged.

Also, the above-described consequences for the motor can cause clogging of the pump cavity on the impulse side. In this case, dirt enters the membrane through the impulse channel.

To remove the blockage, you will have to disassemble the carburetor and clean the membrane.

When to adjust

Carburetor adjustment is necessary in the following cases:

  • the new engine was run-in (4-5 liters of fuel mixture were used);
  • the composition of the fuel has changed (brand of oil and gasoline);
  • the weather has changed (it became hot, cold);
  • the rarefaction of air has changed (applies to mountainous regions);
  • after long-term storage;
  • increased load on the engine (after changing tools, etc.);
  • due to vibration, the adjustment screws spontaneously unscrewed;
  • fuel consumption has increased, the carburetor overflows fuel;
  • carbon deposits quickly appear on the spark plug electrodes (while the fuel mixture is prepared correctly);
  • the engine starts and immediately stalls or gains momentum poorly;
  • no gasoline enters the cylinder;
  • large amount of exhaust gases.

Deformation of the control diaphragm

The membrane can undergo deformation during prolonged operation of the unit and when using aggressive fuels.

Failure of normal adjustment due to a defect leads to:

  • damage to the piston;
  • difficulties when starting up;
  • depletion of fuel;
  • improper engine operation.

Throttle and choke shaft wear

The air and throttle shaft can wear out for the following reasons:

  • insufficient and improper maintenance of the air filter;
  • the air filter is damaged;
  • the air filter is not suitable for this unit.

Due to the ingress of poorly cleaned air, the shaft wears out and can break. Broken shaft parts can enter the combustion chamber or crankcase and cause serious damage to the entire piston system.

To eliminate problems with air purification, it is necessary to replace the defective filter or flush the existing (serviceable) one. The filter must be washed in soapy water and dried.

Clogged strainer

The strainer can become dirty if contaminated fuel enters through a fuel hose or a defective pickup head. In the photo below you can see what a clean filter looks like and a dirty one (parts are separated by a line).

READ  How to Choose an Electric Trimmer

Correcting the malfunction will require thorough cleaning and rinsing of the strainer. It is also recommended to blow compressed air through all holes in the carburetor trimmer housing.

Common carburetor malfunctions

Failure of the trimmer carburetor occurs due to the use of poor quality gasoline, a damaged air filter and the accumulation of dirt in the chamber of this unit. Most often, it is quite possible to repair the carburetor with your own hands. Listed below are typical lawn mowers carburetor malfunctions.

How to install a piston on a scooter?

One of the most serious scooter breakdowns is the failure of the cylinder-piston group, which immediately makes the scooter inoperative. It is the CPG of the scooter that is responsible for its movement, the slightest breakdown will lead to the impossibility of further movement. That is why if you are faced with a non-working piston, immediately take up its repair.

In general, any CPG has a certain life span, with a certain mileage its wear increases and the buyer will have to replace the part. Often it is sufficient to replace the piston, but sometimes more serious problems occur. Where you have to change the piston, rings and cylinder. The installation may vary slightly depending on the scooter model and manufacturer, but we will cover the basic steps. Also, piston scooters may differ in power, but this does not affect the replacement process in any way.

Removing the CPG

If you do not know how to properly install the piston on a 2t or 4t scooter, first remove the old part. Getting to the piston group is not easy, you will have to disassemble the scooter, and sometimes remove the plastic. In general, the actions to replace the CPG are as follows:

  • Removing the engine, disconnecting the wires;
  • Removing the old piston;
  • Installation of a new part according to requirements;
  • Similar engine assembly and electrical and hose connections.

After you have disconnected all the wiring and made sure that the oil and petrol hose are covered, remove the engine. Removal of the engine may be different for different scooter models, so act according to the situation. Having received the finished engine, start removing the plastic cylinder cover, it protects the CPG from external dirt, dust, etc. The next step is to remove the cylinder head. Depending on the type of scooter (2t or 4t), the head may be more complex, 4t scooters also have valves that will then have to be adjusted. But the procedure for removing the head is by unscrewing 4 nuts.

Important: the nuts must be unscrewed gradually, using the cross-over method. That is, as shown in the picture below. Otherwise, you will rip off the threads and damage the piston. This also applies to the installation of a piston, the nuts are also tightened.

