Guide: Newport Pagnell to Milan - a Historical & Technical Appraisal of the Aston Martin DB4 GT Zagato (GTZ)
BACKGROUND
Twelve months after the base DB4 had made its highly anticipated debut, Aston Martin displayed a high performance, short wheelbase version generally supplied without rear seats aimed at those customers that wanted the ultimate British Grand Tourer of its day.
This new offering, dubbed the DB4 GT, could also be configured for competition use; by specifying the Lightweight option, Aston Martin would deliver a car capable of taking the challenge to Ferrari and Jaguar in the flourishing early sixties racing scene for production-based Grand Tourers.
To qualify for the Appendix J Grand Touring class, a manufacturer had to build at least 100 base cars during a twelve month period to which certain adaptions such as tuned engines, special coachwork and modified chassis were then permitted for competition use.
Compared to the base DB4, the DB4 GT most notably adopted the aforementioned shortened chassis, a tuned engine and a host of lightweight equipment to include a reworked air-piercing body.
At domestic level, and in the hands of top drivers such as Stirling Moss and Jack Sears, the DB4 GT proved difficult to beat during 1960. However, there was no doubt that, when the Aston came up against Ferrari’s latest iteration of the eponymous 250 GT, the SWB Berlinetta, the Maranello product had an edge.
For 1961, Aston Martin boss David Brown decided to commission a further uprated version of the DB4 GT – an aerodynamically superior, lighter and even more powerful machine that could challenge for Grand Touring class honours at the Le Mans 24 Hours and in the FIA GT Cup which was set for its second season. The decision followed an ill-fated and short-lived move into Formula 1 for the 1960 season after an enormously successful 1959 campaign had seen Aston Martin win the World Sportscar Championship and the Le Mans 24 Hours.
However, this new-for-1961 iteration of the DB4 GT would not mark an official return to competition for the Newport Pagnell firm, instead, factory support would be given to a couple of partner organisations.
To improve on the already impressive DB4 GT, Aston Martin carried out some minor tweaking of the existing straight six engine, but the big news was a collaboration with Zagato of Milan who were commissioned to develop a brand new lightweight body complete with a simplified interior.
Aston Martin initially expected to build 25 examples of the new DB4 GTZ (also commonly known as the DB4 GT Zagato). Each rolling chassis would be dispatched to Italy for the body and interior to be installed, after which the car would return to England for completion.
The first DB4 GTZ (chassis 0200/R) made its debut at the London Motor Show in October 1960 and customer deliveries began soon after. As per the DB4 GT, this Zagato version could be ordered in either road or racing trim.
CHASSIS
Like the DB4 GT, the GTZ was based around a shortened version of the regular DB4’s pressed steel monocoque. At 2363mm, 127mm (or five-inches) had been cut from the wheelbase to reduce weight, increase rigidity and improve handling.
The front suspension layout comprised double wishbones with coil sprung dampers and an anti-roll bar. At the back was a live rear axle with parallel trailing links, coil sprung dampers and a Watt’s linkage.
Disc brakes were fitted all round (as per the DB4 which had been the first Aston Martin road car thus equipped), but for the GT and GTZ larger diameter Girling as opposed to Dunlop discs were used and the servo-assistance was ditched to lessen weight and improve pedal feel.
More kilos were cut on the GT and GTZ by way of lighter 16-inch Borrani wire wheels which now came with three instead of two-eared spinners.
For increased range, the standard DB4’s 19 gallon fuel tank was replaced by a lightened aluminium alloy 30 gallon unit. The spare wheel was mounted on top of the fuel tank which meant luggage space in the trunk was greatly reduced.
ENGINE / TRANSMISSION
To eke out a little more potency from the existing straight six engine, Aston Martin increased the GTZ’s compression ratio from 9.0:1 to 9.7:1.
As a consequence, peak output went 302bhp to 314bhp at an unchanged 6000rpm and from 270lb-ft at 5000rpm to 278lb-ft at 5400rpm.
Otherwise the engine was to GT specification.
