An exceptional original Ferrari factory engineering drawing for the rear timing case (Scatola distribuzione posteriore) of the Tipo 031 turbocharged Formula One engine, produced during the development of Ferrari's 1985 Grand Prix programme.

Executed by Ferrari's Uffici Tecnici at a full 1:1 scale, the blueprint measures approximately 245 × 104 cm and is printed on original Ferrari watermarked paper. The title block identifies drawing number 031-221101, records an issue date of 15 October 1984, and carries a Ferrari factory revision stamp dated 24 January 1985, placing the drawing directly within the period of development and production of the Tipo 031 engine.

The blueprint originates from the estate of Renzo Medici, who joined Ferrari in 1947 and spent almost four decades within the company, ultimately serving as Head of Parts Production in Reparto Corse. As such, it represents not only an exceptionally rare surviving Ferrari Formula One engineering document, but one with direct provenance to a senior member of Ferrari's racing department during one of the most significant periods in the company's history.

Very good condition, folded as originally supplied.