Then you will have to remove the cylinder, in some cases it is problematic to do this due to the large formation of carbon deposits or a piston defect. If the cylinder is intact, but the piston is faulty, proceed to replacing the piston. How to properly install the piston on a scooter

Replacing the piston involves a number of difficulties, because the complete set with the piston will have several more basic parts. In the kit you will find retaining rings, a pin and several rings (depending on the scooter. 2t or 4t). In 2-stroke scooters, only two rings are usually put, they are compression, the third thin ring is practically not needed, but we recommend placing it under the lower ring for springing. In the case of 4-stroke mopeds, there are three main rings, two of them are compression, the third is an oil scraper.

The ring assembly is presented on the basis of a 2t scooter, it has a simpler design. So, put two rings on the piston, then take your finger and insert it into the bore of the crankshaft so that the piston is securely held. Be sure to secure the finger with locking rings on both sides, this is necessary so that the finger does not come out during operation. Also, the retaining rings should not stick out, they should fit snugly into the special hole. Important: it is necessary to install the piston with the arrow (or the inscription EX) to the exhaust pipe, otherwise the whole procedure will be useless. The next step is to install the cylinder on the piston.

Installing the cylinder

This procedure is quite complicated, because you need to fit the cylinder onto the piston perfectly. First of all, do not forget to put gaskets on both sides, they are both included with the CPG and are purchased separately. There are usually two gaskets, one is placed down between the cylinder and the engine, the second is installed between the cylinder and the head. After installing the bottom gasket, try to slide on the cylinder so that the rings come together in the groove. To do this, during the installation of the cylinder, it is enough to press the rings, having previously lubricated the cylinder and piston with oil.

Then put on the gasket and secure the head with nuts. Tighten the nuts in a crosswise order. Then check the operation of the piston with a kickstarter, if the installation was successful, the piston should move evenly along the cylinder and have a noticeable compression.

That’s it, assemble the scooter in reverse order, connect all wires and hoses.

Ford Fusion Fiesta manual

How to install the piston of the first cylinder at TDC

How to install 21083 engine pistons at TDC

Many repairs to a car engine involve setting pistons at top dead center (TDC).

We will carry out such an installation using the example of an engine 21083 of cars VAZ 21083, 21093, 21099.

The 21083 engine has factory alignment marks, when aligned, the pistons of the first and fourth cylinders will be set to top dead center:

Mark. a point on the camshaft pulley and a protrusion mark on the rear cover of the timing drive.

Mark. point on the crankshaft toothed pulley and mark. cutout on the oil pump housing.

Mark. a line on the flywheel of the engine and a mark (triangle cut) on the scale of degrees in the clutch housing flap.

Required tools

Preparatory work

How to set engine pistons at top dead center (TDC)

  • Aligning the factory engine alignment marks

To do this, rotate the engine crankshaft clockwise by the flywheel splines with a large screwdriver until the mark on the camshaft pulley and the mark on the rear cover of the timing drive are aligned (see photo above).

You can rotate the crankshaft by the bolt of the alternator drive pulley with a key on “19”. But to access it, you will have to remove the right wheel, the right protective mudguard of the engine, the generator pulley. The advantage of this additional work will be control over the alignment of marks on the crankshaft pulley and marks on the oil pump housing.

  • We control the alignment of installation marks

See three photos above.

Mark. the point on the camshaft pulley should be strictly opposite the mark. the protrusion on the rear cover of the timing drive.

The mark is a line on the flywheel opposite the middle of the triangular cutout on the scale of degrees, in the hatch on the clutch housing. Visible if you remove the hatch cover.

And if the mark on the engine crankshaft is controlled:

Mark. point on the crankshaft pulley opposite the mark. cutout on the ebb of the oil pump housing.

With this arrangement of the timing marks of the engine 21083, its pistons in the first and fourth cylinders will be at top dead center (TDC). In this case, in the first cylinder there will be a compression stroke, and in the fourth cylinder there will be exhaust gases.

To install the pistons of the second and third engine cylinders at top dead center, rotate the crankshaft clockwise until the mark on the camshaft pulley goes around a full circle. 360 degrees and becomes opposite the mark on the rear cover of the timing drive. In this case, the mark on the flywheel will not be visible, the mark on the crankshaft pulley will also be located opposite the cutout in the ebb of the oil pump housing.

Notes and additions

Repair work on the engine with the installation of pistons at TDC

Features of installing the piston of the first cylinder in the TDC position of the compression stroke

The piston of the 1st cylinder of the Opel Astra is set to the TDC (top dead center) position of the compression stroke so that when carrying out work related to the removal of the camshaft drive belt, the valve timing is not disturbed. If the valve timing is violated, the engine will not work normally.

