oil for Porsche Cylinder configuration
Cylinder configuration
Common cylinder configurations include the straight or inline configuration, the more compact V configuration, and the wider but smoother flat or boxer configuration. Aircraft engines can also adopt a radial configuration, which allows more effective cooling. More unusual configurations such as the H, U, X, and W have also been used.
Multiple cylinder engines have their valve train and crankshaft configured so that pistons are at different parts of their cycle. It is desirable to have the piston's cycles uniformly spaced (this is called even firing) especially in forced induction engines; this reduces torque pulsations21 and makes inline engines with more than 3 cylinders statically balanced in its primary forces. However, some engine configurations require odd firing to achieve better balance than what is possible with even firing. For instance, a 4-stroke I2 engine has better balance when the angle between the crankpins is 180° because the pistons move in opposite directions and inertial forces partially cancel, but this gives an odd firing pattern where one cylinder fires 180° of crankshaft rotation after the other, then no cylinder fires for 540°. With an even firing pattern the pistons would move in unison and the associated forces would add.
Multiple crankshaft configurations do not necessarily need a cylinder head at all because they can instead have a piston at each end of the cylinder called an opposed piston design. Because fuel inlets and outlets are positioned at opposed ends of the cylinder, one can achieve uniflow scavenging, which, as in the four-stroke engine is efficient over a wide range of engine speeds. Thermal efficiency is improved because of a lack of cylinder heads. This design was used in the Junkers Jumo 205 diesel aircraft engine, using two crankshafts at either end of a single bank of cylinders, and most remarkably in the Napier Deltic diesel engines. These used three crankshafts to serve three banks of double-ended cylinders arranged in an equilateral triangle with the crankshafts at the corners. It was also used in single-bank locomotive engines, and is still used in marine propulsion engines and marine auxiliary generators.
Źródło: https://en.wikipedia.org/wiki/Internal_combustion_engine
Safe buying a used car from abroad
Acquisition of foreign used cars from Germany or France is very popular. When buying a car from abroad we have to be careful if the seller does not deceive us, because there is no shortage of vehicles which, for example, have accidents and are sold as accident-free. Then the car can really be in bad shape, although aesthetically looks good and inconvenience are covered. This creates a really big risk and it is worth to choose the service of your friends in this regard. Imports of cars from abroad is often a way to earn a certain amount of money, so a lot of people lead such activities. So let's go to a friend or a person with a command when you plan to buy this car.
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.