Yesterday a friend left a message to ask small make up the engine is cast iron or aluminum is good, general engine material problems many people will not pay attention to, the friend can think of this issue let small make up quite admire. In fact, strictly speaking, now most of the engine cylinder head is made of aluminum, because of relatively poor lubrication of cylinder head, the heat dissipation of aluminum alloy cylinder head will be better, and even the most cars use full aluminum engine, as the name suggests is the engine cylinder head and are made of aluminum alloy cylinder block, the quality of aluminum alloy is lighter, there are many cyclists are like aluminum alloy cylinder block.
So are cast iron cylinder blocks really out of date? Actually not, the performance of cast iron cylinder block is very excellent.
Most car manufacturers use aluminum cylinders to reduce weight, and many front-engine cars that focus on control use aluminum. Because the engine is in the front, you can't make the front car too heavy. So, the way to reduce the head weight is to reduce the weight of the engine.
However, aluminum alloy cylinder head cylinder block is not without shortcomings, aluminum alloy can withstand the temperature and pressure is relatively small, so the use of aluminum alloy cylinder head cylinder block engine is not too high horsepower.
And cast iron cylinder block although the weight is larger, heat dissipation performance is not as aluminum alloy cylinder block, but cast iron cylinder block can withstand higher temperature and pressure. Say here to believe that a part of friends should be reflected from the application range of cast iron cylinder block.
Indeed, there are plenty of potential retrofits that use cast-iron cylinders, such as Volkswagen's third-generation EA888, which can be retrofitted to more than 600 horsepower. There is also known as the mitsubishi EVO's 4G63 red head engine, which is famous for its potential for modification. There are many 4G63 engines with more than 1000 horsepower abroad, and the mitsubishi EVO red head engine also USES cast iron cylinder block.
If the use of aluminum alloy cylinder block, after modification is impossible to have such high horsepower, the use of aluminum alloy cylinder block engine simply can not withstand the high horsepower and temperature. Using aluminum cylinders does not improve engine performance, it just reduces weight and improves fuel economy and handling.
At present, some luxury cars use all-aluminum engines. In order to cope with the problem of aluminum tolerance, two methods are generally adopted. One is to add an extra layer of cylinder liner in the cylinder, so that the tolerance of high temperature and high pressure is borne by the cylinder liner. The other is to add additional metal elements to improve aluminum tolerance by means of alloys, and of course, the cost of construction increases accordingly.
In addition to differences between for high temperature and high pressure resistance, corrosion resistance, also have very big difference, both in the engine. Simple is the antifreeze, in high temperature and high pressure of the engine body, fangdongye would occur and metal chemical action, and the corrosion resistance of aluminum is also not as good as cast iron, especially for temperature and pressure are higher turbocharged engine, which is why some turbo engine more USES is the cause of the cast iron cylinder block.
In general, the all-aluminum engine has the characteristics of light weight, good heat dissipation and high manufacturing cost. Cast iron engine has high temperature and high pressure tolerance, corrosion resistance, low manufacturing cost. However, for domestic vehicles, the influence of what kind of engine material has on fuel consumption is not too great. The quality of the engine is measured by comprehensive factors such as its power performance, fuel economy and mechanical stability. It cannot be said that a certain kind of engine material is necessarily good.
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