Water Cooling Used Engine Blocks Doosan DE12 Diesel For Excavator DX500

DE12 Diesel Used Engine Blocks For Excavator DX500 Water Cooling

Specification

Description

Pre-cast features and add-on parts
Depending on the applied casting process, additional components and/or functions such as water pump housings and flanges can be incorporated into the main casting. Furthermore, bore holes for bolting and oil channels can be directly cast.

While pre-casting of bolt bores is a standard technique today, the casting of very tiny features such as oil channels is now possible with advanced casting processes, e.g. the core package casting or the lost foam process.

Using high-precision sand cores, a variety of parts and flanges can be incorporated into a single casting. Issues like dimensional stability and accuracy of positioning have to be addressed. But higher costs for using an advanced casting process are easily compensated by savings in the area of machining and assembly.

Cast-in inserts
Engine blocks which are subject to very high loads, e.g. in case of direct injection diesel engines, can be reinforced in critical areas by cast-in inserts of higher strength materials. But cast-in inserts are often used also to provide specific functions.

Cast iron inserts for bearings
Aluminium casting alloys are generally not suitable for bearing applications for two reasons:Their wear resistance is not sufficient to withstand the sliding wear of the crankshaft.

The higher thermal expansion (compared to grey iron and steel) may lead to a not acceptable increase of the gap between the crankshaft and the bearing (which is strongly influencing the required oil pressure and increases the noise level).

For these reasons, cast iron inserts are often pressed into the component after machining, but they can also be directly cast-in resulting in reduced costs for machining and handling.

Cast-in cylinder liners
Specific types of cylinder liners (e.g. grey cast iron cylinder liners) can also be considered as cast-in inserts. Again, an insufficient wear resistance, but also not suitable tribological characteristics are the main driving forces to introduce cylinder liners into the bores of the aluminium engine block.