LIFE E back into CLARA CLA ARA

In the ear­lythir­ties there was a bike that was an im­por­tant part of Ve­lo­cette’s race pro­gramme, but it van­ished for many years. When it was fi­nally re­dis­cov­ered, the re­mains were bought by Ivan Rhodes, but it took even longer to re­store it.the ma­chine con

Classic Racer - - MA­CHINES - Words: Alan­turner Photographs: Main colour im­ages Philip­tooth, re­main­ing im­ages from Ivan Rhodes and Alan­turner archive

Ini­tially, the cammy Ve­lo­cette was anony­mous. The bike came about as the re­sult of a dis­cus­sion be­tween two of the com­pany’s top en­gi­neers. It was based on a stan­dard, 350cc over­head camshaft KTT en­gine but among many oth­ers of that ilk the su­per­charger made this one a unique ex­am­ple. De­signer Phil Irv­ing and tech­ni­cal di­rec­tor Harold Wil­lis were the two engi­neer­ing minds in­volved and the idea for the bike be­gan dur­ing an ‘af­ter-hours’ dis­cus­sion at the lo­cal pub. The broad sub­ject was the evo­lu­tion of the KTT mod­els. Irv­ing had only joined the com­pany in 1930, but he had al­ready ad­dressed prob­lems ex­pe­ri­enced with ear­lier KTT en­gines, where ever-higher states of tune were caus­ing blow-ups that had bar­rels sep­a­rat­ing from crankcases. In try­ing to pre-empt fu­ture weak­nesses, Irv­ing won­dered if the rel­a­tively small main bear­ings were the next po­ten­tial prob­lem area. The pair de­cided to ex­per­i­men­tally in­crease the stress on an en­gine by fit­ting a su­per­charger. Su­per­charg­ing a sin­gle cylin­der en­gine is not easy. The su­per­charger pro­vides a steady charge of pres­surised air, or fuel/air mix, de­pend­ing on where the unit is fit­ted into the in­duc­tion lay­out. The pres­surised gas is de­liv­ered all the time the en­gine is turn­ing, but it has nowhere to go on the en­gine’s ig­ni­tion and ex­haust strokes. This can be partly over­come by hav­ing a plenum cham­ber – a hold­ing tank – as part of the in­take sys­tem. The ma­jor­ity of mo­tor­cy­cles were sin­gle cylin­der at the time, so su­per­charg­ing was not a pop­u­lar method of im­prov­ing per­for­mance and the mar­ket place of­fered few suit­able units.

