Thursday, June 30, 2011

Aston Martin DB4 - The Legendary Sports Car

The Aston Martin DB4 arrived in 1958 and represented the finest contemporary interpretation of the Gran Turismo theme. A magnificent synthesis of the talents at the firm's Feltham works and the Italian Touring styling house, the DB4 was, during its five years of production, the best selling model which paved the way for the even more successful Aston Martin DB5 & DB6 succeeding models.

The story of the DB4's development really began in 1950 when John Wyer started at the Feltham works as competitions manager moving from his post as managing director of sports-car specialists Monaco Engineering. Another 1950 recruit was design draftsmen Harold Beach, whose previous career had included spells at the Barker Coach building Company and Garner Strausler Mechanization, who built commercial vehicles as well as ancillary equipment.

It was in 1964 that Beach began working on a DB2 series replacement, which was to be titled "DB4", the DB3 being one of the firm's sports racers. Known as Project 114 it had a perimeter chassis frame with a sophisticated (for its time) de Dion rear axle employing parallel trailing links, the lower ones connected to laminated torsion bars. At the front end of the car Beach introduced wishbone and coil independent front suspension where the DB2 by contrast had a trailing arm system. A 3-Liter version of the then current twin-cam six was employed and Frank Feely designed a traditional suitable closed body, not dissimilar to that of the DB2.

Significant changes were made to the specifications in 1956 with the appointment of John Wyer as general manager. Previously Mr. Wyer had held title and position as technical director. Beach was later to remember Wyer's promotion as one of the utmost and greatest lasting significant factors in the DB4's development as giving a "true sense of direction and purpose to the project" at Feltham.

The first modification of the concept came with the decision to dispense with the Lagonda engine and replace it with a purpose built Aston Martin unit. It perpetuated the twin overhead camshaft six-cylinder theme and in its production form had square 92 mm x 02 mm dimensions which gave the power plant a capacity displacement of 3670 cc. In its starting out point, in its original format the mechanical engineer designer Tadek Marek specified a cast-iron engine block, but this was subsequently upgraded to aluminum with chrome vanadium wet cylinder liners. The power plant head was of the same materials with valves essentially at 80 degree included angle, while at the other end of the engine was a robust seven-bearing crankshaft. In this form the engine developed a full 2400 bhp at 5700 rpm.

The DB was announced in October 1958 to a rapturous reception overall so much so that it immediately received the moniker "Aston Marvel." The racing mock up the 3 Liter DB III had a top speed in the ranges of 120 mph ( 193 km) yet the top speed of the DB4 - which was of course a high end retail production unit - was an amazing near 140 mph ( 225 kph). What a thoroughbred racehorse of a sports car.


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