Car Engine Basics

Submitted By: Lawrence JT. Reaves
Automotive engines, once simple in design, have evolved into complex assemblies consisting of myriad moving parts. If one component fails or becomes unable to do its job, the assembly's performance, output, and fuel economy may suffer. In some cases, the engine will stop working altogether. Despite its importance to the operation of a car, many people remain unaware regarding how the assembly works. We'll address this issue below.
Our goal in this article is to describe the operation of a car engine in a way that is easy to understand. That way, when problems surface, you'll have a better understanding of the potential causes. We'll begin by presenting the various parts, and describing the 4-stroke combustion cycle that occurs in the cylinders. You'll then learn about the other systems that heavily influence your engine's performance.
Cylinder Configurations And Key Components
Engines are configured differently based partly on the number of cylinders they house. When there are four cylinders, they are usually arranged in a single line. Many 6-cylinder engines follow this same arrangement. Some assemblies with four or six cylinders are designed with an equal number - two or three, respectively - forming two rows. Assemblies offering 8 or 10 cylinders are usually arranged in a "V" format with an equal number on each side.
In order for an engine to work properly, several key parts are necessary. Each cylinder has a spark plug, piston, and a pair of intake and exhaust valves. The opening and closing of the valves are controlled by a camshaft and lobes (one lobe per valve). Each piston moves up and down inside its cylinder, and is attached to a connecting rod. The connecting rods are attached to the crankshaft. The manner in which these components work together will become clearer in the next section.
How Internal Combustion Works Inside The Engine
The operation of an engine is based on its combustion cycle. There are four distinct stages: intake, compression, ignition, and exhaust. During the intake stage, the intake valve opens to allow the fuel injector to spray gas into the combustion chamber. As this occurs, the piston begins to move downward in the cylinder. When the piston reaches the bottom, the intake valve closes, sealing the chamber.
The compression stage begins as the piston starts to move upward. As it does so, it compresses the air-fuel mixture inside the combustion chamber. By the time the piston reaches the top, it will have compressed the air and fuel to a tenth of its normal volume.
The ignition stage starts with a spark from the spark plug sitting at (or near) the top of the chamber. The spark ignites the compressed air-fuel mixture, causing an explosion and rapid expansion of exhaust gases. The gas expansion pushes the piston downward.
When the piston reaches the bottom of the chamber for the second time, the exhaust stage begins. The exhaust valve opens to allow the gases to escape from the combustion chamber into the exhaust system. The piston starts to move upward to force the gases outward.
Once the chamber has emptied of exhaust gases, the exhaust valve closes, and the 4-stroke combustion cycle begins again. This cycle occurs thousands of times each minute.
Secondary Systems That Affect The Engine's Performance
A number of other systems must work properly in order that your engine operates at optimum efficiency. For example, the cooling system pushes coolant through the assembly to absorb heat and transfer it away. If the cooling system fails, the engine will overheat.
The ignition system generates and delivers the necessary voltage to create the spark in the combustion chambers. If any component in this system (e.g. ignition coil, distributor, rotor, etc.) fails, the engine may misfire, stall, or hesitate.
The fuel system is responsible for delivering sufficient fuel to the individual chambers. Parts in this system include the fuel filter, pump, and fuel injectors. If any of them fail or malfunction, the engine will be deprived of gas.
These and other systems, including the electrical, exhaust, and air intake systems, work together to ensure your car's engine performs well. Although the majority of problems that occur in these systems require the help of a trained mechanic, understanding how they influence your engine makes them less mysterious.

Published At: Isnare.com

The 2011 Jaguar XJ Has The Heart Of A Muscle Car Wrapped In A Luxury Package

Submitted By: Jacqueline Cao
Sales for Jaguar have been slim within the last few years. The automotive market hasn’t been doing too well generally and Jaguar’s vehicles didn’t boast anything unique or overly exciting to help it stand out. However, with Jaguar’s flagship vehicle receiving a new look inside and out that is all about to change.
Many of the cars in the luxury market share similarities, but the intention of the 2011 Jaguar XJ is to entice customers with something that is a bit different. And the new XJ looks downright sinister. This four door sedan sports 20in. rims and has a super powerful v8 engine.
The car also received a makeover looks wise. The glass line has been altered and extended with the rear sloping down to meet the trunk. The roof looks much lower almost like the car has been chopped. The Jaguar looks like it has one unbroken large piece of side glass, tinted of course.
Numerous variations with regards to wheel base and motors can be selected from The XJ version has the shorter 119in. wheel base and the XJL (L for large) has a wheel base of 244 inches. The very base model checks in at $72,500 with a DOHC 5-liter V-8 motor that produces 385 hp 385 lb. ft. of torque. The top of the line buys you a supercharged version of the engine cranking out 510 hp and 461 lb. ft. or torque, it also gets you the larger wheel base. Price for everything is $115k for this: the super sport model. Oh and each car gets a 6-speed auto transmission.
Another innovative feature of the XJ is its advanced suspension system which is comprised of continuously variable dampeners. The body though has been made 11% stiffer over last year’s model. The curb weight is just over 4,000 lbs., which in the world of luxury cars is not very heavy. This allows the XJ to perform equally well to much smaller cars.
This car can effortlessly race to 0-60 MPH in 4.4 seconds with the quarter mile zooming by in 12.7 seconds. Faster than a Camaro SS or Mustang GT which consider themselves drag strip bruisers. Fuel economy checks in at 16 mpg in the city and 23 mpg on the highway for the smaller engine and 15 mpg city 21 mpg highway for the 510 hp version. The Jaguar has an electronically controlled rear differential to put the power down. The cabin epitomizes fine living and ultimate luxury with its fabulous leather, beautiful wood trim and ample accessories. The gauges grow bright where the needle is and the XJ has a sport mode. The sound system of the XJ is also amazing with superb sound.
If you are looking for the ultimate luxury car that can outrace everyone else then consider the 2011 Jaguar XJ. This car has the heart of a muscle car wrapped up in a luxurious package and can outrace most muscle cars including the Mustang GT! The 2011 Jaguar XJ is a true contender in the luxury car segment.

Published At: Isnare.com