The P538 or P538S was a rear mid-engined race car launched in late 1965 or early 1966 by Scuderia Bizzarrini of Livorno, Italy. At least two P538s were built with Chevrolet Corvette 327-cu.in. V-8s, and two more with 4.0- and 3.5-liter Lamborghini V12 engines. Five-speed manual transaxles were used, with gearing specific to the race for which each car was constructed. Braking was via inboard four wheel disc brakes, with a fully independent suspension. The body was made of fiberglass over a tubular steel chassis.
The first V-8 powered car debuted at Le Mans in 1966, with Swiss drivers Edgar Berney and Andre Wicky, but records indicate that the team retired after three hours with a cooling problem. A second team in a production-based Bizzarrini A3/C, driven by Sam Posey and Massimo Natili, was disqualified after a pit lane violation, possibly while returning with serious frame damage.
American Ferrari driver Mike Gammino then commissioned a Lamborghini 4.0-liter V-12 powered car, which he raced once. Bizzarrini attempted to build a second, 3.5-liter V-12 car for Le Mans, but was unable to complete it before bankruptcy.
Beginning in the mid-1970s and continuing at least through the 1990s, former Bizzarrini engineer Salvatore Diomante at Autocostruzione SD, Torino, began building continuation P538s on commission for private buyers. These may be distinguished from 1960s-built cars by the use of square as opposed to round tubing. The first two cars of this series using square-tube construction bear serial numbers #002 and #003; 3.5-liter V-12 Van Horneff car also uses serial #002 (see below), and was last known to be located in England. Engines vary, but include Chevrolet V-8s, Lamborghini V-12s and possibly a six-cylinder Fiat. He constructed an unknown number, using original fiberglass body molds, probably fewer than 8. Giotto Bizzarrini and his wife likely assisted in construction of the early cars, and they were built using some original Sixties Bizzarrini components as available.
The surviving P538s
Even Bizzarrini’s “production” A3/C and 5300 GT road cars are often obscure in origin; today, neither Bizzarrini nor Gammino are entirely clear on what happened more than 40 years ago. However, both agree that there has been no correct accounting of the P538s. There are definitely two surviving V-8 and two V-12 cars; there may be as many as four more V-8 cars.
Chevrolet V-8 powered cars:
Bizzarrini used the first P538 built for development work in the beginning of 1966, and it probably crashed that winter. The car that appeared at Le Mans four months later may have been this car; it may have been a second car; or more likely, it reused any and all salvageable parts of the original car, whatever those were.
In 1967, Bizzarrini rebodied at least one V-8 as a coupe and sold it to the Duke of Aosta (it is known as the Duca d’Aosta coupe). Some sources suggest this was a third V-8 car, possibly constructed as a second 1967 Le Mans entry. Another, possibly the 1966 Le Mans car, was also rebodied; it ended up in the hands of Giugiaro at ItalDesign; he rebodied it a third time (at least) as his Manta show car. Both the Duca d’Aosta and ItalDesign cars have remained in those configurations, and are the only V-8s that can be reliably confirmed as Bizzarrinis built in the 1960s.
Lamborghini V-12 powered cars:
Mike Gammino’s 4.0-liter car, often called 001 but actually un-numbered, was completed in 1965, after which he imported it into the US. He ran it once at Bridgehampton, where “we had some problems with it.” He gave it to his mechanic Libero Gerardi, and after his death, it passed through a series of owners until it landed at the San Diego Automotive Museum.
The other V-12 P538 uses a Lamborghini 3.5-liter engine and is stamped P538 002 on a front stabilizer. It was built for the 1967 Le Mans 24h but never completed. According to an interview with Sir Stirling Moss, the transaxle casing appears to be identical to an Alfa Romeo Tipo. Disassembled by Bizzarrini by 1970, he finished it as a commission in 1974 or 1975. It is currently owned by American Van Horneff.