MAST G BASIC 3C4819 - Caterpillar

Turbocharger
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(1) Compressor housing (2) Oil inlet port (3) Bearing (4) Turbine housing (5) Turbine wheel (6) Air inlet (7) Exhaust outlet (8) Compressor wheel (9) Bearing (10) Oil outlet port (11) Exhaust inletThe two turbochargers work together in order to produce boost across the entire engine RPM range. The increased boost at low RPM fills the combustion chamber with dense air. The dense air mixes with the fuel in order to promote a complete combustion.The turbochargers have a compressor wheel (8) and a turbine wheel (5) . The compressor wheel and the turbine wheel are connected to a common shaft. The shaft is supported by bearings (3 & 9) . The bearings are lubricated by pressurized engine oil. The oil enters through oil inlet port (2) . The engine oil lubricates the bearings and the oil removes heat. The oil returns to the oil pan through oil outlet port (10) .The high pressure turbocharger is equipped with a wastegate which is actuated by the boost from the low pressure turbocharger. The wastegate controls boost pressure. The wastegate is controlled by the pressure against the diaphragm in the canister for the wastegate. The canister consists of a spring and a diaphragm. The boost pressure creates a force against the diaphragm. The pressure against the diaphragm causes the diaphragm to move. The actuating lever is connected to the diaphragm. The movement of the actuating lever controls the position of the wastegate. The movement of the wastegate allows exhaust gases to bypass the turbine wheel. When the exhaust bypasses the turbine wheel the rotation of the compressor wheel slows down. Boost level is determined by the RPM of the compressor wheel.Valve System Components
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(1) Rocker arm (2) Pushrod (3) Valve bridge (4) Valve spring (5) Valve (6) LifterThe valve system components control the flow of inlet air into the cylinders and out of the cylinders during engine operation. The valve mechanism also operates the fuel injector.The camshaft must be timed to the crankshaft in order to get the correct relation between the piston movement and the valve movement.The camshaft has two camshaft lobes for each cylinder. The lobes operate the inlet and exhaust valves. As the camshaft turns, lobes on the camshaft cause lifters (6) to move pushrods (2) up and down. Upward movement of the pushrods against rocker arms (1) results in downward movement (opening) of valves (5) .Each cylinder has two inlet valves and two exhaust valves. The valves are actuated at the same time by a valve bridge (3) . Valve springs (4) close the valves when the lifters move down.Variable Valve Actuator
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Do not disassemble the Variable Valve Actuator. There are no components of the Variable Valve Actuator that are serviceable. If the Variable Valve Actuator is disassembled, the warranty will be void.
The variable valve actuator and the Cat compression brake use engine oil for operation. Variable Valve Actuator
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The variable valve actuator is used to control the closing of the inlet valves. The variable valve