Buying Guide Hillman Imp
Let’s not beat around the bush: the Imp has a reputation for being a dud. It didn’t do great things for Hillman, because when it was launched in 1963 it was under-developed, so it suffered from a multitude of problems. The Imp Mk2 of 1965 fixed things though, so the pneumatic throttle linkage and automatic choke of the Mk1 were swapped for a cable throttle linkage and a conventional manual choke. Other improvements included a stronger clutch, better engine cooling and new suspension geometry. But the damage was done; buyers stayed away and instead of 150,000 Imps being built each year, production peaked at just 50,000. That was in 1964; by 1970 just 20,000 Imps were being made annually. Words and pictures: Richard Dredge.
BUYING Hillman Imp
It’s a great shame because the Imp is one of the few cars that can truly rival the Mini. Not only is the Imp great fun to drive but it’s also eminently practical. Where the Mini features a small boot, the Imp’s top-hinged rear window allows it to carry far more than a car of its size should be able to. Handling is brilliant thanks to a low centre of gravity achieved by canting the lightweight all-alloy powerplant over 45 degrees. A mixture of swing axles at the front and semi-trailing arms at the rear provide a smooth ride, and 45mpg is easy to achieve even with enthusiastic driving. There’s also a wide choice of bodystyles with saloon, coupé, Hillman Husky estate and Commer van derivatives all offered, although the latter two are now especially scarce.
When production ended after 13 years, just 440,000 Imps had been made, few of which survive. But there’s an enthusiastic band of Imp owners out there, keen to keep the cars going; the Imp Club’s parts list runs to over 60 pages, with pricing usually on the cheap side of very keen. Even better, you can join in the fun for peanuts thanks to the Imp’s affordability, so don’t be too quick to dismiss this Rootes-built ball of fun, because the fun-per-pound quotient is much, much higher than you think.
The vans and estates have a following, but they’re so rare that your choice is really between the coupés and the saloons. Colin Rooney comments: “The coupés arguably look more attractive than the saloons, but it’s the latter that offer the most practicality, with their opening rear windows. The coupé is also three inches lower, so head room is a lot tighter in the back.
“Cars built up to 1967 were made to a much higher standard. The quality of the welding is far better and the bodyshells are a lot stiffer as a result; you’ll notice that most of the racing Imps are based on early cars because of their extra strength, although they’re also a bit heavier. “Any early car that’s still got the original parts should be working fine by now. I have a 1963 Imp with a pneumatic throttle and it’s much nicer to drive than the later car with its cable-operated throttle, as it’s much more nicely damped. I have disconnected the automatic choke though as it’s a thankless task trying to get that to work properly.”
Key checks: bodywork
Poor rustproofing has killed off most Imps; rust can break out virtually anywhere. New original panels are extinct, but some used bits are available, Ex-Pressed Steel Panels produces numerous high-quality new pressings and lots of repair sections and panels are available through the club. The double-skinned bonnet leading edge rusts with the whole panel quickly rotting beyond repair. Repair sections cost £125, or you might find a decent used steel bonnet for £300, but you’re probably better off buying a glassfibre one for £190 from Honeybourne Mouldings; the same company sells plastic engine covers for the same price. The door drainage holes block up so they fill up with water and the bottoms then rot out. Effective repairs cost at least £350 per door; complete skins are available from Ex-Pressed for £280 each (lower repair sections are £80).
The rear wheelarches rot; repair sections cost £130 per side, or Ex-Pressed offers complete rear wings for £807. The front wheelarches don’t tend to rust as badly as the rears, but mud gets lodged at the base of the inner wheelarch, leading to corrosion where the front wing meets the sill. The sills need careful inspection because they’re structural; budget £300-£500 per side for effective repairs. Ex-Pressed offers inner and centre sills at £63 each, with outer sills priced at £126 apiece.
