Development
The first series had a Maserati 300S-inspired body developed by Celestino Fiandri who also assembled the first few chassis together with Malagoli; Gilco soon took over this aspect. The tubular frame chassis was similar to that of the A6GCS, but with the important distinction of having a de Dion rear axle with transverse leaf springs rather than the A6's live rear end.[4] The wheelbase on the first four or five cars was 2150 mm; this was increased to 2250 mm beginning with chassis #1656.[7] Eight 1955s (first series) were built; some of them may have been fitted with the five-speed gearbox seen on the second series.
The second series followed during 1956; it changed from the original four-speed transmission with Porsche patent synchromesh to a five-speed unit made by ZF.[3] The more angular bodywork was all new, with a more aggressive nose and a truncated rear end. It was developed by Giulio Alfieri with a new focus on aerodynamics, incorporating a faired underbody, and built by Medardo Fantuzzi.[8]
The 1957 Maserati 150 GT was a spider built on a Maserati A6GCS chassis intended for street use, bodied by Fantuzzi and sporting a 150S engine with a lowered compression ratio.[9]
Massimino, the spearhead of Maserati's four-cylinder program, left for Stanguellini in late 1952 and was replaced at Maserati by Gioacchino Colombo.[10] Colombo, as well as Giulio Alfieri who joined Maserati in September 1953, preferred the six-cylinder design and the 150S/200S family was never developed to its full potential.[4] During 1956, partly as a result of unsatisfying competition results, Maserati accordingly stopped developing the 150S. The factory reengined one car (#1655) with a 250S engine, #1665 was equipped with a 200S engine, and chassis #1672 was reengineered to 200SI specifications and given the new chassis number 2407.[2] Briggs Cunningham swapped a 200S engine into chassis #1657 in 1956.[11] Stirling Moss referred to the series 2 car that he drove to victories at Monza and Nürburgring in 1956 as "overbodied and a bit gutless", which helps explain the numerous swaps for two-litre engines.[12] The engine (and its larger siblings), however, found new life in later years, being used to power mid-engined, British Formula Two and Formula One chassis into the early 1960s.
Tipo 6
The engine's second life began in 1956 with chassis number 1666, which was delivered to Brian Naylor in the United Kingdom.[13] Naylor found the car, designed for long-distance racing on the continent, too heavy for the short British circuits against the new, rear-engined British designs. He installed the 150S engine in a crashed Lotus Eleven, which proved highly successful with 27 victories and a class win that season.[13] An additional 150S engine was specifically built for Stuart Young to be installed in a Lotus Eleven in 1957, and a few F2 Cooper-Maserati T51s were similarly equipped. When Formula One changed to 1.5 liters maximum displacement for 1961, Maserati restarted production of the 150S engine as the "Maserati Tipo 6 1500". This iteration was updated and lighter at 130 kg, thanks to the generous use of magnesium alloys, and developed 165 hp-metric at 8,500 rpm rather than the 140 of the original design.[14]
10 such Tipo 6 engines were built for smaller teams like Scuderia Centro Sud, Ecurie Nationale Belge, JBW (Brian Naylor's own team[13]
