The cars : Hillman Imp
Mini steps backwards…

The Suez crisis of the 1956 certainly had a lot to answer for: petrol shortages in the UK meant that those cars that could eke out the most from a gallon of Petrol were judged to be the most desirable. The Rootes Group certainly felt that way, and as a response to these hard times, it was decided that the utmost priority should be given to its new economy saloon.
But what was the Suez crisis and why did it affect Britain so badly? In a word, it was a situation that arose when the Arabs discovered that they could hold the world to ransom using their control of the majority the world’s oil supplies. The situation blew up in September 1956 when Colonel Nasser decided to nationalise the Suez Canal. The British tried to stop him, the Americans pulled the rug from beneath them and the Arabs decided to close their oil pipeline across the Mediterranean. In the ensuing war, the Arabs blew up the Syrian pipeline that provided 20 per cent of Britain’s petrol supply. The upshot of this was that all oil supplies from the Middle East would need to be transported in giant oil tankers around the Cape of Good Hope in South Africa.
Petrol rationing returned to the UK in December 1956 and people began to clamour for more economical means of travel. The sales of 900-1000cc cars quadrupled in the period from 1956 to 1957, while car sales in the wider market slumped. Bubble cars began to appear on these shores, and although they may have been awful to drive, with questionable safety, they did achieve more than 40 miles per gallon, which was the most important statistic a car could boast in those petrol-starved times.
In the beginning…

Mike Parkes pictured alongside the 2-cylinder Slug prototype. (Picture: Autocar)
The Hillman Imp’s beginnings actually date back to 1955, when the Rootes small car project was instigated. The reasoning behind its creation in the first place was simple: Rootes produced medium and large cars, and yet, during the 1950s, the 1-litre class accounted for a significant number of sales in the UK, and Rootes simply had no presence here. Michael Parks (project engineer – who later went on to work for the Ferrari F1 team) and Tim Fry (co-ordinating engineer) were charged with getting the project off the ground, and were given a clean sheet of paper to work with. Essentially, the project was defined by what the car should achieve – and, interestingly, Fry and Parkes thought that the new car should reach these goals:
· Accomodation for two adults and two children.
· Peformance/economy: At least 60mph maximum speed and 60mpg fuel economy.
· Echoing the oppposition of the day, a rear engine layout was preferred.
· The car should be fun to drive.
According to Graham Robson, the project progressed ‘without much impetus’ towards a 2+2 air-cooled economy car. As can be seen from the picture in the Hillman Imp projects and prototypes page, the team soon came up with a highly aerodynamically styled economy saloon – aptly named, Slug. Without doubt, all of its design objectives would have been met with this car, but it was not met with enthusiasm from the Rootes Group powers-that-be. The development team presented its two engineering prototypes to the Rootes board members, and they made it clear they were not interested allowing the Rootes Group to produce a car that so obviously resembled a bubble car.
Not only that, but the board also made it clear that it did not want to see the Rootes Group name compromised by selling that had been so obviously created for times of austerity; intelligent engineering, or not. Given the board’s reticence to move forwards with these proposals (allegedly, Lord Rootes hated the sight of it so much, he refused to ride in it!), because they were so stark, one would assume that the board was against the company producing a small car. This was patently not the case; it was just that the board members were uneasy with the idea of selling a product so outwardly similar to the bubble cars.
The board did conclude that Rootes needed a small car (the Suez Crisis had erupted by this time), but it needed to maintain the quality and solidity of the rest of the Rootes range. Further to this, it also needed to sport a four cylinder engine, and be able to accommodate four adults. The burgeoning popularity of the Ford Popular and Austin A30 in these fuel-starved times encouraged the board that moving upwards was the correct
direction to be moving in.
So, from this desire to create a bigger, better mini car, Project Apex was thus created; and it would be Technical Director Peter Ware that would see it to maturity.
Engineering change: Apex comes of age

The stage two Slug prototype still looked rather utilitarian, but it was a step towards the Apex; after this, all would change.
