343 bhp, alloy V-8, 5,340 cc engine with Bosch fuel injection and dual overhead camshafts, ZF five-speed gearbox, double-wishbone front suspension with coil-over shock absorbers and a De Dion rear located by trailing arms and a Watts linkage, four-wheel Girling disc brakes. Wheelbase: 2,610 mm

• Factory-fitted with prototype experimental engine V/535/001/PX

• Rare prototype V-8 found in a DBS

The story of prototype experimental engine V/535/001/PX and how it came to be installed in a DBS Aston Martin is an interesting one. A book published in 1985 by ex-Aston Martin Engineering Director Michael Bowler, Aston Martin V8, details the development of the DBS/V-8 cars. Page 130 offers the following:

With American air pollution legislation in mind the decision was taken to go for the Bosch injection system. At the close of 1968, it was decided to increase engine capacity to 5340 cc with a bore of 100 mm and a stroke of 85 mm. In March the first of the prototype 5340 cc engines – V535/001/PX went to Bosch complete with cast inlet manifolds, air filters and air boxes. This engine had a 9:1 compression ratio and made 343 BHP @ 5500 RPM.

How did this rare engine end up installed in a six-cylinder DBS? In the 1990s, AML Historian Roger Stowers assumed that this DBS was used as a factory test car. However, later Stowers discovered that this V-8 was fitted on 22 April, 1974, which ruled this out. Further scrutiny of factory service records show that no less than three six-cylinder engines were fitted under warranty by 1973, prompting Stowers’ comment, “the Factory’s release and installation of a prototype V8 may have been a means of placating an irate owner.”

It must also be remembered that Aston Martin had been rescued by Company Developments Ltd. in 1972, which, after a brave attempt at building cars, found itself “on the ropes” by late 1973 when a shaky world economy had evaporated the market for expensive fuel guzzlers. Thus, when a potential customer arrived at the factory in early 1974 inquiring about a V-8 engine installation, a set of the latest alloy wheels and other work, he would have been warmly welcomed!

The factory build sheet shows DBS/5072/RAC was sold to a Demetrios Z. Pierides of Farmagusta, Cypress on 28 June, 1968. The owner at the time of the prototype V-8 conversion in early 1974 was likely a Mr. P. Harris. Mr. G. Russell of Bournemouth is indicated by a 1981 re-upholstery invoice, and by 1983 a Mr. Tibble in Hertfordshire is named on an AML parts purchase invoice. Pranged on the left front, it was sold stateside to A.H. Spencer of Buffalo, New York. In 1989, after driving the car and pronouncing it “scary fast,” he sold it to Chris Nelson, a Canadian who kept it a further 15 years, carrying out a total body and mechanical restoration. In 2004 the previous owner, an ex-Chairman of the AMOC East/USA, bought DBS/5072/RAC. After 10 years or so in an unheated barn, another mechanical refurbishment was in order. It is almost easier to list what wasn’t done, but suffice it to say that the engine, fuel injection, suspension, clutch, braking system and the electrics were renewed. Since club track days were anticipated, performance improvements were also carried out. An HD suspension, four springs, four shocks and front and rear anti-sway bars, as well as an oil cooler kit and “MSD” electronic ignition kit, were fitted. A rare Vantage V-8 three-piece alloy boot-lid spoiler was also sourced and installed.

Fully UK-registered, this interesting DBS has recently benefitted from various cosmetic improvements and a replacement clutch and is supplied with a current MoT certificate. DBS/5072/RAC, with its exceedingly rare prototype V-8, V/535/001/PX, will be a satisfying acquisition for a collector who wants to exploit its dual purpose nature, road and track, in the varied venues offered by the Aston Martin Owners Club.