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/127955
Second coming: The flagship of the new Twin Cam BB comes in the form of a Dyna model. The FXDX Dyna Supe r Glide Sport offers a comb ination custom/sporty look that is accented in black. All Dynas and FLs will carry the Twin Cam BB engine in 1999 . The new, distinctive air cleaner is also actually part of the performance package, its bigger, front-intake oval design (California models feature a freefloating air-intake door) offering both a stylistic and functional departure from the bottom-intake, round air cleaner found on Evos. The oval air cleaner allows cooler air to enter the engine for optimum efficiency. The new engine was engineered with performance upgrades in mi nd . Th e Twin Cam 88 was designed to allow an increase in d isplacement as high as 1550cc, which wiII add another 6-8 hp a nd eig ht fl.-lb . of torque . T husly, Ha rley-Davidson engi neers went to grea t leng ths to design a foun da tion that wo u ld not on ly mak e mor e ' p ow er in bo th stoc k a nd mod ified trim, but be able to stand up and take a hammerin g as w el l. St arting at th e crankcas e, a stre ng the ne d and red esign ed vertical. four-bolt rear flange connects the engine to the transmi ssion , resulting in a more solid ma ting betw een th e p owertrain and chassis, and reducing stress on the inn er primar y. Th e high-pressure, d iecast al u m inu m ca ses are ligh ter and stro nge r due to d esign changes in highstress areas, red esigned tappet gui de s, an d the relocation of the oil pump. Foll o w in g th e cues of late-mo d el Spo rtster engines, a redesigne d ta p pet guide is machin ed into the crankcase, ad di ng s tructural stre ng th, im proving airflow a nd aidi ng in the evacuation of oil fro m th e top end . A cross-d rilled hole in the cran kcase directs d rained oil from the head s to the cam compartment near the tappet guides . The new, beefie r boll om end houses new forged flywheels, and stro nger conn e cting r od s easi ly withs ta n d the increased torque ou tp u t of s toc k and pe rfo r ma nce-modi fie d e ngines . The commo n crankpin is press fit and has an inc reased d iameter with mor e bear ing area, to increase reliability. But the beau ty that is the na mesake of the Twin Cam 88 also resides in the cra n kcase: an a ll -n ew two-cam s u basse mbly, in w hich the cams are carried on both end s by bearings. Mechanical noise is drastica lly reduced via a chaindriv e sy stem instead of a whiny gear mesh. The pu shrod val ve train is said to run tru er with less wear. Rem oving th e ca m cover exposes a Your basic bad: The new FXST Softail standard retains the classic Evolution powerplant - as do all models in the Softail family - and offers the potential custom izer what is es sentially an economically priced blank canvas for personal styling. cam-positio n senso r and a cam support pl ate that is fas tened to the crankcase. The cam su ppo rt plate uphold s the cam assem bly, retain s th e oil pump a n d directs oil to the oil filter, flyw heels and conn ecting rod s. Because the cam cover n o lon g e r suppo r ts t h e ca ms haft, m e chani ca l n o ise is si gnif i can tl y red uced from that are a also. -ring replaces the base ga ske t An O b etween the cra n kcase and cylinders, maintaining an oil-tight seal. A metalto-m et a l joi n t clen ch es th e cra nkcase a n d cy li n ders tog e th e r, ke e p in g the cylinde rs stable as temperatu res cha nge an d 'red u cing b ore dis to rtion. Beller eng ine cooli ng is achieved thanks to a 50-pe rcent in crease in fin area on th e cylinde rs and cylinde r head s. Proceeding to the top of the cylinde r head s, new two -piece rocker box covers are actually cove rs this tim e, replacing th e three-piece co ns truction used on Evos and provid ing easy top-end accessibility. Harley techs also relocat ed the rocker ar m sha fts so they no longer rely on the rocke r boxes for sup po rt. again eli m in a ting a lo t of unwanted noi se. New rubber-coated metal gasket s provid e a mor e consistent seal for better oil retenti on . The breathing system has been completely redesigned , reducing the possibility of oil blowby from the air clean er. Incorporating a new breather filt er ing system, br eather gases are all ow ed to esca pe from the eng ine more efficiently. The timed breather gea r is history. There are major imp rovem ents in the Twin Cam 88 oil-eirculation sys tem, too, like a new, cra nk- mounted and cra nkd riven intern al high-efficien cy geroter oil p u mp th at improves oil flow . Th e sys tem is still a d ry su mp, but oil is now filtered before it is rou ted to the engi ne, e nsu ri ng cl eaner o il gets t o hi gh wear/ stress points. Also, as temperature and oil pressure increases, o il je ts a re u til ized in the crankcase and spray oil under th e p istons, decreasing wea r and reducing piston temperatures by 50 degrees Fahrenheit. An d fina lly, all new Tw in Ca m 88 models featu re a new , five -bo lt d erby cover, de signed for increased durability and - more likely --headaches for any of th e af terma rke t su p pliers wh o figured th a t the new motor w ou ld ca r ry th e same thr ee-bolt derby cover fou nd on Evos. So there you have it: a new engine for the next generation - but, lest you think th a t th e Ev o is dead, th in k agai n . Althou gh the Twin Cam 88 is a radical d eparture from the Eva, the latter is, as Ha rley new-product-developmen t-meis ter William G. Davidson put it, "a darn good e ng ine," a n d w ill co n ti n ue to po w er th e 1999 Softail a nd Sp ortst er models in 1999. The Twi n Ca m 88 wiII d ebu t in all 1999 Harl ey-David son Dyna and FL touring models. Dyna models feature a carbur eted versio n of the new engine. Select tou rin g mod els are available (eithe r carbu reted or fue l-injected on ly), an d some touring model s o ffer fuel injection as an option . Tho u g h a g re a t dea l o f t im e a n d resou rces went into the development of the new Twin Cam 88, Harley-Dav idso n w as n ot co n tent to just sit ba ck a nd throw th e new mot or in to last year's sty les. Instead , the 1999 Ha rley -Dav idso n motorcy cle line up offers severa l new models, includi ng a new Dyna - the flags h ip famil y for the Tw in Cam 88 tw o newSoftai l mod el s an d a no the r cus tom in the hot rod Spo rtster family . Let's take a look. FXOX OYNA SUPER GL:OE SPORT Th e Dyn a Super Glid e Sp ort is the firs t new Harley-Davidson mod el to bear the Twin Ca m 88 engine, and certa inly warrants a loo k, if not a d ouble tak e. After 'a ll, the driving force behind th e new Dyna Super Glide Sport is a b la ck ed-ou t versi on of th e a ll- n e w 1450cc V-twin . The sporty look of the Dyna Su per Glide Sport screams factory cus tom, bu t is crossed with aggressive sty ling and features. Black, dirt-tra ck-styl e flat hand lebars th at are reminiscent of th ose in tr o d u ced way b ack when o n th e XR1000, do uble-d isc front brakes, laced wheels, a 28-degree rake and taller sus-