Rootes had no existing small car engine in production, and the decision was taken to approach local company Coventry Climax. At the time the Rootes board had decided to go sophisticated, Coventry Climax were producing the FWMA all-aluminium racing engine, which Tim Fry thought would fit nicely into the Apex’s engine bay. Fry contacted them and asked if it were possible to get hold of installation drawings, telling them that he was in the process of developing a car that could be an ideal beneficiary. Sensing an opportunity, Coventry Climax was happy to co-operate, and as a result, Fry managed to get the tiny engine and gearbox to fit into one of the prototypes, by now named, Little Jim.
In the meantime, the Coventry Climax engine was developed into something far more suitable for road use: it was expanded to 875cc, detuned to 39bhp, and most of its internals were changed in favour of longer life items. Even in production specification, the engine was a peach, and was more advanced than its immediate rivals, thanks to an overhead camshaft and that lightweight construction.
The clean sheet approach also extended to the gearbox: one of the problems encountered during Apex development was that there had been numerous gearbox failures. No doubt, this was due to the revvy nature of the Coventry Climax engine, which demanded frequent gearchanges. It was decided that the new car would sport a transaxle (gearbox and differential in the same housing), but because Rootes had never used this arrangement in any other cars, it hired Adrian West as Senior Transmission Engineer. West’s task was to design and build a transaxle that was strong enough to withstand enthusiastic use, yet be light enough to appeal to all buyers the car was aimed at. West was chosen because he had wide experience of gearbox design, having spent time at Simca, Renault and Fiat.
West achieved these goals handsomely, and the transaxle he produced boasted fantastic change quality… Much of this was attributable to the use of a baulk-ring synchromesh (something the Mini missed out on at its launch, and suffered from as a result). The combination of Coventry Climax engine and West transaxle was a hard one to beat; and it was light years ahead of the opposition when the Imp was launched in 1963.
The engine/gearbox might have been adjudged a success, but there were questions about the styling. After Peter Ware had ditched the aerodynamic styling of the original prototypes, Apex was quickly moved forwards. Keen to project a more youthful image, Bob Saward’s styling department looked across the pond to the USA for its styling influences. The original three-box Imp prototypes were rather bland looking cars, and it was only when the addition of Americana took place, that the essential character of the car came bursting through. It is easy to see, however, that the Chevrolet Corvair has been used as a reference point, and as this car was seen as being popular with the young at the time, Rootes was keen to follow down this road.
Stormy waters…
The Apex was a technically interesting car – however, the decision to retain a rear-engined layout was one borne out of a long gestation period. In 1955, many existing continental rivals slung their engines out back, but in the UK, the small car opposition had stubbornly remained with the classic front engine/rear drive layout. And that was part of the problem. The UK’s motoring press began to see the conventional products produced by the Rootes Group as being boring, and stung by such criticism, as gentle as it was back then, the company wanted to produce something totally European in its approach. However, in 1959, Alec Issigonis turned the world upside down by proving that front engine/front wheel drive was the way forweards for small cars. The Mini may have taken time to gain acceptance with the buying public, but engineers and designers knew that the rear engined family car, so typified by the Simca 1000, NSU Prinz and Renault 8, had been rendered obsolete.
By that time, the rear engined layout was now carved in stone. To go front engined at this point, would mean scrapping the project up to that point and starting again, and given Rootes’ ambitions of expansion, a launch that took place sooner, rather than later was desired. And it was these expansionist ideas that would add difficulties to the Apex programme, as well as the Rootes Group as a whole.
By the late-1950s, Rootes felt that expansion was the only way to survive. Given that each new Apex sold would be a new customer to the Rootes fold, extra production would be needed drastically. However, the Government of the day made it quite plain that if Rootes wanted to expand using government assistance, it would need to do so in an enterprise area. This struck quite a blow for the future plans of Rootes, because it had already been refused permission to develop Ryton, and now it would be forced to set-up a new plant away from its Coventry heartland. The pressure exerted on Rootes led the company to Linwood, near Paisley and Johnstone, and not too far from Glasgow; and it would be here that a new factory would be built thanks to a government loan, and in it, the new car would be built.
