Number One. The Prototype. Experimental ‘Ex’.
For the avoidance of doubt – and to put it simply – HP 6161 is the very first Alvis 12/50 OHV ever built.
This was the car that changed everything: the machine that placed Alvis firmly on the map in the pre-war motoring world. Still fitted with its original crankcase, marked ‘Ex’ for Experimental, this extraordinary car stands as a tangible link to one of the great turning points in British engineering history.
The Beginning
HP 6161 was one of three prototype racing Alvis cars produced by the works over the winter of 1922–23 (see below) It was No. 1 – the pioneer – and was tested by Maurice Harvey in secret early morning runs during the spring of 1923. Designed for sprints and “freak” hill climbs, it was followed by No. 2 and No. 3, both fitted with solid back axles for high-speed track work.
These three cars represented Alvis’ bold new vision for performance motoring. When entered for the Brooklands 200-mile race of 1923, the team returned triumphant. Yet while the latter two prototypes were soon dismantled for being too specialised for road use, HP 6161’s story took a very different turn.
With its new 12/50 overhead-valve engine – an advanced and rare concept in those days – HP 6161 performed brilliantly. In Harvey’s hands, it achieved multiple FTDs and First in Class finishes throughout the 1923 season, including at West Harling Heath on August 16th 1923 (featured image). By the end of that year, Alvis had decided to place the car in private hands, confident that it would continue to draw crowds and headlines. The 12/50 engine would soon enter production, cementing Alvis’ reputation and pioneering many innovations to come – including front-wheel drive.
A Life in Competition and Companionship
The car’s first private custodian was Tom Simister, an Alvis dealer who continued to campaign HP 6161, often still with Maurice Harvey behind the wheel. The successes kept coming.
Then, in 1924, the car passed to Jack Linnell of Northampton – founder of Sywell Aerodrome and a man who clearly had a taste for adventure. He paid £250 for HP 6161 and would remain its devoted owner for 50 years.
At Brooklands in 1929, Linnell entered the car for the Alvis Day, one of 52 cars on the grid. When an onlooker reportedly sneered at his “old wreck,” Linnell responded the best way possible – by winning the race by two lengths.
The Alvis continued to serve him faithfully, both on the aerodrome and the open road, often observed by a local lad named Robert Wicksteed, who watched with fascination as the little racing car came and went.
In 1930, Jack set off for Brooklands again, hoping to repeat his victory. But fate intervened: the bronze cylinder head cracked en route. The car returned to the works, where Alvis replaced the head with a new steel one, carefully machined to the original pattern.
War, Recovery and Renewal
During the war years, Jack joined the Home Guard, initially using the Alvis on patrol until his superiors decided it lacked sufficient “presence.” Relegated to a field, HP 6161 soon vanished beneath nettles and grass, only rediscovered with the aid of a mine detector in 1945.
The young man who helped recover it was none other than Robert Wicksteed, now home from service and eager to assist. Together, Jack and Robert revived the car in true “make do and mend” fashion, returning it to running order and setting out on decades of adventures.
Robert would later recall a dramatic moment avoiding a busload of children, rolling the Alvis into a field and flattening the body in the process. On another day at the aerodrome, the car was struck by a wayward Proctor aircraft that clipped a Rover, bounced off a hangar, and broke the Alvis’ half-shaft. It seemed HP 6161 was destined to live life at full throttle – and often sideways.
Their friendship was clearly special. In 1974, Jack gifted HP 6161 to Robert, who cherished it until his passing in 2002. For nearly half a century, he campaigned it with the same spirit as its early years – often seen sliding through corners at Silverstone, Shelsley Walsh, and other circuits, as captured in a wonderful 1978 photograph.
The Mechanics of a Legend
More than a century since its first secret runs with Harvey, HP 6161 remains astonishingly original. Beneath its simple sprint bodywork – faithfully rebuilt to its 1923 specification with a compact inboard fuel tank – lies a mechanical heart that tells its own story.
The original crankcase, still stamped “EX 2425,” survives. The cylinder block fitted is from 1931, though the original remains with the car and is usable. The cylinder head is that same Alvis-machined steel replacement, crafted to match the cracked bronze original.
A special Phoenix crankshaft and conrods – lighter and more responsive than standard – were later fitted, with the originals retained. The camshaft is a faithful replica, though the original still turns freely if slightly worn. The dry-sump oiling system benefits from upgraded pump gears, improving oil pressure without altering the car’s period character.
The gearbox, chassis, and rear axle are all original. Even the radiator remains from 1923, having been re-cored only for practical reasons. And while the current body is a sympathetic recreation, much of the original timber and alloy has been preserved and accompanies the car.
Legacy
To oversee the sale of this remarkable machine – the first Alvis 12/50 OHV ever built – was one of the true highlights of our last fifteen years. Today, HP 6161 remains in our care, stored safely on behalf of its overseas custodian.
More than 100 years on, HP 6161 stands not just as a car, but as a testament to ingenuity, friendship, and endurance. From secret dawn test runs to wartime rescue, from Brooklands to Silverstone, it embodies the spirit of inter-war innovation that paved the way for the motoring world we now take for granted.