Monday, June 7, 2010


Harold Willis is a name missing from the roster of British engineers who made great contributions to Motorcycling as well as their respective employers.  His father purchased a large stock of shares in Veloce Ltd, perhaps to ensure his idiosyncratic and motorcycle-mad son had a job!  Willis soon became indispensible to Veloce, developing and racing their motorcycles through the late 1920s and 30s.  The photo below has Willis on the left, with Freddie Hicks and J.A. Baker, at Montlhery in 1928, setting the one hour/100mph world speed record on an early cammy Velo - Freddie Hick's Brooklands racer with an extra-large petrol tank.

Perhaps he's best known for his 'Willisisms', an endless stream of bon mots which succintly named just about anything of interest.  A piston was always a 'bung', an exhaust pipe the 'long hole', an overhead camshaft engine was a 'knocker',  a double overhead camshaft engine a 'double knocker', a valve was a 'nail', etc.  He also invented the positive-stop footshifter, something we all take for granted nowadays, but a huge improvement in racing times in the day.

He also named a few of the racing motorcycles which Veloce fielded, including this one, 'Whiffling Clara', an experimental supercharged 348cc ohc single which Willis rode in the 1932 Isle of Man Junior TT.  When 'Clara's' blown engine was shut off, air pressure leaked out of its plenum chamber with a sigh...hence the 'whiffling'.

Ivan Rhodes has owned Clara for many years, and the photograph above shows the machine in the condition it remained for many years after the blower was removed and the machine became 'just another KTT', retaining its original 'OX8921' registration from 1931 (note the period photo - a road legal supercharged racer!).  The machine needed a few very special parts made to bring it back the 1931 TT glory days, and while Ivan has tremendous skills, it still took many years to get Clara just right.  He mentioned on a visit during 2002 that all the special racing parts (petrol and oil tanks, plenum chamber, etc) were fairly easily replicated, but the original Foxwell supercharger was impossible to find, even to make a copy.

It took the talented hands of Bob Wiggins to draw up and have cast the components of a replica Foxwell; the job was finished only this May 2010, when Clara was fired up at 'Fellside', Ivan's home in Derby.  The Rhodes live at the rear of the property now and part of their extensive workshops have become a museum, occasionally open for private tours, of Ivan's amazing collection of Velocette and AJS racers.  If you have been living under a rock, Ivan also owns the 'Roarer' (another Willisism), Veloce's supercharged ohc twin-cylinder racer from 1939, and quite a few other Works Velocettes, along with a host of 'ordinary' KTTs.

Ivan says Clara is set up for 5psi boost, and runs nicely.  Clara is a contemporary of other blown single-cylinder racers, and is part of the great general trend towards supercharging which began in the mid-1920s in Germany via BMW, spread to Italy and shortly to England and the rest of Europe.  It's considered difficult to successfully force air into a single-cylinder engine, as the blower is pushing fuel-air mix at a constant rate towards the engine, and the engine takes a breath only so often, leading to a buildup of pressure during the long wait between intake moments.  Multi-cylinder engines take more of the blower's output per crankshaft revolution, and even out the 'pulses' in the incoming charge.

Of course, Ivan owns the 'other' supercharged Velocette racer, the 'Roarer' (below), built for the 1939 Isle of Man  Senior TT, but used only in practice as the bike wasn't fully sorted for the race.  Stanley Woods did the testing, but rode Works 350cc and 500cc models, winning the Junior and placing 4th in the Senior behind George Meier (BMW).  

That's a hell of a pair of blown bikes!  Ivan did a huge amount of work to get these bikes to running condition, and is to be commended.

Many thanks to Dennis Quinlan for inspiration for this post from his excellent blog, the Velobanjogent, the photos from Ivan's startup were taken by Eunice and Phil Goude from Victoria, Australia and Clive Larby in the UK.