Modern cars and speed
Although having sporting a modern car very often remains just a dream for motorists, people with such cars more often appear on Polish roads. I must admit that this car really pose a huge threat to all road users. In sports cars do not feel the speed, and special arrangements are responsible for the fact that you can achieve really high speed driving. It is not only dangerous, but in some cases, even deadly. Despite the passionate driving fast sports car is not lacking, and for some of them the adrenaline during such driving is one of the most important experiences, so that they feel really good.
Kind principles on the road
Novice drivers often have no idea how to navigate especially in large cities. Skills acquired during the course of a driving license are often insufficient to freely continue driving after passing the exam. But do not scare initial failures in this respect - nobody immediately not yet led to any vehicle like a professional driver, and each kilometer is a valuable experience. It is worth noting that many motorists used polite rules on driving. A valuable signal to a driver who, for example, let us in on a congested intersection is sending him a thank you for using your own lights. Such light signals can be very useful when driving culture.
Main article: 2-stroke engine
The defining characteristic of this kind of engine is that each piston completes a cycle every crankshaft revolution. The 4 processes of intake, compression, power and exhaust take place in only 2 strokes so that it is not possible to dedicate a stroke exclusively for each of them. Starting at TDC the cycle consist of:
Power: While the piston is descending the combustion gases perform work on it?as in a 4-stroke engine?. The same thermodynamic considerations about the expansion apply.
Scavenging: Around 75° of crankshaft rotation before BDC the exhaust valve or port opens, and blowdown occurs. Shortly thereafter the intake valve or transfer port opens. The incoming charge displaces the remaining combustion gases to the exhaust system and a part of the charge may enter the exhaust system as well. The piston reaches BDC and reverses direction. After the piston has traveled a short distance upwards into the cylinder the exhaust valve or port closes; shortly the intake valve or transfer port closes as well.
Compression: With both intake and exhaust closed the piston continues moving upwards compressing the charge and performing a work on it. As in the case of a 4-stroke engine, ignition starts just before the piston reaches TDC and the same consideration on the thermodynamics of the compression on the charge.
While a 4-stroke engine uses the piston as a positive displacement pump to accomplish scavenging taking 2 of the 4 strokes, a 2-stroke engine uses the last part of the power stroke and the first part of the compression stroke for combined intake and exhaust. The work required to displace the charge and exhaust gases comes from either the crankcase or a separate blower. For scavenging, expulsion of burned gas and entry of fresh mix, two main approaches are described: Loop scavenging, and Uniflow scavenging, SAE news published in the 2010s that 'Loop Scavenging' is better under any circumstance than Uniflow Scavenging.6