Cycle News - Archive Issues - 1990's

- . ·IN ID LOOK . Cagiva F4 Superbike S E· And rea Goggi (left) , form erl y with Caglva 's 500Cc Grand Prix team, stands over his new fourstroke project with Caglva boss Claudio Cast lg lionJ. By Alan Cathcart Photos by Kyolchl Nakamura illustration by John Keogh \0 0'\ 0'\ r-t 0\ r-t OJ § ....... 30 ag iva' s four-cylinder F4 Super bike is nearly there. After being a no-show at Milan last November, su ppo sedly because of restyl ing dictated by new headlight regulations in key markets, though more likely becau se it wa s sim ply not ye t ready, there has been a question mark over the progress of the most eagerl y awaited new motorcycle to come out of Italy since the original Ducati otto va/vole a decade ago. But as a recent visit to Cagiva's Varese factory for a sneak update on the project confir med, co mpany boss Cl audio Castig lion i' s d evel opment engineers are right on course to meet his revised targe t of launch in g th e bike at th e Cologne show on October 1, after which time his development team wiIl begin intensive track testing of the Superbike race and Stra d a s treet prototypes, foIlowed by p roduction of a t lea st th e minimum quantity of street versio ns needed to homologate the bike for superbike racing so mew here in the world (mayb e the United States?) in 1997. Cagiva has been working on the F4, the firs t European 7S0cc four-cy linder m ot orc ycl e to be built since t he MV Ag usta glory d ays 20 years ago, ever since 1988, but now at last the p rotracted development of the bike is nearing fru ition . Originally the Castiglioni broth ers plann ed to market a low-volume, high-priced exotic aimed at acqu iring the same kind of prestige for their Cagiva m arqu e' s street produc ts that its Gran d Prix racers had obtained on the track as the only European make to cha Ilenge th e Japanese SOOcc teams. But the game plan has changed radicaIly in the past couple of years, and now it is in te nded that th e F4 co ncept should form the basis of a family of four-cylind er bikes o f different ca pacities a nd types - from an air/ oil-cooled unfaired Mantra-style "Fashion Bike" up to a liquid-cooled 900cc fuel-injected rival to the Honda CBR900RR, as weIl as a tourer and other models. Hence Ca g iva' s withdrawal from 500cc GP racing to focus 100 percent on creating this new four-stroke product line intended to .propel the Castiglioni fa mily m ar q ue in to the front line of wo rld m anufacturers. The com pany is planning to offer a fuIl range of bikes from SOcc to l000cc which wiIl be promoted through the company' s partici pation in Super bike competition. So altho ug h the longer-stroke 846cc version of the F4 m ot o r has already und e rg on e roa d tests, and will be stroked even closer to 900cc for a 1998 model launch, first p riority is to develop the street version of the 7S0cc engine, w hile also working on the modi fications needed to make it competitive in Superbike racing. Thou gh much has been made of the fact that the F4 original ly evolved o u t of th e pe r sonal fri e ndship between the Castiglion is and Piero Fer rari (so n o f Enzo) res u lting in p lans to develop a fou r-cylind er motorcycl e engi ne incorpo ra ting some aspects of Formula 1 car technology borrowed from the wo rks Ferrari, th e fact is that Ferrari's involve m en t with t he project ended five years ago. It has been a 100 percent in-house Cagiva project eve r since, wh ich exp lains why the F4 won't bea r Ferrari' s i/ Caval/ino prancing horse emblem on any part o f th e engine or bodywork. But Cagiva's own R&D staff under Riccardo Rosa (himself a form er Ferrari eng ineer w ho coincide ntally wo rked on the firs t F4 pr ototyp e during hi s time at Maran e llo ) is w e ll quali fied to take on the task. Mainly comp rising the engineers who hon ed th e marque 's V-four two-stroke into a se rious co n tend er for 500cc GP honors against the best that Japan could offer, Cag iva' s engine team has state-of-the-art expertise in a wid e ra n ge of field s fr om electronics to fue l' injection which th ey are adapting to the new fourstroke project. Massimo Tamburini - designer of th e Ducati 916 wo rld cham p io n supe rbike - is takin g care of the chassis design and styling. . With a cast list like this, G audio Castiglioni ca n' t be accused of overop ti m ism: "We know it won' t h appen overnight," he says, "beca use we learned wit h the Ducati otto valvole that, whe n starting from zero, you mus t expect to have