The first stage sees a ‘core box’ filled with a sand-resin mixture whose binding agent remains unidentified. Compressed air is blasted into it to seal the mixture. “This is what we call the ‘core box’ being ‘shot’,” says Santini. “A bit like a cake tin being cooked in the oven.” It is then hardened by smothering it in sulphuric dioxide gas. Any residue gas is ‘washed’ away by blowing compressed air over the ‘core’. The resultant compacted sand shape is then extracted. In the foundry’s esoteric vocabulary this delicate form is evocatively referred to as an ‘anima’ – a ‘soul’.
“It is effectively an inversion of the shape, the engine part, that we are trying to create,” says Santini. Its fine structure is necessarily reinforced by the insertion of iron wiring that has a diameter of one millimetre or less. That delicate task is done by a very steady, gloved, hand. The ‘anima’ or ‘core’ is then carefully ‘de-fleshed’ – excess material removed by hand, creating cavities and so on. Often times an amalgamation of ‘cores’ are glued together to resemble the desired engine part.
What exits is the real engine piece. The hot moulded shape has any sand removed, and the iron wiring extracted. Again by hand. The same complex modus operandi is used for a variety of Ferrari engine parts, with up to 150 made in any one batch of moulds.
“We make all the V12 cylinder heads right here in the Maranello Foundry,” says Santini, with evident pride. Such precision engineering means working at extremes: “The more you go to the extremes”, he reasons, “the more you need the human touch.”