1954 Lagonda DP115

The Lagonda company, established in 1906 by Wilbur Gunn in Britain, originally focused on manufacturing motorcycles before shifting its production to automobiles. Over the years, it has built a strong reputation for its commitment to quality, innovative design, advanced engineering, and high performance.

Walter Owen (W.O.) Bentley sold his namesake company to Rolls-Royce in 1931 and, after a few years, left Rolls-Royce to work at Lagonda, serving as Technical Director. Other ex-Rolls-Royce employees who joined Lagonda included Stuart Tresillian and Charles Sewell, and design expert Frank Feeley. Under Bentley's leadership, a new short-stroke, single-cam, 60-degree V12 engine was introduced in 1937 and installed in an equally advanced, X-braced chassis with a torsion bar independent front suspension, hypoid rear axle, and Lockheed hydraulic brakes. The 2,580cc twin-overhead cam six-cylinder was also the work of Bentley and Watson, developed near the end of World War II.

After World War II, Lagonda was acquired by gearbox manufacturer David Brown and integrated in with another of his recent purchases, Aston Martin. Lagonda and Aston Martin were both British-based automobile companies with deeply rooted histories. Aston Martin was established in 1913 by Lionel Martin and Robert Bamford. Despite experiencing numerous financially challenging periods and changes in ownership, the brand gained a reputation for its success in competitions as well as its production of sporty road vehicles. Among its accolades was a victory in the 1928 Le Mans 24 Hours with its LM model. Lagonda also had a victory at Le Mans, with Johnny Hindmarsh and Luis Fontés piloting a 4.5-liter, six-cylinder M45 Rapide to 1st place in 1935.

Mr. Brown acquired Aston Martin for its box-section chassis and Lagonda for its engines. The early cars built under Mr. Brown's ownership used Aston's Claude Hill-designed four-cylinder engine, but it was not powerful enough for Brown. So Brown purchased Lagonda for its 2.6-litre straight-6, and the new model was called the DB2. Its performance credentials were proven when it won the 24 Hours of Le Mans in 1950. The 2.6-liter straight-6 later powered the DB3 racing car and the DB2/4 road car. Enlarged to 2.9 liters in 1952, it powered the DB3 and the DB2/4 MK1. Upgraded with triple twin-choke Weber carburetors, this nearly 200-horsepower engine was installed in the DB Mark III. The forthcoming DB4 and later cars were powered by a Tadek Marek-designed 3.7-liter straight-6 engine.

Lagonda DP115
The six-cylinder engine had practical applications for Aston Martin's road-going cars and its sports racing program; a twelve-cylinder engine was less practical. However, it would offer the chance for overall triumphs against competitors with larger engines. Instead of using the Aston Martin nameplate, David Brown chose to revive the Lagonda name for the new engine. The V12 program would not achieve the desired success, but it would inspire and spawn successful Aston Martins both on and off the track.

Mechanical Specification
The V12 Lagonda was given the designation DP115. Willie Watson was tasked with its creation, and he used the existing straight six as inspiration. It was given double overhead camshafts, two plugs per cylinder, and a trio of 40mm four-choke downdraft carburetors. Its dry-sump lubrication was a 'first' for a post-war Aston Martin engine. While the six made use of cast iron, the twelve used aluminum for the heads and crankcase. Although it was a lighter material, it caused the block to expand away from the main bearings as it heated up, causing a loss of oil pressure.

With a bore size of 82.5mm and a stroke of 69.8mm, the engine displaced 4,486cc, a similar size to the Ferrari engines of the era. Initially, the engine produced 280 horsepower but following additional modifications, output reached 350 bhp.

The chassis used to carry this new engine followed a design similar to the one used by the DB3S, but enlarged and strengthened to cope with the more potent unit. The lengthening of the wheelbase proved to be another weak spot for the DB115, as it weakened rigidity and caused issues with handling.

The front suspension had trailing arms and torsion bars, while the rear used a DeDion setup. There was a limited-slip ZF differential, a David Brown manual gearbox, and four-wheel drum brakes.

Testing
David Brown drove DP115 during the V12 Lagonda during a test session at Chalgrove airfield in Oxfordshire in March 1954. An engine fire ensued, but neither the car nor the driver were harmed. The necessary repairs to the engine were made in anticipation of the car's inaugural race debut at Silverstone in May 1954.

Competition
Reg Parnell drove the Lagonda (chassis DP115/1) at Silverstone where an oil pressure issue limited engine revolutions but still allowed the car to manage a respectable fifth-place finish. He was well behind the more powerful Ferraris but ahead of the three-liter Aston Martins.

The twelve-cylinder Lagonda suffered from a lack of power and development; however, with limited time available to address these shortcomings prior to Le Mans, the team made every effort to improve the situation. The previous four-speed gearbox was replaced by a five-speed unit, and a large air intake was added to the nose.

Two DP115s were scheduled to contest LeMans (chassis DP115/1 and DP115/2), but one (DP115/2) withdrew before the start and was replaced by a fourth DB3S. Throughout the race, the inclement weather exacerbated the handling difficulties of the cars, resulting in Eric Thompson spinning off the track during the second hour.

Thompson was able to return to the pits, but repairs were unable to be made due to the extent of the damage. A 5-liter Ferrari 375 Plus won the race, followed by Jaguar D-Type in second and a Cunningham C-4R in third. None of the Aston Martins were able to finish.

The DP115 that had withdrawn from LeMans (chassis DP115/2) made its racing debut at the British Grand Prix, where it finished in fourth position behind a trio of Aston Martins.

Preparations were made to race DP115/2 and a third car, DP115/3, at the 1955 Mille Miglia, however, neither car ultimately participated in the race. Both cars were sold to Rank Organization and starred in the 1956 movie Checkpoint.

Development of the V12 program for the 1955 season included the construction of a new multi-tubular spaceframe chassis. Two examples were built and they were known as the DB166. Using the same engine as the DP115, one example contested LeMans but made it 94 laps before fuel feed issues forced its retirement. With another disappointment, David Brown cancelled the program and focused on its DB3S Aston Martins which had finished second overall at Le Mans and first in class.

by Daniel Vaughan | Sep 2024