Beautiful Vision – Evolution of the Jowett Javelin (Part 3)

With the Javelin’s revolutionary credentials established at an early stage of development, evolution towards running prototypes and production reality gathered pace in a harmonious and efficient manner.

First full-size Javelin prototype Image: Jowett Cars

Possibly the most successful element of the Javelin’s design is its suspension and steering. At the front, double wishbones are employed in conjunction with longitudinal torsion bars. Telescopic shock absorbers are used, and the wheels are steered through a sector and pinion mechanism, located behind the engine which is mounted just forward of the front axle line.

At the rear the live axle is located by four fully trailing links and a Panhard Rod. Springing is again by torsion bars, this time in a transverse arrangement. Telescopic shock absorbers are mounted at a 45 degree angle to reduce intrusion into the interior space.

Drum brakes apart, the Javelin’s chassis would have been considered sophisticated in 1998. Fifty years before, in the world in which it would make its debut, beam front axles, friction dampers, leaf springs, and vague steering boxes were the commonplace currency in the British motor industry. It is in the area of suspension that Palmer is at his most principled, most fundamentally in his advocacy of torsion bars over coil springs and leaf springs.

The Javelin’s principal dimensions were set at an early stage of the project.

Length 14’  0”  Width 5’ 1”  Height 5’ 2½”
Front track 4’ 3”, Rear Track 4’ 1”  Wheelbase 8’ 6”

The numbers are a reminder that the longer-lower-wider era was some time away, at least in Europe, and that car-buying decisions were still the province of middle-aged, hat-wearing men.

Palmer’s styling was literate and eclectic, inspired by some of the best designs of the late pre-WW2 period but not a copy of anything particular. John Tjaarda’s 1933 “Briggs Dream Car” was an acknowledged influence, along with the 1936 Lincoln-Zephyr it inspired.

The much smaller 1936 Steyr 50 and 55 were noted as being influential, with their forward-located flat-four engines, but the Lancia Aprilia was not. Perhaps Palmer was being mischievous in this particular matter.

The possible Aprilia inspiration was rumbled by Bill Boddy in Motor Sport. The identical engine capacity – 1486cc is mere coincidence. The Lancia’s cylinders were ‘squarer’, at 74.6 × 85 mm. What both cars had in common was light weight, a semblance of aerodynamic design, an unconventional engine configuration, and a sophisticated chassis, to use the term in its broadest sense. Much later in his career Palmer admitted that he was familiar with the Lancia Aprilia as in the pre-Javelin days as he had “helped a friend to strip one down to see how it worked”.

The development of the engine, although far from straightforward, proceeded rationally. In 1936 Jowett had put their first flat-four cars on sale, but at the same time were dipping a toe in the more conventional waters of in-line four production.

Jowett’s first flat four engined car, the 1936 10HP saloon. Image: Jowett Cars

For the post-war cars, Jowett chief engineer Steve Poole favoured an in-line four, but was sufficiently impressed by Palmer’s ideas, or possibly so close to retirement, that the Colonial Engineer was given a free hand while Poole updated the mechanicals of the staple Bradford van for the post-war world. A V4 was briefly considered, but instead a flat four configuration was chosen as much for suitably as for continuance of tradition.

The first experimental engines followed the pre-war Jowett flat-fours in having one piece cast-iron cylinder blocks and two-bearing crankshafts, but with overhead, rather than side valves. Palmer led the decision to add a centre main bearing and change the block material to aluminium. Around this time it was sensibly decided to relocate the spark plugs from the underside to the top side of the engine.

Early prototype engines had a capacity of 1184cc, with a 1.5 litre capacity envisaged for export markets. The larger engined prototypes suffered from unacceptable vibration and harshness, addressed by adoption of a more rigid and substantial vertically split cylinder block in place of the previous one piece bottom end.

Javelin engine – exploded view Image: Yorkshire Ferret

The cylinder block was an all alloy split construction, to be gravity die-cast by Renfrew Foundries in their factory south west of Glasgow, although the first 2000 blocks were sand-cast. The cast-iron cylinder heads had in-line overhead valves operated through long pushrods by a top-mounted centrally located camshaft. Palmer specified hydraulic ‘zero-lash’ tappets to mitigate the effect of the long rods’ flexibility on the valve gear’s operation.

