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Aston Martin DB4 restoration – What really goes into a £250k rebuild?

Aston Martin DB4 restoration – What really goes into a £250k rebuild? Classic and Performance Car

What does it take to restore a classic Aston Martin DB4 from the ground up? Mark Dixon finds out how the professionals do it

‘better than money in the bank’. The old saying beloved of dodgy traders seeking to persuade dubious punters to part with their cash has, amazingly, become true of most classic cars in recent years. There’s no doubt that the current economic situation has helped keep our hobby buoyant but, of course, rising values are a double-edged sword. As with the property market, it’s all very well if you’re some way up the ladder; very frustrating if you’re just putting a foot on the bottom rung. 

But even if you will never be able to afford a classic like the DB4 Series 1 pictured here – and that goes for the Octane team – then you can take some small comfort in knowing that high prices are keeping specialists and parts suppliers in business. That benefits all of us in the long run, and it means that more and more cars are being restored, to higher standards than ever before.

If there’s one classic that’s universally loved it’s the Touring-styled DB-series Aston Martin, whether it’s a 4, 5 or 6. Conversations with five of the bigger Aston specialists in the UK revealed that around 80 examples are currently in the process of restoration at these companies alone. Aston Martin’s own Works Heritage division has 18 cars being rebuilt – five each of DBs 4 and 6, and eight DB5s, which is a neat reflection of each model’s relative popularity – while similar numbers are in hand at Aston Workshop in County Durham; RS Williams in Surrey; Desmond J Smail in Buckinghamshire; and Aston Engineering in Derby, the company that restored our featured DB4. And there’s no sign of that trend abating: everyone we spoke to reported full order books and waiting lists of up to a year. 
These restorations involve six-figure sums but a finished car will now be worth more than the money invested. As a wise man once said, the number of rich people in the world is increasing all the time but the number of really good classic cars is finite. Demand fuels rising values – it’s that’s simple.
Aston Martin DB4 restoration

The car featured here is not, in itself, remarkable. It’s a DB4 Series 1, delivered on 17 May 1959. Originally blue, it spent several decades in Australia before being repatriated circa 1981 and, at some point, repainted red. Unfortunately, any benefits from those early years in a dry climate were negated when it came back to the UK, because it ended up in a garden in Derbyshire, where it sat unloved and untended for a long time.

So why have we chosen to make this particular DB4? Quite frankly, because we rarely have the opportunity to feature a restoration that’s been so beautifully documented in pictures. Aston Engineering’s own technician, Paul Smith – a former TV cameraman – recorded progress in the workshop, but at key intervals the whole shell and chassis were taken in a box trailer to the studio of local automotive photographer John Colley, where they were photographed in various stages of deshabillé. The result is a fascinating illustration of the DB4’s evolution from wreck to concours contender.
When embarking on a project like this, to misquote Mrs Beeton: ‘First catch your donor car…’ That’s a lot more costly than it was just a few years ago, now that anything dragged out of a shed and dusted with straw has buyers clamouring to acquire it. Bonhams sold a stripped DB4 Series III, off the road for more than 30 years, at its Aston Martin Works auction last year for £303,900, and that’s not unusual in today’s fevered market. The car was advertised as being ‘substantially complete’, a seemingly innocuous phrase that would set alarm bells ringing with any experienced restorer.

Aston Martin DB4 restoration

Gary Williams is the workshop manager at Aston Engineering. As he explains: ‘It’s vital to buy a car that is as complete as possible, because some small but significant parts are very hard to find now – quarterlight catches, heater control levers and seat runners, to give just a few examples. The DB4 evolved quite rapidly during production and there were lots of minor changes.

‘The car that our client found was in terrible condition but it had the huge advantage of being complete. The fact that it had been languishing outdoors under a tarpaulin for years didn’t matter; when you’re looking to do a ground-up restoration, there’s no point buying something that’s road-legal and looks half-decent, because you’re going to be taking it completely apart anyway. Much better to save yourself 50 grand or more and buy a derelict example – just as long as it’s all there.’

Until very recently, it’s not been cost-effective to have parts remanufactured, due to the small quantities required; lower front wishbones are one of the more significant components that haven’t been available for years. Even so, RS Williams offers a repair kit for those – it’s usually the straight steel brake-reactor section that gets bent in an accident – and there isn’t much that can’t be obtained from specialists or, indeed, Aston Martin itself. Nigel Woodward, Heritage manager at the Aston Martin Works service and restoration facility, points out that the capability to refurbish components for re-use is greater than it used to be, too, which also helps maintain originality. More on that later.

