(first posted 8/19/2011) The Hillman Imp shares much more with the Corvair than its obviously cribbed styling. It’s a classic tale: a maker of very conventional front engine-rear wheel drive cars sets out to ambitiously build a clean-sheet small car. And stumbles badly, when the end result is flawed, despite its many advanced features, and sporty capabilities. What both Rootes and GM (and others) failed to grasp with their adoption of the rear-engine configuration after 1960 was this: what was state of the art in 1938 or even 1948 was no longer so by 1958. And it was none other than the Imp’s competitor, the Mini, that really cemented that fact in the UK. Yet Rootes pushed ahead with a new small car, from the rear.
The Imp has its roots in the same era that spawned the Mini: the Suez Crisis of 1956, Britain’s preview of the OPEC gas crisis. German bubble cars were selling, and the initial impetus was to build something along those lines. A glorified version of a bubble car developed, using a Villiers two cylinder engine. Lord Rootes was not amused. The traditional maker of middle class (Hillman) and somewhat higher level (Singer) and sporting cars (Sunbeam) knew it had to do something smaller, but the “Slug” was not it.
A more ambitious clean-sheet project “Apex” was initiated, this time a proper four seater with a four cylinder engine. The Coventry Climax engine, a very modern alloy OHC four originally designed for a mobile fire pumper, was adopted and extensively modified for the Imp, in 875 cc form. And as these early styling bucks make clear, its styling followed the conventional fifties idioms. (allpar, as usual, has detailed historical info here B/W pictures courtesy allpar).
The Corvair’s arrival in 1959 instigated a complete redesign for the final version, which arrived in 1963. But this was not strictly stylistically only. The issues with the Corvair’s swing axle rear suspension led Rootes to develop a semi-trailing arm rear suspension. The result was superb handling, thanks to the lightweight all-alloy engine tucked in low and the improved rear-wheel geometry.
The Imp’s transaxle was also an excellent unit, one of the cleanest shifting of its kind, and distinctly better than the early Mini’s unit. The Imp’s very modern-looking engine can be seen here, tilted 45 degrees, and its radiator on the left. One of the disadvantages of a water-cooled rear engine is a fan powerful enough to overcome the lack of natural airflow.
Due to the government subsiding the Imp’s production facilities, there was a final rush in getting the Imp into production. The results were predictable: many issues with water pumps, the unusual pneumatic throttle control, automatic choke, overheating, body leaks and rust, etc..the usual litany when a manufacturer bites off too much too quickly. In relative terms, the Corvair had a less problematic birth.
The Imp was eventually improved, but its reputation was permanently dinged. The Imp’s financial drain led to Chrysler eventual takeover of Rootes, and Chrysler was more interested in rationalizing its European production of traditional cars, and it already had a rear-engined car in the similar Simca 1000. The Imp soldiered along for over a decade, but like the Corvair, it’s inevitable demise was sealed within a few years of its birth.
But during its run (which ended in 1976), the Imp generated the kind of enthusiast following as the Corvair did. It may never have become the mainstream sedan success its builders envisioned, but as a sporty pocket-rockette, it brought Impish smiles to its devoted fans. And sporty versions a la Monza, Spyder and Corsa were developed to satisfy them. The whole lineup of models gets a bit confusing for those of us not exposed to them extensively, but there were Hillman Super Imps, the Hillman GT for Australia, and a raft of Sunbeam models, including Imp Sport, Chamois, Stiletto, and Californian.
The coupe versions were know as the Hillman Imp Californian, Sunbeam Stiletto, and Singer Chamois.
And just like the Corvair, a wagon version, the Husky, was also built, as well as a windowless panel-van Commer.
Now that’s what the Corvair was missing: a panel delivery version.
Speaking of the Imp’s utility, it had a rather unique lift up rear window. Not exactly a hatchback, but a different approach to making the rear cargo area behind the rear seat more accessible than in the Corvair and VW. This one was either locked or rusted shut.