Set the TDC according to the marks on the mechanisms for changing the valve timing of the intake and exhaust shafts (when installed according to the mark on the crankshaft pulley, the piston of either the 1st or 4th cylinder may be in this position). After that, be sure to make sure that the marks on the crankshaft pulley match. If at the same time the mark on the crankshaft pulley does not match, then the valve timing is broken (the piston of the 1st cylinder is not set at TDC). In this case, it is necessary to remove the timing belt and turn the crankshaft until the marks are aligned.

To install the piston of the 1st cylinder of the engine mod. Z 18 XER to TDC of the compression stroke:.

Remove the bolts securing the front cover of the timing drive and remove the cover (see Replacing the timing belt for engines Z 16 XER, Z 14 XEP, Z 18 XER, Z 20 LER, Z 20 LEH).

Marks 1 (Fig. 1) on the toothed pulleys of the intake and exhaust camshafts should be located in a horizontal plane and look at each other, and the mark on the crankshaft toothed pulley should be aligned with the mark on the oil pump housing. The mark becomes visible after removing the accessory drive pulley. The rectangular mark on the oil pump housing should line up with the line on the crankshaft toothed pulley.

In addition, marks 2 are applied to the edge of the groove of the accessory drive pulley and to the front cover of the engine.

READ  How To Put Protection On A Gas Trimmer

To install the piston of the 1st cylinder of the engine mod. Z 14 XEP to TDC of the compression stroke do the following.

Remove the air filter (see “Removing and installing the air filter”).

Disconnect the harness pads from the ignition module and remove the module.

Disconnect the harness pads from the camshaft, air flow, oil pressure and coolant temperature sensors located on the cylinder head cover (Fig. 2). Unscrew the sensors from the cylinder head cover and remove them.

Loosen the crankcase ventilation hose clamps and disconnect the hoses from the cylinder head cover connections.

Remove the bolts securing the cylinder head cover and remove the cover.

Remove bolt 1 (Fig. 3) and install tool 2 in its hole. Slowly turn the crankshaft until the tool is fixed in the bore of the crankshaft, while mark 4 on the accessory drive pulley should coincide with mark 3 on the front cover of the engine.

When aligning the marks on the accessory drive pulley and the front cover of the engine, the cams of the 1st cylinder of the camshafts must be directed in opposite directions (Fig. 4).

Install the retaining plate (fig. 5) into the grooves at the rear of the camshafts. If the device was installed without difficulty, the camshaft drive chain is installed correctly, the piston of the 1st cylinder is at TDC of the compression stroke and the initial setting of the valve timing is correct. If it was not possible to install the device (the valve timing is shifted), adjust the valve timing (see Adjusting the valve timing on the engine mod. Z14 XEP).

Install the fixture mod. KM-954 (Fig. 6) so that the protrusion of the device falls into the groove of the rotor of the camshaft position sensor. If the device could not be installed (the valve timing is shifted), adjust the valve timing (see “Adjusting the valve timing on the engine mod. Z14 XEP”).

Install all removed parts in the reverse order of removal.

For installing the piston of the 1st cylinder of engines mod. Z 20 LER and Z 20 LEH at TDC of the compression stroke do the following.

Remove the air filter (see “Removing and installing the air filter and air duct”).

Remove the bolts securing the front cover of the timing mechanism and remove the cover (see “Replacing the timing belt for engines Z 16 XER, Z 14 XEP, Z 18 XER, Z 20 LER, Z 20 LEH”).

Marks 1 (Fig. 7) on the toothed pulleys of the intake and exhaust camshafts should be located in a vertical plane and aligned with the marks on the rear cover of the timing belt, and the rectangular mark on the front cover of the engine should match the line on the accessory drive pulley.

2 Stroke Cylinder Install Onto Piston How To Vittorazi Moster 185

Install the removed parts in the reverse order of removal.

INSTALLING THE FIRST CYLINDER PISTON IN THE POSITION TDC OF THE COMPRESSION STATE

INSTALLING THE FIRST CYLINDER PISTON IN THE POSITION TDC OF THE COMPRESSION STATE

In order to ensure that the valve timing is not disturbed during the work related to the removal of the camshaft drive belt, the piston of the 1st cylinder is set to the TDC (top dead center) position of the compression stroke. If the valve timing is violated, the engine will not work normally.

Set the TDC according to the mark on the camshaft pulley (when installing according to the marks on the flywheel or the crankshaft pulley, the piston of either the 1st or 4th cylinder may be in this position). After that, be sure to make sure that the marks on the flywheel or on the crankshaft toothed pulley match (if the generator drive pulley is removed). If the marks on the flywheel or the crankshaft pulley do not match, then the valve timing is broken (the piston of the 1st cylinder is not set at TDC).

