Beautiful Vision – Evolution of the Jowett Javelin (Part 7)

We take a brief detour and look at the other Javelin, the glamorous Jupiter. 

Image: crowood

You’re part of the plan.

At the 1949 London Motor Show, Jowett exhibited a low-slung tubular steel chassis featuring the Javelin flat-four engine and a modified form of the saloon’s torsion-bar suspension. It was the culmination of months of frenzied activity by a distinguished Austrian designer and four other engineers at Five Lane Ends, in pursuit of a promising but haphazard joint venture between the Yorkshire car firm and the revived ERA (English Racing Automobiles) company.

By early 1949, it was becoming clear that the Javelin was not meeting sales expectations in the USA. Ordinarily, this would have not been a concern, with production of around 6000 per year, and plenty of interest from the home market and from Jowett’s traditional sales territories in Europe and the former British colonies and dominions. However, the UK’s trade strategy was asymmetrical. The US dollar was the post WW2 world’s paramount currency, and British manufacturers who could bring in hard currency would be best favoured with material supplies.

As Gerald Palmer departed Bradford in mid-1949, Jowett’s new management were presented with an extraordinary opportunity which seemed to fit comfortably with the germ of an idea already being considered. The far from indolent Idle board had a notion to use the Javelin powertrain and chassis components in a two seater sports car of a more modern design than the MG Midget which was selling well in the USA despite its antiquated design. Logic suggested that there was a broad, readily exploitable gap between the primitive MG and the all-new, recently launched Jaguar XK120.

Image: Jowett Car Club

To recapitulate briefly, the plan was required to provide a specialised sports-racing car which would build on ERA’s and Jowett’s competition reputation, and a stylish and up-to-the-minute two-seat open tourer which would bring in US dollars and secure all-important material allocations for the company.

That makes two purposes already, but there was a third, as a blank canvas for coachbuilders. This was far from unusual in the late 1940s, with specialist bodybuilders able and willing to provide small-run bodywork for discerning individualists who wanted something different from the stock design. There was a further raison d’être for rolling chassis sales, as some high-tax export markets levied a lower rate of duty on incomplete vehicles.

The unlikely partnership of Jowett and Leslie Johnson’s rescued ERA was established with only an informal agreement over a lavish and convivial lunch also attended by the project’s matchmaker, no less a person than Laurence Pomeroy, Technical Editor of The Motor. Johnson was a successful furniture manufacturer and amateur racing driver, noted for his charm and boundless enthusiasm.

ERA’s most important contribution was the services of Dr. Ing. Robert Eberan-Eberhorst, an Austrian development engineer with a reputation established by work on the pre-war Auto Union Grand Prix cars. Post-WW2 he was a high-grade jobbing engineer, working in his homeland on the Porsche flat-four engine, and in Italy on the Cisitalia GP car, with fellow expatriates Rudolf Hruska, Erwin Komenda, and Karl Abarth.

Dr. Ing. Robert Eberan-Eberhorst with Jupiter no.1 Image: Collection Sloniger

Eberan’s contribution to the project was defining but finite. He arrived from Italy in the summer of 1949, and the chassis he produced for Jowett while employed by ERA was ready by October of that year. In 1950 he left ERA to work for David Brown on the Aston Martin DB3 sports-racing car. Design work for Jowett had scarcely started when their ERA partnership disintegrated.

Eberan relocated from ERA’s Dunstable base to Bradford, where he was allocated an assistant, and eventually a team of four to realise his chassis ideas. Palmer’s suspension components were used in a complex tubular chrome-molybendum steel alloy frame, with extensive use of triangulated bracing for strength and lightness. Anti-roll bars were added front and rear. By decree of Jowett’s management, any alteration to the flat-four Javelin engine was ‘off limits’ to Erberan and his team.

In his biography ‘Auto-Architect‘, Gerald Palmer wrote Von Eberhorst’s steel tube frame was an idealistic layout for a limited production sporting car but it was not easy to manufacture.” Read between these lines and the implication is that the chassis was optimised for the six sports-racing cars Jowett were to provide ERA with under the Pomeroy-brokered Gentleman’s Agreement rather than for the series-produced sports-tourers intended to conquer America.

