26 10 parts of an engine you should know

10 parts of an engine you should know


By Jaon Unrau on 2018-04-18 19:58:39

Ever wondered how an engine works? It’s an incredibly intricate machine that doesn’t seem like it should operate. Petrol or diesel fuel is burned at extremely high temperatures in a confined space. Normally you’d expect it to blow apart. Instead, an engine turns combustion into a source of power.

You might be a car owner. Perhaps you’ve just obtained your provisional driving licence. Or, you could be just an enthusiast curious about how things work. Whatever the case, we’ve listed ten engine parts that you should know.

Cylinder Head

At the top of the engine is an assembly bolted firmly to the engine block. It’s called a cylinder head, fittingly so because it’s at the top. Makes sense, right?

The cylinder head serves as a gateway for a few different operations, controlled by valves precisely fitted into its cast form. The cylinder head and its parts are the pass-through for fuel entering the combustion chamber, the exit for exhaust gases after combustion, and the attachment point for fuel injectors and spark plugs in some cases.

You’ve likely heard of a cylinder head gasket, which is a layered gasket to seal the cylinder head to the engine block. It’s the most well-known fault that can happen with the cylinder head.

Crankshaft

Everything revolves around the crankshaft in the engine – literally. An engine’s main purpose is to rotate the crankshaft which harnesses and transmits the engine’s power to the transmission or transaxle. A crankshaft is fastened into the engine block almost directly through the centre.

The crankshaft is made of extremely hard steel. Its lobes are offset for each cylinder, where connecting rods attach to the crankshaft. You’d think the metal-on-metal action would grind the parts badly, but thin bearings are kept washed in engine oil to form a protective barrier on the moving parts. The crankshaft is one of the most durable parts inside the engine – you almost never hear of a crankshaft needing to be replaced.

Camshaft

A couple important parts connect to the crankshaft, and one is the camshaft. Actually, there may be more than one camshaft in the car. There’s at least one camshaft for every cylinder head, so on a V6 or V8 engine, there’s at least two. Sometimes there are two camshafts per cylinder head, known commonly as DOHC, or dual overhead cam.

Now for its purpose: camshafts open valves in the cylinder head. Intake valves allow the air-fuel mixture into the combustion chamber while exhaust valves allow burnt gases out. Lobes on the camshaft, staggered across the whole cam, time the valve openings perfectly.

Timing Belt or Chain

It’s also very important to know HOW the engine’s crankshaft and camshaft(s) work together, and that’s with a timing belt or chain. Pulleys on the camshafts and crankshaft are connected with a chain or reinforced rubber belt. The two work in tandem to keep the engine’s movements perfectly timed thanks to a timing belt/chain system.

If the timing belt or chain is off by just one tooth on the pulley, the engine will run rough or might not run at all because the combustion chambers aren’t fully sealed for their compression and combustion processes. Also, a timing chain needs to be replaced as part of routine maintenance. A timing chain should last an engine’s lifetime.

Pistons

Deep inside the engine are pistons, and they are what make the magic really happen. They pump up and down inside the engine cylinders. Their job is twofold: to compress the air-fuel mixture in the cylinders, and then to channel the combustion power toward the crankshaft forcing it to rotate. Connecting rods, which you learned about earlier relating to the crankshaft, also connect to the pistons.

Pistons are sealed against the cylinder wall with piston rings and engine oil. Piston rings prevent the air-fuel mixture from leaking down past the piston along with a microscopic oil film on the cylinder walls.

Intake Manifold

Contrary to popular belief, the major fuel for your engine is actually air. Specifically, it the oxygen in the same air you breathe. When your engine is running, it’s constantly sucking air into the engine through an intake manifold. This part is typically cast out of aluminium or plastic on modern cars, and the job it performs is rather light-duty but critical.

From the air filter, air is channelled through the intake manifold to the cylinder head’s intake ports. There’s one for each cylinder on most cars. If you look at the top of your engine, the intake manifold is often a round tube that fans off into several smaller chambers.