(As a digression, this same consideration may have led to Antonio Fessia’s adoption of one camshaft per bank, but still with pushrods, for the Lancia Flavia’s flat four)

The production Javelin’s 72.5mm x 90mm bore x stroke dimensions were daringly close to square by the standards of British pre-WWII engine designs, with export acceptability very much in mind. Palmer would not have anticipated the 1948 introduction of the flat-rate annual car tax in the UK. The preceding ‘RAC horsepower’ system was effectively a tax on cylinder bore, resulting in very undersquare engines.

To avoid long inlet tracts, each bank of cylinders has its own Zenith carburettor. The engine drove a live rear axle through a four speed gearbox with synchromesh on second, third, and fourth gears, supplied by Henry Meadows of Wolverhampton.

Javelin engine cross-section. Image: G Palmer

Should we be surprised that front wheel drive was not considered for the Javelin? Palmer would have experienced Calcott Reilly’s Citroën Light 15, and also mentions in his autobiography working on projects with John Morris, the eccentric and brilliant chief engineer of the SU Carburettor company, who also owned a Citroën Traction Avant and championed it vigorously, particularly to his Morris Motors colleague A A C Issigonis. The British motor industry was more tentative about mass production of front-drive vehicles than were Citröen and DKW, although BSA and Alvis had produced front driven cars in the late 1920s.

Cutaway Javelin showing engine location. Image: Jowett Cars

However, in the era of the Javelin’s development, nobody had yet found a cost-effective method of mass-producing constant-velocity joints. To an engineer of Palmer’s rigour, the use of ordinary universal joints, with the problems of uneven transfer of power when steering lock was applied would have been anathema. It is also recorded in his autobiography that he believed that front wheel drive was well suited to small, inexpensive cars, but was too compromised for sporting or luxury cars, whose drivers would favour the orthodoxy of one pair of wheels driving, and the other pair steering.

The Steyr-influenced packaging of the Javelin, established at an early stage of development brought some of the advantages of front wheel drive without the mechanical exigencies. The short flat-four’s location ahead of the front axle line assisted low-speed traction and directional stability, and the cab-forward packaging provided a passenger compartment length greater than many far larger cars.

Steyr 55 cutaway and section Image:

With a small, closely located design team, a clear objective, and supportive management the new Jowett’s development progressed rapidly and coherently, and in August 1944, 32 months after Gerald Palmer’s appointment, the first hand-built prototype was registered for the road, with a further six to follow shortly after for use in a rigorous proving regime.

19 thoughts on “Beautiful Vision – Evolution of the Jowett Javelin (Part 3)”

  1. A great story about an innovative and underappreciated British car (and company) about which I knew very little before reading this series. Thanks again, Robertas

  2. Thank you again Robertas – you’re doing a very thorough job!
    In addition to the spacious passenger area (all contained within the wheelbase) the Javelin design anticipated, entirely unintentionally, the creation of passenger cells and “crumple zones”; pre-dating the work by Volvo and Mercedes. That steering box, mounted behind the front wheel centres and above the engine, combined with the high floor, meant that in a substantial frontal impact the mass of the engine absorbed energy but instead of then penetrating the passenger are, drove backwards beneath it.
    Jowett did in fact “crash test” a Javelin at the fire station next door to the factory. It was hoisted by its back bumper to the top of the the tower used for drying hoses and dropped on its nose (I kid you not). Photos of cars which had suffered severe frontal impact clearly show that while bonnet and front wings would all crumple, A-posts remained intact and steering columns did not impale drivers.
    Primary and secondary safety both addressed nearly two decades before the industry started to seriously consider the issues.

  3. It could be (and has been) argued that Palmer’s Javelin was a more innovative design even than Issigonis’s Mini. Ergo, Palmer might be considered to be the more imaginative designer of the two men.

