Engine in your car - pick the right oil

mixture to the cylinder.6 In 1899 John Day simplified Clerk's design into the type of 2 cycle engine that is very widely used today.13 Day cycle engines are crankcase scavenged and port timed. The crankcase and the part of the

Engine in your car - pick the right oil reduce smoke Datsun

Historical design

Historical design

Dugald Clerk developed the first two cycle engine in 1879. It used a separate cylinder which functioned as a pump in order to transfer the fuel mixture to the cylinder.6

In 1899 John Day simplified Clerk's design into the type of 2 cycle engine that is very widely used today.13 Day cycle engines are crankcase scavenged and port timed. The crankcase and the part of the cylinder below the exhaust port is used as a pump. The operation of the Day cycle engine begins when the crankshaft is turned so that the piston moves from BDC upward (toward the head) creating a vacuum in the crankcase/cylinder area. The carburetor then feeds the fuel mixture into the crankcase through a reed valve or a rotary disk valve (driven by the engine). There are cast in ducts from the crankcase to the port in the cylinder to provide for intake and another from the exhausst port to the exhaust pipe. The height of the port in relationship to the length of the cylinder is called the "port timing."

On the first upstroke of the engine there would be no fuel inducted into the cylinder as the crankcase was empty. On the downstroke the piston now compresses the fuel mix, which has lubricated the piston in the cylinder and the bearings due to the fuel mix having oil added to it. As the piston moves downward is first uncovers the exhaust, but on the first stroke there is no burnt fuel to exhaust. As the piston moves downward further, it uncovers the intake port which has a duct that runs to the crankcase. Since the fuel mix in the crankcase is under pressure the mix moves through the duct and into the cylinder.

Because there is no obstruction in the cylinder of the fuel to move directly out of the exhaust port prior to the piston rising far enough to close the port, early engines used a high domed piston to slow down the flow of fuel. Later the fuel was "resonated" back into the cylinder using an expansion chamber design. When the piston rose close to TDC a spark ignites the fuel. As the piston is driven downward with power it first uncovers the exhaust port where the burned fuel is expelled under high pressure and then the intake port where the process has been completed and will keep repeating.

Later engines used a type of porting devised by the Deutz company to improve performance. It was called the Schnurle Reverse Flow system. DKW licensed this design for all their motorcycles. Their DKW RT 125 was one of the first motor vehicles to achieve over 100 mpg as a result.14

Źródło: https://en.wikipedia.org/wiki/Internal_combustion_engine


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.


What to consider when buying car 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.