Crankcase
The cylinder block is made of aluminum alloy by precision sand casting and has cast iron cylinder liners. Each of the main bearing caps, made of a composite copper-steel compound, has six bolts that attach to the cylinder block. Along with two outer and two inner bolts, two side bolts are used. To prevent foaming, oil return from the valve train and cylinder head is through channels remote from the rotating and reciprocating components built into the walls of the cylinder block and cylinder head. Piston oil nozzles are installed between two opposite cylinders. The knock sensor is located on both sides of the outside of the cylinder block.
Crankshaft
The crankshaft with four bearing journals is made of forged steel. The axial play of the crankshaft is regulated by bearings of the third main journal. The crankshaft position sensor pulse disk is pressed onto the rear of the crankshaft in front of the rear main journal. The crankshaft is balanced. An oil pump drive is located in front of the crankshaft, built in front of the front main journal.
Pistons and connecting rods
The connecting rods are made from forged steel and feature fully floating piston pins. Piston pins are freely installed in the bronze bushings of the upper heads of the connecting rods. Wire circlips are used to secure the piston pin in the piston. The aluminum alloy pistons have a polymer skirt coating to reduce friction. The pistons use two compression piston rings with reduced expanding properties, as well as one composite oil scraper ring. The top compression ring is plasma sprayed. The second compression ring is made of cast iron «non-pyr». The oil scraper piston ring consists of a steel expansion ring and two chrome-plated oil scraper discs.
Timing gear drive
The timing gear has a primary drive chain driven from the crankshaft sprocket. The primary chain drives two intermediate sprockets. Mounted on pressure lubricated axles, these sprockets each drive two separate secondary drive chains. The secondary circuits drive the intake and exhaust camshaft shifters for each bank of cylinders. The primary chain drive uses two fixed dampers and a hydraulic tensioner built into the guide shoe. The tensioner minimizes chain drive noise and ensures accurate valve actuation by eliminating drive chain slack due to natural wear. The tensioner includes a plunger with a minimum amount of play, which ensures the elimination of slack in the chain. The tensioner is equipped with an oil jet to spray oil onto the timing drive components while the engine is running. In the secondary chain drives, one stationary damper and one movable guide shoe are used. The guide shoe provides tension to the secondary chain under the action of a hydraulic tensioner. All tensioners are sealed at the connection to the cylinder block or head with a rubber coated steel gasket. Gasket catchers have sufficient oil supply to ensure a quiet engine start.
Camshaft phase shifters
The engine is equipped with phase shifters for each intake and exhaust camshafts. The phases of the intake and exhaust camshafts can vary in the range of 25°depending on changes in the operating mode of the engine. Camshaft timing optimizes performance, improves fuel efficiency and reduces emissions without compromising overall engine performance. Variable valve timing also helps reduce exhaust emissions by optimizing intake and exhaust valve overlap.
The camshaft phase shifters are hydraulic, vane type. They change the position of the cams relative to the camshaft drive sprocket. Engine oil is supplied to the appropriate ports of the phase shifter through the solenoid valve. Oil, acting on the phase shifter blades, rotates the camshaft relative to the sprocket. At idle, both camshafts are in the original or «home» position. In this case, the exhaust camshaft is in the position of maximum advance, and the intake camshaft is in the position of maximum delay, to ensure minimal valve overlap for stable rotation at idle. The inner locking pin locks the inner rotor against the outer housing of the phase shifter at idle and during engine start. Under other engine operating conditions, the camshaft shifters are controlled by the engine's ECM to ensure optimal intake and exhaust timing, and as a result, improve engine performance and fuel efficiency.
The camshaft phase shifter includes a built-in camshaft position sensor pulse disk installed in the front cover and necessary to determine the phases of each of the camshafts. Each phase shifter has a specific mark corresponding to the right or left row of cylinders. The internal design of the exhaust camshaft phase shifter differs from that of the intake phase shifter because the intake phases change in the opposite direction to the exhaust phases.
Oil control valves (OCV) The phase shifters direct oil from a channel in the cylinder head to the corresponding port of the phase shifter. There is one control valve for each phase shifter. The OCV valves are hermetically sealed on the front cover of the engine. The valve inlet is slip-fit into the cylinder head. A strainer protects each port of the OCV valve from contaminants that may be present in the incoming oil. The front camshaft journal has several oil holes to supply control oil from the cylinder head to the phase shifter. The camshaft center bolt hole is bored in such a way that oil flows around the bolt and is directed to the phase shifter. The oil in this channel is supplied to move the phase shifter to its original or «homemade» position. Radially outward from the center of the neck, four oil channels diverge. Oil in this group of holes is supplied to move the phase shifter from its original position to a certain position set by the electronic engine control unit. O-rings are used at the front and rear of the front camshaft journal to prevent oil leakage from the phase shifter system. The seal is made of a plastic compound that resists wear well and has a diagonal tear to improve sealing. The phase shifter is mounted on the front of the camshaft, with the groove on the camshaft aligned with the dowel pin in the phase shifter to ensure proper alignment.
Cylinder heads
Cylinder heads are made from aluminum alloy by casting in semi-permanent moulds. They have plug-in guide bushings and cermet valve seats. Two 35 mm inlet and two 30 mm exhaust valves are driven by roller rockers mounted on stationary hydraulic lifters. Separate intake and exhaust camshafts are mounted on four main bearings in the cylinder block. The front camshaft bearing cover is also used as a thrust surface for the entire camshaft. All spark plugs are shielded by tubes pressed into the cylinder head. Ignition coils are also mounted on these tubes. The coolant temperature sensor is screwed into the left cylinder head.
The right and left cylinder heads are identified by the sides of the engine as seen from the rear.
Turbocharger
The turbocharger consists of a turbine and a compressor placed on a common shaft. The shaft bearings are designed for high speeds and are lubricated with engine oil.
The turbocharger is water-cooled for increased durability of the unit.
The turbine wheel is driven by the flow of exhaust gases. The compressor wheel compresses the intake air, forcing it into the combustion chambers. bypass valve (Wastegate) regulates boost pressure to generate high pressure even at low speeds. At a certain boost pressure, it provides a path for the exhaust gases to bypass the turbine wheel. The bypass valve is controlled by pneumatic and electric actuators depending on the pressure in the intake manifold. The exhaust gas flow pressure is reduced by opening the bypass valve, thus lowering the intake pressure.
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