Cycle News - Archive Issues - 1990's

" goes we ll in developm en t. This is only the start of the rebirth of Bene lli - but a lrea dy we kn ow th at we mu st s ta r t work on other mod els using th e sa me techn ology. We're only a small com pan y as yet, a lt ho ug h we h a ve goo d human and financia l reso urces - but the in v est m ent in d e v el op in g o u r o w n eng ine is so grea t, we must sp read the costs over as wid e a ran ge of mod els as p os s ibl e . O u r b reak-eve n p oint for m ot orcycl e p rodu cti on is 6000 -7000 bikes a year, which is di fficult to achieve wit h only one mod el. So, you' ll see more new ideas fro m us very soo n!" Rosa is convi nced the three-cylinder op tion is the way to go in su perbike racing, citing this as 60 pe rcent of the reaso n for its choice for the Torna do. "You have the bes t of bo th worlds," he says, "with good traction at low revs and the pulli ng power of a one-liter Vtwin. But the ability to rev as much as . 2000 rpm higher than, say, a Ducati, so produce more power up high, yet without the width or bulk of a smaller-capacity 750 four. We call our three-cylinder motor a 'cu be engine' - it's only 15mm wider than a 996 Ducati V-twin, yet just 15mm longer than an R1 Yamaha, but without the. complication of the tripleaxis gearbox layout and the need to em ploy two me n for engine assembly on the production line like with the Rl. Our engine needs just one. A t present we have 131 bhp at the rear w heel on the dyno in s treet form a t 11,200 rpm, and with 9.5 kgm of tor qu e at 8800 rpm - but in race gu ise I'm confiden t the Torn ad o will rev safely to 14,000 rpm, given the pist on speeds cu rren tly com mo nplace in F1 ra cing fo r si milar-sized cy linders. However, a ny mo re than tha t will require the use of pneumatic valve gea r, which I plan to develop for mo torcycle use fu r ther down the road, if we ca n homologate the system okay." So co mpa red to th e sligh tly la rger capaci ty 79 x 65m m Trium ph 955i - the wo rld's only ot her thr ee-cylinder sportbike (pe nd ing the lon g-ov erdue arrival of the similar Laverda [ota 900 p roject) th e ultra sho rt-st ro ke 898 cl: 12-va lve Ben ell i Tornad o eng ine is d esigned to re v hard. It m easu res 85.3 x 52.4m m, with chai n-d riven DOH C , cy lin ders ca n ted forward sligh tly a t 15 d egrees fro m vertical, and a gear-d riven cou nterba lan cer locate d in fro n t of the cra nkcase to smooth out vibration from the engine 's 12D-degree cran k throw. The valves are set at a conserva tive 28 degrees included ang le to eac h other, but , says Rosa, w ith a steep a ngle of downdraft from the trio of th rottl e bod ies offeri ng a lin e ar in ta ke d esi g n , breathin g fro m a large 13-litre sealed airbox fed by the twin "nos tril" aird ucts on eit he r side of the distinctive triplestack head lam ps. Gea r camshaft drive is projected for the mo re cost ly SP version which Benelli will develop for superbike racing in 2001, costing roughly double the projected 24 million lire ($13,000) ta x-free seIling price of the Tornado base model just launched . The 900SP will also boast a dry slipper clutch instead of the stock oil-bath unit currently fitted , as well as as a third injector for the Dell'Orto EFl, rather than the two presently employed - one below the thro tt le butterfly, the ot her centrally loca ted outside the in take stack. Throttle bodies will also be upsized from their p resent 53mm, and an Fl-type rota tingbarrel thro ttle design will likely rep lace the existing butterflies. Fu rt her evide nce of t he Benellis ' in tentio n to compete is the street bike's side- loading, extractable, six-speed cassette-type gearbox. In combination wi th the dry clutch, Rosa says race teams will be ab le to change internal gear ratios in just 12-15 minutes - all without having _ to strip the engine or even remove it from the frame. "The shift mechanism is attached to the cluster, so it all exits togeth er and is very accessible," Rosa sai d . Still more unusu al is the cooli ng system, whic h follo ws the lim ited -edition Britten V-lOOO a n d Saxon Tri u m p h-3 desig ns in fea tu ri ng a small, re armounted rad iator un d e r the sea t, instead of in the conventiona l position in front of the engine. The package is complete internal ducting to su pply cool air to the radiator from either side of the front wheel - the first time such a layout has been used on a street bike . The rear-mounted radiator is made possible by the greatest innovation of all - a pair of computerized electric extraction fans to blow hot ai r out the back of the seat, on either side of the taillight. The fans are controlled via the engine management system's ECU, which monitors engine temperature, the ambient temperature in the low-pressure area be hind the radia to r, and road speed . Th is, says Rosa, will reso lve the overheating probl ems which are associated wit h suc h a cooling system in traffic an d which mo tivated the Saxon Triu m ph's and Britte n's rivals to delay the start of a race on a hot day by al mos t any semilegitimate means. Mo rton's fresh, aggressive s tyling makes a featu re of these rea r -faci n g fans, as well as the Tornado's ultradistinctive "face," which takes Tarnburini's single-headlamp MV Agusta F4 fron t- (Above) The Tornado has a dist inctive look from the front, featuring a "face" with verti cal head lights and horizontal air intakes. end treatmen t into a more yo uthful, rad ical d irection . And the use of the rearmounted radiator allows the engi ne to be placed further forward in the fra me than it would be otherwise, in tum loading up the front-wheel with weight f~r added grip, as well as delivering a short 1395mm wheelbase for . a near-lOOOcc bike. Weight distribution in street form was designed to be 52/4S percent frontend heavy, says Rosa, but the prototype has exceeded expectations - with a 54percent front wheel bias . "We mu st have used a lot of filler to make the show bike!" he said. "I'm sure in rea l-wo rld testing it'll be the way we designed it , which already has more weight on the front wheel in street form tha n an y other spo rtbike ." Dry weigh t is a claimed 407 pounds, a lmost ide n tica l to th e MV F4 but a w hopping 29 po unds lighter than the Ducati 996 . The Torna do chassis is a modula r o ne, wi th tw in-tubular-steel frame spars pegged and glued with aircraft epoxy into a cast -alloy rear frame section, in which the beautifully formed cast/fabricated-alloy swingarm pivots. Steering head angle is adjustable over a 13

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