Jensen 541 family: chariots of fibre

By Simon Hucknall

| 22 Nov 2023

Classic & Sports Car – Jensen 541 family: chariots of fibre

Today, you can only look back in wonder at the zeitgeist that clutched Britain’s post-war motor industry.

By the early 1950s, the big-hitters – such as Austin, Morris, Jaguar and Rover – had ditched their warmed-over pre-war-based offerings and were on a mission to out-innovate one another with new designs, technology and engineering.

And all of this to the benefit of a buying public equally keen to embrace new models that were faster, safer, better-equipped and more capacious than ever.

Not afraid to buck the trend, Jensen opted for a new wonder-material, glassfibre, to body its 541 range

The size of a manufacturer didn’t necessarily equal the rate at which it innovated, however, and Jensen was a case in point.

Founded by Alan and Richard Jensen in 1934, Jensen Motors’ core pre-war business was based around building bodies for Wolseley Hornet Specials and commercial vehicles.

But the brothers’ overriding ambition was for Jensen to be a car maker in its own right, which led to the post-war production of two large, well-appointed models: the PW, of which just 18 were built, and the more successful Interceptor (1950-’57), the name from which was recycled in the ’60s for an all-new model that would ultimately seal the company’s fate.

The early Jensen 541 (left) and end-of-the-line 541S show a clear evolution in design

However, the ’50s original – or one of its components, at least – was to set Jensen apart from the pack.

With steel expensive and in short supply in the immediate post-war years, Jensen experimented with making the Interceptor’s large boot panel from a wafer-thin woven glass embedded in resin, otherwise known as glassfibre.

The results were so encouraging that, when plans were drawn up for its new 541, having the body constructed from this wonder-material was a given.

Subtle revisions from the Jensen 541 De Luxe (furthest away) to the 541R included a switch to rectangular rear plates and the exhaust changing sides

Glassfibre was relatively easy and quick to tool up for the low volumes Jensen had planned, but it was also the perfect showcase for in-house designer Eric Neale’s low-set, rakish two-door body.

The 541 not only looked like a slice of the future, but was quite the aerodynamic pacesetter, producing a slippery Cd figure of just 0.365 when tested in Austin’s wind tunnel.

Neale’s design bestowed practical benefits upon the 541, too.

The Jensen 541 entered production in 1955

Unlike key market rivals, such as the Jaguar XK140, it was a four-seater, though rear accommodation was more suited to shorter journeys.

Its glassfibre construction, comprising three main mouldings, also meant that the entire front section could be opened, fully exposing its engine and ancillaries, and providing a boon for maintenance.

Given Jensen’s low production volumes, those mechanicals were plucked straight from Austin’s catalogue.

The Austin 3993cc ‘six’ is a constant throughout the Jensen 541 family

Its overhead-valve DS5 in-line ‘six’, displacing 3993cc, powered the company’s Princess and Sheerline limousines, and for the 541 was mildly tuned to produce an estimated 117bhp (Jensen was always coy about power outputs).

Transmission was via the Sheerline’s manual four-speed ’box (with a switch to Moss ’boxes for later models), plus optional Laycock de Normanville overdrive, to a Salisbury rear axle.

Underpinning the new glassfibre body was an impressively stiff chassis.

Formed from 5in steel tubes along its sides, with four round-tube crossmembers, and infilled with steel pressings for extra rigidity, its torsional strength showed a marked improvement over the old Interceptor.

The Jensen 541’s spacious cabin seats four

Independent front suspension with coils and telescopic dampers was largely borrowed from the Austin A70 (later cars used lever-arms from the A90), with Jensen’s own top inner joints and lower spring pans.

The 541’s Salisbury axle was located by a Panhard rod and suspended on semi-elliptic leaf springs.

Yet this was just the start of a near-decade-long model evolution for the 541, and one that had Jensen punching well above its weight for safety and technology firsts in the marketplace, including the standard fitment of safety belts and the use of all-round disc brakes.

The Jensen’s front grille can be opened and closed to regulate temperature under the bonnet

After its official launch at the 1954 Earls Court Motor Show (it was previewed at the previous year’s show by an aluminium-bodied prototype, before the glassfibre moulds had been perfected), four variants were produced until Jensen production switched to the V8-powered C-V8 in 1963.

And with us today, we have the full set: an early 541 in close to standard factory specification; a visually similar 541 De Luxe, which incorporated a plethora of chassis changes; a 541R, which brought some styling revisions and a (in our test car’s case significant) rise in power; and finally a 541S, which signalled the biggest evolution of the model’s design and, you could argue, was a production prelude to the C-V8 that succeeded it.

This early classic Jensen 541 sits on optional wire wheels

Lee Pilkington’s 1955 model marks the 541’s genesis, though, being the 19th car to roll off Jensen’s West Bromwich production line, and it really does capture the unadorned simplicity of Neale’s original design.