Jupiter Chassis Image: Veloce

Reg Korner, Jowett’s body designer since 1936, was given the task of designing the coachwork for the racetrack and touring cars to meet an April 1950 New York show deadline. On top of the demanding timescale, Korner found a further challenge in the flexibility of Eberan’s chassis. Although inherently strong, torsional movement had been built in.

This presented no problem in a narrow racing body with no openable apertures, but meant that Korner’s drophead coupe bodywork had to be self-supporting, with a substantial steel-section frame clad in aluminium panels. The body was fixed to the chassis at six strategically chosen points, with resilient rubber bushes preventing flexure in the chassis from distorting the superstructure. The unwelcome result was a 2,100lb (955kg) kerb weight, still 158lb (68kg) lighter than the Javelin saloon, but well adrift of the 1500lb design target.


To provide increased power the Jupiter had larger Zenith carburettors, gas-flowed cylinder heads, more freely-flowing exhaust manifolding, and a higher compression ratio than in the Javelin installation. Power output was 60bhp at 4750rpm in early cars, increased to 62.5bhp at 4500rpm after January 1953, in each case 10bhp more than the equivalent saloon.

The Jupiter story continues shortly.

21 thoughts on “Beautiful Vision – Evolution of the Jowett Javelin (Part 7)”

  1. The story continues to be fascinating, thank you Robertas. Do we know why the Jowett/ERA partnership fell apart?

    1. Daniel – that’s a good question. The sources I referred to don’t address the issue, but perhaps our visiting Jowetteers know more.

      I didn’t delve too deeply into the ERA matter, as the consequence of their involvement – that costly, hard to build, and not wholly suitable chassis – is more relevant to the Jupiter story than the short-lived partnership which produced it.

      Given what followed their exit from the venture, it’s possible that ERA chose to concentrate all their resources on development their own Bristol-engined G-Type. This was a complex design also with Eberan’s input, but without the restrictions imposed by use of the Javelin suspension components, and Jowett’s management’s imposition that the flat-four engine could not be modified.

      ERA and Eberan’s original input did at least play a part in the racing and rallying successes of Jupiter in Mk.1 and R1 forms, but more of that story later.

  2. I’m not going to spoil the story by interrupting too soon – you’ll just have to be patient Daniel! However, the appearance of the Jupiter chassis at Earl’s Court in 1949 coincided with a coupé-bodied example going on show at 48 Albemarle Street. This was the work of Seary & McCready, a coachbuilder busy at the time modifying Bentleys for one Harold Radford (he actually took them over) – the Jowett board were generally unimpressed by the car’s appearance and although S&McC/Radford, commissioned by Leslie Johnson, had two more attempts at getting it right, Jowett took the bodying task in-house. It would not, therefore, be unreasonable to assume that dummies might have been thrown out of prams.

    1. The Seary & McCready bodied car seems to have been airbrushed from Jowett history. All I can find is an “artist’s impression” of a ponton-bodied fixed head coupe with enclosed rear wheels and hints of Porsche 356 and Gutbrod Superior about it.

      Leslie Johnson was without doubt the aggrieved party, as all ERA got out of the deal was five chassis, while Jowett went on the build the sports-racing car themselves as the R1.

  3. BRM has something a reputation as a symonym for complexity – looking at your comments above regarding ERA, I’m wondering if there’s a pattern building up here. Was everything Raymond Mays was involved with complicated?

  4. Seems there were quite a lot of Coachbuilt Jupiters, would like to have seen the Radford Coupe body at other angles though so far the Farina bodied cars would have to be the one of the best of the Coachbuilt models.

    Did not know the Jupiter was supposed to be some 275kg lighter than what was ultimately produced, yet not a fan of the exiting Jupiter’s styling.

    People have made comparisons with Jowett to Lancia in past marque-related articles, though wonder how the company could have reached such a goal with both the Javelin and Jupiter (not to mention the Bradford) let alone how they would have gone about replacing them had it been possible (if any details exist of such plans prior to going into voluntary liquidation)?

    1. I suspect that Robertas will, in due course, be making mention of the state of play with regard to the next Jupiter when production ceased (in recent years an example was designed and built to factory drawings and is currently for sale).

