S4L Diesel Used Engine Blocks For Excavator E304 Water Cooling
Specification
| Car name: Engine cylinder block |
| Model Number: S4L |
| Cylinder stroke: 87 |
| Work Form: Turbo |
| Application: Excavator |
| valve: 8 valve |
| Cooling: Water cooling |
| Injection: Eddy |
Description
Criteria for alloy selection
Choosing the alloy requires the consideration of various criteria.
Aluminium foundry alloys used in the production of such complex
cast parts as engine blocks must meet a combination of requirements
which include low cost, excellent castability, good machinability,
and moderate strength at elevated temperatures.
Strength
The strength level of the alloy determines for example the
applicable wall thicknesses and other design aspects. Thus it is
most relevant define the alloy already in the first development
phase of an engine block. Generally the selection of the alloy is a
compromise. High strength casting alloys would be the preferred
option, but they have also drawbacks such as higher cost (e.g.
AlSi7Mg due to its lower limits for impurity elements), poor
castability (e.g. AlCu4Ti) and insufficient high temperature
performance.
Price
For economic and technical reasons, almost all aluminium engine
blocks are produced using alloys based on recycled aluminium
(AlSi8Cu3, AlSi6Cu4). However, new requirements for an increased
ductility could require the use of alloys with a reduced impurity
content closer to the composition of primary casting alloys.
Castability
Castability is generally improved with increasing silicon content.
On the other hand, copper additions which are needed for high
temperature strength have a negative effect on the feeding
behaviour. When the high pressure die casting process is applied,
alloys with a certain iron and/or manganese content are necessary
to prevent molten metal sticking to the die. But iron additions
also reduce the mechanical properties of the cast component.
Other alloy specification aspects
In some cases, other requirements may be more important selection
criteria than cost and castability. In order to avoid the use of
weight-increasing cast iron liners or costly coating solutions for
the cylinder surface, some high performance engines are produced
completely from hypereutectic alloys (AlSi17Cu4) which directly
provide a wear-resistant cylinder lining.
