4M50 Diesel Used Engine Blocks For Excavator HD820V ME994057 Water Cooling
|Car name: Engine cylinder block|
|Model Number: 4M50|
|Cylinder stroke: 120|
|Cylinder diameter: 114|
|valve: 16 valve|
|Cooling: Water cooling|
|Type: Diesel Engine|
Requirements for aluminium engine blocks
It must be noted that in particular in case of cast components, the material properties are not only depending on alloy composition and heat treatment, but also on the applied casting process as well as on the location where the test specimen has been taken (i.e. the specific
local solidification conditions.
Basic engine concept
When looking at existing engine block solutions, a broad variety of designs can be found. The principal concepts can be described by the basic construction of the engine block such as deep-skirt, short-skirt, with and without bed-plate or ladder-frame. Another characteristic is
the number and arrangement of the cylinders.
For smaller engines up to six cylinders which are produced in high volumes, the in-line arrangement is the most common concept. For larger engines with eight cylinders, the V concept is generally used. Space restrictions may lead to the selection of the V concept also for the design of compact engines with four or more cylinders. In addition, for very large engines, e.g. twelve cylinder engines, the W concept is applied. In the W12 arrangement, the aluminium engine block is of a two part design with the interface between the top part of the
cylinder block and the bottom part (“bed plate”) at the level of the crankshaft centre line.
Looking at the bottom end, the simplest design consists of a short-skirt block with single crankshaft bearings and a steel sheet oil pan. But this variant results in a low stiffness of the engine block and unsatisfactory acoustic characteristics. Improvements can be achieved with a properly designed oil pan, often designed as an aluminium casting.
If stiffness is the most important characteristic of the engine block, two-element designs arepreferred. The engine block is
horizontally split at the level of the crankshaft bearing axis. Bed plates and ladder frames are generally made by high pressure die casting using hypoeutectic Al-Si alloys. This solution offers the possibility that bearing caps made from nodular cast iron can be integrally cast-in.
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