How to Overhaul a Diesel Engine
Let us first define some term about the engine:
1] Engine block or cylinder block – is consider the ” backbone ” of the engine to which all other parts are bolted or attached. Some Car manufacturers mass produced engine blocks but some made it one at a time for special cases. They used compacted sand and resin or sand cast to be it’s mold. They put a thin amount of carbon ( by torch ) that acts as a lubricant so that the molten metal will flow smoothly to the spaces of the sand cast. The raw molten metal is heated about 1300 deg. F before it will be poured in to the cast. After some time it will become a super strong aluminum alloy. They used powerful x-ray to scan the engine block to see if there is any microscopic cracks or floss in the metal. Slight vibration from a defect in the engine will be magnified at high speed and the engine could fail.
2] Cylinder Head and valve – It provides a passageway that allows air into the cylinder and allows the exhaust gases to pass-out. These parts opened and closed by puppet type valves, that fits into the guide in the cylinder.
3] Crankshaft – a long shaft inserted in the bottom of the block with offset crankpin
4] Cylinder Sleeve Liner – most diesel engine use a replaceable cylinder sleeve so that it can be replaced easily. There are these linerless type in which the cylinder block itself is machined in the engine block like in the picture.
5] Piston rings - a semi keystone ring is used for no 1 compression ring and a tapered ring or tapered under-cut ring is used for no. 2 compression ring, but a solid ring with coil or a three- piece ring is usually used for the oil ring.
6] Rocker Arm and Push Rod – it transmit the cam action of the crank shaft to the engine valves causes them to close or to open.
- 7] Oil pan - it is the reservoir for the oil, located in the bottom cover of the engine.
8] Oil Pump – it supply oil under pressure. It draws oil from the reservoir to the oil nozzles. bearings, and other parts that needs lubrication.
9] Water Pump – this pumps water to the radiator to the engine block, oil cooler and other parts that needs cooling.
10] Oil Cooler – A device used to cool the engine oil during engine operation. Allows the coolant water and engine oil to circulate simultaneously without being mixed.
11] Fly Wheel – A heavy metal wheel bolted on to gear of the crank shaft that provide a place to mount the starter ring gear and transmission clutch.
12] Intake Manifold – Bolted on the cylinder head assembly that provides a passage way for the clean air to enter the combustion chamber.
13] Exhaust Manifold – This is where the exhaust gas exits from the chamber going to the muffler.
14] Injection pump – It injects the right amount of fuel at the right time with extreme precise and tolerances. Fuel must be injected at particular crankshaft angle before top dead center ( BTDC ) of the compression stroke of the piston. Timing belt or timing gear is used to power the pump with exact timing when to deliver the fuel in to the chamber. Fuel is injected at pressure approximately 2000 psi as it is needed for the for the hot and compressed air to ignite the mixture that creates the power to push the piston downward.
15] Starter – Used to crank the engine for start up.
16] Crank shaft – It is used to translate the reciprocating linear motion of the piston in to a rotational motion or simply to convert the reciprocating motion in to rotation.
17] Camshaft – It transmit the cam action of the crankshaft for the valves to open and close in the right time as needed. The relationship of camshaft and crankshaft is very important to an engine. The valves control the flow of air intake and exhaust gasses. For this purpose camshaft is connected to crankshaft either directly by a timing gear, by a timing belt or by a timing chain. Depending on the position of the camshaft, the cams operate the valves directly or by the use of a push rod and rocker arm. Direct operation of the cam to the valve is much simpler valve mechanism. It leads to fewer parts needed and which means fewer mechanism to fail. It will require that the camshaft is to be positioned at the top of the cylinder.