Hillman Imp: Meet Australia’s wildest V8 Imp!
Australia’s sports sedan class has produced lots of outrageous racing sedans and arguably the wildest of them all was Harry Lefoe’s infamous Hillman Imp. With a hot small-block Ford V8 stuffed in the back, it was a bullet in a straight line with more than enough grunt to lift its front wheels clear off the deck. And it was sometimes even driven on the road with trade plates!
Unfortunately, Lefoe’s unique machine was caught in the middle of sports sedan racing’s rapid transition in the early 1970s from low-cost home-built specials like the Imp (and Peter Brock’s famous Holden six-powered Austin A30) to big dollar professionally-built machines and big name drivers.
Even so, Lefoe persisted with the Imp’s development for several seasons and in the process became a favourite with race fans, impressed more by the sheer courage of building and driving such an insane concept rather than the number of races it won.
A Hillman Imp and a Ford V8 really was a most unlikely marriage, given that the diminutive rear-engined rear-wheel drive Hillman was created by the UK’s Rootes Group in 1963 as an alternative to BMC’s highly popular front-engined front wheel-drive BMC Mini.
Originally powered by an all-aluminium SOHC 875cc four cylinder engine, the Imp’s tiny 2080mm wheelbase was only about a matchbox longer than the Mini, with a kerb weight of just 725kg. Which should give you some idea why the audacious concept of shoehorning a powerful Ford V8 into one - and then trying to race it - captured many a spectator’s imagination.
Making a big Imp-ression
Harry Lefoe was based in Wodonga in north-eastern Victoria and ran earthmoving machinery for a living. He was very hands-on with mechanical things so the idea of building his own racing car, at minimal cost, was the only way to do things. And he enjoyed racing just for the heck of it. Make no mistake; he raced to win but collecting trophies was not his prime motivation.
Lefoe started racing in the early 1960s in an open-wheeler special called the Argit designed and built originally by Bill Stephens at Eskdale near Wodonga. By the late 1960s, though, the days of home-made specials in open-wheeler categories were coming to an end with the rise of more disciplined ‘control’ classes like Formula Vee and Formula Ford.
However, a new playground for home-grown hot-rodders like Lefoe was found in the burgeoning Sports Racing Closed (aka sports sedans) category. The liberal technical rules - if there were any back then - allowed fertile imaginations to run free.
Small cars could be fitted with big engines and large cars could be fitted with even bigger ones. You could also relocate engines in chassis to improve weight distribution and you were also allowed to mix and match drivetrains, chassis, brakes, suspensions, wheels and tyres and create some wild bodywork with wings and things. These home-grown hybrids were raw, fast, loud and spectacular to watch.
Lefoe’s experience with the Argit convinced him that a small and light car with an engine mounted directly behind the driver and ahead of the rear axle line, in true 1960s open-wheeler tradition, was the way to go. However, rather than choose a high-revving four cylinder as one might expect in such a small car, Lefoe opted instead for the immense power and torque of a small-block V8.
This was radical thinking at the time and many years before famous sports sedans like Bryan Thomson’s Chev V8-powered VW Fastback and Frank Gardner’s near invincible Chev Corvair - which both shared a similar mid-engined lay-out - had even been dreamt of.
Lefoe’s choice of a Ford ‘Windsor’ small block V8 ensured that its compact size and light weight would result in not only a shattering power-to-weight ratio but also ensure the least disruption to crucial chassis dynamics like front-to-rear weight distribution, polar moment of inertia and centre of gravity.
And, according to an excellent article on Lefoe penned by the late Graham Howard for Chevron Publishing, the decision to go Ford was also influenced by early attempts by administrators to regulate what was seen by purists as an outlaw class.
“At the time there were no CAMS rules specifically defining sports sedans, but there was an active Australian Sports Sedan Association and guidelines which included restricting the choice of engines to those from cars built by the manufacturer of the bodyshell,” Howard wrote.