Production of the Apex might have presented problems, but there were also issues that befell its development. The Apex engineering team was based in Ryton, and was treated as an entirely different entity to the main engineering office at Stoke. As the Apex programme had dragged considerably, it was also treated to an injection of haste towards the end, which meant that several exciting features that the engineers wanted to hone to perfection (such as the pneumatic throttle, automatic choke and marginal cooling) were never tested fully. Ware knew the dangers of launching a car without thorough development, and in the fullness of time, he was proved correct.
In his book, Cars of The Rootes Group, Graham Robson also relates that the Apex was committed to production far too early, and this was probably down to the fact that Rootes wanted no further delays, or a newly opened factory which would be standing idle at the point it was to be declared open in May 1963.
An Imp is born

The Rootes Group was unable to spring a surprise on the car buying public, as details of the upcoming car were scooped in the first issue of Small Car magazine (which later became Car) in 1962. The remarkably accurate article prepared us for a rear-engined mini-Rootes, although calling it Ajax was slightly adrift from the truth (the magazine must have got its wires crossed with Triumph!) The idea of a mini-Rootes took some getting used to, and even though the company were clearly going to call it Imp and restrict it to the Hillman marque, it was still positioned a long way below anything else in the then current range.
The motoring press was largely favourable about the Imp, although comparisons with the Mini were always going to prove difficult to avoid. Nevertheless, the Imp’s superb engine, gearbox and handling were praised in equal measure. The Motor magazine in its road test of 8 May 1963 was very enthusiastic:
Handling: The fact remains, however, that the Imp can be hurled into corners at speeds which would be suicidal with most saloons and with very little roll and no tyre squeal it just motors round them. It is so close to being a neutral steering car that different driving techniques can tip the balance one way or the other.
Transmission: The gearchange, as we have said is quite certainly one of the best, if not the best we have ever handled.
Performance: For an 875cc car, the performance is astonishingly lively and bears comparison with many family saloons up to 1600cc.
Although it was rear engined, the addition of that lift-up rear screen (do not get carried away and describe it as a hatchback) meant that the Imp’s practicality was also praised. The Motor was forthright in its verdict too, and were most optimistic about the Imp’s future: “If Rootes cannot sell 150,000 Imps a year, as they have planned, we shall eat our editorial hat.” Sometimes hindsight can be a wonderful thing.
However, it soon became clear that the Imp’s rushed final development phase would have a lasting impact on the small car’s reputation with customers.
Problems that would have been picked-up in those months soon manifested themselves: defective water pumps and automatic chokes, overheating, water leaks, throttle problems and lack of performance. These soon became widely known in the trade and with buyers, and a poor reputation for reliability – so easily won – would never be shaken off. The Rootes dealers were ill-equipped to deal with such problems, and at the production stage, it took years to iron them out. Linwood’s industrial relations were poor from day one, so any running changes that needed introducing, were drip-fed rather than rushed in.
One story that sums up the logicistical problems encountered by Rootes comes from John Simister’s retrospective Motor article from 1986: “…for example, the cylinder blocks for the die cast engine were cast in Linwood but had to be sent down to Coventry for machining and assembly and returned to Scotland for installation.” It was madness, and sadly a folly (through no fault of Rootes), which was then repeated with Avenger assembly.
But had the Imp gamble paid off? Arguably, its 1963 launch date was too late for another mini-car; the petrol crisis had receded and the economy was booming. Small car sales were still strong, but the Imp was already below the UK car maket’s centre of gravity. Interestingly, the rear-engined layout was also now seen as past its prime, thanks to BMC’s front wheel drive exploits.