Messrs Irv­ing and Wil­lis found a vane-type Foxwell unit, which was never in­tended for use with in­ter­nal com­bus­tion en­gines (see page 34). Fac­tory records show that en­gine KTT 240 was booked out to Wil­lis. The ex­per­i­men­tal set-up em­ployed a sim­ple bis­cuit tin as a plenum cham­ber, but when the en­gine was tried on the test­bed the out­put mea­sured 30hp, com­pared to the 22 of a nor­mally as­pi­rated en­gine. It was a re­mark­able re­sult, al­though it should be noted that the en­gine was get­ting the full ben­e­fit of the more in­tense in­let charge, as the su­per­charger was be­ing driven by an ex­ter­nal power source. With such a pos­i­tive re­sult, and as the bot­tom end as­sem­bly ap­peared to be ad­e­quate, the de­ci­sion was made to con­tinue the ex­per­i­ment with a com­plete mo­tor­cy­cle. Us­ing the same en­gine as the ba­sis, the draw­ing of­fice came up with var­i­ous nec­es­sary mod­i­fi­ca­tions. Feeding the car­bu­ret­tor with pres­surised air means the en­tire fuel sys­tem, from the car­bu­ret­tor and up to and in­clud­ing the fuel tank, also has to be pres­surised to func­tion. A spe­cial frame was created, al­though it used var­i­ous lugs from the fac­tory parts bins. Heavy fuel con­sump­tion was an­tic­i­pated, so a spe­cial fuel tank of­fered in­creased ca­pac­ity. When it was fit­ted it looked sim­i­lar to the ‘Pis­tol Grip’ style adopted by New Im­pe­rial. As well as his tal­ent for engi­neer­ing, Wil­lis was also an ex­cel­lent rider, post­ing sec­ond pllace fin­ishes in both the 1927 and 1928 Ju­nior TT races. Per­haps hhis most mem­o­rable legacy is his large lex­i­con of words for mmo­tor­cy­cles and their con­stituent parts. Thus Wil­lis re­ferred to th e un­usu­ally-shaped fuel tank as a ‘cow’s ud­der’. Fol­low­ing a ride e, when the pres­surised fuel sys­tem had to vent, it did so with a ‘w whif­fling’ sound, hence the ‘Whif­fling Clara’ so­bri­quet. Clara’s s en­gine used the stan­dard cast iron cylin­der head with coil valve spr ings. Be­hind the en­gine, on the right side of the gear­box, was the ‘O Of­fi­cial Re­ceiver’, Wil­lis’s ap­pel­la­tion for the large tank that acted as plenump cham­ber for the pres­surised fuel/air mix. The Fox xwell blower was mounted low down in front of the en­gine aand was driven by chain from the crank­shaft. With the ‘Of­fi­cia al Re­ceiver’ be­hind, the whole sys­tem re­quired a lot of plumbi ing. Ini­tially, the bike was fit­ted with Wil­lis’s four-speed gearbo ox unit with rack and pin­ion se­lec­tor, but this was changed to a four-speedf con­stant-mesh ver­sion. Ap­par­ently, hard ridin ng could re­sult in the iron cylin­der head glow­ing with the he at. A new de­sign with hair­pin valve springs cast from al uminium bronze (‘door­knob metal’ ac­cord­ing to Wil­lis) a ided heat dis­si­pa­tion and the same head was even­tu­ally usedu on pro­duc­tion KTT Mk. IV mod­els. The su­per­charger ar­range­menta was soon changed, with the car­bu­ret­tor work­ing at at­mo­spheric pres­sure and the, now down-stream, blower com­press­ing the fuel/air mix­ture. Un­even fu­elling re­mained a prob­lem. Un­der rid­ing con­di­tions the plenum cham­ber filled with a fuel-rich mix­ture on the over-run, chok­ing the en­gine when the throt­tle was opened again. This was ad­dressed with a spe­cial pres­sure relief valve, ap­par­ently an item de­vel­oped byb Amal for the Air Min­istry. This was con­nected to a valve l ifter-type lever that had to be op­er­ated man­u­ally by the ri ider, clear­ing the sur­plus gas and al­low­ing the en­gine to ru un cleanly. Af­ter some en­cour­ag­ing test re­sults, hopes were high

that the bike would show its met­tle at the 1931 Isle of Man TT Ju­nior race, but Wil­lis was not happy with the per­for­mance of the en­gine. Ap­par­ently, poor weather dur­ing prac­tice meant he could not tune the en­gine and su­per­charger ar­range­ment sat­is­fac­to­rily. Al­though press re­ports said he re­moved the su­per­charger, it seems he sim­ply used an­other KTT with a nor­mally-as­pi­rated en­gine to achieve a fin­ish in 11th place. Next year, Clara re­turned to the TT and this time Wil­lis per­sisted with the bike. Seem­ingly the fastest of the en­tire en­try off the start line, by lap two he was re­ported as ‘mak­ing ad­just­ments’ some­where on the Moun­tain, and was soon posted as a re­tire­ment near The Bun­ga­low. From the event re­ports of the time, it seems the su­per­charger gave Clara an im­pres­sive top speed, but the ac­cel­er­a­tion could be a vari­able qual­ity. Ex­actly who rode Clara is not clear. Les Archer was the reg­u­lar jockey at Brook­lands, but it seems the South African JG Lind may have rid­den Clara in the Isle of Man, al­though it should be noted that Wil­lis was usu­ally ex­tremely pro­tec­tive of his projects. Pri­mar­ily set-up for road-rac­ing, the bike could be a bit of a hand­ful around Brook­lands, but it was ap­par­ently timed in a sprint event at an im­pres­sive 114mph. Les also rode the bike in the Ul­ster Grand Prix, a one-off oc­ca­sion, and from which he re­tired, fa­mously declar­ing: “I am not a fish,” as the race was run in what the Ir­ish call ‘liq­uid sun­shine’. Pho­tos ex­ist of Clara tak­ing part in the 1933 Brook­lands Grand Prix, with Les Archer aboard as usual, but by then the project seemed to have run its course and af­ter that the bike es­sen­tially van­ished. Many years later, the Perks Broth­ers, of Bil­ston in Stafford­shire, had quite a col­lec­tion of bikes and bits stored at the back of their garage premises. Some of this had come from the Ve­loce fac­tory, as the broth­ers were friends of the fac­tory own­ers, the Good­man fam­ily. Titch Allen was writ­ing his ‘Ve­lo­cette Saga’ – a se­ries of mag­a­zine ar­ti­cles – and some­one had tipped him off that the col­lec­tion in­cluded re­mains of ‘Whif­fling Clara’. Titch and Ivan Rhodes went to look and cer­tainly, one of the bikes had el­e­ments of the long-lost ma­chine. But was it the gen­uine ar­ti­cle?

