Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/141061
it sh o ul d break it can be swiftly and e a s il y r epaired. Dennis purposely avoided a monocoque chassis be cause if it is damaged it can' t be repaired quickly . The bike's overall length is 15'9", it 's 31 " tall at its highest point and it wei ghs only 85 0 pounds wet with Boris in , it. T he c hassis h as gauges lo cated in stra tegic areas to show if a crac k has developed . Murray _ and .. Manning N N > ~ ~ z w W ..J U ~ Story and photos by Brent Bailey We'll begin with a brie f back ground of eac h man. Manning Dennis Mannin g is 26, m a rri ed to Meliss a Mannin g, and cu rren tly lives in Yorba Lind a. Den n is ' beginn in gs wit h b ikes d ates b ack to 19 6 1 whe n hi s o lder b rother J im brought ho me a Honda 125 road racer. Dennis att ende d his fi rst race in S to ck to n , California. T on y M urph y, Bud dy Perrier, J o hn ~ IcL augh lin , an d R on Grant h ad it o u t th at da y. Because of his ex posure . road racin g was th e first for m o f co mp e titio n Dennis d abbled in . After fo llo wing hi s bi g brother for a while Dennis boug h t his bike in 1963. After a brief road racin g career Dennis discov ered drag racin g. "I t o ok th is girl ou t one nigh t , and all d u ring th e movi e sh e told me h ow super-nea t drag racing wa s. So in order to ge t t o go o ut with her aga in I figu re d I'd better go to a drag ra ce. ,. Dennis ' fi rst sig h t of drag racing w as at n ight a t Pomon a. No bi kes , b ut lots of " sm elly , sm o k y. neato cars ." Next week he to ok the same girl to Li ons wh ere there h appened to be lo ts of bikes. Th is re ally jazzed Dennis , so he began participating with his trusty little road racer. He so on be came bored of slow speeds so he purchased a 305 Honda in 1964. Dennis' first thought was to go super fast, so the first thing he d id was to try to run the bike on nitro. He got th e bike to run 12.20's, 119 MPH hut des tro yed it in the process. His ne xt st ep was to bu y 'a n old MG b lo we r o ff his broth er and b ol t it on along wi th a cus to m Hilborn fuel injection system. Try to imagin e a blown, fuel burning Honda 3 05 ! His first run made with the blower Was at Li ons. He bl ew th e c ra nk. Abou t . this tim e, Len Wyman was starting a U.S . mot or c ycle drag ra cing team to go to En gland. He had heard of Dennis' unusual bike and invited him to join. Naturally Dennis was more than happy to oblige. This was where he and Boris Murray first met. After the Eng lish trip Dennis began ca mp aign ing a blown Honda 450 drag bike that also doubled as a Bonneville machine. Dennis' first ex pe rience at Bonne ville wa s 1967. His bike ran in th e 130 MPH bracket o n gas . In tr ying to q ualify , th e bike broke an d th at en de d Den n is' £irs t trip . That fir st trip pl anted th e LSR see d in Dennis ' brain . Th e next year he was ready with a co mplete streamlin er powered b y Suzuki. But Bonnevill e was rained out in 1968. Dennis' spo ns ors t he n "b orrow ed" hi s bike and proceeded to d estroy it . After puttering a ro un d Bonneville for a few , years Dennis came back in 1970 with Cal Ra yborn' and Harl e y. That year Cal set th e re cord at 265.492 that has sto o d e ver sin ce . It to ok Dennis only 24 runs to o btain th e motorcycle land sp eed reco rd . Murray Bo ris M u rray has an eq ua l!y i mpressive b ack ground. Startin g In 195 8 , Bori s began ru n ni ng Triumphs at lo cal drags trips. He has since b uilt seve ra l in cred ibl e bi kes. Th e last two have been twin engine T riump hs. Bo ris c u rren tly h olds th e NHRA time and sp eed records at 8.87 and 174 MPII . llis bikes ha ve become fa mo us for wild sm oky pass es. An yone with doubts abo ut Bo ris' abi lity to pil o t a Bonn eville bik e mi ght try pullin g a wh eeli e a t 170 MPH. Boris h as d on e it se veral times. His knowledge of fuel b urn ing Triumph engines is unsurpasse d. He has ma n aged to ge t approxi ma tely 15 0 h o rsep ower out of each , of hi s IWO e ngi nes. That 's n o t re ally so hard. Wh at is hard is th at h e can m a ke each one do it w it h a mi ni m u m of br ea kage. Th at 's wh ere h is ro le in th e Bo nneville bi ke reall y cou nts. The Bonneville Bike T he Bonneville bik e is a no the r m odel o f efficien cy. Loo kin g a t iL sitting in th e garage it 's n ot hard to im agin e it go ing 3 0 ll+ MPH . 