18115-ZY3-003 Honda GASKET, R. EX. MANIFOLD (Honda Code 6990691).

Illustration 1 g01356032
Air inlet and Exhaust System
(1) Exhaust Manifold
(2) Injector
(3) Glow Plug
(4) Intake Manifold
(5) Aftercooler core
(6) Exhaust Outlet
(7) Turbine side of Turbocharger
(8) Compressor side of Turbocharger
(9) Air Intake from the Air Cleaner
(10) Inlet Valve
(11) Engine Cylinder
(12) Exhaust ValveThe components of the air inlet and exhaust system control the quality of air and the amount of air that is available for combustion. The air inlet and exhaust system consists of the following components:
Air Cleaner
Turbocharger
Aftercooler
Inlet Manifold
Cylinder Head, Injectors, and Glow Plugs
Valves and Valve System Components
Piston and Cylinder
Exhaust ManifoldA turbocharger increases the temperature and the density of the air that is sent to the engine cylinder. This condition causes a lower temperature of ignition to develop earlier in the compression stroke. The compression stroke is also timed in a more accurate way with the fuel injection. Surplus air lowers the temperature of combustion. This surplus air also provides internal cooling.Air is drawn in through the air cleaner into the air intake of the turbocharger (9) by the turbocharger compressor wheel (8). The air is compressed and heated to about 160° C (185° F) before the air is forced to the aftercooler (5). As the air flows through the aftercooler, the temperature of the compressed air lowers to about 35° C (60° F). Cooling of the intake air increases combustion efficiency. Increased combustion efficiency helps achieve the following benefits:
Lower fuel consumption
Increased horsepower output
Increased engine torque
Increased durability of the engineFrom the aftercooler, air is forced into the intake manifold (4). Air flow from the intake manifold to the cylinders is controlled by inlet valves (10). There are two inlet valves and two exhaust valves for each cylinder. The inlet valves open when the piston moves down on the intake stroke. When the inlet valves open, cooled compressed air from the intake port is forced into the cylinder. The complete cycle consists of four strokes:
Induction
Compression
Power
ExhaustOn the compression stroke, the piston moves back up the cylinder and the inlet valve (10) closes. The cool compressed air is compressed further. This additional compression generates more heat.Note: If the cold starting system is operating, the glow plugs (3) will also heat the air in the cylinder.Just before the piston reaches the Top Center (TC) position, fuel is injected into the cylinder. The air/fuel mixture ignites. The ignition of the gases initiates the power stroke. Both the inlet and the exhaust valves are closed and the expanding gases force the piston downward toward the Bottom Center (BC) position .From the BC position, the piston moves upward. This initiates the exhaust stroke. The exhaust valve (12) opens. The exhaust gases are forced through the open exhaust valve into the exhaust manifold (1).Exhaust gases from exhaust manifold (1) enter the turbine side (7) of the turbocharger in order to turn turbocharger turbine wheel. The turbine wheel is connected to the shaft that drives the compressor wheel. Exhaust gases from the turbocharger pass through exhaust outlet (6).Turbocharger
Illustration 2 g03823382
Typical Example
(1) Air Inlet
(2) Exhaust Outlet
(3) Exhaust Inlet
(4) Compressor Housing
(5) Compressor Wheel
(6) Bearing
(7) Oil Inlet Port
(8) Bearing
(9) Water-Cooled Turbine
(10) Turbine Wheel
(11) Oil Outlet PortAll of the air that enters the engine passes through the turbocharger. All of the exhaust gases from the engine pass through the turbocharger.The exhaust gases enter water-cooled turbine housing (9) through exhaust inlet (3). The housing of the turbochargers turbine is water cooled. This prevents the heat of the exhaust gases from radiating into the environment that surrounds the engine. The exhaust gas pushes the blades of the turbine wheel (10). The turbine wheel is connected by a shaft to the compressor wheel (5).Air that passes through the air filters enters the compressor housing air inlet (1) by the rotation of compressor wheel (5). The compressor wheel causes the inlet air to be pushed into the inlet side of the engine. Boost pressure is caused when the compressor wheel pushes more air into the inlet side of the engine. This results in a positive inlet manifold pressure that exceeds atmospheric pressure. This allows the engine to burn more fuel. When the engine burns more fuel, the engine produces more power.When the throttle is opened, more fuel is injected into the cylinders. The combustion of this additional fuel produces greater exhaust temperature. The additional exhaust temperature causes 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.Bearings (6) and (8) for the turbocharger use engine oil under pressure for lubrication and cooling. The oil comes in through oil inlet port (7). The oil then goes through passages in the center section in order to lubricate the bearings. This oil also cools the bearings. Oil from the turbocharger goes out through oil outlet port (11) in the bottom of the center section. The oil then goes back to the engine oil pan.Crankcase Breather
The engine crankcase breather is a filtered system. The crankcase breather system consists of two main elements, a primary separator in the valve mechanism cover and a filtered canister that is mounted on the side of the engine. The gases exit the engine through the valve mechanism cover. The gases then pass through the primary separator. The primary separator removes most of the liquid oil from the gas. The liquid oil is then returned to the engine.The gas then passes through the filter element before exiting to atmosphere in an open breather system or back to the induction system in a closed breather system via the breather vent pipe.Any liquid oil that is captured by the filter drains from the bottom of the canister. The liquid oil is returned by the drain pipe that runs from the bottom of the canister back to the crankcase. A valve connects the drain pipe to the crankcase. This valve prevents the bypass of gas past the filter and oil from passing up the drain pipe.A pressure relief