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
NEWS/KES t999 Har/ey-Davidsons The next generation: Harley -Davidson's new Twin Cam 88 engine has been chosen to propel the popular Milwa ukee motorcycle company into the 21st century. With a combination 0 1 tec hnology and heritage , the 1450cc eng ine should pro vide mo re than enough perlorman ce and relia bil ity to get it there. By Scott Rousseau o t o n th e heel s o f it s 95 th a n ni ve rs a ry birthday ba sh in Mil waukee, th e Harl ey-Davidson Motor Compa ny is intent on provin g th at w h ile it ho no rs tr ad it ion , it refuses to remai n mired 'in the past. That seemed to be the message that H -D wa s sen di ng as it u nv ei le d it s mu ch-anti cipated new Big Twin powerplant - the fifth in a legacy of V-twins t hat be g a n w it h th e o rigi na l 1909 Harl ey-D avidson V-t w in. which w as su bsequently superseded by the Fla thead (1929), Knu cklehead (1936), Panhead (1948) and Shovelhead (1966), and the Evolut ion or "Blockhead " (1984). With its new Tw in Cam 88 (or "Fathead " ), Ha rley-D a vid son appears se t to e n te r th e n ew mill eni um wit h a fr esh tec hn o lo g ic al a p p roach to it s m o to rcy cl e s, bu t wit h all th e sam e st yle that has mad e the H a rle y nam e legendar y worl dwid e. Th e n e w e n g in e b o a st s m aj or improv em ents in performance, reliability and durabilit y over the hearty Evolu tion, all the whi le stay ing true to the cla ssic s t a p les o f Harl ey -D avid so n engin e design - the same 45-d egr ee Vtwin, air-cooled , pu shrod-actuated twovalve config u ra tion Harley -David son has been using since '09. And of course, like all of it s pred ecessors, the Twin Cam 88 offers the classic and unmistak- H able rumble that mad e Milwaukee fam ous. Displacin g 1450cc, the Twin Cam is, however, quite a d ifferent animal than "Pap a Evo," boas ting a Computer-Aided Design, with only 18 of the 450 compo nen t parts used in its m a nu f a ctur e bei n g ca rried ove r from th e 1340cc mill that came before it. Harl e y e ng in ee rs invest ed some four years in th e d esign and te sting of the Twin Cam 88, flogging it to the tun e of almost 2.5 million mil es in o r d er to e ns u re that it s increased performance d id not come at the expense of durability and reliability. An~ what increas ed performance it has, tha nks to its larger di sp lacement, bigger bore and sho rter stro ke, re-tun ed d u a l ca ms , n ew ignition sy s te m a nd new air clean er. The new mo tor derives its 88 cubes via 3.75-inch bore and shortened 4-inch stro ke, as compared to the Evolu tio n' s 3.5-inc h bo re an d lo ng er 4.25-inch thro ws. The resu lt is that the Twin Cam 88 revs more freely wit h less vibration a nd at a higher rev limi t (5500 rpm) than the Evo. The grea ter capacity yields an 8-10 percent increase in horsepower an d torqu e. Th e new d u al-cam d esign ai d s in the inc rease in o ve ra ll p e r fo rm a n ce. Ano the r p erforman ce enhancer comes by way of Harle y' s new sing le- fi re ignit io n sys te m , whi ch is desi g ned to eli m in a te w ast ed s pa rk. i, Reworked exha us t and in take ports and va lves op ti mi ze emissions efficiency and power output. A resha ped combustion chamber features an 85cc bathtubstyl e configu ra tion which crea tes a more efficient flow o f gase s and generates more power with lower emission s. The compression ratio is 8.9:1.