Lee has owned this car for 35 years and is clearly passionate about retaining its originality, meaning that it’s the only one of our foursome to wear crossplies on its factory-option 15in wire wheels.

Viewed from any angle, there’s a complete absence of flat panels, from the domed roof to the finely sculpted rear, accentuated by a long, curving bumper.

This Deep Green Jensen 541 was converted to De Luxe spec during a restoration

The prominent raised front wings are neatly dressed with bold, Mercedes 300SL-esque strakes running across the upper wheelarches, flowing down towards the flared rear quarters, which incorporate more subtle feature lines of their own.

The only spoilers are the incongruous indicator lights attached to the C-pillars, which were thankfully removed on the 541S.

But the whole is cohesive, sweetly proportioned and quite daring, considering the inherently conservative market into which it was being launched.

The Jensen 541 De Luxe brought a 5bhp boost in power, now 122bhp

Even more so when you twist the two knurled wheels that sit behind the front bumper and raise not just the bonnet but the whole front end, to expose far more of Austin’s straight-six than would ever have been seen in a Sheerline or Princess; at a time when owners were prone to do their own tinkering, the accessibility benefits must have been manifest.

With the nose back in place, Lee demonstrates how the 541’s trademark body-coloured radiator flap can be flipped down, with a pull of an under-dash handle, to allow for faster engine warm-up from cold, or left in a horizontal position under normal running.

Inside, the 541 is far more conventional.

You face a large, wood-rimmed wheel with three drilled spokes (replacing the original Bluemel’s item), behind which is a charmingly haphazard selection of switchgear, plus four Jaeger dials, the main two partially obscured by the wheel.

The brighter De Luxe trim adds to the Jensen 541’s spacious feel

The generously trimmed transmission tunnel is broad enough to make the footwells quite narrow, but with enough space to incorporate a foot-operated dip-switch to the left of the clutch, and a sliding air vent by the mushroom-shaped throttle.

You sit low in the small bucket seat, looking over a high scuttle, and, after turning the ignition and thumbing the starter, you’re transported into another world.

The bassy thrum of the big ‘six’ is the sound of Old England, with a distinctive Jensen twist.

Engage first through the narrow-gated ‘side-shift’ lever (mounted to the right of the tunnel, versus later cars’ central location) and you can’t help but feel a touch caddish as you pull away, imagining how an early owner might have toured ’50s Mayfair, glamorous companion at their side, revelling in the envious glances from passers-by.

Early Jensen 541s have a bottom- rather than top-hinged bootlid, as seen on the 541R (behind) onwards

Performance is strong but, topping out at just over 4000rpm, it’s the torque that propels you at distinctly un-’50s velocities.

Most starts can be made in second gear, first being low and close, and third, fourth and overdrive top cover most other scenarios – a relief, given that it’s easy to catch out the synchromesh if you rush changes.

The only disappointment is that the staggered pedals in this car mean that heel-and-toeing is off the menu.

Dynamic rewards are certainly on it, though. The steering is heavy at low speeds, and power assistance was never offered – hence the large-diameter wheel.

The toolkit is stashed away under the Jensen’s dashboard

This early car has a cam-and-roller steering box, which is no precision tool, but make allowances for the rather vague turn-in and the Jensen generates strong front-end grip (none of these cars understeers in the dry), with a pleasing driftability from the narrow-tracked rear axle that starts early and is easily controlled.

But the 541 is a long-distance grand-tourer par excellence: the ride is supple and forgiving, and for a separate-chassis car it feels remarkably composed at higher speeds on flowing A- and B-roads.

Plus, thanks to the low-revving engine, the cabin is always a civilised place to be, with normal conversation possible at 70mph, or around 2500rpm.

‘The whole is cohesive, sweetly proportioned and daring, considering the conservative market into which it launched’

All of those qualities are equally evident in the Deep Green 541 Colin Wilson has owned for eight years, most of them spent undergoing a comprehensive restoration and conversion to De Luxe specification.

The De Luxe was built from 1957-’60, with the key change being the addition of Dunlop disc brakes all round, making it the first British-built production four-seater so equipped.

There was more power, too, with the standardisation of the previous cost-option high-compression cylinder head, meaning an uplift in output to around 122bhp.

The addition of rack-and-pinion steering for the Jensen 541R sharpens responses

Introduced after some 100 541s had been built, the cosmetically similar DL’s launch coincided with an upgrade to the steering box, adding strengthened idlers and, illustrating Jensen’s interest in product safety, a universal joint built into the steering column, allowing it to collapse on impact.

Colin’s DL rides on 15in, 185-section radial tyres, so it’s hard to tell how much the steering revisions are responsible for the marked change in the car’s handling.

Either way – and sorry for the spoiler – this is the sweet-spot of the quartet.

Even at lower speeds, the steering is more decisive on turn-in, lighter and more granular in feel.

