The ill-fated Hillman Imp has become a beloved classic thanks to its unique mechanicals, fun driving experience and cute looks. Here’s how to buy one
Words: James Bowers
For the Rootes group, the mission statement was clear. By the mid-1950s, small-engined compact cars were a lucrative business, but the company didn’t produce anything of the sort. Wanting a slice of the pie, Lord Rootes commissioned his engineering team to come up with an answer, though the project would turn out to be anything but straightforward.
Things started badly with the first concept, which looked a bit like a bubble car and was unflatteringly referred to in-house as ‘The Slug’. This didn’t go down well at board level, raising fears that such a vehicle would diminish Rootes’ carefully cultivated upmarket image. So it was back to the drawing board. Years passed, but eventually the formula evolved enough to win some powerful fans, paving the way for the newly named Hillman Imp to enter showrooms in 1963.
The Imp was very different to many of its rivals. The engine, for instance, was an all-aluminium unit derived from a Coventry Climax racing engine, while the gearbox featured the rare luxury of synchromesh on all four ratios. The placement of the power unit was unusual too.
Instead of the common front-engine, rear-wheel-drive platforms that most other British marques opted for, the Imp featured a rear-engine layout as seen on many European small cars. Ultimately, though, this would render the car outdated upon arrival. During the Imp’s protracted development, BMC launched the front-engined, front-wheel-drive Mini and, after a couple of years to get used to the idea, the public loved it. This way of packaging a small car became the new standard, leaving the Imp – cutting-edge when conceived – trailing behind.
As a result, the little Hillman was deemed both inferior and odd enough to be alienating. Such a negative sentiment could perhaps have been overcome if the examples that did get sold proved to be trustworthy, but sadly that wasn’t the case. Difficulties during the car’s development phase meant that it was launched with an array of faults, ranging from defective chokes and throttle problems to water leaks and a chronic tendency to overheat. These teething issues were eventually ironed out, but not fast enough to prevent the Imp’s reputation from being irreversibly damaged.
Compounding the Rootes Group’s woes, the petrol crisis of the previous decade had begun to fade, and the economy was strengthening, meaning that compact cars weren’t the hot property they used to be. It truly was a nightmare scenario, and after having invested so much into the Linwood factory up in Scotland, the car that Lord Rootes thought would take his company to the next level was now crippling it instead.
By many accounts, the Imp was the car that killed the Rootes Group. However, that label almost feels too harsh when attached to a vehicle with such charming quirks and excellent handling.
Bodywork
As with most cars of this age, rust is the biggest killer of the Hillman Imp. The most important area to check is the sills, as these are a key structural component of the car. Elsewhere, you may find that blocked drainage channels have caused the bottoms of the doors to rust, while another obvious place to check for rot is in the wheel arches. If the rot has spread sufficiently enough to write off a front wing, they are available brand new, at a cost – Ex-Pressed Steel Panels sell Imp front wings for £660 each, plus VAT…
The rear arches are particularly prone to rusting, though it’s worth casting an eye over all four. Again, Ex-Pressed Steel Panels stock whole new rear quarters at an eye-watering £930 plus VAT per side, while more cost-effective repairs can be executed with new arches at £150 plus VAT each. The underside of the floorpan is also very vulnerable to the elements, but a whole new floor panel can be yours for £436 plus VAT, while each side is surprisingly affordable at just £136 plus VAT.
Engine and transmission
Let’s start with that peppy Coventry Climax power unit. If you want to avoid failure of the all-aluminium lump, then maintenance of fluids is paramount. Check that the car has the correct levels of antifreeze and water in its system, as this is integral to the engine’s well-being. If neglected, the aluminium alloy will begin to corrode, resulting in flakes of metal floating around the radiator. Over time, this will reduce the radiator’s efficiency as it becomes increasingly clogged, eventually leading to catastrophic overheating.
If everything appears as it should in the engine bay, the next step is to fire it up and check whether any blue exhaust smoke emerges from the rear. If so, the inlet valve seals are probably in need of replacement. At worst, however, you could be looking at worn piston rings or cylinder bores – in which case, you’ll be facing an expensive engine rebuild.
So, if the smoke is persistent or if you have any doubts, it’s always a safer bet to walk away from the deal. If you’ve got this far without issue, then it’s time to check the car’s service history. In particular, ensure that the water pump has been changed at least every 25,000 miles.
The synchromesh on the Imp’s two lower gear ratios can be quite weak. So, if shifting between first and second feels crunchy, that’s a sure sign these components are in need of attention. Otherwise, laboured shifting – particularly higher up the range – is likely to be due to a worn bush at the base of the gearstick itself. The clutch pedal, meanwhile, should feel light underfoot. If it doesn’t, a hydraulic hose is probably to blame, or the slave cylinder might need replacing..
Steering, suspension and brakes
The rack-and-pinion steering in these should feel quite light, so if you find that it’s a bit of a battle to point the car where you want it to go, the kingpins and their respective bushes are most likely worn out.
As for the brakes, the Imp uses a rudimentary drum set-up. You might find that the air vent for the brake master cylinder has become blocked over time, and if this is the case, it will cause a brake-binding effect due to the wheel cylinders remaining engaged when they shouldn’t be.
Happily, braking issues usually aren’t too expensive to put right on the Imp, though in this day and age, you might as well just upgrade to a set of discs on the front – at the time of writing, an eBay shop will sell you a full front disc conversion kit for cars with 13-inch front wheels (including callipers, discs, pads, steel braided lines and all necessary components) for £395, see item number 167645720043.
Rusty suspension is expensive to put right, whether it be the mounts or the swing axles. Protech Shocks will sell you a full set of height and damping adjustable items should you fancy a lower stance and sportier handling, but budget £623 for the upgrade.
Interior and trim
The Imp’s basic interior and electrical system mean there’s little to go wrong – but if something is awry, the wiring loom is fairly easy to get to grips with. Check that all the displays read correctly and that all the input controls function properly. As for the interior fabric and trim, replacements are hard to come by; depending on the extent of the upholstery repairs required, authenticity may need to take a back seat.
Hillman Imp: our verdict
A victim of circumstance, the Hillman Imp can surely be forgiven for its failings now that it has attained classic status. A well-sorted example remains huge fun to drive, while the car’s unique yet simple mechanical layout makes it an enjoyable project for DIY tinkerers.