Not exactly huge, but storage space in a rear-engined car is always a bit scarce, and this was a way to put it to good use; just drop the shopping bags in through the window. I assume the rear seat folded down too.
And here’s the best seat in the house. From the look of that instrument cluster, this Imp is of relatively early vintage. And I should point out that the Imp was only sold as a Sunbeam in the US, for what exact reason I’m not sure. Normally, the Sunbeams were the more sporting variants, but this one is just a basic Imp.
Hillmans were fairly popular in the US during the import-mania of the fifties, but Imps were always a rare sighting, and a noteworthy one. I don’t have any statistics, and the only thing the very flawed standard catalog of Imported Cars has is a brief entry saying Imps were imported starting in 1964, with a 42 hp version of the 875 cc four and priced at $1495 ($10,400 adjusted), somewhat less than a VW.
Like the Corvair, the Imp makes for great history, and amusing driving. Meanwhile, the rest of the automotive world was moving forward, and in terms of small cars, ever more so by their front wheels.
It is remarkable, when you think of it, how much engineering effort on two (or more) continents went into the concept of a rear-engine/rear-drive vehicle. And ultimately a dead end (with the sole exception of a single really, really expensive German sports car). My only other thought was how much the Corvair could have benefitted from the Imp’s rear suspension design.
Also, I have never seen a opening rear window on a notchback before. A really neat idea.
Thank you for again expanding my automotive horizons with a great article about an obscure but cool car.
> Also, I have never seen a opening rear window on a notchback before. A really neat idea.
There were those ’50 and ’60s Lincolns and Mercurys with the reverse-canted “breezeway” windows that rolled down (or slid sideways?)
Brilliant write-up Paul, thanks. I’ve always been hugely fond of these little guys but never imagined them being sold in the States… Seeing one sharing the road with the usual 60s/70s domestic crop must have been pretty comical!
Can’t remember the last time I saw one on the road here… though howmanyleft tells me there are 681 Hillman badged examples still registered for use on the UK’s roads which is a happy thought! I’ll keep my eyes peeled for a curbside example.
There are quite a few guys in the Imp club that still use them as daily drivers, I went to their national rally a couple of years ago and there were over 200 cars there.
The British govt by subsidising the Imp also interfeared in Rootes plans for building it by refusing permission for an expansion of Rootes factory They were forced to build a plant in Scotland to assemble Imps miles away from the regular works complete with inexperienced assembly workers and all the logistical hassles of railing parts hundreds of miles. I remember these things new a real departure from the rugged cars Hillman was known for but when running well these little suckers went and were raced against Minis with success This was possibly the best handling rear engined car with none of the lethal tendancies of VW Porsche & Corvair Still some around in NZ there was one a couple of blocks from me but it wasnt there last time I went past with camera
I actually spotted one of these on I-90 last year I think, it was green and I believe a ’67 for it had the separate reflectors below the taillights.
It was not restored, but a Sunbeam Imp sport none the less.
Even took a photo of it as I was right behind it.
Spotted another odd, British perhaps wagon/van of similar vintage and style later on that I could not identify and the photo I got of it was wretched and washed out as it was taken with the cell phone if I recall since the sun was right there to the left of the car – again, on I-90 and both times, I was heading home from work in Bellevue to Seattle.
I believe that is the same car I routinely see parked on a street in Ballard (Seattle neighborhood).
I assume you’re thinking of the one that lives (or lived) on 8th Ave. NW a few blocks north of NW Market St. I once chatted with the owner in the parking lot at Ballard Market. I no longer drive that stretch of 8th NW often enough to know it it’s still there.
