Having just bought Aston Martin and Lagonda, gearbox manufacturer David Brown wanted to focus on developing a production car first. He bought both companies as he liked the newly developed box-section Aston Martin chassis and the W.O. Bentley and 'Willie' Watson designed straight six cylinder engine. The first Aston Martins built under Brown's ownership still used the old four cylinder engines and Brown reluctantly had one prepared for the 1948 Spa 24 Hours. Despite being built at the very last minute, the Aston Martin took a surprise win. It was the start of Aston Martin's renewed racing efforts, first with production based machines and later with full blown racers.
Still using the Lagonda design as a basis, Aston Martin fielded the brand new 'DB3S' sports racer at the start of the 1953 season. It was a commendable racer in the three litre class, but for overall victories it was regularly beaten by the larger engined Lancias, Ferraris and Jaguars. To go for the much coveted overall victories, Aston Martin needed a considerably larger engine, but there would be no road going Aston Martin model to fit it in and make it viable. Instead David Brown decided to revive the Lagonda name and design a brand new engine that would propel both the new racing car and a luxury Lagonda road car.
Impressed in particular by Ferrari's engines, Brown commissioned 'Willie' Watson to develop a V12 engine with a displacement of 4.5 litre. Following the basic design of the original straight six, the new engine featured double overhead camshafts and two plugs per cylinder. To keep the weight down, the entire engine was constructed of aluminium. Equipped with three quad-choke Webers, the Lagonda V12 initially produced 280 bhp, but with some work Watson estimated 350 bhp could be achieved. Mated to a four speed gearbox, the engine was installed into a slightly larger and beefed up DB3S chassis. A body similar to that of the DB3S was fitted although with three separate front air intakes.
At the very first test, with David Brown at the wheel, the Lagonda with code name 'DP115' caught fire. The car was repaired in time before the 1954 Silverstone sportscar race and Reg Parnell drove it to a fifth position, well behind the Ferraris and Jaguars, but ahead of the three-litre class winning Astons. At that time the engine produced around 310 bhp, whereas the Ferraris topped 350. Another problem was that the engine would not fire up in cold conditions, so it had to be preheated by filling the radiator with hot water. Parnell also complained about the handling characteristics, but there was no time and budget available to rectify the problems before Le Mans.
For Le Mans the four speed gearbox was replaced by a five speeder and the nose of the Lagonda modified with a single large air-intake similar to the one on the DB3S. Initially two DP115s were entered, but one was withdrawn and replaced by a fourth DB3S before the race. The Lagonda's poor handling characteristics did not quite suit the wet conditions and Eric Thompson spun off the track violently after just two hours, while lying in third position. He did manage to bring the car back to the pit, but it was damaged too severely to be repaired in the pits. None of the Astons managed to reach the finish either. The second DP115 made its debut at a support race for the British Grand Prix and finished fourth behind three Astons. Neither car was raced again in period.
Even though the 1954 results were far from promising, David Brown refused to give up on the V12 engine. He commissioned the construction of a brand new multi-tubular spaceframe/backbone chassis for the 1955 season. Two examples were constructed and known as the DP166. They used the same engines as the DP115 and one was entered at Le Mans. It retired after just 94 laps with fuel feed problems and that really was the end of the V12 program. There was good news for Brown as one of the DB3S Astons entered finished in second overall and first in class. The backbone chassis of both DP166s were later reused to form the mighty Aston Martin DBR2s.
Featured is one of the two DP115s as used in the 1954 season. Now fully restored, it is piloted with great skill during selected historic races. Its most recent outing was the 2007 Goodwood Revival where it won the Freddie March Memorial Trophy race.