By the year following the Imp’s launch, the Rootes Group’s finances had been compromised enough for it not need to accept its first parcel of cash from the acquisitive Chrysler company in the USA. This was due to the company feeling the effects of mounting losses caused by disappointing Imp sales and the after effects of the huge Linwood investment. Not only this, but Linwood could not produce the Imp efficiently at anywhere near projected volumes, as its engine and gearbox were extremely labour intensive to produce.
Losses continued, and Chrysler’s takeover of the Rootes Group followed in 1967.
The range expands into badge engineering

Even though the Imp was clearly defined as a Hillman at the time of its launch, it soon became apparent that the policy of badge engineering would need to be followed in order to maximise sales potential. In short order coupé, van, estate car versions became available, and plusher Sunbeam- and Singer-badged versions were phased in. It was never going to be enough, though. By the time Chrysler was fully in charge of the company, it was clear that any further meaningful development of the Imp was never going to happen.
A scant year after its launch, the first badge engineered version appeared, and in short order, a raft of further derivatives followed:
| Imp marque and model variations | |
|---|---|
| May 1963 | Hillman Imp launched |
| Oct 1964 | Singer Chamois launched |
| Sep 1965 | Commer Imp Van launched |
| Oct 1966 | Sunbeam Imp Sport (and Singer variation) launched |
| Jan 1967 | Hillman Californian launched |
| Apr 1967 | Singer Chamois Coupe launched Hillman Husky Estate Launched |
| Oct 1967 | Sunbeam Stiletto launched |
| Oct 1968 | Commer Imp van renamed Hillman |
| Apr 1970 | Singer models phased out |
| Jul 1970 | Husky and van phased out |
| Mar 1976 | Hillman and Sunbeams phased out |
Facelifts were investigated and then dropped; as were larger engined derivatives… Rootes had now become known as Chrysler (UK), although the structure of the company remained largely in place. This would not last too long into the 1970s, and it is this process of rationalisation that explains why Ryton’s front wheel drive supermini projects never proceeded very far from the stylists’ sketch boards.
So, the Imp marked something of a dead-end in the company’s history, and even though it was eventually turned into a reliable car, and was one that handled and performed well, it was never taken on by Chrysler and developed to face the challenge of the 1970s. Certainly, the rear engined layout played against it from day one, but that did not mean that its excellent engine and gearbox could be utilised in any other installation. It is fair to say that the Coventry Climax engine was expensive and labour intensive to build, but surely some of its nicer features could be used elsewhere.
Chrysler saw it another way, and refused to kill it or develop it. The vastly simpler Avenger was also built at Linwood, but it was not a replacement for the Imp, and so, the little car remained in production until it became clear that the Sunbeam would be introduced to replace it. The travesty there is that this likeable small car did not owe anything at all to the Imp (or its front wheel drive design studies) apart from the slant-four engine in the 928cc version, which was a development of the Coventry Climax engine. However, by the mid-1970s, Chrysler’s European arm was deep in crisis, a wider product strategy demanded a different solution.
But ultimately, the Imp was a victim of the oft-repeated mistake of launching a car before it had been fully developed. Reputations are hard earned and easily lost…

Extension of the Imp: this idea was not pursued.
Written with reference to “Charmed Life” by Graham Robson, MOTOR, 9 Mar 1974.
Further sources: The MOTOR magazine, 8 May 1963, MOTOR 15 November 1986 and AUTOCAR&MOTOR, 27 November 1991.




20 Responses
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does anyone know were i could source the book-the story of the imp?
Francis Which book? there is ebay or Try here http://www.imps4ever.info/impclub/regalia/web9707.html or Franka’s website (free) http://www.imps4ever.info/
Are you thinking of buying? These are Not for the faint hearted (I have two of them ) and prices have rocketed lately, But good fun when they work.
The best book was “Apex: Inside Story of the Hillman Imp” I’ve got a copy, somewhere…
Imps are brilliant cars – better than the Mini in every way – expect the one the buying public cares about! Styling.
