Pic. 5.1. Longitudinal section of the VAZ-21126 engine: 1 - oil pump; 2 – generator drive pulley; 3 - connecting rod; 4 - piston pin; 5 - timing belt drive; 6 - cover of the gas distribution mechanism; 7 - camshaft pulley; 8 - intake manifold; 9 - candle well; 10 - oil filler cap; 11 - thermostat; 12 - flywheel; 13 - nozzle for cooling the piston bottom; 14 - oil receiver; 15 - crankshaft
The VAZ-21126 engine is installed on the VAZ-2170 Lada Priora car (pic. 5.1, 5.2), created on the basis of the VAZ-2112 engine. Increase in working volume of the engine mod. 21126 up to 1.6 l compared to the displacement mod. 2112 is achieved by increasing the piston stroke with the same cylinder diameter.
Pic. 5.2. Cross section of the VAZ-21126 engine: 1 - drain plug; 2 - oil crankcase; 3 - oil filter; 4 - water pump; 5 – collector; 6 - exhaust valve; 7 - valve spring; 8 - exhaust camshaft; 9 - intake manifold; 10 – a cover of a head of the block of cylinders; 11 - intake camshaft; 12 - hydraulic valve tappet; 13 - camshaft bearing housing; 14 - fuel rail; 15 - nozzle; 16 - valve guide sleeve; 17 - inlet valve; 18 – laying of a head of the block of cylinders; 19 - compression rings; 20 - oil scraper ring; 21 - piston pin; 22 - connecting rod; 23 - cylinder block; 24 - connecting rod cover; 25 - oil receiver
Cylinder block cast from special high-strength cast iron, which gives the engine structure rigidity and strength.
Coolant ducts forming a cooling jacket are made along the entire height of the block, this improves the cooling of the pistons and reduces block deformation from uneven overheating. The cooling jacket is open at the top towards the block head. At the bottom of the cylinder block are five crankshaft main bearings, the covers of which are attached with bolts. The supports are equipped with thin-walled steel-aluminum liners that act as crankshaft bearings. Grooves are made in the middle support, into which thrust half rings are inserted, holding the crankshaft from axial movements.
Compared to the engine block mod. 2112 cylinder block mod. 21126 is 2.3 mm higher, the height from the axis of the main bearing beds to the upper surface of the block is 197.1 mm.
Crankshaft cast from special ductile iron. The main and connecting rod journals of the shaft are ground. To lubricate the connecting rod bearings, oil channels are drilled in the crankshaft, closed with plugs. To reduce vibration, eight counterweights are located on the crankshaft. Crank radius of the engine crankshaft mod. 21126 is 2.3 mm larger than the motor mod. 2112, due to which the piston stroke increased from 71 to 75.6 mm. To distinguish the shafts on one of the counterweights of the crankshaft of the VAZ-21126 engine, a marking is cast «11183».
At the front end of the crankshaft, an oil pump, a camshaft drive belt pulley and an alternator drive pulley with a built-in vibration damper are installed. At the rear end of the crankshaft is a cast iron flywheel. A steel toothed rim is pressed onto the flywheel.
connecting rods steel, forged, with covers on the lower heads. The connecting rod caps are made by tearing off a solid connecting rod. This achieves a higher accuracy of installing the cover on the connecting rod. Thin-walled liners are installed in the lower head of the connecting rod, and a steel-bronze bushing is pressed into the upper head.
Pistons cast from aluminum alloy. Three rings are installed on each of them: two upper compression rings and a lower oil scraper. The bottom of the pistons is flat, with four recesses for the valves, and on the pistons of the engine mod. 21126 recesses are larger than those of the 2112 engine. The pistons are oil-cooled, for which special nozzles are installed in the main bearing supports. They are tubes containing spring-loaded balls. During engine operation, the balls open holes in the tubes and a jet of oil hits the piston from below.
In the engine mod. 21126 kit applied «piston - piston rings - piston pin - connecting rod» reduced weight (the weight of the piston is reduced from 350 to 235 g, the piston pin - from 113 to 65 g, the connecting rod - from 707 to 485 g, the entire set - by 32%).
oil sump steel, stamped, bolted to the cylinder block from below.