to wo rk hard for seve ral years with a new d esign before achieving the success you' re aimin g for. But we' re certa in the Cagiva F4 will open a new chapter in four-cylinder, fou r-stroke m otorcycle develop me n t. 1997 will be a d evel op m ent se ason for t he F4, a nd I d on 't expect we' I1 be serious contenders tiIl the very end of the year. But we ha ve a very , tal ented g ro u p of e ng ineers an d a n excellen t design with many innovative features derived from current Formula 1 practice, which we shaIl be bringing to the marketplace with the F4 street range. I'm sure that by the end of the F4's d ebut season, we' I1 be extremely competitive." If so, wo n' t that pose a threat to the do mi na nce of th e Du cati V-tw ins p roduced by the factory that is also part of the Cagiva Group? "Yes! But Ducati an d Cagiva are two sep arate members of the same family, and there are many examples of brothers or sisters racing agains t each other at the highest level. Competition is good , because it promotes excellence. Ju st as we ha ve d eveloped the fines t twi n-cylin der mot o rcycle eve r built, so ou r aim is to achieve the same goal with a four-cylind er machine. After all, remember that the trans verse in-line fou r-cylinder motorcycle origina ted in Italy nearly 70 years ago, with the Gilera Rondine! It's only proper that we should remin d the world that this is a European con cept, by developing the ultimate in four-cy linder motorcycles." Though he 's too polishe d to say so d irectly, the clear imp lication of Claudio Casti glioni' s words is that Cagiva plans to an sw er aIlegations th at Ducat i has only w on five World Superbi ke titl es because the rules favor it s tw in s by building a better four-cy linder bike than wha t's currently out there. . Several d ifferent ver sions of the F4 engine have been built in th e la st six years, each incorporating radical design concepts which di stinguished it from es tablishe d Japanese practice. Among these were dry-sump lubrication (see below); a rever sed cylinder head with fo rw a rd-facing in le t a nd re ar-fa cing exhausts (rejected becau se of the difficulty of instaIling an airbox, as well as optim izing exhaust length); va riable valve timing (kep t back for a later evoluzione version); five valves pe r cylinde r (fou r va lves gave better pe rformance on the d yno) ; and ; m o st rema r kabl y, offset cylin der bores to reduce engine width, resulting in wh at was effectively a very narrow-angle (about 15 degrees) V-four. Many of these origin al ideas, though not _ all, have been discarded in d evelopment of the final pr eproduction versio n that was designed in 1995. Claudio Casti glioni showe d me this fina l p rod uction version in the Varese dyno roo m, befor e leaving his youthful developm en t en gineer Andrea Goggi formerly the top engine ma n in Cagiva's 500cc V-fou r team - to teIl me all about it. Designed from the gro u nd up as a p erformance m ot or for th e year 2000 with the accent on compact dimensions an d light w e ight , th e li q u id -cooled DOHC F4 Ca giva has a Yamaha-typ e slant-block con figurat ion, th ou gh with the cylinde rs inclined less steeply than on th e YZF750 - about 35 degrees - to avoid unduly lengthening wha t is a very sho rt engi ne d esign . It was felt important to keep the engine very compact to help chassis designer Massimo Tamburini optimize hand ling by centralizing the engine 's mass in the frame . Even with the less extre me slant, the F4' s engine archite ctu re stiIl d elivers a su bsta ntial degree of downdra ft . Th e four la rge 42mm throttl e bodies for th e Weber / Marelli fuel injection are nearly vertical, and the inlet tract w idens to 46mm at the head, with a single injector per cylinder positioned after the throttle, very close tothe valves . Provisio n for a sealed airbox force-fed by twin ram-ai r d ucts will mean the fuel tank must be located beh ind and aroun d the cylinder block, over the gearbox, to avoid making the bike too tall. This will have the ad de d ad vantage th at as the fue l lo ad d ecreases, it will have less effect on the bike's handling because of its location near the center of mass. About the only design aspect retained from the origina l link with Ferrari is the 16- val ve cylinder h ead with central chain drive to th e twin overhead camshafts. Though choosirig th e right cylinder-head design was the subject of much development, the 750 Cagiva still

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