My first car was a 1965 mini, which was 13 years old and really at the end of it’s life. Then I got a 1965 Imp in 1980. It was a lovely white basic model with a knackered engine. This car looked brand new. So I got a Sunbeam stiletto for £15, whipped the engine out and put new piston rings & big end shells in, then stuffed this engine and new radiator in my Imp. This thing was mental. After I had run it in for about 500 miles or so I discovered it would do about 70mph in 2nd gear with only my skinny 18 year old frame in it. I have never driven anything that revv’d like this even since. I put the plush Stiletto interior in the Imp (Reclining seats, oh yes!) and enjoyed the looks on the faces of the drivers of mini 1275 GT’s as I left them in a haze of blue smoke (from my exhaust, not tyres) at every opportunity. From the outside it looked like your Granny’s standard imp. The thing was, it was reliable and would turn at 8500 rpm all day if it had to. The key to running a reliable Imp is the radiator. If you even suspect it could be blocked or inefficient replace it do not even think of trying to clean it out, it will not work. That is the only car I have ever had that I wish I still had.
My brother had a 1964 white IMP for a while. He had some trouble with the alloy engine (well documented), but otherwise it was a nippy little car. Good memories overall.
It would be interesting to modernise an Imp. High efficiency radiator with electric fans and good temperature/level monitoring, drive by wire, multipoint injection and electronic ignition…
@8 My Imp has a rad at the front – it has never overheated – even at sustained foot-flat on the motorway driving with the speedo hovering between 85-90mph. I’m putting a megasquirt FI system together at the moment, using Suzuki GSXR600 throttle bodies and injectors.
I managed to break off the gear stick on mine (at its lowest point) when engaging reverse in a hurry. luckily it was down hill most off the way home so a combination of coasting with my foot on the clutch and short bursts of reversing got me home with the fish and chips still hot. I believe there was a small notch in the gear stick to enable it to snap off in the event of an accident?. A hoot to drive when no passengers, but a bit of a chore when loaded. Best Scrap yard purchase I made.
@4-5 ive just bought the inside story of the imp £47! i had one years ago eat rotoflex’s for fun.I’m just interested in the linwood story and its downfall in general,i have a feeling it will make me sad as will the book end of the road:the downfall of Rover.
@ 6 Jeff
The sport engines are quite sort after which differs from the normal 875s by having a high lift Camshaft with bigger valve’s, necessitating double valve springs which also causes another problem of “No valve stem oil seals” (although have managed to fit Ford CVH type on mine) which again necessitates an oil drain (later L4 engines have these but kids to school Cam).
Also the Block has a drilling to accommodate the oil drain, and to help keep things cool an oil cooler is fitted, along with (troublesome)Twin Stromburg Carbs which lifts the humble 39ish BHP to a dizzy 51ish BHP.
Although based on the Coventry Climax FWE there is very little if any interchangeability in parts, some say Rootes Killed the Classic from Birth Climax engine for production purposes, though still to this day Tuneists can easily play with these to well over 100BHP, Ohh and all Imp engines were de rated prior to Launch due to them accelerating to over 100mph, meaning they were alot faster than bigger more expensive Minx’s etc.
Incidentally Climax were desperate to sell their Engines in the USA for Marine use but only 4 banger and and under 2 litres meant few noticed… At the same time Rootes spent a few £Mill on this engine along with a state of the art Die Casting Factory at Linwood (which once cast were sent to Coventry to be machined/fitted then returned back to Linwood), Not really sure of why Rootes went to such extravagant lengths when Climax had the capacity and were begging for work?…They were later absorbed by Jaguar.
@8 Mr Kilpatric and SteveLee
The many upgrades Impers are taking is fitting Motorcycle carbs/fuel injection, even the whole engine/gearbox in quite a few cases (Suzuki Bandit is popular) this makes a lot of sense as with any upgrade to the standard Imp engine means your still lumbered with the Gearbox @ only 15mph per 1000 rpm and was only designed for 39 bhp along with those evil rubber doughnuts for the driveshafts.