Fuel Injector

Petrol or diesel needs to be injected into the cylinder to fuel the combustion process – air won’t ignite on its own, no matter how hard you try. Fuel injectors are the parts that disperse fuel from your tank into the engine to be burned. There’s one fuel injector per cylinder on most cars. Some may have two, while others might have a single injector that attaches to the throttle body, but that’s not common anymore.

The fuel injector opens for a fraction of a second when your car’s engine computer sends it an electrical pulse. When it opens, it injects a fine mist of fuel into the combustion chamber where it mixes with air. The finer the mist, the more complete the ignition cycle will be. That means a cleaner-burning engine, more power, and less tailpipe pollution.

Spark Plug

Petrol-powered engines employ spark plugs to ignite the fuel in the engine. Each cylinder has a single spark plugs, except a select few engines that are hardly worth mentioning that use two per cylinder. When the air-fuel mixture has been injected into the cylinder, the intake and exhaust valves are closed, and the piston has come fully up in the cylinder to compress the air-fuel mixture, the spark plug snaps a small spark between its centre electrode and ground electrode.

This is the apex of the internal combustion engine’s process. It’s what makes the crankshaft go round. Once the spark plug ignites the fuel in the cylinder, the piston is forced downward, rotating the crankshaft. A spark plug fires several times per second, even at idle speeds.

Oil Galleys

Cast throughout the engine block and cylinder head are oil galleys. They’re essentially channels where the engine oil circulates throughout the engine. Oil galleys squirt small amounts of oil onto moving parts like crankshaft and camshaft bearings to keep everything moving smoothly and frictionless.

It all starts with an oil pump that sucks up engine oil from the oil pan. It sends engine oil all over, and then it drips back down into the oil pan where it collects. Dirty engine oil can plug up oil galleys and starve moving parts of oil, which is a primary reason engines seize up.

Coolant Jacket

Also cast throughout the engine block and cylinder head are channels designated only for engine coolant. This is how the engine regulates its temperature. Coolant circulates through the coolant jacket, absorbing heat from the metal components. Then, the water pump forces the hot coolant through the radiator where outside air cools it, dissipating excess heat. Coolant then goes back into the engine and starts its cycle all over again.


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

73 10 parts of an engine you should know

10 parts of an engine you should know


By Jason Unrau on 2018-07-06 18:12:12

Ever wondered how an engine works? It’s an incredibly intricate machine that doesn’t seem like it should operate. Petrol or diesel fuel is burned at extremely high temperatures in a confined space. Normally you’d expect it to blow apart. Instead, an engine turns combustion into a source of power.

You might be a car owner. Perhaps you’ve just obtained your provisional driving license. Or, you could be just an enthusiast curious about how things work. Whatever the case, we’ve listed ten engine parts that you should know.

Cylinder Head

At the top of the engine is an assembly bolted firmly to the engine block. It’s called a cylinder head, fittingly so because it’s at the top. Makes sense, right?

The cylinder head serves as a gateway for a few different operations, controlled by valves precisely fitted into its cast form. The cylinder head and its parts are the pass-through for fuel entering the combustion chamber, the exit for exhaust gases after combustion, and the attachment point for fuel injectors and spark plugs in some cases.

You’ve likely heard of a cylinder head gasket, which is a layered gasket to seal the cylinder head to the engine block. It’s the most well-known fault that can happen with the cylinder head.

Crankshaft

Everything revolves around the crankshaft in the engine – literally. An engine’s main purpose is to rotate the crankshaft which harnesses and transmits the engine’s power to the transmission or transaxle. A crankshaft is fastened into the engine block almost directly through the center.

The crankshaft is made of extremely hard steel. Its lobes are offset for each cylinder, where connecting rods attach to the crankshaft. You’d think the metal-on-metal action would grind the parts badly, but thin bearings are kept washed in engine oil to form a protective barrier on the moving parts. The crankshaft is one of the most durable parts inside the engine – you almost never hear of a crankshaft needing to be replaced.

Camshaft

A couple important parts connect to the crankshaft, and one is the camshaft. Actually, there may be more than one camshaft in the car. There’s at least one camshaft for every cylinder head, so on a V6 or V8 engine, there’s at least two. Sometimes there are two camshafts per cylinder head, known commonly as DOHC, or dual overhead cam.