For the base DB4, Aston Martin’s existing dual overhead cam straight six had been redesigned by Polish engineer Tadek Marek. Among the most significant new features were an aluminium alloy instead of cast-iron block (saving 22kg) along with substantially increased displacement (from 2922cc to 3670cc).
Both the GT and GTZ retained the 92mm bore and stroke of the standard DB4 along with its wet-sump lubrication system, but an array of new equipment was specific to these high performance specials.
The block and head were now fashioned from lighter than normal RR50 alloy.
The GT / GTZ-specific head featured high-lift camshafts and twin instead of single plug ignition fed by two distributors as opposed to one. The modified head also allowed the compression ratio to be increased.
A bank of three sidedraught Weber 45 DCOE carburettors with cold air collection box replaced the twin SU HD8 items fitted to regular DB4s.
Transmission for the GT and GTZ was through a close-ratio version of the existing David Brown four-speed gearbox, a 9-inch twin-plate rather than 10-inch single-plate clutch and a Salisbury Powr-Lock limited-slip differential which was fitted as standard.
BODYWORK
Zagato’s design for the DB4 GTZ was the work of Ercole Spada who came up with a classic, beautifully proportioned creation that eschewed the kind of quirky features often found on the Milan firm’s work.
Aluminium panels were draped over the chassis in a minimalist fashion that meant muscular bumps and gentle curves appeared in surfaces that had previously been comparatively flat.
The front end was dominated by a gaping primary intake shaped in familiar Aston Martin fashion. Carved out from the front apron were three additional cooling slots, the size and profile of which often varied from car-to-car.
Located at the leading edge of the front fenders were headlights equipped with body shaped glass covers fastened in place with elegant chrome-plated bezels. Further up the plunging nose, Spada ensured adequate clearance for the engine by incorporating a trio of power bulges that further enhanced the GTZ’s dramatic appearance. Hot air was able to escape from the engine bay thanks to a pair of vents cut from the sides of the front fenders.
Instead of a Double Bubble roof as typically favoured by Zagato, the GTZ came with a smooth roofline for the five-window cockpit that swept back to a truncated tail in Fastback style. The cockpit sail panels were seamlessly integrated with macho rear fenders that featured a pronounced kick-up effect and recessed quick fuel filler caps.
In standard trim, the tail fascia was home to a pair of recessed circular lights on each side, below which was a distinctive cut away rear apron.
Compared to the standard DB4 GT, the GTZ was 53mm shorter, 51mm lower and 19mm narrower.
Much of the steel used in the GT’s body assembly was switched to aluminium. In the same weight-saving vein, no bumpers were usually installed and the side and rear windows were Plexiglas.
INTERIOR
In terms of cockpit fixtures and fittings, every GTZ came with simplified appointments compared to the GT version, but precise details varied from car-to-car.
Behind the wood-rimmed steering wheel with its three semi-gloss black spokes was also a GT-style seven-gauge instrument binnacle. This housed a large 7000rpm rev counter and 180mph / 300kmh speedometer in between which was a small ammeter.
Outboard of these were four additional small diameter read outs for water temperature, fuel, oil pressure and oil temperature. A clock was mounted off towards the centre.
Some GTZs imported the GT dash assembly with its ribbed upper and lower bands, top-mounted ashtray and lockable glove box. Others did without the ribbed bands, ashtray and glove box lid, but still had the forward upper section trimmed in the same black leatherette. The raciest specification adopted a more basic flat upper and vertical fascia away from the instrument binnacle.
New two-piece comfort seats had more heavily bolstered tilting backrests and were upholstered in a pleated pattern that mimicked the regular GT version. Some cars came with distinctive lightweight buckets of the type fitted to many Zagato-bodied competition cars of the day. These seats had fixed backs, either pleated or un-patterned faces and trademark semi-exposed bolsters.
GTZ door trim was also different to the GT – the basic un-patterned panels featured a window winder and grab handle and could be kitted out with an elasticated storage pocket.
Fully trimmed interiors were upholstered in a mix of leather and carpet. Behind the seats was a luggage platform broadly similar to that of the GT.
