EXHAUST COLLECTORS – The design of exhaust manifolds is a difficult task, First of all, there are problems with strength and heat – the operating temperature range is several hundred degrees C.. As a result, it is extremely critical to attach the manifolds to the engine heads, especially aluminum. Collectors are usually made of one of two technologies – as iron castings or as complex welded structures made of bent pipes. The latter technology has many advantages – parts are lighter, and above all, it is possible to select the length of individual cables in such a way, to use the wave phenomena occurring here for the benefit of engine operation. In medium and heavy duty units it is very important, among other things, to achieve the same length of individual manifold pipes from the exhaust valve to the connection point. You cannot omit an advantage as well, which is the constant diameter of the conductor and the smoothness of the walls. These aspects are of little importance in mass-produced engines, which are not too straining, and they should be as cheap as possible. It is the cost of execution that causes, that cast iron is the most popular material for exhaust manifolds.