The usual rules apply when upgrading… to change one item you must change 3 others to accommodate it.
Francis
Which book did you buy? £47.00?? The Apex is by the Henshaws is probably most accurate but very detailed, whilst the George Mowat Brown is roughly the same but more spread out with lots of pics, some say some of His facts are a little ?? There is also the Book Geoffrey Rootes Dream of Linwood by our Imp Spare’s Man, This shows the factory being built to the opening day.
All of the books show a promising work of art that sadly due to reliability problems… well will let you find out yourself !!!!
Happy Reading..
The Imp was a good car but in my opinion it was very ‘cosmetically challenged’- the Mini was a prettier car without a stylist being let anywhere near it!
Nice to see that there are still some left however.
@13 apex the inside story of the imp (pic of crash test imp on cover)i thought the imp was a well executed car that just needed to be developed further-engine lighter,and better than A series etc.
Francis
The Imp was for 1963 an excessive over the top work of art.. All Alloy Engine with racing Heritage (though only loosely on which itself was a development of the Godiva Water Pump engine used by the British Army) A lovely all syncro Box that even Jag E Types owners were envious of, (They wouldnt receive full Synchromesh until much later), Built in a Brand new Factory at the time the most Modern in Europe, complete with a very Novel IBM Computer which despite taking up the space of a whole room controlled the factory, itself cost a few £Mill.
It was also one of the most tried and tested cars upto that point being driven across the US almost no stop. Even Jernalists loved it, the buying public initially couldn’t buy them quick enough, However you name after the honeymoon it all fell apart.
It has been written many times that The Factory workers new little else but the working practices of Ship Yards, Many couldnt grasp that Car production was continuous rather than Contracts of Building Ships come to an end and therefore why hurry themselves onto the Dole. Many workers still waited at the Factory Gates each morning waiting to get a Job, which was not the way Car Factory’s were run.
Engineers begged for more time with the Imp because Driving it flat out showed little problems but the average drive to the shops showed alarming overheating which warped the Cylinder Heads and sometimes the Block, faults with gearbox’s and varying degrees of build quality, though actually little different from BMC, but if your Mini over heated you just waited by the road until it cooled down then drove off again, you couldn’t do this with the Imp as the Damage had been done.
The biggest problem was Rootes were nearly bankrupt, it has been said many times Mothers was ill before troublesome infant arrived, Chrysler stepped in who fixed a couple of faults (not all of them ) but the damage had been done! This was the Austin Allegro/Maestro of the 1960s. Chryslers response was to cheapen the range and quality slipped further.
The Crashed Imp on the Apex Book, note the steering column in an accident this can Decapitate the driver! The secret is not to crash..
My favourite of the IMP’s was probably the Sunbeam Stiletto with the smart wheeltrims, vinyl roof & twin headlamps. I remember one of the first Stiletto’s on display in a dealers in 1967 – was only 12 then!
The Singer Chamois & Sunbeam Imp were also more luxurious than the basic Hillman versions. That would be Rootes’s aim of course…
Did Rootes ever consider a Humber branded version?
I was one of the Rootes Trainees that went to Invergordon in Scotland to Carry out extended Road Testing of the first two prototype Imps (L1 and L2)
Are there any others of you out there still who were similarly employed.?
The late Mike Parkes was our Project manager at Invergordon.
I worked for Rootes Motors from 1960-1970 in several capacities.
A mates mum had one of these back in 78/79 a 75/N reg in a metallic aqua. On an evening out with two friends [i was front passenger] all of us being around 18/19 years of age and all recently passed testswe headed to the local rural pub but on a corner of a country lane my mate lost it on mud and proceeded to take off over a ditch and hit a tree head on!. An age without seat belts or air bags and with Gods luck no one was hurt and the poor old car with a big V in the front dissapeared from view in the hedge.
That was the end of a fine old car!
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