Marine Engines Or Parts of Internal Combustion Engine

Here i am sharing the simple marine engine; 9 hp; for small ship:

Marine engine and its parts ( please enlarge to view clearly)

Description of important parts:

1. Cylinder head: In an internal combustion engine, the cylinder head (often informally abbreviated to just head) sits above the cylinders on top of the cylinder block. It closes in the top of the cylinder, forming the combustion chamber. This joint is sealed by a head gasket. In most engines, the head also provides space for the passages that feed air and fuel to the cylinder, and that allow the exhaust to escape. The head can also be a place to mount the valves, spark plugs, and fuel injectors.
2. Intake valve & Exhaust valve: The valves through which fresh fuel enters into the combustion chamber is called intake valve and valve through which residual gases leave are called exhaust valve. These valves are controlled by CAM shaft.
3. Valve rocker arm: Generally referred to within the context of the internal combustion engine of automotive, marine, motorcycle and reciprocating aviation engines, the rocker arm is an oscillating lever that conveys radial movement from the cam lobe into linear movement at the poppet valve to open it.
4. Pre-combustion chamber: This chamber is located at the cylinder head and is connected to the engine cylinder by small holes. It occupies 40% of the total cylinder volume. During the compression stroke, air from the main cylinder enters the pre-combustion chamber. At this moment, fuel is injected into the pre-combustion chamber and combustion begins. Pressure increases and the fuel droplets are forced through the small holes into the main cylinder, resulting in a very good mix of the fuel and air. The bulk of the combustion actually takes place in the main cylinder. This type of combustion chamber has multi-fuel capability because the temperature of the pre-chamber vaporizes the fuel before the main combustion event occurs.
5. Intake Silencer: It serves the purpose of silencing the air intake in engine.
6. Mixing Elbow:  Its function is to cool the engine exhaust gases by mixing them with the cooling water discharged from the engine heat ex-changer  It requires no regular maintenance, but neither should it be completely forgotten. Over time, the exhaust mixer elbow can become restricted with accumulated soot from the engine exhaust, resulting in increased exhaust gas back pressure and loss of engine power.
7. Camshaft: A camshaft is a shaft to which a cam is fastened or of which a cam forms an integral part.
8. Tappet: A tappet is a projection which imparts a linear motion to some other component within a mechanism.
9. Pushrod: An overhead (OHV) engine, also informally called pushrod engine or I-head engine, is a type of piston engine that places the camshaft within the cylinder block (usually beside and slightly above the crankshaft in a straight engine or directly above the crankshaft in the V of a V engine), and uses pushrods or rods to actuate rocker arms above the cylinder head to actuate the valves.
10. Piston:  In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. 
11. Connecting rod: In a reciprocating piston engine, the connecting rod or conrod connects the piston to the crank or crankshaft. Together with the crank, they form a simple mechanism that converts reciprocating motion into rotating motion.
12. Crankshaft: The crankshaft, sometimes abbreviated to crank, is the part of an engine that translates reciprocating linear piston motion into rotation. To convert the reciprocating motion into rotation, the crankshaft has "crank throws" or "crankpins", additional bearing surfaces whose axis is offset from that of the crank, to which the "big ends" of the connecting rods from each cylinder attach.
13. Flywheel: A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels have a significant moment of inertia and thus resist changes in rotational speed. The amount of energy stored in a flywheel is proportional to the square of its rotational speed. Energy is transferred to a flywheel by applying torque to it, thereby increasing its rotational speed, and hence its stored energy. Conversely, a flywheel releases stored energy by applying torque to a mechanical load, thereby decreasing its rotational speed.