Block head, mounted on top of the cylinder block, is cast from an aluminum alloy. Channels are cast in the lower part of the head, through which the liquid circulates, which cools the combustion chambers. At the top of the head are two camshafts: one for the intake valves, the other for the exhaust. Engine cylinder head mod. 21126 differs from head mod. 2112 with an increased area of flanges for the inlet pipeline and candle wells made in one piece with the head of the block.
Camshafts installed in supports made in the upper part of the block head, and in one common bearing housing, bolted to the block head. The camshafts are cast iron. The camshaft pulleys of the 21126 engine differ from the pulleys of the 2112 engine by 2°offset marks for setting the valve timing.
To reduce wear, the working surfaces of the cams and the surfaces under the stuffing box are heat-treated - bleached. The camshafts actuate the valves through the tappets. The 21126 engine is equipped with valve lifters that automatically compensate for valve clearances. This engine does not need to adjust the clearances in the valve mechanism during operation. The engine has four valves per cylinder: two intake and two exhaust.
Guide bushings and valve seats are pressed into the block head. The guide bushings are also equipped with retaining rings to keep them from falling out. Oil scraper caps are installed on the guide bushings, which reduce the ingress of oil into the cylinders.
Each valve has one spring. The camshafts are driven by a rubber toothed belt from the crankshaft.
cylinder head cover made of aluminium. The junction of the cover with the cylinder head is sealed with a gasket. The cylinder head cover of the 21126 engine differs from the 2112 cover in the absence of a platform for attaching the ignition module and the presence of holes for attaching individual ignition coils next to the candle wells.
Lubrication system engine combined: spraying and under pressure. Under pressure, main and connecting rod bearings, camshaft bearings are lubricated. The system consists of an oil sump, a gear oil pump with an oil receiver, a full-flow oil filter, an oil pressure sensor and oil channels.
Cooling system engine consists of a cooling jacket, a radiator with an electric fan, a centrifugal water pump, a thermostat, an expansion tank and hoses.
The power supply system includes an electric fuel pump installed in the fuel tank, a throttle assembly, a fuel fine filter, a fuel pressure regulator, injectors, and fuel hoses. Differences in the elements of the power supply system of the engine mod. 21126 from engine mod. 2112:
- the tubular fuel rail without fuel return is made of stainless steel instead of aluminum alloy;
- reduced size fuel injectors are not interchangeable with the previous ones;
- redesigned fuel pressure regulator installed in the fuel pump module instead of on the fuel rail;
- there is no hole in the throttle assembly connecting the air supply hose to the intake module bypassing the throttle valve. Throttle assembly flange configuration has been changed.
The power system functionally includes a fuel vapor recovery system with a carbon adsorber (see «Replacement of components of the fuel vapor recovery system»), preventing fuel vapors from escaping into the atmosphere.
Ignition system consists of individual ignition coils mounted on the cylinder head cover and spark plugs. The electronic control unit controls the ignition coils (ECU) engine. Installation of individual ignition coils instead of the engine ignition module mod. 2112 eliminated high-voltage ignition wires and improved system performance and reliability.
Crankcase ventilation system
Pic. 5.3. Engine crankcase ventilation system: 1 - intake manifold; 2 - throttle assembly; 3 - a hose of a small circuit of the ventilation system; 4 - air supply sleeve; 5 - a hose of a large circuit of the ventilation system; 6 – a cover of a head of the block of cylinders; 7 - exhaust hose; 8 - separator; 9 - separator oil deflector
engine closed, with removal of crankcase gases through separator 8 (pic. 5.3) oil separator installed in the cover 6 of the cylinder head into the intake pipe. Further crankcase gases are sent to the engine cylinders, where they burn out. When the engine is idling, crankcase gases enter through hose 3 of the small circuit through a calibrated hole (jet) in the throttle body. In this mode, a high vacuum is created in the intake pipe and crankcase gases are effectively sucked into the throttle space. The jet limits the amount of exhaust gases so that the engine is not disturbed at idle. When the engine is running under load, when the throttle is partially or fully open, the main volume of gases passes through the hose 5 of the large circuit into the air supply sleeve 4 in front of the throttle assembly and then into the intake manifold and combustion chambers.