Useful gadget for the car
Among the many highly advanced technological solutions can not fail to make life easier for drivers. A perfect example is the so-called parking sensor, which means that you can safely fit in the car, even in a small space. This gadget is not currently too expensive, and its value for the majority of drivers will be huge - definitely worth it to invest, as we move through the crowded city streets, and we have every day problems with the appropriate parking the car. This sensor, as well as many other facilities for drivers are becoming more popular, and above all, their price falls. This is certainly an argument for buying small appliances that make life easier on the road.
News for motorists
Despite the fact that people interested in the automotive industry very keen viewing messages associated with handwritten carrying out repairs in the car or parts replacement, however, a large part of radio listeners or people viewing web pages are waiting for a completely different type of information. This is important especially when we are on the way. Well, very important are the current traffic information. More than one radio provides such information, which is certainly often awaited by drivers standing in unexpected traffic jams and so on. Thanks to that we will hear information about the accident or other traffic problems well in advance, we can even change your route so you can avoid traffic problems.
The defining characteristic
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