The truth will out

Look­ing like a very down-at-heel Thir­ties KTT, the bike had been mod­i­fied, pre­sum­ably to keep it com­pet­i­tive, as it had ap­par­ently been used for grasstrack rac­ing. The unique fuel tank was the most ob­vi­ous clue and the en­gine num­ber – 240 – ap­peared to con­firm these were, in­deed, the re­mains of Clara. The en­gine had the bronze bevel hous­ings that Wil­lis was known to pre­fer. The frame showed signs of re­pair, where the orig­i­nal was known to have bro­ken at one point in its his­tory. This was in 1970 and the Bri­tish mo­tor­cy­cle in­dus­try was sink­ing rapidly, but Ivan Rhodes was tak­ing a keen in­ter­est in his­toric Ve­lo­cettes. He man­aged to ne­go­ti­ate the pur­chase of the bike, to­gether with a num­ber of other bits and pieces. Ivan had ev­ery in­ten­tion of restor­ing it, but there were many other jobs with greater pri­or­ity. Some years later, when Clara might have re­ceived at­ten­tion, fur­ther de­lays were caused when Ivan and his team were obliged to work flat out on the bikes dam­aged in the dis­as­trous fire at the Na­tional Mo­tor­cy­cle Mu­seum in 2003. How­ever, Clara had not been com­pletely out of mind, as Ivan had been ac­cu­mu­lat­ing parts to re­place the worn, or in­cor­rect, com­po­nents. The ab­sent Foxwell su­per­charger was a ma­jor stum­bling block. Ap­peals through the press and even ad­ver­tis­ing brought no re­sponse – even parts for such a de­vice seemed to be un­ob­tain­able. Even­tu­ally, other Ve­lo­cette en­thu­si­asts came to the res­cue and mak­ing a replica su­per­charger en­abled the project to move for­ward. The en­gine had been up­dated with a Mk VIII crank­shaft, so this was ex­changed for a nicely set-up, and heav­ier, as­sem­bly that had been re­moved from Mau­rice Cann’s ‘Dirt Track’ en­gine some years pre­vi­ously. Apart from that, the en­gine and gear­box re­builds were straight­for­ward. When the fac­tory ceased to use ‘Whif­fling Clara’ for de­vel­op­ment, it seems the frame was al­tered at the fac­tory to re­turn it close to stan­dard spec­i­fi­ca­tion, al­though it still re­tained some of the orig­i­nal fea­tures, such as some ad­di­tional lugs. The sub-frame had been ex­changed for a 1934 ver­sion. This made restora­tion less than straight­for­ward. Care­ful study of all the avail­able pho­tos re­vealed what was re­quired. The en­gine had to be moved back an inch from the stan­dard po­si­tion and the front down-tube re-worked to pro­vide a mount­ing lug for the su­per­charger lo­cat­ing plates. Ivan said: “Much jug­gling took place to de­ter­mine the po­si­tion of the blower rel­a­tive to the rest of the unit. The front down-tube had to be short­ened, the length of it was crit­i­cal. This was a two-man job, but I was ably as­sisted by a pal from New Zealand, Pete But­ter­worth, a vice-pres­i­dent of the Ve­lo­cette Club. Pete is an engi­neer in his own right and a very good rider. He spent a week or two with us to help out with Clara and the mu­seum bikes.” When found, Clara was fit­ted with a Mk IV front wheel. Pe­riod pho­tos showed a 1931 KTT hub was cor­rect. Ivan man­aged to buy a new re­place­ment from Tom Bartlett, a model engi­neer­ing en­thu­si­ast liv­ing in Kent. Ivan takes up the story: “We were very lucky to have a brand new Avon 3.25x20 rear tyre that

