HOW TO SWAPPING OUT SPARK PLUGS.

Swapping Out Spark Plugs: An Overview

Changing spark plugs isn't too hard, even for the mechanically disinclined. If you're careful, you should have little trouble.

How do you know if your plugs need to be changed? The surest sign is on your odometer. Spark plugs usually need to be changed every 30,000 miles (48,280 kilometers). Some high-performance plugs can go as long as 100,000 miles (160,934 km) before replacement. If you don't know when yours were last changed or if you have an engine that runs roughly or has recently exhibited a decrease in fuel economy, well, that could mean that your engine might benefit from some fresh, clean sparks. As always, check the owner's manual to see what works best for your vehicle.

SPARK PLUG PARTS; THE TOP TO BOTTOM TOUR.

Spark Plug Parts: The Top-to-Bottom Tour

At the top of the spark plug sits the connector, or terminal. This is where the spark plug wire attaches. The terminal connects inside the plug to the copper core of the center electrode, which is surrounded by insulation.

SPARK PLUG BASICS

Spark Plug Basics

It seems pretty obvious that a spark plug provides the spark that burns the fuel, but its secondary role as a heat dissipater is equally important. A spark plug's ability to transfer heat to the cars cooling system is based on the length of the insulator nose and the materials used for the center electrode and the insulator.

How Spark Plugs Work

Spark plugs are one of the few things that an amateur mechanic can repair without much trouble

As Engine and their electronics become more complex, one of the few things left to hobbyists and auto enthusiasts who like a little grease under their fingernails is the ability to change their spark plugs. Although just about every other car repair out there takes a code reader and a college degree to diagnose and fix, spark plugs remain accessible and easy to understand.

WATER PUMP ( CENTRIFUGAL TYPE )

Water Pump

                                    A centrifugal pump like the one used in your car.

HOW DOES THE THERMOSTAT WORKS IN CAR.

How does the thermostat in a car's cooling system work?

Any liquid-cooled car engine has a small device called the thermostat that sits between the engine and the radiator. The thermostat in most cars is about 2 inches (5 cm) in diameter. Its job is to block the flow of coolant to the radiator until the engine has warmed up. When the engine is cold, no coolant flows through the engine. Once the engine reaches its operating temperature (generally about 200 degrees F, 95 degrees C), the thermostat opens. By letting the engine warm up as quickly as possible, the thermostat reduces engine wear, deposits and emissions.

SUPERCHARGER ADVANTAGES

Supercharger Advantages

The biggest advantage of having a supercharger is the increased horsepower. Attach a supercharger to an otherwise normal Car or Truck, and it will behave like a vehicle with a larger, more powerful engine.

But what if someone is trying to decide between a supercharger and a turbocharger? This question is hotly debated by auto engineers and car enthusiasts, but in general, superchargers offer a few advantages over turbochargers.

Superchargers do not suffer lag -- a term used to describe how much time passes between the driver depressing the gas pedal and the engine's response. Turbochargers suffer from lag because it takes a few moments before the exhaust gases reach a velocity that is sufficient to drive the impeller/turbine. Superchargers have no lag time because they are driven directly by the crankshaft. Certain superchargers are more efficient at lower RPM, while others are more efficient at higher RPM. Roots and twin-screw superchargers, for example, provide more power at lower RPM. Centrifugal superchargers, which become more efficient as the impeller spins faster, provide more power at higher RPM.

Installing a turbocharger requires extensive modification of the exhaust system, but superchargers can be bolted to the top or side of the engine. That makes them cheaper to install and easier to service and maintain.

CENTRIFUGAL SUPERCHARGERS

Centrifugal Superchargers

ProCharger D1SC centrifugal supercharger

A centrifugal supercharger powers an impeller -- a device similar to a rotor -- at very high speeds to quickly draw air into a small compressor housing. Impeller speeds can reach 50,000 to 60,000 RPM. As the air is drawn in at the hub of the impeller, centrifugal force causes it to radiate outward. The air leaves the impeller at high speed, but low pressure. A diffuser -- a set of stationary vanes that surround the impeller -- converts the high-speed, low-pressure air to low-speed, high-pressure air. Air molecules slow down when they hit the vanes, which reduces the velocity of the airflow and increases pressure.

TWIN SCREW SUPERCHARGERS

Twin-screw Superchargers

Twin-screw supercharger

A twin-screw supercharger operates by pulling air through a pair of meshing lobes that resemble a set of worm gears. Like the Roots supercharger, the air inside a twin-screw supercharger is trapped in pockets created by the rotor lobes. But a twin-screw supercharger compresses the air inside the rotor housing. That's because the rotors have a conical taper, which means the air pockets decrease in size as air moves from the fill side to the discharge side. As the air pockets shrink, the air is squeezed into a smaller space.

ROOTS SUPERCHARGERS

Roots Superchargers

The Eaton supercharger, a modified Roots supercharger.

There are three types of superchargers: Roots, twin-screw and centrifugal. The main difference is how they move air to the intake manifold of the engine. Roots and twin-screw superchargers use different types of meshing lobes, and a centrifugal supercharger uses an impeller, which draws air in. Although all of these designs provide a boost, they differ considerably in their efficiency. Each type of supercharger is available in different sizes, depending on whether you just want to give your car a boost or compete in a race.

The Roots supercharger is the oldest design. Philander and Francis Roots patented the design in 1860 as a machine that would help ventilate mine shafts. In 1900, Gottleib Daimler included a Roots supercharger in a car engine.