Guide: Aston Martin DB4
Background
Various iterations of the DB2 had served Aston Martin well throughout the 1950s but, towards the end of the decade, the platform was clearly beginning to show its age.
When the DB2 was launched in March of 1950, it was widely regarded as the finest Grand Touring car in the world. Early class wins at Le Mans and the Mille Miglia were evidence the handsome machine was a match for any road-going model Ferrari or Maserati had to offer.
The DB2 was replaced by the DB2/4 in 1953. In Coupe trim, the DB2/4 featured fold-down rear seats and a hatchback body style. Mk1 and Mk2 variants were manufactured prior to the DB Mk3’s introduction during 1957.
Although Aston Martin’s WO Bentley-designed dual overhead camshaft straight six engine had been progressively developed throughout this period, the firm’s chassis technology had remained largely static.
That was to change with the arrival of the DB4 in late 1958.
Styled by Touring of Milan, the DB4 was the first Aston Martin to be built at the company’s Newport Pagnell factory in Buckinghamshire. Formerly the Tickford coachworks, Tickford had been acquired by David Brown in late 1955 as Aston Martin had outgrown its Feltham plant.
Launched at the Paris Motor Show in October 1958, the DB4 was offered alongside the DB Mk3 for about a year, after which it became Aston Martin’s solitary offering.
Chassis
Every major component of the DB4 was new.
A pressed steel monocoque replaced the old fashioned tubular chassis; its wheelbase was 2489mm compared to 2515mm for the DB Mk3.
Independent front suspension was via double wishbones, Armstrong shocks, coil springs and an anti-roll bar. The live rear axle used parallel trailing links, coil springs and a Watt’s linkage.
Aston Martin equipped the DB4 with all round disc brakes; a first for one of their production models. Dunlop and later Girling discs were used while power-assistance came courtesy of a Lockheed servo.
16-inch wire wheels were shod with Avon TurboSpeed crossply tyres as standard or optional Pirelli Cinturato radials. Track dimensions were unchanged from the DB Mk3 at 1372mm front and rear.
A 19 gallon fuel tank was fitted underneath the boot floor.
Engine & Gearbox
In the engine bay was a thoroughly reworked version of Aston Martin’s dual overhead camshaft straight six.
The DB4 redesign was carried out by Aston Martin’s Polish engineer, Tadek Marek.
Whereas the original motor used a cast-iron block, this latest iteration was switched to an all-alloy construction and came in 22kg lighter.
Each cylinder bore was expanded from 83mm to 92mm while the stroke was taken out from 90mm to 92mm. Displacement rose from 2922cc to 3670cc.
Wet-sump lubrication was employed along with single plug ignition. Twin SU HD8 carburettors were fitted and compression was increased from 8.2 to 8.25:1.
Aston Martin quoted a peak output of 240bhp at 5000rpm and 240lb-ft at 4200rpm. This compared very favourably to the DB Mk3 which produced 162bhp at 5500rpm and 180lb-ft at 4000rpm.
Transmission was via a David Brown four-speed manual gearbox, single dry plate Borg & Beck clutch and a Salisbury rear axle.
Bodywork
During the early and mid 1950s, several Aston Martins received special bodywork from Italian coachbuilders.
Firms like Pininfarina, Bertone, Touring, Ghia and Vignale had been responsible for some of the most beautiful automotive creations ever seen, so it came as no surprise when David Brown looked to Italy’s myriad design studios to clothe his latest model.
Brown eventually handed the contract to Touring of Milan.
The result was a stunning fastback 2+2 that utilised Touring’s patented Superleggera construction technique. This involved aluminium body panels skinned over a skeletal frame of small diameter steel tubes that conformed to the body shape.
As the DB4 used a steel monocoque, the Superleggera framework was only required for the bonnet surround, windscreen, roof, rear wings and tail.
Bodies were produced in-house at Newport Pagnell under licence from Touring.
Exposed headlights were mounted either side of a mesh grille that followed the by now traditional Aston Martin shape. Full width chrome bumpers were fitted front and rear.
The bonnet was home to a large hood scoop that fed fresh air to the engine. Cooling vents complete with a decorative chrome bar were carved out from behind each front wheelarch.
One continuous line swept from the front to the rear of the car. Upright tail lights were integrated to the subtly finned rear fenders.
Frameless front windows were initially fitted.
Visually the new model was an enormous success. It was modern, uncluttered and well proportioned. Compared to the Pininfarina-styled Ferrari 250 GT Coupe and Touring’s Maserati 3500 GT, the DB4 looked an absolute winner.
Interior
The light and airy cockpit was equipped to an exceptionally high standard.