The spare wheel well in the luggage compartment fills with water then rots out. New panels are unavailable so you have to patch it up, which is fine if the suspension mount isn’t affected. If this has rotted it’s a tricky repair that’s best left to an expert; budget £300+ for the labour to fix things.
Analyse the entire floorpan and home in on the rear suspension, as corrosion can cause big problems. The suspension pans where the coil springs are located can corrode so the spring goes straight through. The spring mounting points also rust badly, allowing the spring to crash through the bodywork; budget £400 to put things right. At the front things are potentially just as serious, with the box-section swing axles prone to rotting, which weakens the suspension. New parts are obsolete and because the suspension can’t be welded you’ll have to replace the corroded parts with decent used ones at £100 or so apiece.
Key checks: trim and electrics
Interior trim is scarce, although some used parts are available. The seats of Mk3 cars (post-1968) aren’t easy to repair as they’re moulded, but earlier cars’ interiors can be patched up quite easily. Replacement carpet sets are available through Malcolm Anderson for £145 per set.
Exterior trim is equally rare, with new items all but extinct. Badges are mazak, so hard to restore, while the rest is either anodised aluminium or stainless steel. Everything is available on a used basis though.
The Imp’s wiring loom is straightforward, although bodged splicing and age may have taken their toll. Nothing is especially problem-prone, so just check that the instrumentation and switchgear all works. Pre-1968 switchgear is scarce, but other than that it’s easy enough to track down replacement parts, whether it’s exterior lighting, switchgear or instrumentation.
While the various derivatives are worth slightly different amounts, it’s mainly an Imp’s condition that dictates its value. There are projects around for £1000, although you can pay £3000 for something more together but which still needs a rebuild. Colin Rooney comments: “Values have gone up a lot in the last few years. I’ve seen tatty Imps go for £6000 whereas that was enough for a mint car not long ago. If I’m undertaking a complete restoration for someone the bill will come to around £20,000 and the car will be worth about £16,000 when it’s finished, so the sums don’t quite add up just yet, but it’s not far off.
“The general ceiling for these cars is about £16,000. I sold a really good Imp Sport last year for £12,500, but in place of the usual interior it had two bucket seats and a roll cage, so it was quite hard-core. Other real-world prices include £4500 for an Imp Sport restoration project, £16,500 for a fully restored Imp van and £17,000 for a superb Stiletto – all prices achieved within the last year. The Stiletto is the most valuable of all, with the Chamois worth maybe £1500 less. The key thing to bear in mind is that most buyers want something that’s had a few sympathetic upgrades, and few of these cars come onto the open market. Most change hands within the club, so membership is essential.”
Key checks: mechanicals
The all-aluminium engine is a lot stronger than its reputation suggests. The key is to maintain anti-freeze strength and level; fail to do this and corrosion sets in, the alloy breaks up, and the radiator gets blocked so everything overheats. Look for head gasket failure by checking the underside of the oil filler cap and check the coolant level; if it drops below the base of the header tank, the engine will overheat, probably warping the head and possibly the block too. While both can be skimmed, there’s only so much metal that can be removed before either unit is scrap.
Listen for pinking as you accelerate through the gears. This could signify that the ignition hasn’t been set up correctly, but the cylinder head might have been skimmed too many times. The only fix is to find a decent used head that’s serviceable; you’ll pay £50 for one, with good-quality gasket sets costing at least £35.
Post-1966 engines had a stronger block, which is much less prone to deforming if it overheats. See if the top of the block features a straight edge or a curly one. If it’s the former, it’s the stronger block.
Start the engine from cold and check for blue exhaust smoke which signals that the inlet valve seals have worn out. New ones cost £10 per set and replacing them can be done on a DIY basis, although the head has to be removed to do the job. The Sport has no valve seals, but its valve guides wear and replacing them isn’t a DIY job. They’re cheap though at £40 for a set of eight, or you could just go for a reconditioned head, for £300-£500. Continuous smoke points to worn piston rings or cylinder bores, which requires an engine rebuild. It’s not a difficult job, or you could buy an exchange rebuilt engine for £1000, or £1500 for an Imp Sport unit. On the test drive keep an eye on the temperature gauge, which should settle at the one-third to half-way mark when cruising. If the gauge doesn’t even register this, the thermostat has probably been removed, to mask a more serious cooling problem. The water pump should have been changed within the last 25,000 miles; reconditioned items cost £140 exchange or £160 outright. They fail even more quickly on rarely used cars, as the bearings fail, and the engine then loses most of its cooling.