Aston Martin DB4 restoration

Gary Williams would be the first to admit that our featured DB4 was in a particularly bad state, and needed a lot more work to the chassis and floorpan than is usual. ‘We started cutting into the sills, and just kept going… Normally you would cut the outer sill away, and perhaps the outer half of the box-section that lies behind that, and you’d find the inner half intact – but on this car we had to replace the entire sills and most of the floorpan too.’
Because it will have several projects on the go at any one time, any major restoration company needs to follow a tried-and-tested set of procedures to keep the work flowing efficiently. 

At Aston Engineering, the process goes like this: the car is stripped, and components labelled and stored together on racks. The chassis is shotblasted and the bodyshell chemically dipped. While body and chassis are being repaired, parts can be sent off at intervals for refurbishment. Then a rolling shell is built up, before being wired and trimmed.

The last stage is what Gary Williams calls the final build. ‘It’s always the worst stage of the job!’ he exclaims. ‘Adjusting door fits, sorting out all the minor glitches that will come to light during 350-500 miles of road testing. It’s the phase that makes or breaks the job, and it’s the point where some restorers will fall down, particularly non-specialists who have taken on an Aston. People think that if they can rebuild an MGB, then they can handle an Aston Martin – but these are much more complex cars to restore.’

Aston Martin DB4 restoration

Although any handbuilt car like an Aston Martin will always require skilled labour to restore, advances in technology have made it easier to achieve really durable and consistent results. For example, at Aston Engineering, after the chassis and Superleggera framework have been shotblasted, instead of being painted in red-oxide as they were at the factory, the bare metal is now powdercoated with a semi-matt black and very tough chip-resistant coating, which is electrostatically attracted into every nook and cranny. 

‘In the old days,’ says Gary Williams, ‘you’d scrape most of the old underseal off by hand and then get busy with the Nitromors on the body panels. Now the body is chemically dipped. And whereas the body panels were originally wrapped around the steel framework with graphite-impregnated cloth in between, today we use a neoprene material that doesn’t deteriorate or hold water like the cloth when it ages.

Aston Martin DB4 restoration

‘People forget that these cars were far from perfect when they were new. The welding is often quite average and the Superleggera tubes were simply chopped away to install wiper motors and so on. Also, because they were handmade, they can differ from one side to the other. It’s sometimes difficult for today’s buyers, who are used to the perfection of modern cars, to appreciate that.The actual panel fit was pretty good – as far as we can tell, for very few Astons of this period haven’t had at least one repaint and some bodywork by now.’

It goes without saying that restoring a DB’s alloy panels demands a high level of skill and a lot of time – our DB4 needed fresh metal letting in where accident damage had been poorly repaired, notably the front valance. Altogether, it took about 18 months to transform this car’s bodyshell to the virgin state pictured below.

Aston Martin DB4 restoration

Paradoxically, although classic Astons are being rebuilt to better-than-new standards and using modern solutions to age-old problems, owners are veering more and more towards originality in the way their cars are finished. At least, that’s Aston Engineering’s experience: ‘We have a couple of cars for sale at the moment, and the first questions we get asked – even before we start to talk values – are whether they are “matching numbers” and finished in the original colours,’ says Ross Allerton, commercial manager. 

Over at Aston Martin Works, the trend is even more pronounced, according to Nigel Woodward. ‘Within the last 18 months, originality has been everything,’ he says, ‘whereas three years ago it was all about 4.2-litre engines, air conditioning, power-assisted steering and so on. People bring their cars to us because they want them original and they believe it adds value in the long run, having them restored by the original manufacturer. The fact that we’ve just sold a DB5 saloon and a convertible for what may be record prices would suggest they’re right.’

In the wider world, however, performance upgrades and luxury add-ons still seem to be popular – indeed, Aston Workshop (not to be confused with Aston Martin Works) reports that most of their commissions are for bespoke cars. The important thing is that any changes have to be discreet and, ideally, reversible. The latter is true even of the six-speed gearbox conversions offered by Aston Workshop, using either Toyota or BMW units to improve on the typically noisy ZF five-speed ’boxes fitted to DB5s and 6s.

Aston Martin DB4 restoration

Our feature car is fairly typical of today’s state-of-the-art restored Aston. The engine has been enlarged to 4.7 litres – it was 3.7 litres back in 1959 – and springs and dampers have been uprated to provide sharper handling. Overdrive has been fitted, and the back axle ratio upped to 3.31:1, to make high-speed driving more relaxed. The four-speed David Brown gearbox remains, however, and externally the car looks standard, riding on a set of Borrani chromed wires. Painted wire wheels would have been more typical but Borranis were an option, and today’s owners can’t get enough of them, despite their hefty price tag of around £8000 a set. 