In this case, it is necessary to remove the camshaft drive belt and turn the crankshaft until the marks are aligned.

Turn the crankshaft only by the bolt attaching the pulley to it (do not turn the crankshaft by the camshaft pulley).

Since it is inconvenient to turn the crankshaft by the bolt attaching the pulley to it, you can do this in the following ways:

Include any gear (preferably IV) and slowly roll the car until the mark on the camshaft pulley matches the mark on the rear cover of the camshaft drive belt.

Shift into any gear and hang out one of the front wheels. Then turn the suspended wheel until the mark on the camshaft pulley matches the mark on the rear cover of the camshaft drive belt.

TDC marks are applied to the camshaft toothed pulley (protrusion) and on the rear cover of the camshaft drive belt (tendril).

In addition, marks are made on the flywheel (risk) and on the scale of the rear cover of the clutch housing (triangle cut). For clarity, the gearbox is removed.

Additionally, marks are applied to the crankshaft toothed pulley (dot) and the oil pump cover (triangle cut).

insert, piston, trimmer, cylinder

These marks are visible only when the alternator drive pulley is removed.

You will need: box wrench “17”, socket wrench “10”.

Disconnect the wire from the negative terminal of the storage battery.

Place the gear shift lever in neutral, place chocks under the wheels of the car.

Remove the right front wheel and the right mudguard in the engine compartment.

Open the hood and remove the three screws securing the front camshaft belt cover. Please note: the screws on the side fixing the cover also secure the wire holders. Remove the front cover.

Turn the crankshaft by the bolt securing the alternator drive pulley to it until the marks on the camshaft pulley and the rear cover match.

Remove the plug from the hole in the clutch housing and check the alignment of the marks on the flywheel.

Opel Astra H (Family) / Manual

Top dead center (TDC) for piston # 1. setting

1 The movement of the piston from the bottom to the top position is called the piston stroke. Top dead center. the point of the highest position occupied by the piston when the crankshaft rotates. Since the piston reaches its highest position twice in a working cycle (once at the end of the compression stroke and again at the end of the exhaust stroke), the TDC is usually taken as the highest position of the piston at the end of the compression stroke.

2 Installing the piston at TDC is the basic procedure for many operations, such as adjusting the clearance in the valve drive mechanism, replacing the timing chain and camshaft / crankshaft sprockets.

3 Before starting this procedure, place the transmission lever (selector) in neutral and apply the parking brake (or wedge the rear wheels). Disconnect the ignition system by disconnecting the primary circuit connectors from the ignition coil / ignition module (see chapter 5). Also relieve the pressure in the fuel system (see chapter 4A, paragraph 12).

4 To set any piston to TDC, the crankshaft should only be turned clockwise (when viewed from the timing chain side). This can be done in one of the following ways:

a) Preferred method. The crankshaft is turned with a head with a crank (“ratchet”) for the crankshaft pulley speckle bolt.

b) You can ask the assistant to turn the starter with short turns of the starter (the key is in the ignition lock). For accurate installation of the crankshaft, you still need a head with a crank. Make sure that the assistant has already left the car by removing the ignition key from the lock.

5 Remove the candles and install the compression gauge in the spark plug hole of the first cylinder (see.Fig.3.5)

(it is preferable to use a device with a threaded tip and a flexible hose fifteen centimeters long).

6 Rotate the crankshaft clockwise until the pressure gauge needle starts to rise, indicating a compression stroke.

7 After the compression stroke has begun, the piston of cylinder No. 1 must be set to the highest position, which will correspond to its TDC.

8 Continue to crank the crankshaft until the mark on the crankshaft damper coincides with the number “O” (TDC) on the timing cover (see Fig. 3.8).

At this point, the piston of cylinder is at TDC on the compression stroke. If the marks coincide, but there is no compression, then this means that the piston is at TDC of the exhaust stroke. Rotate the crankshaft one more full (360 °) revolution.

Note. If a compression gauge is not available, you can insert a blunt object into the plug hole and then, as the crankshaft cranks, determine the start of the compression stroke by the hiss of the exhaust air. The rest of the procedure is identical to the above.

9 After piston is set to TDC on the compression stroke, the remaining pistons can be set to the same position alternately by turning the crankshaft 180 ° each time, in accordance with the firing order (see Specifications). For example, turning the crankshaft by 1 80 ° (from TDC of the piston of cylinder No. 1), TDC of the compression stroke will take the piston of cylinder No. 3.

See TDC TDC and BDC in an internal combustion engine