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Explanation of the Engine

Explanation of the Engine

Instead of pumping blood, your car's engine performs the job of a heart by moving air and fuel through the system. The car's wheels are propelled by the engine's ability to generate rotational motion from the flow of air and fuel. Whence comes the ability? Let's begin by taking a look at the engine's primary components, and then we'll delve into the nitty-gritty of the mechanics.

Engines typically contain four, six, or eight pistons that rise and fall in the cylinders. The combustion chamber, which is located on the top side of the piston, is where the fuel and air combine before the engine is started. The crankcase is on the opposite side, and it's full of oil. Fuel and air can't get into the combustion chamber, and oil can't get into the oil.

A connecting rod connects the crankshaft to the pistons. Straight line motion is transformed into rotational motion when the piston rises and falls in the cylinder.

The valve train is made up of the camshaft, rocker arms, pushrods, lifters, and other components that operate the valves. Using the colors given above (blue, yellow, and green), the only purpose of the valve train is to serve as a traffic enforcer. It regulates the flow of air and fuel into and out of the engine. With a chain or belt connecting the camshaft to the crankshaft, the timing may be adjusted.


Having a rough idea of what's going on, let's get down to the specifics. There are four separate events that make up the cycle of a four-stroke (or four-cycle) engine nowadays. The piston slides down the cylinder when the camshaft opens the intake valve. Air and gasoline are drawn into an area above the piston that is vacuumed up. Compression stroke: the intake valve shuts and seals the combustion chamber as the piston begins traveling back up the cylinder. Compression of the air and fuel is the result of this. When the piston reaches the top of the cylinder and the fuel and air are ignited, this is known as the power stroke. As a result, the crankshaft moves the piston back into the cylinder. To put it another way, the gases that are left over from the combustion of fuel and air are expelled out of the exhaust system as soon as the piston is at rest.

A full cycle may be formed by arranging these four occurrences in the sequence shown above. Is it time to go to sleep? What follows is a discussion of practical issues and issues you can experience while using any of the previously discussed components.

Pistons: You may recall my discussion of the rings that seal the combustion chamber from the crankshaft. The rings wear out over time. Fuel and air enter the oil via the worn seals, diluting the oil. The oil's capacity to lubricate your engine is reduced as a result of this dilution, which may lead to premature wear. Also, worn rings might enable crankcase oil to reach the combustion chambers. Your tailpipe will emit a grayish-white smoke as a consequence of this. It's possible you have warning rings if your automobile begins to spew grayish white smoke and doesn't cease within the first few minutes of starting up. Observe the valve train section if the smoke disappears after startup.

Over time, bearings that support the crankshaft might wear out. The crankshaft and the rods that link the pistons to the crankshaft are supported by the bearings. Most of the time, the engine makes a loud, medium-pitched banging sound to alert the bearings. The crankshaft must be removed, and either the bearing surface must be machined or the crankshaft must be replaced. Make sure you use high-quality oil and replace it at the recommended intervals (3 months or 3000 miles is a good amount) to avoid this type of issue. You should also make sure your oil level is maintained in between oil changes.

Train of valves: Keep in mind the concern with oil smoke in the piston regions that was previously noted. You may have leaky valve seals if your automobile only emits grayish or white smoke when it is starting up. The oil above the valve is kept out of the combustion chamber by valve seals. If these seals get worn, oil may leak into the combustion chamber and build up until you restart the engine. When the engine is running, the seals expand and seal the oil leak, preventing it from spilling out of the valves.

When the timing chain or belt fails or slips, it might stop the cam shaft from turning. Keep in mind that the camshaft controls when the valves open and close, so if it stops turning, the valves will cease to open and close as they normally would. If the valve does not move, the engine will not operate:-)

"Interference engine" is a word used when discussing timing chains and belts. Interference engines have close proximity between pistons and valves, which means that a broken belt or chain would result in both piston and cylinder crashing into one another if the crankshaft continued to spin. Crashing a car may do a lot of damage to an engine, including broken valves, bent pushrods, and even cracked pistons. (That's the interference). Why do most manufacturers suggest replacing the timing belt or chain after 60,000 miles? Timing belts degrade over time, so even if your vehicle hasn't racked up 60,000 miles, you should consider replacing it when it's six years old.

Maintenance as a Precaution:

Regular oil changes are necessary.

If at all possible, let your engine warm up before you go on the road. Before you begin to drive, let the oil circulate throughout the engine. In colder weather, when the oil is lukewarm and slow, this becomes even more crucial. Make sure to replace your timing belt or chain on time, according to the instructions provided by your vehicle manufacturer. Additives marketed on late-night television should be avoided. Your engine will operate at its peak performance if you do regular oil changes and practice proper maintenance practices. Allow your turbocharged engine to cool down for a few minutes before shutting it off. It is during this cooling down stage that the bearings may be cooled by oil circulation. As soon as you get out of the car after a long drive, you should turn the engine off to prevent the oil from accumulating around the heated bearings.

Mechanics: What to talk about

When the time comes to replace your engine, weigh the advantages of choosing a pre-owned one over a brand-new one. A new engine can be your best option if you want to maintain your automobile for a long time. In certain cases, the most cost-effective approach is to purchase a brand-new engine rather than have one that has been rebuilt. Be as specific as possible while attempting to figure out what's going on with your car's engine. At what throttle setting does it begin to make a noise? And how long has this noise been going on? A new noise may be heard if the amount of oil in the engine is increased or decreased. Make certain that your technician is aware of any recent changes to your oil's brand or weight.

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