The bull-nosed, swan-tailed Jowett Jupiter qualifies as one of the more eccentric vehicles to ever emerge from Britain. On the one hand, it was a competent racer, racking up class wins at Le Mans, Monte Carlo, the Isle of Man, even Watkins Glen. On the other hand, it was an abysmal and expensive road car. Fewer than 850 factory-built Jupiter roadsters were produced, and only about 300 came to the US. Certainly several examples must have perished during the decades since the factory closed in 1954. But this guy has two. Here on facebook Marketplace are a pair of 1952 Jowett Jupiter roadsters, located in Elverta, California. The package price of $17,500 includes parts and manuals. Thanks to T.J. for spotting these rare beasts!
Ok, weird thing number one: the engine. It’s a water-cooled, 1486 cc flat four that limped out of the 1940s when it was standard fare in Jowett’s Javelin sedan. By 1952, it was slightly improved with a higher compression ratio, twin carbs, and 60 hp. Yeah, that’s the radiator behind the engine – and the water pump is perched up there somewhere driving a thermo-siphon system. The whole contraption sits down inside the frame in front of the front axle. The driveline runs above the frame to the rear. The frame is not weird: it was designed by Robert Eberan-Eberhorst, who headed up the racing department at Auto Union in the ’30s. Eberan-Eberhorst gave the Jupiter a chrome-moly tube frame. Hung onto this was a torsion-bar suspension, independent in front/live axle augmented with a Panhard rod in the rear. Steering is rack and pinion; dual circuit brakes arrived in 1951. The column-shift manual gearbox was problematic, as Jowett had begun making its own with hit-and-miss success. Cutting gears turned out to be more challenging than thought.
Jowett’s tiny operation didn’t have the scope to handle reliability problems – and there were plenty. That engine didn’t like to stay cool. It suffered vapor lock. It cracked cases and crankshafts. The valve train was fragile. Jowett fiddled with the engine bay configuration – venting the cowl to evacuate hot air, adding an oil cooler – but the reputational damage was done.
Its habit of stranding owners was bad enough, but the Jupiter was also expensive. It had roll-up windows, a radio, a heater, a removable windscreen (in case you wanted to go racing), a handsome banjo steering wheel, and full instrumentation … but these features were offset by its odd bench seating and cheap wood veneer dash board. And it looked ungainly with the top erected.
The body is heavy gauge aluminum (Jowett had a tough time obtaining an allocation of steel in the wake of the war). Two versions were made – these are Mk 1s, with no boot lid and an 11 gallon gas tank. In late 1952, the Mk 1a was introduced, with a proper trunk but a diminished gas tank. The company closed its doors in late ’53, but such was the unpopularity of the car that it was still selling backlogged inventory into 1954. If you have your heart set on a Jupiter, join a club to become familiar with parts sources and be prepared to improvise – or, buy a restored example. This one sold a couple of years ago for $55k; if you’re patient, you can pay a little less.
Very interesting and kind of coil. Even though Elverta a couple of hours away…….
No thanks!
Very interesting and kind of coil. Even though Elverta is only a couple of hours away…….
No thanks!
Please don’t say that again.
Very interesting and kind of recoil.
Jewett was an interesting company and quite viable in the prewar UK market done in mostly by tectonic changes in the postwar domestic and export market. The Javelin was well liked and many still survive as drivers. They had plans to re-body the Jupiter but they ran out of time. Kind of a shame as this were technologically advanced for their time even though hampered by inadequate development and testing.
It would be cool to own these and when someone asks “What do you drive?’ And you proudly reply…”A Jowett Jupiter.” And then watch the facial expressions…LOL
Just when you thought you saw everything…
I wonder how many left-hand drive cars were built? Can’t be very many…
About 300, as best as anyone can tell.
I wonder if that cream restored one is here in the Sonoma, Ca area now.One just like it showed up for the Breakfast Club Rally about a year ago..I think I was the only one who knew exactly what it was.As said an eccentric, but lovely, car.I blieve to completed the rally that day without a hitch. I hope someone saves both of these..
I had a left hand drive jupiter which i lost to a shyster long with a Triumph 1800 and a XK 150 . I still have a lot of parts left and books and badges and even a rare original hand book and service manual. The jowett company dates back to the 20’s and i have seen earlier cars come up for sale from time to time mostly in uk and Europe.. jowett javelin was a famous car and my uncle had one and it was a cool car . looked like a DKW from Germany. I loved my jupiter and i want to buy another one but old age is catching up with me fast and i wish i could keep them all but my body and pocket book says no.
Are both of these Jowetts going for $17,500 OBO for both?
Please respond
John, the price is for the pair – the partially restored one with the original floorboard in it has the bottom doorhinge part of each A pillar professionally rebuilt, and has the running engine. The greyer car with complete instrument panel needs both lower doorhinge pillars rebuilt following the pattern of the other car. So each car sort of complements the other regarding how to reasemble them both. And each car is nearly complete – hence the pic of engine alone, and there are gearboxes for both cars needing reinstallation. The whiter car comes with a convertible top, but is missing the rev counter. The grey car has all the instruments, and both switch panels have all original unbroken casein plastic knobs. And both have working doorlocks & keyed ignition switches with new keys.
Boxes full of original and new replacement parts & too many pics to list come with the pair. Plus a Jupiter expert restores them in the LA area along with racing his own at LaGuna Seca and other venues.
Hello Tilak, sorry to hear about the shyster who got your cars. As I’m the oddball car lover – Citroens, Panhards, Goliaths, NSUs, Bristols & Saabs & almost a Lloyd – with a total of 5 Jupiters, I’m curious about what parts you have left & what you’d want for them? (who knows what I’ll need to put together all 5?) Having worked as an apprentice in an Oxford UK engine rebuilding and general engineering shop the summer of ’66, I’m a bit used to the British approach to car design so this brand doesn’t scare me. Would like to learn about your experience with them if possible. BF has my email, but I don’t know if I’m allowed to list personal contact info here – if someone knows the rules, please inform me!
Nice writeup Michelle, but for two details: The waterpump does the water circulating for cooling – so not a thermocycle, and there is a thermostat in the pump. The rear end of the pump shaft drives either a 2 or 4 blade fan ahead of the rear positioned radiator. One of each is included, along with parts for both pumps.
Both dashes facias are Teak – “plywood yes, but not cheap plywood any day. Remains of both come with the cars and provide patterns for new flat panels – simple to make in any material desired.
My sincere apologies Michelle – I realized that I didn’t have a photo of the waterpumps for both cars, which is why you concluded that they were thermosyphon cooled – neither engine had the pump attached. I ran the one engine for the video very little with the block filled with coolant for protection to avoid damage. If anyone’s interested, I can provide many photos of the pumps and all the other parts to put both cars back in running condition.
gotta complement the writer. Most show the above, I post a link toa good rep of the actual car. Here you ‘dood it’. I really like the BaT pic.s (& hate the site).
Thnx Michelle (double).
This is my first ‘unknown’ of the year. I get 2, 3 every yr from this site. Now I got one (also ‘a never heard of’… a twofer!