C7.1 Diesel Used Engine Blocks For Excavator E320D2 Water Cooling
|Car name: Engine cylinder block|
|Model Number: C7.1|
|Engine type: Diesel|
|valve: 24 valve|
|The number of cylinder: 6|
|Work form: Turbo|
A crack of the cylinder block
Once a crack or leak has been identified, it’s important to inspect the casting closely to determine the full extent of the crack. Cracks that are visible on the surface of a casting often extend some distance under the surface in both directions. So when making crack repairs, don’t assume a crack ends where the surface appears solid because it may extend under the surface like the roots of a tree.
The repair technique for fixing a crack will depend on the type of metal (cast iron or aluminum), the location of the crack (a stressed or non-stressed area), and the size of the crack.
Cracks typically appear in the most highly stressed areas of a casting. These include the areas between the valve seats in a cylinder head, the area between the valve seats and spark plug hole, the deck area between combustion chambers, the top center area of the head, and the exhaust ports. Cracks can start in the combustion chamber and extend into intake or exhaust ports, or radiate from blind holes, open bolt holes or valve guides.
Cracks in the block can occur between the cylinders on the deck surface, in the cylinder walls or in the web area around the main bores and crankshaft. You might also find cracks around the lifter bores or cam bores, or even in the sides or corders of the block near motor mounts or expansion plug openings.
The greater the thermal stress and/or mechanical load on a particular area of a casting, the more likely it is to crack – especially if the casting is relatively thin.
Brand new castings are usually assumed to be crack-free but defects in the casting, improper cooling after the part was cast can result in cracks, too. A more common problem with new aluminum castings is porosity leaks. That’s why new castings should be inspected just as carefully as used, high mileage castings to make sure there are no cracks or porosity leaks that will cause problems later on.