Oil leaks are common, because of the all-alloy engines and gearbox casings. Aluminium expands and contracts more in use than cast-iron, making life difficult for the seals and gaskets. Things aren’t helped by the lack of a rear crank seal, so expect slight seepage, but if it’s more than that there may be a problem with gaskets that need to be replaced.
A four-speed manual gearbox was fitted to all Imps, and it should be a joy to use. If changes aren’t slick and precise it’s because the nylon ball cup at the base of the gearstick has worn and needs to be replaced. It’s easy to do, and cheap at just £8. Synchromesh was fitted to all four forward ratios, but on the lower two gears it’s notoriously weak. If there’s crunching when you change gear, the ‘box is due for an overhaul; exchange rebuilt transmissions cost £550.
A heavy clutch pedal points to a faulty slave cylinder or a hydraulic hose that’s collapsed internally. The solution is to switch to an aeroquip braided replacement for £30, but if the bite point is at the end of the pedal’s travel the clutch will need renewing soon, which means taking the engine out, but it’s not a difficult job. Laycock clutches are the strongest and while driven plates and release bearings are readily available, covers are scarce. Budget £140 for a three-piece kit when available.
The driveshafts incorporate rotoflex couplings which perish. There aren’t any symptoms as such, but a visual check will show if the rubber has perished or split. New ones cost £40 each, or you can buy heavy duty replacements for £110 apiece from Malcolm Anderson.
The Imp’s rack-and-pinion steering should be light and precise. Any heaviness or play suggests the kingpins and their bushes have worn. Jack up each front corner and hold the top and bottom of each wheel. Rock it to check for play; any discernible movement means it’s time to replace the kingpins and bushes. A kit of parts for both sides costs £40, or reconditioned kingpin assemblies are £180 (exchange) per pair. Also check for worn rear wheel-bearings; they’re £55 per side, but are getting hard to find.
See if the brakes are binding by trying to push the car on a level surface. If it quickly stops the wheel cylinders aren’t returning properly – usually caused by the ventilation hole in the brake master cylinder reservoir cap becoming blocked. This is easily fixed by a prod with a pin.
Originality isn’t especially prized in Imp circles and there are all sorts of upgrades that are seen as desirable, or even essential. But before any upgrades are implemented the cooling system must be in tip-top condition, with anti-freeze concentration maintained, the fan belt correctly adjusted, and a high-efficiency radiator (for £185) is worth fitting too. Most Imp derivatives came with an 875cc engine, including the Imp Sport, Singer Chamois and Sunbeam Stiletto. The Rallye Imp got a 998cc engine instead, and this can make an excellent basis for a go-faster Imp, although there’s plenty you can do to the smaller unit, including increasing its displacement.
Helping the engine to breathe more easily is a good move; fitting an Imp Sport’s more free-flowing exhaust is worthwhile; the club sells stainless steel manifolds and exhaust kits for around £1000 combined. It’s also worth fitting a K&N air filter to help the engine breathe.
In standard form the Imp handles brilliantly, but fit shorter, stiffer Monte Carlo springs (at £48-£58 per pair) with Spax dampers and you can make things even better. These lower the car by an inch, or at £68 per pair there are springs that lower the car by two inches, but these are too extreme for most people.
All Imps featured drum brakes all round, which are all that’s needed. Imp Sports and Sunbeam Stilettos got a larger master cylinder and a servo. Some owners have upgraded their Imps to Sport spec by fitting the larger units, and it’s a simple swap, or the Imp Club offers a front disc brake conversion for £350.
