Cycle News - Archive Issues - 1980's

~ ~ C a: 0 u. u, ::; U a: w .... w CL > CD en 0 .... If;I 0 00 :I: CL C') ...... ~ 0 ...... >-...... ::= ~ This Pernod 250 is f itted with Hummel piston-port cylinders; the standard rotary valves are blocked off. The latest version of the Cagiva V-four has an aluminum f rame and individual Dell'Orto carburetors. Notesfrom YugoslavillnRRGP So ut h Africa n is bored wi th li fe a t home even though he h as just opened u p a mot orcycl e shop in Durban with recentl y-retired South Africa n Supe rbike Champion Rod n ey G rey. Ekerold is to form h is own team a nd will bring wit h him a yo u ng So u th Afr ica n so tha t h e ca n p ass o n some of h is ha rd-won experience as well as aim ing to improve u pon h is tota l of seven Gra nd Prix wi ns . By Peter Clifford Peter Clifford n osed around th e pits at th e Yu goslavian World R oad R acing G rand Prix . picking u p bits of racing and tech n ical information as he went. Th is is h is report . . . Editor. . After the Belgian Formula One car G rand Prix was called off in the m iddle of p ractice because the circu it at Spa was breaking up, the motorcycle Grand P rix scheduled fo r July 7 has been ver y much in do ubt. The 4.3-m ile circu it was co m p letely resurfaced·before th e ca r race bu t whereas th eir regulat ions sta te th at th e sur face sho u ld n ot be changed within th ree months o f th e race. snow was still lyin g in th at area in March and th e resu rfacin g was do ne o n ly weeks before th e event. with a very-hi gh-grip tarmac th at is slo w curin g . The ca rs rip p ed up th e circu it a nd as p hotographs shown to th e riders in Rijeka showed there is no way that it could be raced on. T he Bel gian gove rn ment had step ped in to provide th e money and manpower to resurface th e track again im me dia tely but with n ormal tarmac which will not take long to cure. Lu igi Brenni , P resident o f th e FIM Road Raci ng Committee. spoke wit h severa l of the rid ers a nd th eir rep resentative Mike Trim by a t Rijeka and agreed th at th ere would be no Belgian GP un less th e surface was good. So th at th e su ita bili rv of th e trac k . ca n be tested th ere wii l be a short pra cti ce sessio n o n the T uesda y before th e Dutch TT which is o ne week before Spa so th a t the riders ca n try th e track. The 500cc riders will the n vo te a nd the deci sion as to whe ther or not th e event is held will depend o n the maj ority. Paul Lewis gets Skoal Bandit ride 26 The Skoal Ban d it Grand Prix T eam. ru nn ing th e Hero n Suzu ki ca r bo n -fi be r bike ridden by Ro b McElnea. have signed Australian Paul Lewis to rid e a t Don in gton Pa rk on Ju ly 22 an d at the British Grand Prix a t Silverstone. La st yea r Lewis cras hed a t Silversto ne tr ying to sta y ahead o f McElnea but h is firey an d aggress ive riding hav e a ttracted the attention o f th e team which is looking to strengthen their lin eu p . McElnea has sco red 15 • • • • • 1 •• • • j .s. ~. I - • •• • • points so far this year a nd is tied for eigh th pl ace in the champio ns hi p despite th e fact th a t his Suzuki is well underpowered . T he power disadvantage may also cha nge as Su zu ki has fina lly sent the British team th e latest cylin de rs which th e Ital ian HB Gali na Suzu ki Tea m have been running si nce the begi n nin g of th e yea r. T he Ita lia n Suzuk is have been fas t in a straigh t line even if th e hand li n g o f th e works a lu mi n u m frames h as left a good dea l to be desired . Don ington co u ld well see two Gree n a nd Wh ite Skoal Ba ndit bikes battling for th e lead wi th th e Roth ma n s H ondas of Wa yne G ardn er a nd Ron H aslam after a so me what fru strat in g season so fa r. Czechoslovakian RS500 gearbox Boer van Du lmen has been using a Czechos lova kia n gea rbo x in hi s RS500 H onda si nce the Ge rman Gra nd Prix at H ocken h eim. T he Dutch privateer ordered the parts before the end of 1984 when h e was thinki ng of swappi ng from Suzu ki to H onda . H e did so beca use the H o nda gearboxes at th a t time ha d a bad reputation for brea ki ng and certai nly th e Czechoslovakia n parts hav e proved very relia ble. Wh en H o nda found ou t that he had the special piece th ey asked where they were ma de but th e wi ly Du tch ca m paig ne r wo ul d no t tell th em. T hey th en as ked 10 be able to ta ke th em to J apan for closer scru ti ny an d van Dulmen tol d th em th at th ey were welcome to do so p ro vided th at th ey giv e h im a works NS engine or a t least so me spec ia l p art s in exchange. Honda d id n ot go for th at so they as ked to bu y th em and th ey gal th e answer. " Yes certai nly. in Sep tember." Ekerold comeback Jon Ekero ld, 350cc Wo rld Champion in 1980. is poised to make a Grand Prix comeback in 1986. The •• ••. . •. . . . . -.-.