55459A 2 Mercury RETAINER ASSEMBLY, TOP COWL

Illustration 1 g00692826
Air Inlet And Exhaust System Schematic
(1) Aftercooler (aftercooled engines)
(2) Air inlet manifold
(3) Exhaust manifold
(4) Exhaust outlet
(5) Turbocharger
(6) Air inlet
(7) Air cleaner The components of the air inlet and exhaust system control the quality of the air that is available for combustion. These components also control the amount of the air that is available for combustion. The components of the air inlet and exhaust system are listed below:
Air cleaner
Turbocharger
Aftercooler (aftercooled engines)
Cylinder head
Valves and valve system components
Piston and cylinder
Exhaust manifold
Illustration 2 g00693191
Air Inlet And Exhaust System
(1) Aftercooler (aftercooled engines)
(3) Exhaust manifold
(4) Exhaust outlet
(6) Air inlet
(8) Exhaust valve
(9) Inlet valve
(10) Compressor wheel
(11) Turbine wheel Inlet air is pulled through air cleaner (7). The inlet air is then compressed and heated by the compressor wheel of turbocharger (5) to about 150°C (300°F). The inlet air is then pushed through one of the following components: air-to-air aftercooled (ATAAC), jacket water aftercooled (JWAC) and air inlet cover. The inlet air is forced to air inlet manifold (2). The temperature of the inlet air at the air inlet manifold is about 43°C (110°F). Cooling of the inlet air increases the combustion efficiency. Increased combustion efficiency helps to lower fuel consumption. Also, increased combustion efficiency helps to increase horsepower output.The air to air aftercooled (ATAAC) system incorporates a separate air to air aftercooler core. This core is installed in front of the radiator of the engine or the core is installed beside the radiator of the engine. Air that is ambient temperature is moved across the aftercooler core by the engine fan and by the ram effect of the vehicle's forward motion. This cools the turbocharged inlet air.The jacket water aftercooled (JWAC) system uses engine coolant from the water pump in order to cool the hot turbocharged air. The JWAC system incorporates a water-to-air system that is mounted to the air inlet manifold.Inlet manifold (2) is a one-piece casting that also serves as a base for the valve cover. From the inlet manifold, the air is forced into the cylinder head in order to fill the inlet ports. Air flow from the inlet port into the cylinder is controlled by the inlet valves.There is one inlet valve (9) and one exhaust valve (8) for each cylinder. The inlet valve opens when the piston moves down on the inlet stroke. When the inlet valve opens, cooled compressed air from the inlet port is pulled into the cylinder. The inlet valve closes and the piston begins to move up on the compression stroke. The air in the cylinder is compressed. When the piston is near the top of the compression stroke, fuel is injected into the cylinder. The fuel mixes with the air and combustion starts. During the power stroke, the combustion force pushes the piston downward. After the power stroke is complete, the piston moves upward. This upward movement is the exhaust stroke. During the exhaust stroke, the exhaust valve opens, and the exhaust gases are pushed through the exhaust port into exhaust manifold (3). After the piston completes the exhaust stroke, the exhaust valve closes and the cycle starts again. The complete cycle consists of four stages:
inlet stroke
compression stroke
power stroke
exhaust strokeExhaust gases from exhaust manifold (3) enter turbine side of turbocharger (5) in order to turn the turbine wheel (11). The turbine wheel is connected to a shaft which drives the compressor wheel (10). Exhaust gases from the turbocharger pass through the exhaust outlet pipe, the muffler and the exhaust stack.Turbocharger
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Turbocharger
(1) Air inlet
(2) Compressor housing
(3) Compressor wheel
(4) Bearing
(5) Oil Inlet port
(6) Bearing
(7) Turbine housing
(8) Turbine wheel
(9) Exhaust outlet
(10) Oil outlet port
(11) Exhaust inlet The turbocharger is installed on the center section of the exhaust manifold. All the exhaust gases from the engine go through the turbocharger. The compressor side of the turbocharger is connected to the aftercooler by pipe.The exhaust gases go into turbine housing (7) through exhaust inlet (11). The exhaust gases then push the blades of turbine wheel (8). The turbine wheel is connected by a shaft to compressor wheel (3).Clean air from the air cleaners is pulled through compressor housing air inlet (1) by the rotation of compressor wheel (3). The action of the compressor wheel blades causes a compression of the inlet air. This compression gives the engine more power by allowing the engine to burn more air and more fuel during combustion.When the load on the engine increases, more fuel is injected into the cylinders. The combustion of this additional fuel produces more exhaust gases. The additional exhaust gases cause the turbine and the compressor wheels of the turbocharger to turn faster. As the compressor wheel turns faster, more air is forced into the cylinders. The increased flow of air gives the engine more power by allowing the engine to burn the additional fuel with greater efficiency.
Illustration 4 g00425163
Turbocharger With Waste Gate
(12) Actuating lever
(13) Canister
(14) Line (boost pressure) When the engine is operating under conditions of low boost, a spring pushes on a diaphragm in canister (13). This action moves actuating lever (12) in order to close the valve of the waste gate. Closing the valve of the waste gate allows the turbocharger to operate at maximum performance.As the boost pressure through line (14) increases against the diaphragm in canister (13), the valve of the wastegate is opened. When the valve of the wastegate is opened, the rpm of the turbocharger is limited by bypassing a portion of the exhaust gases. The exhaust gases are routed through the wastegate which bypasses the turbine wheel of the turbocharger.Note: The turbocharger with a waste gate is preset at the factory and no adjustment can be made.
Illustration 5 g00693226
Turbocharger Oil Lines
(15) Oil supply tube
(16) Oil drain tube Bearings (4) and (6) for the turbocharger use engine oil under pressure for lubrication. The oil comes in through oil supply tube (15) to oil inlet port (5). The oil then goes through passages in the center section in order to lubricate the bearings. Oil from the turbocharger goes out through oil outlet port (10) in the bottom