Not a Mini but a Sunbeam Imp

Photography by John Webber

If an Imp could speak, it would echo Marlon Brando’s anguished lines in the 1954 movie “On the Waterfront”: “I coulda been a contender. I coulda been somebody.”

Despite its innovative features and stellar reputation as a driver’s car, the Imp was never a contender. This tiny machine was launched too late to compete, beset with corporate mistakes and bedeviled by a lack of development. As the BBC program “The Car’s the Star” described it, the Imp was “the wrong car built at the wrong time by the wrong people at the wrong place.”

Nevertheless, this diminutive machine still has its share of fans and loyalists today.

Rootes Group

In the mid-1950s, the Rootes Group was headquartered in Coventry and operated plants in several locations. The firm was considered the General Motors of Britain, which in those days was a good thing. 

For years, Rootes rolled out dozens of popular brands, including medium-sized Hillmans, Singers and Sunbeams, massive Humbers, and Commer trucks. Solid citizens all, but staid—few of these products were prized for their sporty performance or stylish looks.

After the Suez Canal fuel crisis in 1956, Rootes marketers saw a chance to compete in the small-car market against Ford Standard, Triumph, Vauxhall and—by the time the Imp was finally launched—the Mini. Their first baby-car prototypes, known as Slugs, were powered by air-cooled twin engines. However, the Rootes board of directors rejected the design because it too closely resembled that of the German “bubble” cars. 

The Imp was the Rootes Group’s answer to the other small cars sold during the ’50s. Small doesn’t mean plain, as little details decorate the interior and exterior.

They wanted a larger car, something powered by a four-cylinder, rear-mounted engine. It had to seat two adults and two kids while being simple, affordable and fun to drive.

And so the Apex project was born. Peter Ware took the reins as technical director, while project engineer Michael Parkes and coordinating engineer Tim Fry assisted. This team faced many challenges. Rootes was known for its glacial development time and had never built a small car; the company also lacked an appropriate engine and transmission, a suitable factory, and the necessary funds. 

When the company went to the British government to get loans for the needed expansion, officials decreed that the new plant be built in Linwood, Scotland, a depressed area badly in need of jobs. Unfortunately, workers there had no auto assembly experience and a history of labor unrest. These factors plagued the project from the start. 

The Linwood location also hampered logistics, since many component suppliers and finishers—along with Rootes Engineering—were hundreds of miles away. Shuttling components between these facilities added cost and time. 

The Little Engine That Could—Pump Water

In the early 1950s, Coventry Climax produced fire pumps, forklifts and marine engines, among other things. Taking cues from motorcycle technology and design help from ex-Bentley/Jaguar engineer Walter Hassan, Climax developed a four-cylinder, all-aluminum, OHC engine that featured wedge-shaped combustion chambers. 

This engine was called the F.W. (Feather Weight) and produced 38 bhp. When installed in a portable fire pump, it washed away its competitors and won a big government contract for the company.

It didn’t take long for the racing community to see the potential of this innovative, high-revving powerplant, so in 1953 Climax developed the F.W.A. (A for automobile) version. It was bored out to 1097cc and featured a stout crankshaft, high-compression pistons and twin carbs. This engine produced 72 bhp at 7100 rpm and helped launch Coventry Climax into the racing business. 

As race fans know, several versions of this versatile engine powered generations of purpose-built Lotus racing cars with great success. A variety of home-built sports racers and sporty street cars were motivated by Climax power, too, including the Lotus Elite and the TVR Grantura.

Climax Meets Imp

Taking notice of Coventry Climax’s remarkable little engine, Rootes contacted the company about using it in the Apex project. Engineers developed a detuned, 875cc version with internals more suitable for road use. 

The die-cast, all-aluminum block featured three main bearings and cast-iron piston liners. The OHC aluminum head had wedge-shaped combustion chambers that yielded a 10:1 compression ratio. It was to be Britain’s first all-aluminum, OHC production engine, and it represented a real engineering leap for the stodgy Rootes Group.

Then the engineering team went to work fitting this unit into a space originally designed for an air-cooled twin. After many layout attempts, they tilted the engine 45 degrees; then they mounted the radiator, water pump and cooling fan beside it. This lightweight package—the engine and transmission weighed about 240 pounds—filled the available space well while providing easy access and good balance. 

Rootes developed the Imp’s transaxle from scratch. The strong and light aluminum-cased four speed featured synchros in every gear, a luxury that even the Mini didn’t offer initially. The gear ratios were well matched to engine output, and the shifter offered precise and quick gear changes.

The rear-mounted Coventry Climax engine gave the Imp plenty of storage space. There’s a trunk up front, the rear seat can be folded down to provide more carrying room, and the rear glass lifts up hatchback-style to improve access. While clever, practical and stylish, sadly the Imp was not a huge sales success; few can now be found in the U.S.

