Light alloy technology is actively involved in the production of Maserati mechanical parts used in the new eight-cylinder engine. This expertise is an important stage in a production cycle geared around excellence.
Cylinder blocks, heads and crankcase panels are made at the Ferrari foundry in Maranello, Italy, the same facility that makes Ferrari road cars and Formula 1 race engines. A special metal alloy is used in this procedure that goes by the technical code A356 or ALSI7. This code indicates a composition based on aluminium, silicon (7%) and an extremely low percentage of iron to improve the mechanical characteristics of each individual element.
The production cycle begins with an in-depth check of the metal to be used. When a new batch of metal destined for casting arrives, it is checked to make sure it conforms to the established technical standards. Once it has been certified as top grade material, the ‘cores’ and ‘shell’, which will hold the metal cast for making the cylinder heads and crankcase, are prepared.
Technically speaking, the ‘cores’ are sand models that reproduce all the cavities of the piece to be cast and are obtained by injecting a special sand-resin mix into a pre-formed cavity. The ‘shell’ is a negative mould of the final casting and is the form inside of which the liquid metal (at 720 degrees) is cast. The latter is obtained by fusing the ingot after it has been refined and artificially degassed to ensure that specific chemical characteristics and densities have been attained. Once the cores have been positioned inside the shell and the metal is cast, a controlled cooling process begins to prevent bubbles forming inside the casting.
Heat is used to dispose of the sand cores, placed inside the shell to prevent the cast from filling the cavities and tubing (like the air intakes and exhaust). In a hot air furnace (heated to around 500 degrees C) the resin that kept the sand mould compact and united melts and all of the grains are ready to be recycled. At this time any residues in the metal are removed and the interior of the structure is heated to homogenise it. Then comes an ageing procedure, again through heat treatment, that makes the components more hardwearing.
Finally, to maintain high standards, each component undergoes a final examination. On top of this, a series of radioscopic sample checks are made every single day.