- .. _--- -_ .. _ ~_ Cagiva debut Marco L u cch in ell i rode th e n ew Vfour 500cc Cagiva in its fir st Gran d P rix a t Rijeka . T he reed- valve -induction bike loo ks very much lik e a Ya m aha a nd it was su ggested th at Ya m aha act ually loaned o ne of th eir o ld engines to the Ital ian co mpa ny to measure in th e interest of keeping more ma n ufacturers involed in 500cc Grand Prix racin g. True or n o t. the Cagi va has th e same reed-va lve induction direct into th e cra n k cases between th e two banks of cylinders. which are 90° a part. T he Cagiva is one step behi nd th e Yamaha. th ough . in tha t it ha s a n ex tra sha ft between th e two cra n ks wh ich dr ives the water pump on its right h and end. T he Yamaha ha s th e wa terpump undernea th the engine and the two cra n ks are much closer toge ther. mak-" in g for a more co m pact p owerplant. T he fact th at the two ban ks o f cy linders are furt he r a pa rt ca n be seen fro m th e p oint th at the four ca rb chokes o f th e Yama ha are in lin e wh erea s th e Cagiva ha s four sepa ra te Del'Ortos sta ggered two u p an d two down. . L ike th e Yama ha. the Cagiva ha s exhaus t p ower valves bu t these loo k like th ose used on th e Yamaha s two years ago . T he frame. ho wever. is sim ilar to th e lat est Yam aha des ign wit h tw in spars run n in g either side of the engi ne . L uch in ell i described the bike as promisi ng. " I thin k tha t th e bik e ca n be good bu t at the moment we h ave many pro b le ms. s ma ll o nes b ut many." H e q ual ified 23rd wi th a time of 1:36.84 . five secon ds slower th an Spencer. Pernod back T he Frenc h Pernod tea m were back in action at Rijeka with Jea n Francoi s Balde a nd Jacq ues O n da ri d ing two d iffere n t a nd much m odi fied -m a chi nes a fter mi ssin g the Italia n a n d Aus tria n rounds because the ir di scvalve 250cc twins were un com peti tive. Agai n Chev a ll ier, th e Frenc h en gineer. had been hired by th e team for the fir st tim e th is yea r to try . a n d brea th e so me life into a machine th at a part fro m winn in g the '83 British Grand Prix has had little success d espi te costing a fortune. _ __.•••. ...•. . Ch eva lli er admi ts tha t h e is in a n a lm os t im possi ble sit ua tio n ha ving in h erit ed a n uncompetit ive en gine desi gn th at is too wide and wi ll not rev. In a n a tte mp t to so lve both p rob lem s h e bu ilt two different eng ines in th e th ree-week break th e team took before sett ing o ff for Yugo slavia . The safes t bet was to u se p ro ven cylinders a nd th ese are rea dily availa ble from H an s H ummel. T hey a re the cyli nders th a t a ll the Yamaha riders used la st year including Sarron, w ho won the champions hip. T he major stu mbli ng block was th a t th ey were bu ilt for a 56x50m m bore an d stroke Yamaha engi ne arid the Pern od is 54x54 m m . Not daunted . Chevallier design ed and bui lt a new crank with a 54m m stroke th at would fit th e ex istin g cases. He brok e severa l bea rings a nd cra n ks before m aking it wo rk bu t while he was a t it removed a m aj or impediment to engine . rpm . . th e all-ba ll bearin gs. Most cra n ks h av e a ball bearing o n o ne en d th at locat es it an d th e rest are ro llers so tha t as th e cra n k a nd th e cases expa nd a t differen t ra tes the rollers ca n slide side ways an d ta ke u p th e expa nsion. Che vall ier suggests that in tryin g to expa nd th e ball gearing cra n k h as been partiall y seizin g a nd th at exp la ins why the bik es have a lways go ne slower as th e race progressed . The best Pernod engi ne Chevall ier tested p roduced 66 bhp a nd no matter what h e tried "': huge exha ust ports or wh at ever exha us t p ipes - he co ul d not mak e it rev above 12.200 rpm so tha t despite th e fact th a t th e di scvalve engine made good torq ue th e Hummel cyli nder pisto n-port-ind uetio n co nversion made more power ins ta ntly. 79bh p a t 12.800. T he third engi ne Cheva llier m ad e used th e Per nod cylinde rs but agai n avo ided using th e d isc valve inductio n bv hacksa wing ho les in the to p of the 'cra n k case a nd bond in g in reed valves much in the sa me way as th e la test 250cc Yarn ahas. This has the advantage of inc rease d transfer port area but a t th e time of th e Yugosla via G P Chevall ier had not had tim e to mak e a new ro ller bearing cra n k for this 54x54 m m en gine and th e reed valves were crea tin g ca rbu retio n p roblem s that meant that a lt ho ugh the engi ne wa s a lrea dy p ro d uci ng 68 bh p , acce lera tio n was a p roblem. T he effort th at Cbe vallier has pu t into th e p roj ect is a ma zing but h e inherited a poor design in th e first p lace a nd th at handicap may prevent h im from ac hievi ng a ny rea l success . Hi s fra me for th e 250 is a rea l work o f a rt a nd a ltho ugh at first glance it looks like a tubu lar construction it is

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