Leather was used to upholster the well-padded seats, the side panels and gear gaiter. Dashboards were a mix of painted black metal and hard-wearing crinkled vinyl.
The instrument binnacle was home to a full complement of Smiths instrumentation.
Directly behind the wood-rimmed three-spoked steering wheel was a 6000rpm tach and 160mph speedometer. Immediately to the left was a combined ammeter and water temperature gauge. To the right was a combined oil temperature and fuel gauge. A clock was positioned in the centre of the dashboard (above the ventilation controls) and various toggle switches were scattered elsewhere.
Thanks to slim pillars and a large glass area, visibility was excellent.
Rear head and legroom was sufficiently generous that four adults could travel in comfort.
Options
Options included a choice of final drive ratios, an overdrive manual gearbox or Borg-Warner three-speed automatic. If a radio was specified, the head unit and speaker were mounted between the transmission tunnel and dash.
Weight / Performance
Aston Martin quoted a kerb weight of 1354kg.
With the standard 3.54 final drive ratio the DB4 had a top speed of 140mph and 0-62mph time of 7.2 seconds.
Production Changes
The DB4 was extremely well received at both the Paris and London motor shows in October 1958. However, updates were soon being phased in.
After the first 50 or so examples had been completed, bumper overriders and door window frames were introduced.
By January 1960, 149 DB4s had rolled out of the factory, 73 of which were left-hand drive.
Series 2
Aston Martin then made a series of more significant changes.
Retrospectively referred to as Series 2 derivatives, these latest examples came with a bonnet hinged from the front instead of the rear, a sump enlarged from 14 to 17 pints, an uprated oil pump, more effective front brake calipers and opening rear windows made with flat instead of curved glass. This additional equipment added around 45kg to the overall weight.
New options included electric windows and an oil cooler. When the oil cooler was specified an intake scoop was added underneath the front bumper.
349 Series 2 DB4s were built between January 1960 and April 1961, around 90 of which were left-hand drive.
Series 3
Further improvements were made from April 1961.
Most noticeably, the original tail lights (which had been sourced from the DB Mk3) were switched to a trio of individual pods mounted inside a chrome shroud.
The heating system was improved with five windscreen demister vents instead of three, an electric rev counter was installed and the two steering column-mounted control stalks were reduced to one.
The handbrake, clutch cover and brake pedal linkages were also modified.
A new but rarely specified upgrade was the installation of an expensive DB4 GT engine.
Constructed from lighter RR50 alloy, these high compression GT motors came with a twin plug head, two distributors, three Weber 45 DCOE carburettors and high-lift camshafts. Output was a class-leading 302bhp at 6000rpm with 270lb-ft at 5000rpm.
176 Series 3 DB4s were built between April 1961 and September 1961, approximately 60 of which were left-hand drive.
Series 4
Relatively few changes were made to the subsequent Series 4 variant.
Most importantly, the previously optional oil cooler was made standard.
Visually, these latest derivatives came with a flatter and wider bonnet intake scoop and a bar rather than meshed front grille.
Inside, the ashtray was moved from from the top of the dash to the transmission tunnel.
A new DB4 Vantage was also offered from the start of Series 4 production. Covered in detail elsewhere, the DB4 Vantage came with a more powerful engine and GT-style bodywork with faired-in headlights.
At the London Motor Show in October 1961, Aston Martin launched a Convertible DB4. This elegant drophead came with a smaller 16-gallon fuel tank and could be ordered with an optional hardtop.
Series 4 production continued until September 1962 by which time around 200 had been built. Around 60 are estimated to have been left-hand drive.
19 non-Vantage Convertibles were also built. Vantage-engined Convertibles did not receive the GT-style bodywork.
Series 5
The final iteration of the DB4 was produced from September 1962 to June 1963 but only 50 Series 5 Coupes and 19 Series 5 Convertibles were built, principally owing to the popularity of the more powerful Vantage.
Mechanical changes included an airbox for the carburettors, an electric fan in front of the radiator and smaller brake pads.
Cosmetically, the Series 5 was a little taller and slightly longer than before to allow for more cockpit space and a bigger boot. The wheel diameter was reduced from 16 to 15-inches to keep the overall body height the same.
These last-of-the-line examples also came with tail light clusters that featured a reverse light instead of a red reflector. The reflector was moved to a re-shaped pod on the bumper.
A bigger body coloured number plate light was also added to the tail. For safety reasons the front the indicators were made larger.
The DB4 was subsequently replaced by the DB4 Vantage-based DB5.
Text copyright: Supercar Nostalgia
Photo copyright: Aston Martin - https://www.astonmartin.com