had been spe­cially pro­duced in the Nineties, but is, re­gret­tably, no longer avail­able. All the con­trol ca­bles were made up from my stock of orig­i­nal pe­riod ma­te­rial and only two fea­tures re­main in­cor­rect. The front brake should have a rod and wing-nut ad­juster to com­plete it. We used a Bow­den pe­riod twist­grip, in­stead of the orig­i­nal lever con­trol favoured by both Harold Wil­lis and Alec Ben­nett, ac­cord­ing to a let­ter from high author­ity – Percy Good­man.” Mean­while, Ivan’s son Gra­hame was kept busy with the stove enam­elling. Jim Plant do­nated a pri­mary chain­case, which was re-worked ap­pro­pri­ately with an ad­di­tional cover pro­tect­ing the chain drive to the su­per­charger. Ivan had dis­cov­ered from Irv­ing’s notes that this was driven at half crank­shaft speed. Suit­able sprock­ets came from Derek Stride attd Cross in Birm­ing­ham. Most of the work was done ‘in house’ and Ray Pet­titt of Not­ting­ham made the fi­nal com­po­nents. Sheet metal skills were needed to re-cre­ate the plenum cham­ber and oil tanks. The lugs that once lo­cated them had also been re­moved, but these were re-in­stated from Ivan’s stock of ex-fac­tory parts. John Goodall was yet an­other per­son who helped with the project, lo­cat­ing and mod­i­fy­ing an oil cooler to try and match the pho­tographed orig­i­nal. He made the pres­sure relief valve that bolts into the plenum cham­ber. John was also re­spon­si­ble for the in­let man­i­fold and the air fil­ter body that is a dis­tin­guish­ing fea­ture of the tim­ing side of the bike. One tricky part was the pipe that fed from the blower to the plenum cham­ber.this led un­der the en­gine and the re­stricted space al­lowed lit­tle room for er­ror. The ex­haust pipe was an­other fab­ri­ca­tion project. The work was com­pleted in 2010 and the bike was soon fired up. Af­ter fur­ther ex­per­i­ment­ing, it was found that the en­gine runs nicely on a mix of petrol/methanol in an 80:20 ra­tio. Use­fully, this also works sat­is­fac­to­rily with the ‘Roarer’, an­other of Ivan’s high-pro­file Ve­lo­cette restora­tions. With 5psi boost, the en­gine per­forms ex­tremely well. It climbed the Brook­land­stest Hill with some aplomb! Per­haps, in iso­la­tion, ‘Whif­fling Clara’ was not a suc­cess, as no other bike was sim­i­larly mod­i­fied. How­ever, the lessons learned in su­per­charg­ing doubt­less proved valu­able for Ve­lo­cette’s later ex­per­i­ments, as well as guid­ing fu­ture de­vel­op­ments of the KTT. What­ever the con­clu­sions – it’s good to have her back.

ROD­NEY WILD­SMITH.

Top: Harold Wil­lis and Clara at the TT weigh-in

Right:the Restora­tion Team! Left to right, Sam Rhodes, Gra­hame Rhodes, Ge­off Berry, John Kid­son, Ivan Rhodes on bike, Harold Beal, Rob Wig­gins, John Goodall (the late) Brian James, Bob Higgs and David Tong. Pete Welch helped with spe­cial­ist ma­chin­ing but could not make the photo-shoot.

IVAN RHODES. IVAN RHODES.

Above: Clara as found – at one time, the bike might have been se­cured for a fiver!

Right:the dis­tinc­tive tank took some work to bring it back to orig­i­nal fac­tory stan­dard.

IVAN RHODES

The gear­box sup­port stay has been stiff­ened fol­low­ing a frame break­age.

Above: Les Archer, pos­si­bly at the 1933 Brook­lands Grand Prix, Pa Archer is far left, Harold Wil­lis third from left, then Eric Ferni­hough.

AU­THOR

Ivan demon­strates Clara at the 2012 In­ter­na­tional West Kent Run.

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