The engine

The engine is the source of power that makes the car move. It is usually called an internal combustion engine because gasoline is burned within its cylinders or combustion chambers. Most automobile engines have six or eight cylinders.

The operating cycle of the four-stroke engine that takes place in the engine cylinder can be divided into four strokes. The upper limit of the piston movement is called the top dead centre. The lower limit of piston movement is called the bottom dead centre. A stroke is the piston movement from the top dead centre to the bottom dead centre or from bottom dead centre to the top dead centre. In other words, the piston the completes a stroke each time it changes the direction of its motion.

Where the entire cycle of events in the cylinder requires four strokes (two crankshaft revolutions), the engine is called a four-stroke cycle engine. The four strokes are: intake, compression, power and exhaust.

Two-cycle engines have also been made, and in such engines the entire cycle of events is completed in two strokes or one revolution of the crankshaft.

On the intake stroke the intake valve is opened. The mixture of air and vaporized gasoline is delivered into the cylinder through the inlet valve. On the compression stroke the inlet valve is closed so that the mixture can be compressed. On the power stroke both valves (inlet and exhaust) are closed in order to raise pressure during the mixture combustion. On the exhaust stroke the exhaust valve is opened to exhaust the residual gas.

Super Stoppers

Disk and drum brakes are conventional ones. Improved hydraulic systems and anti-lock devices are designed to make brakes more effective. But they don't improve the brakes themselves.

Recently a clutch-type brake of extreming simplicity was created. Most brakes are cooled by air, like an air-cooled engine. But like a car engine they could be liquid-cooled, a water tank cools the brakes with its water when the brakes reach a certain temperature. That method should be used only for sport cars, but not for conventional passenger-cars.

The inventor became interested in liquid cooling of brakes and developed several systems.

In passenger cars the engine's water and radiator were used to cool (he brakes. The idea is that both the engine and the brakes will not be generating peak heat at the same time.

Radar-controlled brakes are being studied now. In such cars radar is used for measuring the distance to the next car, printing that information into a simple computer, which points the accelerator, and brakes what to do.

The Саr and the Environment

Most of us know that cars cause air pollution. Scientists tell us that if we don't do something soon, we will be unable to repair the damage that we are causing to our planet. What are some of the things we can do to help?

1.Buy a fuel-efficient car and keep it that way

Good gas is a way to stop pollution. Choose a car that is friendly to the environment when you buy one.

2.Keep your car tuned up

A car that badly tuned releases more pollutants into the air. If you keep track of your gas mileage, you'll know when something is wrong. A badly tuned car uses almost 10% more gas than a well-tuned car. Other ways to waste gas are:

Idling your car unnecessarily. If you are stopped for longer than a minute, it is more fuel efficient to turn off your engine.

Using dirty fuel filters. Dirty fuel filters waste gas.

Air Conditioner Maintenance. Of course, this causes a big prob¬lem for both us and our mechanics. Our mechanics will have to make sure that there are no leaks, and fix them if there are, before they can add any R-12 (freon) to our air conditioning systems. Naturally, this cost will be passed along to us.