Engine

The conversion of fuel energy into power in an engine starts when petrol is mixed with air in a device called a carburettor , to form a highly combustible mixture. Read more

The fixed-jet carburettor resembles the simpler variable-jet type (See How variable-jet carburettors work ) in having a venturi - a constricted neck - through which air flows on its way to the engine . Read more

The purpose of the ignition system is to generate a very high volt age from the car's 12 volt battery , and to send this to each sparkplug in turn, igniting the fuel-air mixture in the engine 's combustion chambers . Read more

Although some experienced mechanics can tune a car's carburettor fairly well by ear, to do the job really accurately you need the help of special equipment. Read more

The engine is, in many respects, self-sustaining: it supplies the power that drives a number of ancillary - subordinate - components without which it could not work. Read more

A good way to check engine wear is to test the compression of each cylinder using a compression tester, which you can buy or hire. Read more

Over a period of years, sediment builds up in a car's cooling system even if antifreeze containing corrosion inhibitors is left in all year round. Read more

Check the engine oil level weekly more often if the engine is consuming some oil, and always before a long drive. Change the oil and renew the oil filter at recommended service intervals. Read more

Fitting a new disposable cartridge is a simple task, but you must make sure that the new sealing ring that comes with it is correctly fitted in its proper place, on the inner end of the cartridge. Smear its outer face with clean engine oil. Read more

The valve which allows mixture into the cylinder is the inlet valve; the one through which the spent gases escape is the exhaust valve. They are designed to open and close at precise moments, to allow the engine to run efficiently at all speeds. Read more

The rubber anti-vibration mountings of an engine may crack or come away from the metal plates to which they are bonded. Read more

Engines prone to rock on their rubber mountings, particularly at idling speeds, have extra dampers or plain bars with rubber-bonded bushes at either end to hold them steady. Read more

In many ways a diesel engine is less complicated than a petrol engine , with greater reliability and a longer working life. There is little difference between servicing a diesel and a petrol engine except that the diesel has no ignition system to worry about. However, the fuel system needs very careful attention, as part of the regular service, to prevent dirt and water in the fuel damaging it. Read more

Although car cooling systems are designed to maintain a fairly constant working temperature, the actual engine temperature can vary for a number of reasons. It may even reach such a high level that engine damage becomes a possibility. Read more

Traditionally, diesel engines have always been seen as noisy, smelly and underpowered engines of little use other than in trucks, taxis and vans. But as diesel engines and their injection system controls have become more refined, the 1980s have seen that situation change. In the UK in 1985 there were almost 65,000 diesel cars sold (about 3.5 per cent of the total number of cars sold), compared with only 5380 in 1980. Read more

Almost all car engines work on the four-stroke cycle , so called because it takes four strokes of the piston induction , compression , ignition and exhaust - to produce one firing of the fuel /air mixture. This means that the crankshaft rotates twice to complete each cycle. Read more

One of the problems with conventional car engine designs is that the pistons move in a straight line up and down in their cylinders , to produce what is known as reciprocating motion . Read more

In an ideal, 100 per cent efficient internal combustion engine , the fuel would burn to give just carbon dioxide and water vapour. In practice, of course, engines are far from efficient and the combustion process. also produces carbon monoxide , oxides of nitrogen and unburnt hydrocarbons , as well as carbon dioxide and water vapour. Read more

Most people have some idea of what an engine 's power is, but are hazy about exactly what the torque figure represents. In fact, many cars that feel powerful are showing the effects of strong torque rather than high power output. Read more