QSM11 Diesel Used Engine Blocks For Excavator R385 - 9 4060393 4060394
|Engine type: Diesel||Model Number: QSM11|
|Cylinder stroke: 145||Cylinder diameter: 114|
|Application: Excavator||valve: 24 valve|
|Cooling: Water cooling||Injection: Direct or Electric|
The strength potential of aluminium has been hardly exploited in gasoline engines today. An optimisation of the common AlSiCu and AlSiMg casting alloys, the available casting processes and of subsequent heat treatments still offers significant growth potential for hardness and strength. Also for diesel engine blocks, the maximum lightweighting potential of aluminium has not yet been reached. The remaining potential in the areas of component design, alloy development and process improvements, but in particular also cylinder surface treatment technologies like plasma sprayed coatings suggest that aluminium will continue its advance in diesel engines.
On the other hand, in view of the increasing component loads due to the significantly higher firing pressures in future diesel engines, cast iron in the form of compacted graphite iron (CGI) is again competing with aluminium. Compared to the conventional lamellar graphite cast iron, CGI enables the realisation of smaller cross sections. The nodularity and tensile strength of the material also increases as wall-section decreases. The thermal and damping characteristics of CGI are midway between ductile and gray iron. It is five times more fatigue resistant than aluminium at elevated temperatures, and twice as resistant to metal fatigue as gray iron. Theoretically, a CGI engine block can be fabricated lighter than an aluminum block for equal power densities. Therefore CGI engine blocks are now gaining ground in high performance diesel engines, in particular in V-engines as there is a lot of flexing in the V-area between the cylinders when it is under power. CGI strengthens this physical area considerably.
Compared to all-aluminium engine blocks, additional lightweighting can be realized with a composite magnesium-aluminium alloy engine block as produced at BMW’s Landshut plant. The new magnesium-aluminum alloy crankcase for six-cylinder in-line gasoline engines is 24% lighter than a conventional aluminium block. A specific magnesium alloy system and a high pressure die casting (HPDC) process were developed together with the engine’s design.
Aluminium inserts incorporating cylinder liners and coolant ducts are used in the engine block. As the magnesium housing shrinks around the aluminium insert, the thermally complex casting process ensures that both components heat up and cool down at precisely the right time during production. The magnesium alloy engine shell never comes into direct contact with coolant water, since the water only flows inside the aluminum cylinder inserts.
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