Daimler SP250 ‘Dart’: Edward Turner’s great ‘eight’

By James Page

| 28 Oct 2025

Classic & Sports Car – Daimler SP250 ‘Dart’: Edward Turner’s great ‘eight’

Daimler took a brave leap into the unknown with the SP250.

Following decades of turning out stately coachbuilt limousines and fine saloons, the royal family’s favourite marque would have been nobody’s first choice if they were in desperate need of a sports car.

Yet, in an admirable attempt to break with tradition, that is exactly what it produced in the messy and cash-strapped aftermath of the Docker era.

Best known for his motorcycle designs, Edward Turner also created Daimler’s brilliant V8, which found a perfect home in the SP250

Edward Turner was the man given the task of coming up with a plan to reinvigorate the Daimler name, then making that a sporting reality.

The company was keen to break into the American market, as Triumph and MG had done so lucratively during the 1950s.

Thanks to the popularity of cyclecars, there was plenty of crossover in engineering know-how between ’bikes and cars in the years immediately after WW1, but Turner made the leap almost 40 years later following a stellar career in two-wheelers.

Looking a little like a cross between Auric Goldfinger and Winston Churchill – or, for those of a golfing nature, Peter Alliss – he could, by all accounts, be difficult, autocratic and quick to anger, but a glance at his track record proves beyond doubt that he was also hugely talented.

A keen rider from an early age, he showed the reliability of Triumph’s 149cc Terrier by taking one from Land’s End to John O’Groats. And that was in 1953, when he was the company’s managing director.

If you look at the photographs, he seems happier in the weatherproof gear that the run dictated than he ever did in a suit.

He was prescient, too. In 1960, Turner visited Japan to assess its motorcycle industry.

Impressed, he returned to write a report spelling out what he believed would happen to the British manufacturers if they didn’t respond...

The Daimler SP250 ‘Dart’ has strong straight-line performance, while overdrive makes for relaxed cruising

Turner certainly had the respect of his workforce, who – like those who later worked at Lotus for Colin Chapman – were well aware that their boss could probably do their jobs better than they could.

While he was managing director at Triumph, for example, he came across an experienced machinist who was struggling with a particular job, so he simply stepped in and did the work himself.

And his fearsome professional reputation doesn’t tell the whole story of the man.

He remembered the years after he joined Triumph as being the happiest of his life, but in July 1939 – the day after their 10th anniversary – his first wife Edith was killed in a car accident.

Turner kept working in the aftermath of that tragedy, and would eventually remarry in 1952.

He became a father late in life, too – he was into his 50s by the time that Jane, Charmian and Edward Junior came along – and he doted on his children.

If he was going away on business, he would record stories that they could listen to until he returned.

Turner had been born in Southwark, south London, on 24 January 1901, two days after Queen Victoria had died and Edward VII took the throne.

He was the third in a family of seven, and both his father and grandfather had engineering backgrounds.

The auxiliary gauges in the Daimler SP250’s traditional dashboard

The young Turner’s talent for drawing quickly became obvious, but as soon as he was old enough, he signed up to be a junior telegraphy officer in the Merchant Navy during WW1.

Turner stayed with Marconi until 1920, and briefly considered a career in showbusiness – as unlikely as that sounds.

Instead, he followed the family example and went into engineering, buying Chepstow Motors, a small motorcycle business and Velocette agent in Peckham.

Throughout the 1920s, he began working on his own designs, and the Turner Special broke cover in 1927 with a variation on one of Edward’s earlier single-cylinder, overhead-camshaft 348cc engines.

It competed on the London to Exeter Trial, with Turner’s friend Alf Russell riding.

In an effort to get his ’bike into production, Turner did the rounds of the manufacturers and, although his efforts came to nothing, Ariel showed an interest in a four-cylinder engine that he had also been planning.

The neat 500cc powerplant would become the renowned ‘Square Four’ – in effect, two vertical V-twins laid out one behind the other – and when Turner joined the company to work under Val Page, it marked the beginning of a long and successful – if sometimes tempestuous – relationship with Jack Sangster.

It was Sangster who kept Ariel going after it went bust in 1932, with Turner being steadily promoted along the way.

