The pistons and connecting rods

Removing the connecting rod and piston in the following sequence:

- Remove the cylinder head (see. Sect. 3.1.6), the oil pan (see. Sect. 3.1.10) and the oil pump (see. Sect. 3.1.12);

- Install the piston cylinder ?��1 in the bottom dead center (BDC) by turning the crankshaft. Put a mark on the connecting rod bearing caps and connecting rods for subsequent proper installation;

- Unscrew nuts 12 (Fig. 3.31) fastenings of a cover of a rod and remove the cover 11;

- Check the presence of the finger making the upper part of the cylinder wall;

- Vytolkinite wooden handle hammer piston 7 with a rod assembly 10;

- Replace the cover 11 of the connecting rod on a rod and tighten the nut securing the connecting rod cap 12;

- Remove the piston from the connecting rod assembly remaining cylinders;

- Put labels of mutual position of pistons and rods. The tides on the connecting rod cap and the assembly should be directed to the front of the engine;

- Remove the locking ring 8 of the grooves in the holes of the piston, push the piston pin 4 and remove the connecting rod 10.

Cleaning and Troubleshooting pistons and rods. Carefully clean the pistons with rods from the oil. Remove the piston rings 5 and 6 (see. Fig. 3.31) pliers. For removal, you can use the old probe. To do this, move the piston ring to the top of the piston, lift one of its edges, insert a probe and a probe slowly circle around the piston. When the ring out of its groove, lift it up.

Clean the pistons of a deposit. Clean piston ring grooves for a fragment of an old piston ring. Clean pistons and rods in gasoline or kerosene, wipe them dry.

Carefully inspect each piston. When there are cracks on the skirt or around the piston pin hole the piston must be replaced. Measure the diameter of the piston skirt micrometer at a distance of 10 mm from its lower edge in a plane perpendicular to the axis of the piston pin hole (Fig. 3.32). The values of the diameter of the pistons are shown in Section. 3.1.1. Rapid wear of the piston skirts may be caused by overheating of the motor. In this case it is necessary to check the cooling and lubrication systems.

Carbon deposits on the side surfaces of the pistons indicates the breakthrough gas into the crankcase. Burnout piston crown or burning the edges indicate that the combustion occurred with knocking, which was the result of improper installation of the ignition timing.

Pitting of the piston causes the penetration of coolant into the cylinder as a result of the breakdown of the cylinder head gasket.

Building and installing connecting rod and piston in the following sequence:

- Heat the piston 7 (see. Fig. 3.31) in hot water (50-80 ?� C); Set in the piston rod 10; check that the tide on a rod and arrow on the piston in one direction; Install the piston pin 4 and set locking ring 8;

- Check the side clearance between the ring and the piston groove (Fig. 3.33). If the clearance is not correct (see. Sect. 3.1.1), the ring or the piston must be replaced;

- Check the clearance in the piston ring. For this insert ring in a cylinder and drowning it down to 15 mm using a piston. Measure the clearance probe. If the gap is greater than the required (see. Sect. 3.1.1), the ring should be replaced. If the gap is less than that required in the castle, you can sawdust ring ends with a file, hamstrung as shown in Fig. 3.34;

- Install new piston rings 5 and 6 (see. Fig. 3.31) on the pistons 7 with a special puller. When installing the inscription "TOP" on the ring should be directed to the bottom of the piston. Rings can be installed with a feeler gauge, and the installation will start from the lower oil scraper ring;

- Set 2 inserts into the rod 10 and the rod cover 11 so that the projections inserts into the slots of the connecting rod and cap;

- Rotate the crankshaft in a position corresponding to the BDC Piston number 1;

- Turn on the piston ring so that their locks are at an angle of 120 ?� to each other;

- Lubricate with fresh engine oil number 1 cylinder wall, the piston defined accordingly piston rings, connecting rod bearing shells 2 and the corresponding crank pin of the crankshaft;

- Set the piston into the cylinder using a wooden hammer handle, compressing the piston rings special device (Fig. 3.35). The arrow on the piston to be directed towards the front of the engine;

- Replace the cover 11 (see. Fig. 3.31) in accordance with the marks on her, and the connecting rod, tighten the nuts securing the cover 12 to 30 N ?� m, then tighten the nut to 90 ?�;

- Define the axial play of the bottom head of a rod with a feeler gauge (see. Sect. 3.1.1);

- Cranked shaft and check the smooth running of the piston set;

- Install the remaining pistons with rods;

- Install the oil pump (see. Sect. 3.1.12), the oil pan (see. Sect. 3.1.10) and the cylinder head (see. Sect. 3.1.6).