ClassicRacer 31

G LIFE

CLARA

E

ARA

back into

IntheearlyThirtiestherewasabikethatwasan

importantpartofVelocette’s raceprogramme,butit

vanishedformanyyears. Whenit wasfinally

rediscovered,theremainswereboughtbyIvanRhodes,

butit tookevenlongertorestoreit. Themachine

concernedwas‘WhifflingClara’andtherestoration

involvedthetalentandenthusiasmofmanypeople.

Words:AlanTurnerPhotographs:MaincolourimagesPhilipTo oth,

remainingimagesfromIvanRhodesandAlanTurnerarchive

I

nitially,the cammyVelocette was

anonymous.Thebikecameabout as the

resultofadiscussion between twoofthe

company’stop engineers.Itwas based

on astandard,350cc overheadcamshaftKTT

engine but amongmany othersofthat ilk the

supercharger madethis one auniqueexample.

Designer Phil Irving and technical director

Harold Willis were thetwo engineering minds

involved and the ideafor thebikebeganduring an

‘after-hours’ discussionatthe local pub.Thebroad

subject wasthe evolutionofthe KTT models.

Irvinghad only joinedthe company in 1930, but

he hadalready addressed problems experienced

with earlierKTTengines,whereever-higher

states of tune were causing blow-ups that had

barrels separating fromcrankcases.Intryingto

pre-empt future weaknesses,Irvingwondered

if the relatively smallmainbearings were the

next potential problem area.Thepair decided to

experimentally increasethe stresson an engine

by fittingasupercharger.

Supercharging asingle cylinder engine is not

easy.The superchargerprovidesasteady charge

of pressurisedair,orfuel/air mix, dependingon

wherethe unit isfitted into the induction layout.

Thepressurisedgas is delivered allthe timethe

engine is turning,but it hasnowhere to go on the

engine’s ignition and exhaust strokes.This canbe

partly overcomebyhaving aplenumchamber–a

holdingtank –aspart of the intakesystem.The

majorityofmotorcycles were single cylinder at

the time,sosuperchargingwas not apopular

methodof improvingperformanceand the market

placeofferedfew suitable units.

CLA

030 WhifflingClara_Sep.indd 31 27/07/201714:36:43