A concealed air conditioning system has also been installed. ‘Clients often don’t request it until I point out that wives and girlfriends will hate travelling in the car without it!’ explains Gary Williams. There’s also a modern but period-looking Becker Mexico ICE and navigation unit in the dash; these have proved hugely popular but are only made in batches and may not be available for much longer.

Engine modifications are a slightly controversial subject. For years it was standard practice to bore the straight-six out to 4.2 litres, not least because a set of 4.2 forged pistons and rings costs less than just the rings for a 3.7. By changing the crankshaft and con-rods to increase stroke, the 4.2 can be enlarged to 4.7 litres, as in our feature car.

Now, however, there are even further options, and engines can be specced at 3.8 or 4.0 litres – the latter being the DB5’s factory spec. You might ask why anyone would want to specify a smaller-capacity engine when it looks the same externally as a bigger one, but it’s all part of the new emphasis on originality, says Gary Williams. A 3.8 is also the easiest to build, since it involves less machining of the block and the original liners can be retained.

Not surprisingly, electronic ignition is standard-fit during a rebuild, and the Aldon Ignitor system has proven reliable; it fits invisibly under the distributor cap to retain that all-important ‘original’ look. 

Aston Martin DB4 restoration

A relatively inexpensive change, yet one that improves a DB Aston’s drivability more than any other, is the addition of electrically assisted power steering from Dutch manufacturer EZ (though Desmond J Smail prefers the British-made EPAC2 system from GTC Engineering). The EZ system bolts on without major work and is speed-sensitive, with an ECU that can be mapped to suit individual tastes. 
‘It used to be that you didn’t need to worry about improving a DB4’s handling,’ jokes Gary Williams, ‘because the steering was so heavy that you’d have run out of corner before it became an issue!’ An exaggeration, of course, but power-assisted steering does make a 
huge difference. 

With or without power steering, however, the DB’s turn-in can be sharpened and its general poise made more neutral by uprating the suspension. For road use the spring rates would typically be increased by 25% and the front anti-roll bar thickened by 50%. DB4s originally had Armstrong telescopic dampers to the fore, and lever-arms at the rear; adjustable Konis have superseded the former, while it’s now possible to specify adjustable lever-arms too.
The latter are a spin-off from parts developed for racing, a once-popular activity for DB-series cars. While a number of cars are still out there competing, the massive increase in values has meant that more and more former track-warriors are being rebuilt as road cars. In that sense, the wheel has come full circle.

Aston Martin DB4 restoration

Talking of wheels, the DB4 was originally fitted with 16-inch rims, reduced to 15 inches for the DB5. You can fit either size to a DB4 and the advantage of the latter is that they’ll take Avon’s excellent ZZR 205-section tyres. These aren’t available in a 16-inch size so, if you want the period look, 185 Avon Turbosteels are recommended.
The quality of paint and trim is what you notice first when judging any restored car, so any restorer worth its salt puts huge effort into making them perfect. Waterbased paint is standard now, for environmental reasons, but brings its own challenges: some shades, says Gary Williams, appear different to the old synthetic colours and need tinting to make them match – especially that old favourite, Silver Birch. Needless to say, multiple layers of primer, basecoat and lacquer are applied, with plenty of labour-intensive flatting and polishing during and after, and an oven used to prevent microblistering.

That’s all pretty much standard stuff. Retrimming poses more of a headache, not least because it’s so hard to find suitably skilled people these days – and skilled people who will work in the style used by Aston Martin, rather than default to the way they usually operate.

Then there’s the question of which leather to use. The correct Vaumol hide became unavailable in the 1980s, and restorers had to use other varieties called Autolux and Autocalf; the former was smoother-grained, the latter closer in looks to Vaumol but thicker. Vaumol is now available again – ‘but, because of its pronounced grain, it can appear “grubby” in some colours,’ Gary explains. Our feature car has been retrimmed in Autolux.
The elephant in the room, of course, is… how much does a full-house professional restoration like this cost? Aston Engineering is upfront about what it charges: a standard restoration to original specification will typically be £180,000-200,000. Add in some options and upgrades and you’re looking at £220,000-250,000. Plus, of course, VAT at 20%. And the cost of the donor car.

So, yes, it can make sense to spend a lot of money having an Aston Martin restored. At the moment, the DB4, 5 and 6 are the cars everyone wants – but we’re already seeing some V8s being given the same treatment, as prices rise on their coat-tails. Given that buyers tend to seek out the cars they remember from their youth, it’s a trend that’s sure to continue.
Not everyone will rejoice at the way Aston Martins have become so monetised; the days when an ordinary man could run a DB Aston every day are long gone. The irony is that a really good example still makes a fantastic daily driver...

Words: Mark Dixon // Photography: John Colley

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