    With its six-seater cabin, its surprisingly capacious boot and a cleverly ‘hidden’ spare wheel, the Javelin made rather better use of its 14 ft length than the Mini did with its 10 ft. Furthermore, the Jowett launched some 12 years before BMC’s baby.

    In his later career, Palmer worked with Issigonis. According to some accounts, the two men didn’t always get on! A little professional rivalry perhaps?

    Well done Robertas for well researched content.

  4. Really interesting, Robertas. You’ve left me wanting to find out more, including about the Steyr.

  5. Some wonderful illustrations here – I knew the Javelin was good but I didn’t realise how good the suspension was.
    Presume there is a Part 4 to come – and some mention of the Jupiter ?

  6. Thanks everybody for your kind words, and nuggets of information. There is of course lots more to come – the Javelin’s story is convoluted (unlike its springs!) and needs constant reference to the political, social and industrial context of its time. We will soon be turning the key on the drawing office, crossing the shop floor, and exiting through the factory gates to a world very different from the one we know now.

    The Jupiter will feature, and also the ill-fated CD.

    And Greek Al is never too far away. How could it be otherwise, given what was occupying his time from 1943 to 1948?

  7. Given Gerald Palmer’s involvement with the Minor based Riley 1.5 / Wolseley 1500 and his later work at Vauxhall with the Victor FB and Viva HA/HB, have always wondered whether he could have done a much better job of developing an early Marina (both Viva and Cortina analogues) had he stayed at BMC and been tasked with RWD cars than Roy Haynes did under different circumstances later on (the original brief for the Marina being an Escort-sized rebodied 1100-1500 Minor before it grew to challenge the Cortina).

    Would have been nice seeing his vision for the B-Series Twin-Cam and C-Series Twin-Cam engines been fully realized and of course reliable, on the subject of FWD cars it seems the from his autobiography that the Mini 9X prototype was closer in concept to Palmer’s thinking compared to the original Mini.

    On the other hand not sure what he was thinking in suggesting a very compact 90-degree V4 SV (or Semi Side-Valve) engine of around 900cc for BMC, which could apparently have been used in a transverse-engined FWD layout under the rationale of reducing the cost of the latter layout.

    Quite liked Palmer’s original idea for the Riley 1.5 / Wolseley 1500 styling that rather tastefully resembled a smaller version of the MG Magnette ZA and Wolseley 4/44.

    Have to wonder whether the 1184cc engine was considered for the Bradford CD prototype as well as whether the 1.5 Javelin could have grown even further.

    1. Ah the temptations of “What if….?”! In 1964 ‘Small Car’, then edited by Doug Blain, ran a short series of design ideas that might have come from defunct manufacturers, had they managed to remain in business. The June edition featured a Jowett and the presumption that the firm would have concentrated on “elegance and sophistication outside, ingenuity and in the cause of luxury within”. Their concept car was apparently the work of Lionel Burrell and envisaged the flat four, now 1600cc, mounted at the rear…..

    2. With the comparisons to Lancia in mind cannot help but envisaged a what-if Jowett being similar to the Lancia Flavia as well as the unbuilt Borgward Hansa 1300 prototype, the latter was to apparently feature a fuel-injected 1300cc flat-four putting out 90 hp with styling by Frua that (or the unbuilt Isabella replacement) was later said to have been recycled into the similarly-sized Glas 1700.

      That said apart from the lower-end Bradford models, it would have been fascinating to see how Jowett could have pushed further upmarket in better circumstances. Would they have opted for a large flat-four up to 2500, a V6 or even some 4-cylinder/V8 engine family (either a Triumph/Lotus/Porsche-like Slant-four and V8 or a 90-degree V4/V8 as was briefly considered by BMW prior to almost going bankrupt).

    3. Hard to imagine anyone making a worse Marina. I suppose it cost nuppence. Says much about Brits’ toleration of the frankly poor that they sold so many. An R12 was just so much better.