This classic Jensen 541R’s Moss ’box moves the gearlever to the centre of the transmission tunnel

Where the earlier 541’s drum brakes required a concerted pedal effort to shed speed, the Dunlop discs on this car offer significantly greater reassurance, both in effort and feel.

The performance of the De Luxe feels more sprightly than that of the earlier 541, too.

In theory, David Hillman’s 541R, a model also added to the range in 1957, should represent a sea-change.

Aesthetically it does, the most obvious clues being a redesigned rear with neater light clusters and a top- rather than bottom-hinged bootlid.

The Jensen 541R can be coaxed into gentle oversteer that’s easy to control

In addition, the 541R received longer chrome side strips, bolder rear wheelarch strakes and overriders.

Beneath the glassfibre was a switch to rack-and-pinion steering, but, curiously, a retrograde move from telescopic to lever-arm dampers, sourced from the Austin Atlantic.

The R’s drivetrain had a Moss gearbox, with its lever sprouting from dead-centre along the tunnel, and was powered by Austin’s DS7 engine, a more potent, better-breathing version of the DS5, making 150bhp.

The arrival of the Jensen 541S signalled another restyle

Despite eye-catching performance figures – The Autocar achieved a 127.5mph maximum, up 13mph on the DL The Motor tested two years earlier – production reverted to the original unit after only 53 cars, due to questionable reliability.

David has sought to redress the balance in his later car, with a DS5 engine in semi-race tune generating 180bhp.

From the off, the engine note is more vocal, a deep-throated snarl accompanied by extra induction noise.

The unit is freer-revving… but 40% more powerful? It doesn’t feel it, yet is an enthralling drive all the same, in part because the higher output excites the 541’s body-on-chassis set-up far more, and you’re left feeling that it’s perhaps a step too far – especially riding on archaic lever-arm dampers.

The Jensen’s entire front end lifts up, not just the bonnet, making the Austin ‘six’ very easy to access

The saving grace is the extra precision of the R’s steering rack and, though it’s a minor point, use of a leather- rather than wood-rimmed wheel, which feels more tactile and is easier to grip.

This car also has the strongest brakes by some margin, even if they do feel slightly over-servoed.

By the time Derek Simonds’ 541S reached the market in 1960, Jensen was already looking seriously at Chrysler’s V8 as a way of delivering higher outputs out of the box, with no impact on complexity or durability (it had fitted the unit to one of the last 541 De Luxes to analyse its performance and drivability).

This shapely Jensen 541S was the third example built

The S grew in width by 4in with a view to accommodating the larger engine, though ultimately it wasn’t used until the C-V8’s arrival in 1963.

The S is easily identified by its conventional front grille and redesigned bonnet, with the earlier models’ front flap a thing of the past.

It got yet another small rear-end redesign, losing the high-mounted indicators and introducing two larger, separate tail-lights just above the bumper.

The much-improved cabin makes the Jensen 541S feel more modern

Sitting in the fetchingly bright and comfortable cabin, it’s clear that Jensen had turned its attention to ergonomics, too: gone is the rather Heath Robinson dash, replaced by a more logical arrangement with a raised top-roll for better dial visibility.

The S standardised GM’s four-speed Hydramatic auto, operated via a column-mounted quadrant, with the Moss manual ’box available only as an option.

With no ‘Drive’ position you start in fourth, and while the new transmission dictates a more relaxed driving style, it also saps much of the performance.

‘Jensen’s core pre-war business was building commercial vehicles and special bodies, but the ambition was to be a car maker in its own right’

At some point in the ’70s this S was fitted with Jaguar power steering, which saves you a workout at low speeds but also robs the car of some of its cornering finesse, which really should be every bit as good as the R.

But see past such non-factory mods and the 541 is a genuine Aston and Jaguar challenger, with an additional layer of exclusivity and innovation that made it the thinking driver’s GT.

That it spurred on Jensen to break still more technical ground in the future makes the 541 special beyond the sum of its parts.

Images: Max Edleston

Thanks to: David Turnage and the Jensen Owners’ Club

Factfiles

Jensen 541

Sold/number built 1955-‘60/173
Construction steel chassis, three-section glassfibre body
Engine all-iron, ohv 3993cc straight-six, triple SU carburettors
Max power 117bhp @ 3700rpm
Max torque 190lb ft
Transmission four-speed manual, RWD
Suspension: front independent, by wishbones, coil springs rear live axle, semi-elliptic leaf springs, Panhard rod; telescopic dampers f/r
Steering cam and roller
Brakes drums, with servo
Length 14ft 8in (4470mm)
Width 5ft 3in (1600mm)
Height 4ft 6in (1372mm)
Wheelbase 8ft 9in (2667mm)
Weight 3262lb (1480kg)
Mpg 18
0-60mph 10.8 secs (with HC head)
Top speed 115.8mph (with HC head)
Price new £1285 + Purchase Tax (1955)
Price now £30-55,000*