      As for the weight issue, an the 5th production chassis was acquired by a chap in Hull who had it bodied by his local coachbuilder Barnaby Motor Bodies, a firm more used to building buses (they only ever bodied three cars). They copied photos of the Jowett factory bodies, managing some possibly unintended detail quirks in the process, using traditional timber-frame techniques and in doing so managed to reduce the overall weight by 125kg. The car was completed in time for the 1951 RAC International Rally; it exists today and is still used extensively:

    2. Look forward to it, know there was the R4 as well as a mk2 Jupiter that was said to be like the R4 though not sure if it extended to the R4’s fiberglass body or instead featured a non-fiberglass body.

      More curious to see whether Jowett planned on further developing the 1466cc Flat-Four engine as opposed to carrying it over unaltered.

  5. Are you saying one person machined up a car from the drawings? That´s remarkable. I saw the blue prints for a train (circa 1950) and they were sketchy to say the least. It is a work of skill and interpretation to take the move from the drawings to 3D.

    1. In the interests of brevity I used the phrase ‘factory drawings’ without a proper explanation. They were preliminary sketches which, although depicting the car from many angles, were by no means production drawings as you might understand them. The result can be seen at It was exhibited at the 2017 NEC (Birmingham) Classic Car Show, since when it has been completed. Very much one person’s interpretation of another’s…

    2. It´s a commendable job so it´s a but churlish of me to criticise. Still, I was born under the sign of the churl, so I will carp about the wheel cut-outs. The rear one is not regular. There is a geometrical process to get from the bodyside to the eventual wheel arch cutout so that this effect is avoided.

  6. You are not the only churl – you should hear one of my colleagues on the subject of glorified kit-cars! And I have to agree; it needs a lot more work and I doubt the price asked will ever be realised, despite being a fraction of what the project must have cost. But a very brave and honourable attempt to realise what might have been.

    1. The way they made the Jupiter coupé was very ingenious, but I’ll leave that to Robertas. For a small company, the genesis of models is pretty complicated. Perhaps it’s easier to experiment on a smaller scale.

  7. JTC – that’s a great story about the Barnaby Motor Bodies Jupiter.

    There will be a section on the coachbuilt Jupiter in the third chapter, but it concentrates on the more widely known examples.

    Was the motivation for the Barnaby Jupiter weight saving or cost saving? Or even just obtaining a car, given the factory’s problems with obtaining a sufficient supply of bodies from King and Taylor? Also were Barnaby’s other two cars Jupiters?

    The windscreen looks a bit incongruous, more like something from a ’70s beach buggy than a ’50s sports car. I’m wondering if it was a later addition and if the car started out with aero screens.

    Using bus builders and timber frame construction was not unusual in the ’50s. Alvis used Willowbrook of Loughborough for the 1955 TC108/G after Mulliner and Tickford terminated their supply arrangements. The quality of the Graber-styled bodies was disappointing, but had they not been available, Alvis would probably have ended car production.

    Thanks also to Charles and Bob for the additional information on the ERA-Jowett.

    1. Sorry to be so slow replying Robertas – distracted by Pathfinders, 901s & Ferraris!
      The Barnaby Jupiter resulted from your third option and was largely down to Tommy Wise who, with Cuth Harrison, persuaded Jowett’s to enter a Javelin in the 1949 Monte, thus kick starting the Javelin/Jupiter sporting successes. In 1950 Wise approached his friend Ted Booth with the offer of a discount price Jupiter chassis to be bodied in time for the 1951 RAC International. Fred Barnaby apparently owed Ted a rather big favour, hence the choice of Barnaby’s to build the body (which, incidentally, was the work of Barnaby’s Cliff Golan, a senior coachbuilder). The car is unique – the only other surviving Barnaby car is a Minerva and the identity of the third is not recorded (but it wasn’t a Jowett).
      As for that windscreen, the car started with an ugly vee-shape two-piece affair with very thick frame (would have suited a van or lorry!) but had gained the current one within a few months. It does indeed look incongruous but with its triple wipers and single pane it’s apparently more practical than the factory version. And then there’s the bonnet; it lifts higher, giving better access

  8. I also note that the fine-looking Fishburn Jupiter Mk.2 has a Ford gearbox – I’m guessing a Type 9.

    If only Jowett had made an arrangement with a mass-manufacturer rather than going it alone with the J-box…

    1. JTC – Thanks for enlarging on the history of the Barnaby’s Motor Bodies Jupiter. I hope you won’t mind if I include the pictures and story in an upcoming chapter.

      It’s detail like this which enriches the content on DTW – and relieves the loneliness of the long-form content provider…

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