“Hillman was part of the Rootes group which built, amongst other things, the Sunbeam Tiger – which used a small-block Ford V8. So under ASSA guidelines it would be legal: a Hillman Imp with a Fairlane V8. The games could begin.”
At the start of the Imp’s build, Peter Wilson - who helped to maintain Lefoe’s earthmoving equipment and assist with his racing machinery - recalled the Ford V8 engine sitting on the workshop floor in central Wodonga and the stripped Imp bodyshell being lowered over it.
At each point where the body and engine made contact, metal was cut away from the steel shell until it could sit comfortably over the engine. At the end of this process, Wilson recalled that more of the Imp’s rear floor and bulkhead were removed than what remained in the car.
With so much of the body’s original structure gone, a complete half-chassis with roll cage had to be constructed in its place, fabricated from welded steel tube to support the V8 engine and ZF five-speed transaxle, plus provide pick-up points for new rear suspension. Despite the small block V8’s compact size, it was still a tight fit. The front of the engine sat just ahead of the B pillar with barely enough clearance for the driver’s left elbow.
The wheel housings were also enlarged to fit fat race tyres on widened steel rims, along with a front spoiler complete with air intakes to cool the front brakes and the V8’s much larger radiator.
Race engine builder John Bennett, who ran the HeadMod performance engineering business in Melbourne, played a major role in the Imp’s construction and ongoing development of its engine and suspension.
Bennett replaced the Imp’s original swing axle-type front-end with a superior twin wishbone set-up adapted from an HB Torana. He also fabricated a de Dion-type rear using (amongst other things) ex-Porsche 911 drive-shafts and universal joints. And each corner had a disc brake.
Not surprisingly, given the huge grunt from the Ford V8 and the powerful ‘pendulum’ effect it created under cornering loads, changes to the Imp’s super short wheelbase were explored to provide more straight-line stability and tame a tendency to snap into power oversteer through the turns.
“Less obviously the Imp’s wheelbase also progressed,” Howard wrote. “There are legends that the shell was lengthened by six inches, or alternatively that the front wheels were moved forward and the rears moved back to the maximum the bodywork would allow. To disguise this – especially when Imp owners brought their cars into the pits after a meeting – the racing Imp was always left with the front wheels on full lock.
“Even with a few extra inches, it was still a very short wheelbase gadget with a lot of power and with the bulk of its weight close to the rear axle. John Bennett recalled the car could ‘carry’ its front wheels even in the higher gears and Harry’s daughter Michelle remembered a photo of the Imp doing wheel-stands down the Hume Highway for the benefit of the local Border Morning Mail.
“It was manageable enough for John Bennett to occasionally drive it on the road when it was left at his (Melbourne) shop between races. He would strap trade plates on it and take one of his motorcycle racing mates for a brisk drive. ‘It was diabolical on a wet road,’ Bennett recalled. “After you’d driven them from Lilydale to Emerald in the wet they could hardly get out of the car.’”
Mission Imp-ossible
Lefoe’s V8 Imp stunned media and spectators at Sydney’s Oran Park on its debut in September 1970 where the strengths of its radical design were immediately apparent.
With such an implausible power-to-weight ratio and most of its weight over the rear tyres it left the start line as though being fired out of a cannon, just as Thomson’s VW and Gardner’s Corvair would do a few years later. The Imp was also very quick out of slow corners and blindingly fast in a straight line, with ballistic top speeds of up to 140mph (225km/h) claimed on Oran Park’s main straight.
Changing direction though, proved to be its major vice. It was truly a ‘beast’ in every sense which had to be muscled into submission at every turn. The general feeling was that Harry, with his mix of natural talent (he must have had plenty!) and sheer bravado, was the only guy that could have driven it at anywhere near its fearful limits.
The Imp V8’s stability and traction improved in 1971 with the addition of an aerofoil mounted on tall posts attached to the rear guards. It sat well above roof height to benefit from clean air flow and was similar in appearance to an even larger version fitted to Bob Jane’s Repco V8-powered Torana.
