ENGINE

a machine with moving parts that converts power into motion.

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ENGINE BLOCK

This is the very core of the engine. Often made of aluminum or iron, it has several holes to contain the cylinders as well as provide water and oil flow paths to cool and lubricate the engine. Essentially, it is the chassis of the engine, it provided the framework and structure. The engine block also houses the pistons, crankshaft, camshaft, and between four and twelve cylinders—depending on the vehicle, in a line, also known as inline, flat or in the shape of a V or a W. The main purpose of the engine block is to support the components of the engine. Additionally, the engine block transfers heat from friction to the atmosphere and engine coolant. The material selected for the engine block is either gray cast iron or aluminum alloy. The engine block can cause many problems due to bad driving or a driving accident, like external engine coolant leak, a worn/cracked cylinder and a porous engine block.

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PISTONS

Pistons are at the very heart of the reciprocating internal combustion engine, which is why they are often called a "piston engine". At its most basic, the piston is simply a solid cylinder of metal, which moves up and down in the hollow cylinder of the engine block.  The role of the piston is to transfer energy created from combustion to the crankshaft to propel the vehicle. Pistons travel up and down within the cylinder twice during each rotation of the crankshaft. Pistons on engines that rotate at 1250 RPM, will travel up and down 2500 times per minute. Inside the piston, lie piston rings that are made to help create compression and reduce the friction from the constant rubbing of the cylinder. 

Basically, the pistons combust small pits of fuel that are injected into the chamber. The fuel then explodes creating a lot of energy that powers the car. Pistons can create hundreds of small explosions a second.

CRANKSHAFT AND CAMSHAFT

A camshaft uses egg-shaped “cams” to open and close engine valves, while a crankshaft converts “cranks” to rotational motion.

Camshafts and crankshafts perform separate functions, but must work together in a well-choreographed sequence for your engine to operate smoothly. However, they are and look very similar. The crankshaft is located in the lower section of the engine block, within the crankshaft journals. Varying from vehicle to vehicle, the camshaft may either be located within the engine block or in the cylinder heads. Many modern vehicles have them in the cylinder heads, also known as Dual Overhead Camshaft (DOHC) or Single Overhead Camshaft (SOHC) and supported by a sequence of bearings that are lubricated in oil for durability. 

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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. Visually, it looks really similar to the engine, just smaller and more compact. Attached to the engine through cylinder bolts, sealed with the head gasket. The cylinder head contains many items including the valve springs, valves, lifters, push rods, rockers, and camshafts to control passageways that allow flow of intake air into the cylinders during the intake stroke as well as exhaust passages that remove exhaust gases during the exhaust stroke.

There are a few types of cylinder heads: flat head cylinder heads, overhead valve cylinder heads and overhead camshaft cylinder heads. 

The most common problem with cylinder heads is cracks that occur often due to engine overheating. A cracked cylinder head may leak the coolant, due to which the engine will fail to cool efficiently. Luckily, replacement cylinder heads are very common.

TIMING BELT/CHAIN

The camshaft and crankshafts are synchronized to ensure the precise timing in order for the engine to run properly. The belt is made of a heavy-duty rubber with cogs to grasp the pulleys from the camshaft and crankshaft. The chain, similar to your bicycle chain wraps around pulleys with teeth. As the name suggests, it keeps the engine in time and synchrony so it can function smoothly. It keeps from one thing from moving faster than another. The timing belt must control all of the opening and closing of the valves and the timing of the pistons throughout each phase. The timing belt allows each step to occur in the precise order.

The timing belt is very important for an engine to run smoothly. They should be changed roughly every 100,000 kilometres of 150,000 kilometres. After that, they should definitely be changed. There is no way to find out if it is wearing out, they just break.

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