OPTIONS / PRODUCTION DIFFERENCES
In addition to the already mentioned front apron ducts, dash, seat and door trim differences, GTZ customers could have their car personalised in practically any way. Full width bumpers, glass instead of Plexiglas windows, alternative grille patterns, steel instead of aluminium body panels, an open hood scoop, exposed instead of covered headlights and different tail light configurations were all requested.
The 1960 London Motor Show car (chassis 0200/R) was configured with unique decorative side trim that swept back from the side-mounted engine cooling vent to the trailing adge of the door.
Elio Zagato’s own car (chassis 0181/L) was equipped with special bumperettes and door handles along with a transmission tunnel-mounted oddments tray.
WEIGHT / PERFORMANCE
In standard trim (i.e. with all the cockpit niceties on offer), the GTZ weighed in at 1171kg which represented a 98kg reduction compared to the DB4 GT.
Aston Martin officially quoted the GTZ as having an identical 153mph top speed and 6.1 second 0-62mph time as the GT. However, in reality, these cars, even in standard trim, could hit nearer 160mph and sprint to 62mph in under 6 seconds.
LIGHTWEIGHT (DP207)
Although Aston Martin had officially withdrawn from motor racing following 1960’s Formula 1 debacle, the company did support a quasi-works outfit in the shape of John Ogier’s Essex Racing Stable.
Having campaigned a pair of Lightweight DB4 GTs during the team’s inaugural 1960 season, Ogier acquired a brace of new Lightweight GTZs for the 1961 campaign: chassis 0182/R (registered 1 VEV) and chassis 0183/R (registered 2 VEV).
Thanks to a drilled chassis and interiors with thinner carpet, rubber matting and diamond-quilted leatherette, these Lightweight examples (dubbed DP207) tipped the scales at around 70kg less than a standard GTZ (circa 1100kg). Their engines were also assembled to the finest tolerances and the suspension settings were optimised for track use.
1961 SEASON
In addition to the pair of Essex Racing Stable Lightweights, two other GTZs went racing in 1961.
The example to give the model its competition debut was chassis 0200/R (the ex-1960 London Motor Show machine) which made its one and only appearance that year at the Goodwood Fordwater Trophy under a Rob Walker Racing Team entry. With Stirling Moss behind the wheel, the dark blue car finished third behind the Essex Racing Team DB4 GT of Innes Ireland and Mike Parkes’ winning Maranello Concessionaires Ferrari 250 GT SWB Berlinetta.
Although neither the two Essex Racing Team Lightweight GTZs or the solo entry of French Aston Martin distributor Jean Kerguen subsequently finished at Le Mans, the Zagato-bodied DB4 GT went on to pick up some good results in its other half dozen outings that year.
Lex Davison won the British Grand Prix Support Race for GT cars at Aintree driving one of the Essex Racing Team Lightweights (0183/R) having bagged a third place finish driving the same car a week prior in the British Emprie Trophy GT car Support Race at Silverstone.
Roy Salvadori and Jim Clark then finished third and fourth in the Goodwood Tourist Trophy FIA GT Cup race driving 0182/R and 0183/R respectively. In the next round of the FIA GT Cup, the Monza Coppa Inter Europa, Tony Maggs came home second in 0182/R and Jean Kerguen was fourth in 0180/L.
The same two cars then appeared at the FIA GT Cup finale, the Paris 1000km at Montlhery, where Jim Clark / Innes Ireland finished sixth and Jean Kerguen / Jacques Dewez were 14th.
SUPER LIGHTWEIGHT (DP209)
Towards the end of 1961, Aston Martin started development on a further evolution of the GTZ theme in the hope of creating a machine that would have the edge on Ferrari.
The result was the DP209 or Super Lightweight, the first example of which was chassis 0191/R which served as a prototype.
The Super Lightweight DP209 (covered in detail separately owing to their substantial number of technical differences) featured a completely redesigned chassis, uprated suspension, an enlarged 3.8-litre engine with a host of magnesium parts and a brand new low drag Zagato body. All in all, around 70kg was cut from the existing DP207 for an overall weight of around 1030kg.