However, these towering and ungainly devices were soon outlawed due to safety concerns, just as they had been in F1 and other open-wheeler categories.
The Imp’s 1971 season was characterised by lightning starts, frequent trips across the grass and the odd mechanical failure, but on some occasions it also proved to be very competitive. Those included a win at the Easter Trophy meeting at his local Hume Weir track and a strong podium finish at Calder behind top-shelf cars like Jane’s Torana and Allan Moffat’s Cosworth-powered Ford Escort.
After the traditional Easter meeting at Bathurst in 1972 Lefoe’s Imp was not seen again until 1974, by which stage sports sedans were enjoying unprecedented popularity with big dollar series playing in front of packed houses at Sydney’s Oran Park and Calder Park in Melbourne.
The rich prizemoney on offer and increasing TV coverage triggered a rapid spike in the cost and complexity of cars, including John McCormack’s new Valiant Charger with a mid-mounted F5000 Repco-Holden V8 and Elfin open-wheeler componentry.
In response, Lefoe's Imp had also enjoyed some upgrades during its absence. Beyond a new lick of paint and larger front spoiler and wheel arch flares, a Borg & Beck multi-plate clutch had been installed along with a F5000-type Hewland DG300 five-speed transaxle to replace the tired ZF unit.
John Bennett had also been busy on engine development. The Imp had started out with a fairly basic 289/302cid (4.7/4.9 litre) small block V8 fitted with a big four-barrel Holley carb and custom-made GT40-style exhaust extractors.
At one stage Bennett and Lefoe had also experimented with a (gulp) 351cid/5.8 litre Ford V8. As you can imagine, acceleration and straight-line speeds were organ-displacing, but the penalties paid in even more compromised chassis balance and handling caused by the 351’s increased bulk were too great. Not to mention the massive torque, which threatened to twist the little Hillman into a pretzel.
“The ultimate engine was a Boss-block 302 with 5.7-inch Carillo rods, dry sump, Gurney-Weslake heads, downdraught Webers and a lot of John Bennett’s own ideas,” Howard noted. “This engine had excellent torque particularly at low and medium engine speeds.”
Even so, by 1975 the sports sedan benchmark was a rapidly ascending target, with new cars like Pete Geoghegan’s HJ Monaro, Allan Moffat’s Capri RS3100 and Jim Richards’ NZ-built Ford Mustang joining McCormack’s Charger, Thomson’s VW, Jane’s Torana and his formidable HQ Monaro at the head of the pack.
The following year would see more new arrivals in the form of Moffat’s US-built DeKon Chev Monza, HDT’s LH Torana-Repco and Gardner’s Corvair. The chance of cars like Lefoe’s home-built Imp V8 remaining competitive at this stratospheric level of competition were somewhere between zero and nil.
“By 1975 the Imp was lapping Calder in mid-49s, two seconds faster than its 1972 times but the opposition was faster too – Jane’s Monaro and McCormack’s Charger were into 45s. In a 20-lapper in December the Imp was lapped by the leaders,” Howard wrote. “It was all getting too expensive and too serious and it was taking time away from the business.”
The Imp’s final Bathurst 500 start was in 1969 with only one Hillman GT entered for George Geshopoulos/Ray Scanlan (is that why it carried the coveted No.1?) It was not to be a happy curtain call, with an accident ending its race after 88 of 130 laps.
Lefoe (who died of cancer in 2000) decided to sell the car to John Bennett, given the considerable creative thought and hands-on engineering he had invested in the car. Bennett soon found a new owner in Torana XU-1 racer Neil West and together they continued to develop the Imp to a stage where Bennett claimed it was the best it had ever been.
Sadly the venerable Hillman-Ford V8 barrel-rolled at high speed during a race at Sandown Park. Neil West escaped without injury, but the car was destroyed. It was the end of a short but highly entertaining era in sports sedan racing, when the humble Hillman Imp rose to unprecedented heights of performance thanks to the skill and daring of its free-thinking Aussie creator, Harry Lefoe.
