SENR9977 7 Systems Operation Section The engine has a cast iron cylinder head. The inlet manifold is integral within the cylinder head. An inlet valve and an exhaust valve for each cylinder are controlled by a pushrod valve system. The ports for the inlet valves are on the left side of the cylinder head. The ports for the exhaust valves are on the right side of the cylinder head. Fuel injection pump Lower idler gear which turns the gear of the lubricating oil pump Lip type seals are used on both the front of the crankshaft and the rear of the crankshaft. Pistons, Rings, and Connecting Rods Camshaft The engine has a single camshaft.
The camshaft is driven by an idler gear in the front housing. The camshaft uses only one bearing on the front journal. The other journals rotate in the bore of the cylinder block. The front bearing and the camshaft bores in the cylinder block support the camshaft. As the camshaft turns, the camshaft lobes move the valve system components. The valve system components move the inlet and exhaust valves in each cylinder. The camshaft gear must be timed to the crankshaft gear. The relationship between the lobes and the camshaft gear causes the valves in each cylinder to be opened and closed at the correct time.
The relationship between the lobes and the camshaft gear also causes the valves in each cylinder to close at the correct time. The pistons have a combustion chamber in the top of the piston in order to provide an efficient mix of fuel and air. The piston pin is off-center in order to reduce the noise level. The pistons have two compression rings and an oil control ring. The groove for the top ring has a hard metal insert in order to reduce wear of the groove. The skirt has a layer of graphite in order to reduce wear. The correct piston height is important in order to ensure that the piston does not contact the cylinder head.
The correct piston height also ensures the efficient combustion of fuel which is necessary in order to conform to requirements for emissions. Engines are equipped with connecting rods that have bearing caps that are fracture split. The bearing caps on fracture split connecting rods are retained with torx screws. Connecting rods with bearing caps that are fracture split have the following characteristics: i02242605 Air Inlet and Exhaust System Higher integrity for the rod The splitting produces an accurately matched surface on each side for improved strength. Modern design The connecting rod is matched to each cylinder. The piston height is controlled by the length of the connecting rod.
Six different lengths of connecting rods are available in order to attain the correct piston height. The different lengths of connecting rods are made by machining the small end bearing off-center in order to form an eccentric bearing. The amount of the eccentricity of the bearing creates the different lengths of the connecting rods.
g01130516 Illustration 4 Air inlet and exhaust system (typical example) (1) Exhaust outlet (2) Turbocharger turbine wheel (3) Turbocharger compressor wheel (4) Air intake (5) Aftercooler (6) Intake manifold (7) Engine cylinders (8) Exhaust manifold Crankshaft The crankshaft changes the linear energy of the pistons and connecting rods into rotary torque in order to power external equipment. A gear at the front of the crankshaft drives the timing gears. The crankshaft gear turns the idler gear which then turns the following gears: Camshaft gear