How to do car engine knock (Dieselpartsworld) 2016-01-19
How to do car engine knock
In order to reduce the knock, the use of suitable standard gasoline (labeled low lead to knock, high lead to carbon deposition), reduce the compression ratio, delay the ignition advance angle is fundamental, but any programs need to choose. Lower compression than at the expense of the engine power (307 1.6 power is 80kW from reduced to 78kw), delayed ignition advance angle is at the expense of the ignition efficiency, fuel efficiency, inadequate torque under low speed, start slow speed and shifting of the strong sense of frustration, although not will have a great impact, but the impact is very wide. So how to better reduce the engine knock it?
What is knock
Knock, commonly known as knock cylinder, called the rod. Detonation is generated in the combustion process of engine abnormal combustion phenomenon, knock to say is engine designer of predators, many improve horsepower, reduce fuel consumption, reduce pollution of the design, such as high compression ratio, supercharging device, improve the cylinder wall temperature (Materials Science and technology progress makes strength no Yu), because of the knock limit.
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Knock feature is at the start of ignition and combustion wave propagation are normal, but in the end should be a part of oil and gas burning, we called the "tail" (End Gas), because of compression by combustion gas caused by the expansion, to reduce volume, temperature and pressure, before burning without Beauchamp to this, a part of the oil and gas temperature has been reached "spontaneous combustion" reached the ignition point after after a period of "self ignition delay" will be self ignited, and with 300m/s ~ 200m/s rapidly spread outward, and when the normal combustion and detonation two opposite the combustion pressure wave meet that will lead to severe gas shock, and a unique clang, so called "knock".