The XK150’s SE ‘Blue Top’ unit offers the same horsepower as
the engine of the XK140 SE, but maximum torque – up by 3lb ft, to 216 – comes
in a whole1000rpm lower, at 3000rpm, thanks to a combination of relatively
small inlet valves and the larger exhaust valves of the C-type head. A
triple-carb XK150 S became available in 1958, initially for export, and the
Racing Green car was up-gunned in 1960 to this 250bhp spec – at the time when
Jaguar had added the option of 220bhp and 265bhp 3.8-litre engines for that
model year.
The XK150 has a
harmony and a broad-chested elegance to its lines
The Jensen is rigorously orthodox, if you look beyond its
pioneering glass fiber body, which can be claimed to be the world’s first
production four-seat reinforced-plastic shell. Conscious of the possible
frailties of this material, Jensen resolved to give the 541 robust
underpinnings, so it designed a new ladder-frame chassis. Featuring four
round-tube cross members and beefy 5in-diameter side rails, it was intended to
be stiff in torsion – and so it proved when it was tested for resistance to
twist. It’s unlikely that the preceding Interceptor’s elongated Austin A70
frame would have been anything like as rigid.
The Austin coil-and-wishbone front suspension was carried
over from the Interceptor, albeit adapted to take telescopic dampers instead of
lever-type Armstrongs. Also inherited from the older car was the 3993cc Austin
straight-six and its matching gearbox, taking drive to a straight-forward
leaf-sprung live back axle with telescopics and a Panhard rod. To provide some
extra urge, the all-iron engine sported triple SU carbs, pushing power up to
117bhp.
The Jensen is
rigorously orthodox, if you look beyond its pioneering glass fiber body, which
can be claimed to be the world’s first production four-sear reinforced-plastic
shell
Such, at any rate, was the initial specification when the
541 was announced at the 1953 Motor Show, trailed by the not-quite-complete
alloy-bodied prototype on the Jensen stand. Production began in late ’54, and
built up slowly to the point where it was only in September ’55 that The
Autocar was able to test an example.
In October ’56, a De Luxe version was introduced, with
four-wheel Dunlop disc brakes and with all the key options of the regular 541
as standard – high-compression head, overdrive, wire wheels, twin exhaust and
rev-counter. A year later, a third model joined the catalogue. The 541R had the
latest version of the Austin engine, with separate in let ports, and reverted
to twin SUs; despite this, power rose to c150bhp from the estimated 130bhp –
Jensen never quoted output – of the De Luxe. BMC was by then fitting only
automatic gearboxes to the Vanden Plas, so Jensen switched to the same Moss
’box as used in the Jaguar. Equally significantly, the steering changed from a
box to a rack, and the chassis was redesigned to take an Austin A90 front
suspension cradle – meaning a back-wards move to lever-arm front dampers.
To strengthen the body, the 541R also boasted blisters over
the rear wings in place of the simple ‘speed’ molding of the 541 and 541 De
Luxe, and there was an extractor vent in the bonnet and one at the bottom of
each front wing, while the boot hinged from the top rather than the bottom.
These coachwork changes were eventually standardized on all 541s. The 541 and
541 De Luxe were phased out during ’59, leaving the 541R to carry on until the
larger 541S was announced in October 1960. Later examples of the ‘R’ – all but
the first 50 or so – went back to a triple-carb set-up, as on Bird’s car;
seemingly this made little difference to power output.
The 541 has two
nicely shaped rear seats that can happily accommodate reasonably sized children
With 546 built, of which 193 were 541Rs, the Jensen has
always had rarity on its side against the more commonplace Jaguar, of which
8884 XK140s and 9395 XK150s were made over virtually an identical period. With
that sort of mass-production, you might expect the Jaguar to have a
better-honed cabin and for the Jensen to be prosaic – crude, even – in its
presentation.
In fact, the Jaguar is surprisingly plain inside. Gone is
the glossy walnut veneer of the XK140 coupé, replaced by a leather-covered
dashboard and doors with top-to-bottom trim in a coarse-grained leather cloth.
The seats are flat slabs, and in the rear there are just tiny lift-out cushions
and backrests – and no pockets. There’s Jaguar’s usual lovely set of
white-on-black Smiths dials, and the handy provision of deep full-length door pockets,
but any quality is frankly skin-deep – as I can testify, having helped to carry
out a full re-trim of an XK. It’s all a bit smoke-and-mirrors, and doesn’t age
well, as demonstrated by the balding flocked cardboard in the glovebox.