Now for its purpose: camshafts open valves in the cylinder head. Intake valves allow the air-fuel mixture into the combustion chamber while exhaust valves allow burnt gases out. Lobes on the camshaft staggered across the whole cam, the time the valve openings perfectly.

Timing Belt or Chain

It’s also very important to know HOW the engine’s crankshaft and camshaft(s) work together, and that’s with a timing belt or chain. Pulleys on the camshafts and crankshaft are connected with a chain or reinforced rubber belt. The two work in tandem to keep the engine’s movements perfectly timed thanks to a timing belt/chain system.

If the timing belt or chain is off by just one tooth on the pulley, the engine will run rough or might not run at all because the combustion chambers aren’t fully sealed for their compression and combustion processes. Also, a timing chain needs to be replaced as part of routine maintenance. A timing chain should last an engine’s lifetime.

Pistons

Deep inside the engine are pistons, and they are what make the magic really happen. They pump up and down inside the engine cylinders. Their job is twofold: to compress the air-fuel mixture in the cylinders, and then to channel the combustion power toward the crankshaft forcing it to rotate. Connecting rods, which you learned about earlier relating to the crankshaft, also connect to the pistons.

Pistons are sealed against the cylinder wall with piston rings and engine oil. Piston rings prevent the air-fuel mixture from leaking down past the piston along with a microscopic oil film on the cylinder walls.

Intake Manifold

Contrary to popular belief, the major fuel for your engine is actually air. Specifically, it the oxygen in the same air you breathe. When your engine is running, it’s constantly sucking air into the engine through an intake manifold. This part is typically cast out of aluminum or plastic on modern cars, and the job it performs is rather light-duty but critical.

From the air filter, air is channeled through the intake manifold to the cylinder head’s intake ports. There’s one for each cylinder on most cars. If you look at the top of your engine, the intake manifold is often around the tube that fans off into several smaller chambers.

Fuel Injector

Petrol or diesel needs to be injected into the cylinder to fuel the combustion process – air won’t ignite on its own, no matter how hard you try. Fuel injectors are the parts that disperse fuel from your tank into the engine to be burned. There’s one fuel injector per cylinder on most cars. Some may have two, while others might have a single injector that attaches to the throttle body, but that’s not common anymore.

The fuel injector opens for a fraction of a second when your car’s engine computer sends it an electrical pulse. When it opens, it injects a fine mist of fuel into the combustion chamber where it mixes with air. The finer the mist, the more complete the ignition cycle will be. That means a cleaner-burning engine, more power, and less tailpipe pollution.

Spark Plug

Petrol-powered engines employ spark plugs to ignite the fuel in the engine. Each cylinder has a single spark plug, except a select few engines that are hardly worth mentioning that use two per cylinder. When the air-fuel mixture has been injected into the cylinder, the intake and exhaust valves are closed, and the piston has come fully up in the cylinder to compress the air-fuel mixture, the spark plug snaps a small spark between its center electrode and ground electrode.

This is the apex of the internal combustion engine’s process. It’s what makes the crankshaft go round. Once the spark plug ignites the fuel in the cylinder, the piston is forced downward, rotating the crankshaft. A spark plug fires several times per second, even at idle speeds.

Oil Galleys

Cast throughout the engine block and cylinder head are oil galleys. They’re essentially channels where the engine oil circulates throughout the engine. Oil galleys squirt small amounts of oil onto moving parts like crankshaft and camshaft bearings to keep everything moving smoothly and frictionless.

It all starts with an oil pump that sucks up engine oil from the oil pan. It sends engine oil all over, and then it drips back down into the oil pan where it collects. Dirty engine oil can plug up oil galleys and starve moving parts of oil, which is a primary reason engine seize up.

Coolant Jacket

Also cast throughout the engine block and cylinder head are channels designated only for engine coolant. This is how the engine regulates its temperature. Coolant circulates through the coolant jacket, absorbing heat from the metal components. Then, the water pump forces the hot coolant through the radiator where outside air cools it, dissipating excess heat. The coolant then goes back into the engine and starts its cycle all over again.


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
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