I had one of these in the summer of 1976 between high school and college. My Dad was an American working for Chrysler UK. It was bright orange, which this one may have been before time took its toll on the paint job. They were a blast to drive, with a rev-happy engine and great handling. Talk about the fun of driving a slow car fast! Top speed was 80 mph (ask me how I know…), but only if the air temperature was not too warm because it would overheat and you were limited to about 60 mph. They had a surprising about of room inside. The rear seat did fold and you could load it through the lift up rear window. It made for a sporty 2-seater with a huge trunk. It had a manual choke operated by a small lever between the front seats and 4-speed stick. Mine was the base rubber floor-mat edition with single-speed wipers. Fortunately it did have a radio so I could blast BBC Radio 1 while tearing around the countryside.
My first car was a 1964 Hillman Imp, bought just after I passed my driving test in 1983 for £150. It had its problems, but like all first cars of a 17-year-old, still holds fond memories for me. Mine had something of a propensity for going through head gaskets, and in the relatively short time I owned it, I remember replacing the gasket at least twice. I suspect previous overheating had slightly warped the aluminum head.
That lift-up rear window was certainly a somewhat unusual feature, and while not quite so convenient for cargo hauling as a traditional estate/wagon tailgate, with the rear seat folded down it provided a good amount of luggage space in the back. Of course, there was the luggage space in front under the bonnet/hood as well. I would echo the sentiment that for a small car it felt surprisingly roomy inside, and with good visibility all round.
Alongside the choke lever between the front seats mentioned above was a second, similar lever which was mechanically linked to the flow control valve in the engine compartment for heater temperature. One lever was white, the other red.
One option on my Imp was a floor-mounted screen washer pump, operated with the left foot. It had a metal ring surrounding it which operated the wipers when using the screen wash, but just tapping that ring with the tip of the shoe also provided a convenient single-wipe feature (normal wiper operation was just single-speed on/off on the ubiquitous Lucas-style toggle switch).
The headlamp dip/dimmer switch on the Imp was the separate stalk on the left side of the instrument panel (on the RHD version): Up for high beam, down for low, and a biased position pushing down further for headlight flash.
Fascinating write-up, thank you! And that Allpar site you noted was very interesting too. My late Uncle bought an Imp new in the 60s for my Aunt here in New Zealand. It was before my time, but features in family photos from then. I’m not sure if it was greatly loved or not. I had no idea Imps were sold in the States, so am feeling suitably educated now! Cheers!
Allpar is a great site Paul just been reading up on the Valiant Hemi and Centura ,owned examples of these in OZ great cars especially if your in a hurry on long trips or want to tow Those 265cube 6s pull better thanV8s, I put a couple of pics on the cohort page of a local Val recently just in case you guys have never seen one.
Great article Paul, I have had an Imp for >10yrs, they are great fun to drive. They have a swing-arm front end to build in understeer – early cars from the factory had a few degrees of positive camber and a real knock-kneed look, combined with lower tire pressure setting on the front. Fixing that makes them a real go kart, and having proper suspension unlike a Mini they are comfortable riding. The engine weighs 170lb complete, the transaxle 70lb. I had the engine out, radiator changed and all back driving in a bit over half an hour – the rear crossmember (behind the bumper) unbolts and the whole lot can be wheeled out.
During the course of development they were de-tuned with smaller valves, less capacity etc because Rootes did not want them to be faster than the more expensive Minx. Lots of the issues were known about prior to production, but the launch date was not changed as the engineers pleaded for. Incidentally on of the key team members was Ferrari F1 driver Mike Parkes.
A standard single carb car will rev over 6000rpm, I have had mine to 8000 while full race motors will go over 10k, they were making 120hp/litre in 1966 for racing. In the 60’s guys would put these engines in motorbikes for extra power. They pull 4000rpm for 60mph but are very rev-happy so it is not a problem, and not particularly noisy as the noise is behind you. A mate and I did a 1000 or so mile round trip a couple of years ago in his Imp, while a few weeks back he beat Priuses etc in an economy run with 50mpUSg on a mixed/hilly route.
