Future Road-Burner Revealed?
FUTURE ROAD-BURNER REVEALED?
ROUNDUP
THE EARTH SHAKES, plates raffle in the china cabinet. Out of the East thunders this rumor: A new Kawasaki ZZR1300 may appear as soon as 2006 with more than 190 horsepower and peak torque of 110 foot-pounds. The machine is chain-driven, has dual upswept mufflers and a proba ble wheelbase just over 59 inches.
How would this performance be achieved? Tight cylinder spacing on modem motorcycle engines forbids significant overbore, but stroking the ZX-12R engine from 55.4 to 60.0mm yields 1298.5cc. At levels of piston speed Kawasaki has used in the past, this engine would rev to about 9700 rpm. At its preferred levels of strokeaveraged combustion pressure (BMEP), that would translate to 178 hp. To get to the claimed 190 hp would either require pushing the breathing and compression to racetrack levels-and a BMEP of 200 psi-or pushing piston speed above Kawasaki’s traditional numbers.
The tickle of doubt in this rumor comes from the torque, which translates to 85 ft.-lbs. per liter of displacement. While not impossible, that is definitely up in race-engine territory.
Stroking isn’t new to Kawasaki-engineers have already stroked the ZX to 69.2mm for use as a monster 1498cc personal-watercraft powerplant. The long stroke limits it to 7500 rpm, which holds power to a “mere” f 160 hp.
Another route would be to keep the ZX-12R stroke and somehow enlarge the bore from 83 to 86mm. This gives us a 1287cc engine that reaches 10,500 rpm at moderate piston speed, retains an entirely workable borestroke ratio, and makes 190 hp with ease.
ZZR is Kawasaki-speak for sport-touring or “gentleman’s express”-a category that includes the Suzuki GSX1300R Hayabusa and BMW’s new transverse-Four K1200S. Despite their high horsepower, such machines are distinct from sportbikes by reason of their extended wheelbases. In one sense that makes them modern-day Brough-Superiors, able to cover ground with civilized speed and aplomb. In another sense, they are thinly disguised dragsters.
Is the ZZR 1300 real? We have the pleasure of anti cipation. Kevin Cameron
