Editing Engine block (section)

=== Materials ===
Engine blocks are typically cast from either [[cast iron]] or an [[aluminium alloy]]. Aluminium blocks are much lighter and transfer heat more effectively to coolant, but iron blocks retain some advantages, such as durability and reduced [[thermal expansion]].

'''Weight reductions through material selection'''. Presently, most of the engine blocks in mass production are gray castings. Reducing weight has resulted in using aluminum-silicon alloys more frequently for the engine block in small-displacement engines. Engine blocks of comparable design, but using Al-Si alloys, are not lighter than cast iron engine blocks in the same ratio as that for the specific weights of the materials.

In engine blocks made of gray cast iron, weight can be reduced by optimizing the structure and thin-wall casting. With this casting technique, a wall thickness of as little as about 3 mm is generally possible. In comparison, the walls of cast iron engine blocks are usually from 4.0 to 5.5 mm thick.

Using vermicular graphite cast iron (GGV), a casting material with great strength, enables weight reductions by about 30% compared to conventional casting materials such as GG 25. Weight reduction, to this extent, requires engineering for the engine block, taking into account the particular needs of the material.<ref>{{cite web |title=Minimizing Engine Block Mass |url= https://studedu.org/s1396t1.html |access-date=2024-05-14 |website=studedu.org}}</ref>