3 11 0 MPH is their minimum goal. So far . wind tunnel testing alone has cost o ve r $5000. The frame is of 101 8 steel so that if Viewed from the front the bike looks uncomplicated and Quiet in the darkened shop Come speedweek it will be pushing 300 MPH. . The engines powering it wiII be built b y Boris (natch] and will be mu ch the same as the ones in his drag bike. They will be bored to 750cc (45ci) using a Bob Chantland bore kit. The cams will be from Norris, utilizin g basically jus I a hot street grin d. Th ey'lI run about 8 0% nitro. . T he carbs a re old Amal IT fuel ers, alth ough Bo ris has be en con side ri ng fu el inje ction. Other th an that, th e en gin es wiII be m o stly stock . T he tr an sm ission is a ve ry bee fed Triu mp h fivespeed, A uniq ue fea t ure is the design of th e coc kp it . O n ly five gauges wiII be used . One temperature and oil pressure fo r each engine and one tach om eter. Instead o f th e twist grip throttle and handlebar mounted cl u tc h . th ey will be pedal operat ed. On e o f the hike's more radical feature is that th e exhaus t system will be used to draw fresh air to th e engines. T he escapin g ex haus t gasses c rea te a vacu um, drawin g fresh air in. This system ca n be regula te d by Boris accord ing to what th e heat ga uges say. Man y sa fe ty features are also built in to th e bik e. The fu el valve and parachutes are o pe rate d by me rcury switch es wh ich wiII au to m a tic ally sh u t o ff the f uel and d eploy th e ch u te s should Boris have an accident. Sev eral fire bottles lo cated in st r at egi c ar eas can be operated both manually and automatically. . Through th e wind tunnel they have learned that it takes only about 100 horsepower t o push the bike 300 MPH. That's how aerodynamically perfect it is. They have als o in co rp o rated many adjustmen ts in to th e bike. The shock ra tes are adjustable, the front cas te r is a d j u s t a b le , the steeri n g ratio is adjustable and the en tire fr ont en d can be extended o r retra cted as desired. Like Dennis said " we have learned to ad ap t". Bu ilding and ope rating a Bonneville bike is not chea p. "To be done right • with" at least IWO back -up motors. a good trailer, and the use o f private time, the cos t can easily be up to $ 80,000. " Private time means yo u rent the track for a day to test out the bike. It costs $2 ,0 0 0 for the first day and $ 1,000 a day thereafter, . With such e xpe nse in mind it's easy to understand th at these guys need some reliable majo r sponsors. Dennis h as re c e ived several offers from p otential sp onsors, but they 've o n ly be e n in te res ted in sp onsoring th e bike afte r it's broken th e re cord. Boris' drag bike is also in clude d in th e deal. T h is wa y th e sp onsors produc t won't be displ ayed on only o ne bike for one sm all part o f th e yea r : it'll be di spl ayed on both bikes an d Boris' bike will be seen in several differen t areas. Boris and Dennis are pu zzled as to why no one would wan t to sponsor two people with a reputation as go o d as th eirs. "American public is speed o rien ted. Wh y does a 14 ye ar old kid go wanderin g around on a showroom flo or lookin g for th e spee d o me te r tha t reads the fas tes t? Wh y d o we have highway spee d laws ? Wh y d o pe ople b uy fa m ily ca rs that ar e ca pable o f go ing 120 plus MPH ? Wh y does the airlin e pilot always an n ounc e hi s speed an d all the people go 'ah '?'" D enni s u ses th e title , " spe ed m e rchants " . They are vtw o professional racers turned sales ma n trying to offe r a lar ge package o f good advertisi ng for a low price to th e busin ess minded publi c. When their bikes blow the present record into th e ne xt co u n try this su m m e r th ere 's go ing t o be some mighty unhappy peopl e wh o would have wish ed th e y'd de cided to tak e advantage of this op port un ity. Dennis is perfectly honest a bo u t th e mot orcy cles capa bili ties . "W e 're no t goi ng to say as so me of o ur co mpe ti to rs h ave that our bike wiII go 5 00 ~IPH. If yo u g rea se d ou r co m pe t i to rs" m otorcycles an d dropped th em o ut of an airplane with a d own draft they wouldn't go 5 0 0 MPH ." Do y ou sen se a t ouch o f sar casm ? With th e co mb ined skill , expe rie nce , and knowledge of th ese two pro s there's just no way (sh ort of an adverse act of God) that they won't bump th e LRS this year. . 1 for one am go ing to be th ere to see it.