US market cars had two braces under each bumper which it appears are not on the car you photographed (they run vertically from the inner bumper bracket bolt) – these are not 5mph bumpers!
when i was a child my auntie had a coper/bronze black vynal roofed …sunbeam stilleto..the upmarket imp coupe 4 headlamp front end uprated engine and sports steering wheel ,wheel trims and bucket seats like a baby monza..sooo stylish and worth ..big money now
Your comparison with the Chevrolet Corvair is certainly valid, but I think the Imp owes more to the German NSU Prinz, NSU 1000C and the TT and TTS-series.
The body-style is almost similar, as is off course the engine location.
I think the Imp was already obsolete when it came on the market, as rear-engined cars were rapidly succeeded by front-wheel driven cars with the engine in front.
But nevertheless I have always liked its design and engineering.
The main difference with the NSU is they had transverse engines.
Funnily enough this layout has been reborn in the current Renault Twingo.
My first competition driving experiences were in my mother’s ’67 Imp. In New Zealand, hill climbs were typically the training ground and I used to “borrow” her car for the day, take everything I could remove out of it (spare, seats, tools,), jack up the rear tire pressures and go hill climbing. I never told her what I was doing, but I remember my father being outraged when I destroyed a set of tires in about 1,500 miles … oops.
I live in the US now and I’ve never seen one here, but they were fun.
I bought a brand new black Sunbeam Imp from a dealer in Union NJ
We just transferred there from Maryland. I was recently married and we needed a second car because both my wife and I worked in different directions from our apt.
I traded in a rather worn MGA prepared for racing and received a decent price for it.
The Imp took us all over New Jersey and as far south as Ocean City, MD about a 350 mile round trip. It handled well if you remembered to check the different tire pressures from front to back. It also handled the groceries well through the back window and was a lot of fun to drive. And yes, the first thing that went was the water pump, which was in stock at the dealer [wondered why they had so many of them] I rarely saw another on the road.
It ran good in the snow with rear weight bias and was a lot of fun for 3 years. It was sold and we went to a 1960’s VW Beatle with an “automatic stick shift” Just flip it from low to high with an automatic electric clutch. I could never defeat it. and it lasted 4 times longer than the Imp, 12 years
Ah, if only Chrysler did not put the kibosh on the Hillman Zimp! Styled by Zagato and based on Hillman Imp mechanicals, only three prototypes were built. Hillman attempted to make a deal with Zagato to put this sporty little car in production, but the bosses at Chrysler would not allow it. You can read about it here, on the Imp Site:
http://www.imps4ever.info/specials/zimp.html
All you really need to know about Imps is on this site, pages and pages of it that make the Allpar take a bit thin:
http://www.imps4ever.info/
Just how amenable to engine and suspension tuning these cars are is shown by the results of 998cc Imps vs. 1275cc Mini Coopers in UK (and elsewhere) historic racing. They’re a lot of fun to drive, even in 39 bhp standard form.
What I find fascinating about the Imp would have to be the extent of its unrealised potential as it was.
This was a car that was roughly of similar size to the Fiat 850 and Simca 1000, yet amongst other things could have benefited from being a 4-door from the beginning (like the latter plus the SEAT 850) or at least featuring a 4-door bodystyle as part of the Imp project. The fact it was only available as a 2-door likely helped limit the Imp’s appeal in the UK against the Mini, which at least had the appeal of being a front-engined FWD car despite also featuring 2-doors (yet the latter also had unrealised scope for featuring 4-doors via a Minivan wheelbase as well as a hatchback).
It is also possible a smaller 2-door only Fiat 600 or SEAT 133 type car could have been developed to sit at the very bottom of the range, alongside the planned sportscar, forward-control van and bus as well as non-Husky estate bodystyles
Meanwhile the various experimental projects involving Polish built Fiat 126p prototypes provides some idea as to how the Imp or related derivatives could have been converted to a front-engined FWD hatchback or saloon via the Polski Fiat 126p NP prototype.