Following completion of the prototype (which initially served as an un-raced development mule), two further copies were made. Chassis 0193/R was destined for Jean Kerguen and made its debut at the 1962 Le Mans Test in April. Chassis 0183/R was supplied to John Ogier’s Essex Racing Team (to replace the destroyed original 0183/R following an accident while out on loan during its only outing of 1962 at May’s Spa Grand Prix). This DP209 debuted at the Clermont-Ferrand Auvergne Trophy in July.
1962 SEASON
Aside from 0183/R and its solitary fateful outing at Spa, three other non-DP209 GTZs went racing in 1962.
From its four outings, the best results for the Essex Racing Team’s sister car to 0183/R (chassis 0182/R) were fourth for Jim Clark at the Silvertsone International Trophy GT car Support Race and third for Tony Maggs at the Oulton Park Open.
Chassis 0200/R was purchased by Mike Salmon whose most impressive results in 14 outings were fourth overall and first in class at the Silverstone Martini 100, second in the following day’s US Air Force Trophy at the same circuit and fifth at the Spa Grand Prix.
Viscount Portman took his car racing (chassis 0177/R) and in four known outings most notably scored a win in a Silverstone Handicap.
END OF PRODUCTION
Although a production figure of 19 DB4 GTZs is normally quoted, one car (chassis 0183/R, better known as 2 VEV) was built twice; following a massive crash at the 1962 Spa GP, the original was destroyed and a completely new car assembled to Super Lightweight DP209 trim which was given the same identification number to avoid any new car tax.
There were also two other cars built to DB209 Super Lightweight trim so the actual number of conventional GTZs was just 17 units.
Of the ‘19’ examples of the GTZ, twelve were right-hand drive and seven were left-hand drive.
Two cars were completed in 1960 which confusingly used what became the last two numbers of the GTZ sequence.
13 cars followed in 1961 which included the brace of DP207 Lightweight versions for John Ogier’s factory supported Essex Racing Team (0182/R and 0183/R) plus the first DP209 Super Lightweight (0191/R).
Four cars were officially assembled in 1962, a figure that included the second DP209 Super Lightweight (0193/R). That year there was also a fifth car: the ‘20th’ GTZ, that was the second incarnation of 0183/R and the last of the three cars completed to Super Lightweight DP209 trim.
SANCTION 2 & 3
In late 1987, joint Aston Martin Chairmen Peter Livanos and Victor Gauntlett gave the go-ahead for a batch of officially recognised Sanction 2 GTZs.
Zagato in Milan and expert Aston Martin restoration firm Richard Stewart Williams in Cobham, Surrey, were jointly commissioned to handle the project which saw four existing DB4 chassis uprated to GTZ trim and renumbered 0192/R, 0196/R, 0197/R and 0198/R.
Differences to the original GTZ included an enlarged 4.2-litre 352bhp engine, optimised braking and suspension and 15 instead of 16-inch wheels.
All four Sanction 2 cars were completed in 1991 and unveiled at the Richard Stewart Williams premises that July.
In 1998, Richard Stewart Williams were given permission from Walter Hayes (the vice Chairman of Aston Martin majority shareholder Ford) to create a further two GTZs dubbed Sanction 3 examples on chassis 344/R and 424/R which were completed in the year 2000.
CONTINUATION CARS
Following in the footsteps of the recreated DB4 GT of 2017, in April 2019 Aston Martin’s official heritage department (Aston Martin Works) began assembly of 19 GTZ Continuation cars which had to be purchased as part of the £6m DBZ Centenary Collection package that included a new DBS GT Zagato.
Instead of the 4.2-litre engine from the DB4 GT Continuation, a new crankshaft in the engine of these GTZ variants enabled them to be taken out to 4.7-litres and a conservatively estimated 370bhp.
Other technical differences included a full bolt-in roll cage, modern carbonfibe bucket seats with harnesses, an FIA compliant motorsport-grade fuel tank, a battery isolator switch and an onboard fire extinguishing system.
Text copyright: Supercar Nostalgia
Photo copyright: Aston Martin - - https://www.astonmartin.com & Bonhams - https://www.bonhams.com/department/CAT-MOT/motoring/
