Born in Livorno, he began his career at Piaggio, makers of the Vespa scooter, but quickly moved up to larger engines. He worked at Isotta Fraschini before World War II, and then joined Reggiane to design aircraft engines.
Lampredi's fame brought him to Ferrari in 1946 where he designed large 3.3, 4.1 and 4.5 L versions of its V12 (the "Lampredi engine") which first saw use in the 1950s 275S, 340 F1 and 375 F1 race cars. Lampredi returned to Isotta Fraschini in March 1947 but returned to Ferrari at the beginning of 1948. Lampredi's engines were used as large naturally aspirated alternatives to the diminutive Gioacchino Colombo-designed V12s used in most Ferrari cars until that time. Especially after the failure of Colombo's supercharged engine in Formula One, Lampredi's design began to find favor in the company. Lampredi oversaw Ferrari's racing effort during its early success in 1952 and 1953.
Lampredi's work at Ferrari ended permanently in 1955 when Ferrari bought Lancia's racing team and famed engine designer Vittorio Jano, formerly of Alfa Romeo. Though Lampredi's engine designs lived on in Ferrari road cars, Jano's V6 and V8 engines quickly replaced Lampredi's large V12s for racing use.
After Ferrari, Lampredi went to Fiat, where he oversaw that company's engine design efforts until 1977. It was at Fiat where he designed the Fiat Twin-Cam and SOHC engines, which provided motive-force for most Fiat automobiles for over 32 years. He was also made manager of Fiat's Abarth factory racing group from 1973 through 1982.
He was responsible for designing the engine that allowed Fiat to allocate in the Brazilian market in 1976, the FIASA (acronym of Portuguese "Fiat Automóveis S.A). That engine equipped the Fiat 147, direct derivation of the European Fiat 127 but exclusively Brazilian. That was a big impact for the Brazilian automotive industry, because the Fiat 147 was the first national vehicle to have motor positioned in transverse position and command of valves controlled by a belt. It was also the first engine made on a large scale to be moved by Ethanol. Then, in 1979 the Fiat 147 is known to be the world's first car sold on a large scale to be moved by Ethanol. The project was so good, that Fiat used it with little changes in the original project until 2001, when the FIASA was superseded by the FIRE engine, also a straight-four engine, but bi-fuelled (Ethanol and Gasoline) and much lighter.
Lampredi died in Livorno in 1989.