The Rootes designers styled the Imp with younger buyers in mind, but many critics thought it missed the mark. It was called boxy and bland, and from the rear and front it was said to resemble Chevy’s Corvair. This was no coincidence, since Rootes stylists believed that the Corvair appealed to youthful drivers. 

The Imp sat on an 82-inch wheelbase, and its total length measured 141 inches. It weighed less than 1600 pounds. Despite its size, the Imp was somewhat practical, since its swing-up rear window and fold-down rear seat allowed for a lot of hauling space.

The car rode on a four-wheel independent suspension supported by coil springs and tube shocks on each corner. The front featured conventional swing arms, and beefy wishbones kept the rear wheels planted to reduce the dreaded rear-engine oversteer. The rear axles were connected by rotoflex joints, also an innovative touch. One account says that this improved configuration was all an accident; the design team had suffered a mishap when evaluating a swing-axle Corvair around a tight curve. No matter how they arrived at the solution, the layout worked well. 

Rise and Fall

Despite a low number of finished cars and pleas from the design team for more development time, Rootes released the Hillman Imp in May 1963. Initially the launch went well. The press loved the car’s roominess and value—buy-in was less than $1500.

Some testers said it cornered better than the Mini and was quieter and more comfortable, too. While a few automotive scribes were not overly thrilled with the Imp’s quirky looks, most praised the car’s handling and performance. 

“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,” reported a Motor 1963 road test. “It just motors around them. For an 875cc car, the performance is astonishingly lively and bears comparison with many family saloons up to 1600cc.”

Three-time F1 champion Jack Brabham voiced his compliments in a 1963 issue of Modern Motoring and Travel: “The steering system is of the rack-and-pinion type, which I have always regarded as the best. It proved light and delightfully precise, enabling me to place the car exactly where I wanted it.”

During an Imp road test, Car and Driver raved about the smooth Coventry Climax engine: “If the engine had any fault, it is its willingness to rev. The power peak is at 5000 rpm, but it can be wound up to an easy seven grand with most of the noise coming from the Rootes engineers.”

Power comes from a four-cylinder Coventry Climax engine that has a lot in common with the one used in the firefighting pump above.

Unfortunately for Imp sales, the good press didn’t last long. Quality control problems started to appear, and the car developed a reputation for unreliability. Overheating, water leaks, blown head gaskets, throttle/automatic choke ills and other gremlins angered owners. 

Contributing to the car’s woes, Rootes dealerships were not happy about selling a car with little margin; they weren’t prepared to perform warranty repairs on a product unlike anything they had ever seen. Continuing labor problems at Linwood led to a lack of cars and parts. In 1964 alone, workers went on strike 31 times. Labor unrest and poor productivity plagued the plant throughout the Imp’s production run. 

All these problems cost Rootes a bundle. In a 1974 retrospective article for Motor, automotive writer Graham Robson suggested that the tremendous losses at the Linwood factory “were the main reason for Rootes falling into Chrysler’s hands.” 

Still, the Imp managed to soldier on, helped in part by publicity from rally and competition wins, including an overall win in the 1965 Tulip Rally. Through the years, in an attempt to take advantage of the appeal of its other brands, Rootes introduced several Imp variants, including the Singer Chamois, Sunbeam Stilleto, Commer Imp Van, Sunbeam/Singer Imp Sport and others. Most of these involved only badge and trim changes, but some, like the appealing Singer Chamois fastback, featured significant styling changes. A few models offered performance upgrades. 

Finally, poor sales caught up with the Imp. Rootes halted production in 1976, and the plant at Linwood closed, never to open again. Few more than 440,000 Imps were produced, and most were sold in the U.K. An estimated 4000 to 5000 drove off lots in the U.S., most of which were Sunbeam models. Safety and emission regulations enacted on all 1968 cars effectively killed Imp sales in the U.S.

An Imp in the Garage

Florida-based Sunbeam collectors Nick and Carolyn Kintner are unabashed enthusiasts of the marque. Their well-equipped shop is always open, and the coffee is always hot. Through the years, many Tigers and Alpines have limped into Nick’s garage for repair or restoration, then roared out transformed. 

Several years ago at a Sunbeam United event, this couple spotted their first Imp. “Carolyn fell in love with it and had to have one,” Nick says. So like any good husband, he began the search. After several false starts, he won a 1964 Sunbeam Imp De Luxe MK I in an eBay auction for $1250. He and son Josh hauled a trailer to Cleveland, Ohio, and picked it up. 

Once back home, Nick concluded that the car’s condition matched the ad description—overall, it was clean and solid. Then he completely disassembled it. He replaced one rusty quarter panel; he also removed every nut and bolt and evaluated every component, replacing parts as needed. Thanks to his experience restoring several difficult Sunbeam Tigers, Nick finished revamping the relatively simple Imp in a little over a year of part-time effort.