The Daimler SP250 has an instantly recognisable front end

When Sangster later rescued Triumph, he made Turner a director and a shareholder.

While the latter recalled in a later television interview that he had joined the firm when it was “in very low water” – it had previously been announced that motorcycle production would be stopped altogether – he revelled in the seniority of his new role.

Turner established that a fresh range was needed for 1937, and came up with the Tiger series plus the legendary Speed Twin.

From facing closure not long before, Triumph’s motorcycle division was soon back in profit, with no less a personage than Sir Malcolm Campbell stating that: “In my opinion, the Triumph Speed Twin has no equal.”

There was a brief sojourn to BSA during WW2 – Turner temporarily fell out with Sangster over the site of the new factory after the old one had been bombed – but he remained a Triumph man at heart.

In 1951, the company was acquired by BSA, the automotive arm of which included Daimler.

At that time, the venerable marque was in serious financial trouble, and it took a management coup to oust Sir Bernard Docker in 1956.

Led by Sangster, that action resulted in Turner becoming the car division’s managing director.

This classic Daimler has a very upright driving position

It soon became obvious that his talents for two-wheeled engineering would readily translate into the world of four-wheelers.

In that long-overdue attempt to modernise its range, the Daimler board asked Turner to come up with a V8-powered model – initially a saloon, which was designated DN250.

Turner looked overseas for inspiration, drawing upon Cadillac’s experience with simple – and therefore cheap-to-produce – pushrod units.

His drawings for an iron-block, alloy-head engine, with hemispherical combustion chambers and oversquare dimensions giving 2548cc, were presented to the Daimler team in October 1958.

Little more than eight months after, the first one was running on the testbed. Turner would later pay generous tribute to the Daimler engineers, whom he rated extremely highly.

Rather than placing this new powerplant in a saloon, though, the company decided to throw caution to the wind and use it as the basis for an open-top sports car that would give it a much-needed slice of the American market.

Lower tooling costs and less lead-time meant that glassfibre was chosen for the body – then an innovative decision, even if the use of a separate steel chassis was not – and the car was first shown at the 1959 New York International Auto Show.

The in-house styling was certainly distinctive, and still looks a little confused today.

The Daimler SP250’s eclectic styling mixes flowing arches and sharp tailfins

The elongated and slightly gormless mouth contrasts sharply with the tailfins that were no doubt seen as being essential on a car that was intended to do well in the States.

Then there are odd details, such as the Art Deco-style sidelights perched atop the otherwise curvaceous front wings.

I must admit that I find it rather endearing, but it could never be considered beautiful, and seems even more outlandish when you drop into a leather-lined cockpit that could belong to any number of 1950s British sports cars – Triumph TR, Austin-Healey, you name it.

Such is the vertical nature of the driving position and the close proximity of the steering wheel, in fact, that it feels even more aged.

Even if you’re slight of stature, it will feel as if you’re sitting on an SP250 rather than in it, but that does afford a commanding view of its extremities.

If the shape sets the car apart when stationary, Turner’s engine does the same when it’s on the move.

It is a superbly flexible unit with an impressively purposeful exhaust note and, even in top gear, a gentle prod of your right foot elicits an instant response.

Which is nice, because although the gearbox is fairly short of throw, it has a notchy feel. Much better to hook it into fourth and let the torque do its job.

The Daimler SP250’s comfortable cabin

Our featured example is a C-spec car, which means that it boasts a standard heater, and it has been treated to a rack-and-pinion steering conversion – a common modification among SP250 owners, and considerably lighter and sharper than the standard cam-and-peg set-up.

It also has overdrive on third and top, which makes a 70mph cruise a far more relaxing experience than in some of its contemporaries.

This later example, in fact, feels impressively composed in most everyday situations. It rides comfortably, and never crashes or bangs its way down the road.

Narrow lanes with hedges on either side are not the place in which to discover whether its reputation for oversteer is well deserved.

Instead, at modest speeds it grips well, even in greasy conditions. You certainly don’t need to expend much energy in order to make good progress, with plenty of accessible power on tap.

Concerns over chassis flexing – doors could fly open unannounced, for example – led to extra bracing being fitted for the B-spec SP250, which was introduced in 1961.