Steel wheels were fitted to all Imps, but aftermarket alloys are popular. If these have been fitted, make sure the offsets are correct by looking for evidence of rubbing against the bodywork. While clearance at the rear isn’t normally an issue, at the front when the wheels are on full lock, there’s usually some contact with the wheelarch lips.
I BOUGHT ONE
Peter Gardiner, pictured here with his son Thomas, has been around Imps for over 25 years. In that time he has owned more than 30 of them and still has five, including one with a BMW motorcycle engine. He comments: “I love the fact that they’re different and quirky – and that they’re not a Mini. The Imp is easy to work on, parts availability is excellent and it makes a great family-friendly classic. They handle superbly and they’re easy to tune, but even in standard form they’re enormous fun to drive if they’re set up correctly. It’s always worth incorporating a few small mods; all of my cars have alternators for example, while lowered suspension, decambered at the front, is another good idea.”
The Imp Club theimpclub.co.uk
Colin Rooney runs Surrey-based CA Restorations and he’s been around Imps for around 50 years; his father raced them when Colin was a young child. Colin says: “I bought my first Imp in 1987 and I’ve owned at least one of them ever since. My company offers everything for the Imp owner, including maintenance, complete restorations and upgrades. I’ve built several racers and I also sell some used parts, so I’m a one-stop shop for Imp owners, and at £35 per hour my rates are very affordable.”
|Vital statistics||Hillman Imp||Hillman Rallye Imp||Singer Chamois||Sunbeam Imp Sport||Sunbeam Stiletto|
|Top speed (mph)||78||92||78||90||87|
|Gearbox||4-speed manual||4-speed manual||4-speed manual||4-speed manual||4-speed manual|
- 1963 The Hillman Imp is launched with an 875cc engine and basic or Deluxe trim. The latter has a heater, windscreen washers, carpets and opening quarter-lights.
- 1964 The Singer Chamois arrives. It’s mechanically the same as the Imp but with a more upmarket interior.
- 1965 The more luxurious Imp Super is now on sale, with the Imp Mk2 launched in September, in Super and Deluxe forms only. The limited edition Rallye Imp and Rallye Chamois are released, along with the Commer Imp van.
- 1966 The Singer Chamois Sport and Sunbeam Imp Sport appear. They’re identical mechanically, but the Singer is more luxuriously trimmed.
- 1967 The Imp Californian, Chamois Coupé, Stiletto coupé and Husky (estate) arrive. The first three have fastback styling and four headlamps, and the 875cc engine.
- 1968 The Mk3 Imp appears, with new instruments and improved trim, and the 875cc engine as before.
- 1969 The Singer Chamois and Sunbeam Imp Sport get quad headlamps and a new entry-level version of the Imp is reintroduced.
- 1970 Hillman drops the Imp Californian, van and Husky, while Singer discontinues the Chamois. The Sunbeam Imp Sport is renamed the Sunbeam Sport.
- 1973 The basic Imp is dropped once more.
- 1975 The Imp Caledonian special edition is launched, with red paint and white side stripes.
- 1976 The last Imp is produced, with 440,032 examples across the various brands made in all.
- CA Restoration, Surrey 07515 533 742 facebook.com/ColsClassicResto
- Chesman Engineering, Coventry 02476 689 665 chesmanengineering.co.uk
- Corley Conversions, Warks. 01926 612 432 corley-conversions.co.uk
- Ex-Pressed Steel Panels, N.Yorks. 01535 632 271 steelpanels.co.uk
- Honeybourne Mouldings, Worcs. 01789 774 603 honeybournemouldings.co.uk
- Malcolm Anderson, Somerset 01823 350 360 malcolmanderson.co.uk
- Mark Maynard, Glos. 07957 855 330 tinyurl.com/5n929w6k
- Shrigley Engineering, Manchester 07738 473 930 shrigleyengineering.co.uk