In engines with more than one cylinder
The base of a reciprocating internal combustion engine is the engine block, which is typically made of cast iron or aluminium. The engine block contains the cylinders. In engines with more than one cylinder they are usually arranged either in 1 row (straight engine) or 2 rows (boxer engine or V engine); 3 rows are occasionally used (W engine) in contemporary engines, and other engine configurations are possible and have been used. Single cylinder engines are common for motorcycles and in small engines of machinery. Water-cooled engines contain passages in the engine block where cooling fluid circulates (the water jacket). Some small engines are air-cooled, and instead of having a water jacket the cylinder block has fins protruding away from it to cool by directly transferring heat to the air. The cylinder walls are usually finished by honing to obtain a cross hatch, which is better able to retain the oil. A too rough surface would quickly harm the engine by excessive wear on the piston.
The pistons are short cylindrical parts which seal one end of the cylinder from the high pressure of the compressed air and combustion products and slide continuously within it while the engine is in operation. The top wall of the piston is termed its crown and is typically flat or concave. Some two-stroke engines use pistons with a deflector head. Pistons are open at the bottom and hollow except for an integral reinforcement structure (the piston web). When an engine is working the gas pressure in the combustion chamber exerts a force on the piston crown which is transferred through its web to a gudgeon pin. Each piston has rings fitted around its circumference that mostly prevent the gases from leaking into the crankcase or the oil into the combustion chamber. A ventilation system drives the small amount of gas that escape past the pistons during normal operation (the blow-by gases) out of the crankcase so that it does not accumulate contaminating the oil and creating corrosion. In two-stroke gasoline engines the crankcase is part of the air?fuel path and due to the continuous flow of it they do not need a separate crankcase ventilation system.
At one time, the word engine
Main article: History of the internal combustion engine
At one time, the word engine (from Latin, via Old French, ingenium, "ability") meant any piece of machinery ? a sense that persists in expressions such as siege engine. A "motor" (from Latin motor, "mover") is any machine that produces mechanical power. Traditionally, electric motors are not referred to as "Engines"; however, combustion engines are often referred to as "motors." (An electric engine refers to a locomotive operated by electricity.)
In boating an internal combustion engine that is installed in the hull is referred to as an engine, but the engines that sit on the transom are referred to as motors.3
Driving license for bus drivers
Buses are one of the most important means of communication. Thanks to them we can quickly get to a certain place without thinking about parking and so on. To become a bus driver it is necessary to invest in a special driver's license. Although at this rate it differs significantly from the "normal" driving license, license for driving cars, if only because of the size of the vehicle, which we, however, provides a number of people interesting experiences. Driving license this category is much less common than the traditional license category B, so that we can greatly increase your chances for example in the labor market, when put in their application documents mention of such a document.