      The 1.5/1500 needed its suspension sorting, which never happened. Their use of internal space was very good (as the ZA/B and 4/44 had been) and, with a set of Konis or Spax, anti-tramps and thickish a/roll bar you could avoid finding the nearest ditch. And with the alloy crossflow head (banned in its racing class) sometimes with twin 40DCOEs you had an easy 100mph.

      Long pushrods are always a problem, on the Flavias and the 2500 Gamma possibly the biggest flat-four). Thicker ones would solve one problem but give you another. Rover had got round this with its overhead inlet-side exhaust but this was a rather prewar solution.

  8. I am really enjoying this Robertas, although as a proud Yorkshireman I have no surprise that a car made in “God’s Country”, should be so special; how could it be anything but!
    Allow me the pleasure of pointing out that the front suspension preempted the class leading Alfa-Romeo tipo 116 by about 25 years (A design that was still considered credible when the Alfa 75 finished production in 1992). There is also more than a whiff of Jowett Javelin in the Rover SD1 rear suspension- another arrangement considered to be rather clever a generation later- I wonder if Palmer thought about jointing the prop shaft to create a central trailing arm? It would have given better ground clearence amidships but he may have wanted to minimise the number of universal joints in the drive train.

    1. Since King, Bashford, and Wilks took quite a bit of inspiration from GM for the design of the SD1’s simple and very effective rear suspension, and Gerald Palmer was actively involved in the design of the all-coil sprung Vauxhall Viva HB, it would be pleasing to make a connection between the Javelin and SD1.

      Nothing is straightforward, and the 1966 Viva rear suspension is nothing like that of either of the aforementioned cars.

      In his autobiography GP states “The next Kadett and the Viva HB had a more sophisticated rear set-up with coil springs and trailing arms. It was realised that a Panhard Rod was not necessary on a small car and that lateral stability could be controlled by diagonal upper arms trailing from the frame and attached to the top of the differential casing”.

      He stops short of stating the design originated in Luton; it was used by most GM divisions for many years afterwards and copied by other manufacturers.

      Viva HB Rear Suspension

      Despite what Gerald implies, the Kadett B rear suspension was completely different from the Viva’s:

      Yet the resemblance to the SD1’s is strikingly obvious:

      Both have only two trailing arms, and a torque tube. The Opel has a Panhard Rod where the Rover has a Watts Linkage.

      To add a further twist to the tale, the TR7 and BLMC-A P76 used a very Viva-like rear suspension design – this is from the TR7:

  9. I had to look up pinion and sector, Robertas. It´s a cousin of the pinion and rack. That led me to look into worm and rack and worm and roller. I presum the pinion and sector is a variant of the pinion and rack; a sector is just a bent rack, as I understand it. What would be the effective difference between a sector and a rack? Is there one?

    1. Some refer to the Javelin steering ‘box’ as ‘Gear and Pinion’. It’s a remarkably space-efficient design, if bordering on being over-complex. And it’s a bit of a nightmare to adjust. But once it’s set up properly, it gives light and accurate steering as good as a rack and Pinion, but all within a remarkably compact space. Just another shining example of Palmer’s engineering brilliance, – ‘thinking outside (and inside) the box’, one might say!

  10. Thanks Robertas for this, by the way. I didn´t know how much a loss the demise of Jowett was. Would it be right to characterise them as a British equivalent of Lancia? I might ask a culture-historical question about why such technical high-mindedness does not thrive in the UK.

    1. In the wake of global conflict, particularly WW2, the UK was effectively bankrupt – a situation which could, of course, never be admitted by a governing establishment still harbouring empirical delusions. Therefore the bean-counters were very much in charge and their horizons are, by definition, severely limited. In the grip of the mantra “export or die”, there was no place for those who dared to deviate from the tried and tested, usually meaning cheapest and nastiest, solutions to technical challenges. And thus died a reputation for having produced world-leading innovators.

  11. I certainly think it’s valid to compare Jowett with Lancia. I can think of another example, but I want Robertas to continue with his (excellent) account before I comment, as it comes later in the story.

    1. One thing that might come in pretty soon is Lancia realising that Hardy Spicer joints couldn’t handle much power, so invented the Rzeppa joint for the Flavia.

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