The odometer indicated 21,000 miles, and based on the car’s lightly used condition, this number seemed accurate. As a result, Nick was able to reuse many components—which is fortunate, since Imp parts can’t be purchased at NAPA or AutoZone. Nick generally found what he needed by prowling online auctions and establishing contacts in England; he paid reasonable prices, but shipping was costly. 

When he opened up the engine, it looked so clean that he took a chance and didn’t rebuild it. This gamble paid off; with a new carb and fuel pump, the engine ran fine. The transmission needed a second-gear synchro, so he had it rebuilt at Twin-Cam Sportscars in Sarasota, Florida. 

On the outside, the Imp got some dings repaired and received a new coat of Balmoral Gray, its rare original color. Inside, Nick reused the original, hardly worn front and rear upholstery and door panels; the carpet, however, was replaced. Nick fabricated and fitted a new under-dash cardboard cubby that runs the width of the car. He got a surprise when sorting out the electrical system: “First car I’ve ever seen without a single fuse,” he said.

His goal was to keep the Imp as stock as possible, with upgrades only for dependability and safety. Mark I Imps were equipped with a troublesome pneumatic throttle assembly, but a previous owner had replaced this unit with a cable assembly, a setup Nick retained. To ensure that the Imp keeps its cool in traffic, Nick recored the radiator and installed a puller electric fan. He also converted the car from positive to negative ground. 

Early Imps were known for excessive front camber, so Nick modified the suspension. He also replaced the 12-inch steel wheels with 13x5-inch Superlite alloys wrapped with modern Sumitomo tires. This sporty combination not only provides more grip, but it looks good, too. 

While the Imp stayed in production for 13 years and made a lot of friends—our Florida couple among them—it never did come close to catching the Mini. Enthusiasts maintain that with the proper development, support and attention to quality, the Imp could have indeed proved a worthy match. They insist that, pound for pound, it “coulda been a contender.” 

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TurnerX19 SuperDork
9/22/20 10:10 a.m.

I owned four Imps here in the USA between 1971 and 1980. Three were Mk1s, and I never saw a pneumatic throttle. I suspect they were gone from production by the time left hand drive cars were produced. Earliest VIN# I had was  B411038955. Pictured below with fresh paint

wspohn Dork
9/22/20 11:08 a.m.

Lightweight car hampered by indifferent handlng due to front suspension choices (swing arm), but cute and the engines were great, if underpowered - I bought one new and then resold it a couple of weeks later as I live in a hilly area and there was literally no way to get it to start on a steep hill without burning the clucth out trying.

With a larger displacement (even the 998 rally Imp engines were a help, but patterning on a larger Climax precursor like the 1200 cc would have been even better)  they could have been a great little car. In fact the engines went on to power many, many small bore sports racers. The 998 cc engines put out 65 bhp, comparable with the similar sized BMC A series.  They managed to get them up over 100 bhp for racing, which beat anything short of the BMC 1275s back in the day.

They even created a race class for space frame Imps - basically a sports racing chassis with a (very) lightweight body that had to look more or less like an Imp.  

Here is one with a special DOHC head that put out 110 bhp at 10,000 rpm.....


David S. Wallens
David S. Wallens Editorial Director
9/24/20 8:26 p.m.

In reply to wspohn :

So was the Mini just the better mousetrap? (And, for that matter, the Beetle?)

wspohn Dork
9/26/20 10:20 a.m.
1/31/22 12:32 p.m.

I had a Sunbeam Imp I bought new in 1966 - a 1967 model IIRC. I drove it until 1969 when I could afford an MGB. The only real problem I had was that the ignition system was sensitive to dampness - it seemed as if the car wouldn't start if somebody spat on the sidewalk within 20 feet. The solution was carbon tetrachloride which I carried in a 16 oz bottle purchased at the pharmacy (I believe it's no longer sold to consumers). I hadn't heard of WD-40 in those days, and when I first encountered it, people thought of it as a lubricant, not realizing that WD stands for Water Displacement. My advise to Imp drivers is: Always carry WD-40 in your tool kit.

Tim Suddard
Tim Suddard Publisher
2/3/22 9:12 a.m.

I still want an Imp. Maybe someday.

2/25/22 5:37 a.m.

In reply to keithjackson :

I when to a rooted come Chrysler garage at 17  they used to take 6 to 7 hours to change the clutch after a while I realised you could leave the box and rear cross member in place  took me 35 minutes  another thing we did when repairing the gearbox was to clean the  mating surfaces with carbon tetrachloride   Love working on these loverly cars  remember one of the guys doing a p d I and customer wanted sill kick strips por man drilled through heater hoses we were called apprentice but the real name was slaves  paid a pittance later I when they to work for a Ford dealership during the time the cortina axels fell apart made so much money on bonce gave my wage package to my mum she thought I'd been paid two weeks holiday pay as well. Happy days met some great people not all but some great skills 

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