It is said both automatic and semi-automatic gearboxes were considered for the Imp, while better circumstances during Roote’s expansion and development of the Imp would have either led to a properly-developed linerless engine capable of outclassing the 1275cc Mini Coopers or led to two versions of the dry-liner engine with a tall block version still capable of outclassing the Minis (e.g. existing 800-948cc / 998-1150cc+ tall-block units whereas the linerless engine would theoretically feature a capacity range of 800-1150cc+).
https://www.theimpclub.co.uk/wp-content/uploads/2018/02/201410-Impressions-Article-Oct-2014.pdf
One of the UK magazines did a cutaway drawing of a fwd Imp with the engine mounted ahead of the axle, but it wasn’t realistic for a longitudinal inline four cylinder engine IMO. Only the ‘backwards’ Renaults have done that, that I can recall.
The four-door idea is interesting, the Austin A30 had already done that, and although it would have added cost, it would have been an interesting point of difference from the Mini.
There may have been a remote possibly a fwd Imp could have had its engine mounted transversely, based on lessons from the rear mid-engined transverse mounted Swallow prototype whose engine was more or less larger version of the basic Imp engine that was used the original Lotus Elite.
Even though rear-engine cars were becoming obsolete, there was still a decade plus or so lag until it became apparent and that also still does not account for the long commercial success of the Simca 1000 which was mainly down to featuring 4-doors.
As much as it would have been ideal for the Imp to have resembled in concept an OHC version of the fwd DOHC Alfa Romeo Tipo 103 prototype. IMHO existing layout was redeemable and in fact the Imp should have underpinned two cars, one a 4-door like the Simca 1000 and the other a smaller sportier 2-door two-box more like the Fiat 133 that was spun off from the 850 with Suzuki Whizzkid foreshadowing elements.
The smaller version resembling a two-box Imp partly drawing upon the similarly Corvair-inspired Vauxhall / GM XP-714 prototype.
That would have allowed Rootes to fit the non-produced 800cc version of the Imp engine in the smaller model, with someone quickly recognising the basic Imp engine could only grow to 950cc rather than intended 998cc. Meaning the Imp is no longer a single-capacity engined car, but rather encompasses three different engine sizes not all that different to what else the lower-end engine ranges found in the Simca 1000.
Front suspension by large radius swing arm, pivot near car centre line (“sagittal plane”) kept a good camber angle, thanks to car’s low centre of mass hence low roll forces. Redolent of a few Austin 7 & Ford Prefect/Anglia/Popular specials, and the occasional Lotus 7 ancestor, where a keen DIY dude had sawn the original solid axle in half and welded (or brazenly BRAZED) on a couple of tube segments for bushes. What solution did most Allards adopt to the IRS-or-bust imperative? The Imp transaxle-engine combo, with a bit of boring, sleeving, stroking or awaiting Rootes enlargement, found its way into FJ (Open wheeler FORMULA JUNIOR, under 1100 cc class, the poor man’s Grand Prix racer, not the early 1950s stopgap model Holden, a purely cosmetic newie) Ford’s excellent 105E short stroke pushrod unit long ruled in FJ and backyard built sports specials, its pushrods, cast iron and Uncle Tom Cobley and all. The Imp engine was light alloy and sohc, and could rev rambunctiously.
When the Mini came out, the Rootes design team realized that this was the direction they should have gone. But at that point the Imp was so far along that it wasn’t possible to start over.
Even “abandoned” , the poor little thing retains it’s “boxy cute, akward appeal”
I saw an immaculate Commer Imp van at coffee n cars a week or so ago, oddly enough there are still plenty of Imps in New Zealand still and barn finds keep appearing and being restored, Hillmans in general arent rare here yet they sold well new and were fairly durable so survivors abound.
A blue ’65 version was our family car when I was a kid. I do remember the water pump dying one night and us barely making it home.
I would love one of the coupes – I’ve heard they are an absolute blast to drive and would make an interesting comparison to my old Minis.
Even better would be a Ginetta G15 – lighter, more slippery and therefore quicker – yes please!