That was the year after Jaguar had bought Daimler from BSA.

The SP250 didn’t feature strongly in Sir William Lyons’ plans, even though he reworked it into the SP252, which had more conservative – but handsomely Italianate – styling, and a dashboard along E-type lines.

The Daimler SP250 can easily be made to oversteer, but grip is good at lower speeds

Sadly, the revised model wasn’t considered to be commercially viable and didn’t make it into production.

It would have cost as much to build as the E-type, and offered nothing in the way of profit for its maker.

Instead, it was decided that Turner’s engine would be better off in a Daimler saloon, and the SP250 was sadly killed off in 1964.

American sales of the model never really took off – despite the option of an automatic transmission, as also fitted to police-spec SP250s in the UK – and the car did not provide the fresh start that Daimler had hoped for, but it is far from being a mere oddball.

There is something very appealing about soft-top motoring in a traditional British sports car to the accompaniment of a V8 soundtrack – as Sunbeam’s Tiger later reinforced.

Perhaps buoyed by the whole project, Turner set about trying to convince Sangster that BSA should find another way to branch out into car-making.

It wasn’t to be, however, and Turner retired at the beginning of 1964 – although he continued to keep in touch with the company throughout the decade, acting as a consultant on various projects.

Shortly after leaving, he went through a divorce before settling in Ockley, Surrey. He died in 1973.

A remarkably talented engineer who has long been fêted by the motorcycle community – a Blue Plaque adorns his former home in south London – Turner deserves to be equally well respected by the four-wheeled brigade.

Whether it’s housed in the brilliant SP250 or the V8-250 saloon, his automotive powerplant can stand proudly alongside anything he produced for Ariel or Triumph.

Images: James Mann

Thanks to: Jonathan Wills and Dave Bowden at Cotswold Classic Car Restorations

This was first in our January 2016 magazine; all information was correct at the date of original publication

Jaguar and Daimler: badge engineering

Once Jaguar bought Daimler, the SP250 was on rocky ground, but Turner’s engine found a new home in the V8-250 saloon.

Not that it just dropped into the Jaguar Mk2 bodyshell.

The water pump needed to be moved and adapted, for a start, but the engine and gearbox together weighed 64kg less than the Jaguar’s 2.4-litre ‘six’ and ’box, so the suspension was modified to suit via the use of softer springs.

The Daimler V8-250 was launched in October 1962, with the most distinctive external change over the Mk2 being the adoption of Daimler’s traditional ‘crinkle’ grille.

There were other detail differences, and the interior used a new type of bench seat, while the adoption of a Borg-Warner automatic gearbox made it more of a ‘mature’ motor car when compared to the raffish Mk2.

A manual version was offered from 1967, but didn’t find many buyers.

The Daimler’s short gearing made for reasonable acceleration on early cars, with 0-60mph taking 13 secs, but it came at the expense of fuel consumption and ran counter to the more relaxed image of a Daimler.

In 1964, therefore, Jaguar changed the final-drive ratio from 4.55:1 to 4.27:1, which also had the effect of raising the top speed to 114mph.

In September 1967, the V8-250 received the same visual updates as the Jaguar 240 and 340, which most obviously included slimline bumpers.

The model stayed in production until August 1969, and was clearly seen as a very British car – none were officially exported to the USA, for example.

Factfile

Daimler SP250 ‘Dart’

Sold/number built 1959-’64/2645
Construction steel ladder chassis with glassfibre body
Engine iron-block, alloy-head, ohv 2548cc V8, twin SU carburettors
Max power 140bhp @ 5800rpm
Max torque 155lb ft @ 3600rpm
Transmission four-speed manual, RWD
Suspension: front independent, by wishbones, coil springs, telescopic dampers rear live axle, semi-elliptic leaf springs, lever-arm dampers
Steering cam and peg
Brakes discs
Length 14ft ¾in (4286mm)
Width 5ft ½in (1536mm)
Height 4ft 2¼in (1276mm)
Wheelbase 7ft 8in (2336mm)
Weight 2240lb (1018kg)
Mpg 24
0-60mph 9.6 secs
Top speed 120mph
Price new £1489