Lagonda Straight-6 engine

The Lagonda Straight-6 is a famous automobile engine used by Aston Martin and Lagonda marques in the 1950s. Designed by Walter Owen Bentley (eponymous of the Bentley Motors Limited company), it vaulted Aston Martin to fame as a maker of desirable sports and racing cars.

History

After World War II, W. O. Bentley began working on a new straight-6 engine for the Lagonda marque. This had become his new employer after the purchase of his company by rival Rolls-Royce, who refused to return it to racing and had replaced many of his chassis and engine designs with their own.

Bentley and his team developed a modern dual overhead cam straight-6 engine. It initially displaced 2.6 L (2580 cc/157 in³) with an 83 mm (3.3 in) bore and 90 mm (3.5 in) stroke and produced roughly 105 hp (78 kW) with dual SU carburettors.

The Lagonda straight-6 caught the attention of David Brown, who had purchased Aston Martin in 1947. Aston's Claude Hill-designed four cylinder was not powerful enough for Brown, who desired a powerful, and high-tech, powerplant for his new automobile company. So Brown purchased Lagonda as well, incorporating Aston Martin Lagonda Ltd. that same year.

The first production vehicle to use Bentley's new engine was the 1948 Lagonda 2.6-Litre. This was a large car for the place and time, available as either a 4-door saloon or 2-door convertible, and it could only reach 84 mph (135 km/h).

Sales were slow, but Aston's 4 cylinder 2-Litre Sports model was barely selling at all. Brown decided to share the straight-6 with Aston, creating the wildly successful DB2 model. This car placed first and second in class at the 24 Hours of Le Mans on its introduction in 1950, propelling Aston Martin into the top tier of post-war sports car companies.

The 2.6 L straight-6 went on to power the DB3 racing car and DB2/4 road car (the world's first hatchback), before being enlarged to 2.9 L (2922 cc/178 in³) in 1952. Power eventually reached 195 hp (145 kW) with twin three-choke Weber carburettors in the "DBB"-spec DB Mark III, but the engine by then was showing its age. It was replaced for the DB4 and later cars by a 3.7 L straight-6 designed by Tadek Marek.

Applications

* 2.6 L (2580 cc/157 in³)
** 1948–1953 Lagonda 2.6-Litre
** 1950–1953 Aston Martin DB2
** 1950–1952 Aston Martin DB3
** 1953–1954 Aston Martin DB2/4
* 2.9 L (2922 cc/178 in³)
** 1952–1953 Aston Martin DB3
** 1953–1956 Aston Martin DB3S
** 1953–1958 Lagonda 3-Litre
** 1954–1955 Aston Martin DB2/4
** 1955–1957 Aston Martin DB2/4 Mark II
** 1956–1959 Aston Martin DBR1
** 1957–1959 Aston Martin DB Mark III