2007 Harley-Davidson
WHAT'S REVVIN' IN'07
2007 HARLEY-DAVIDSON
Hello 96 cubes, bye-bye carburetors
PAUL DEAN
THIS HAS BEEN THE BIGGEST NEW-ENGINE PROGRAM IN Harley-Davidson's history," says Skip Metz, speaking at The Motor Company's 2007 new-model introduction in San Diego, California. "It involves more than 700 new part numbers." That's quite a bold claim, considering everything Harley has accomplished during its storied 103-year existence. But as a 25-year veteran of H-D's engineering department. Metz should know. And in his current role as the company's Powertrain Program Manager. he led the development of the new Twin Cam 96. the engine powering all production-line Big Twins in 2007.
That's not a typo: the new engine displaces 96 cubic inches, not 95. Some people. you see, expected that for `07 Harley would simply begin installing its own Screamin' Eagle Big Bore Kits on all production Twin Cammers. That's been a popular aftermarket mod that bumps displacement from 88 inches to 95 by increasing piston diameter from 33/4 inches to 3¾. The TC 96, however, retains the 88's 3¾-inch cylinders and mates them with the company's 43/x-inch stroker crankshaft essentially the same crank sold through the Screamin~ Eagle catalog and used in the 103-inch limited-production models the company's Custom Vehicle Operations (CVO) has built in recent years. So while the new engine looks virtually identical to the TC 88 externally-aside from the `96 Cubic Inches" emblazoned on the air-filter housingdisplacement is just one of countless internal changes to the powerplant. the transmission and the primary drive. That boost in engine size was no last-minute decision. `~We started thinking about changes to the powertrain back in 2002," recalls Metz. "People always are looking for more performance, and adding displacement is one of the best ways to get it." Harley was also faced with a lot of other concerns, such as dealing with ever-tightening emissions and noise regulations here and abroad; upgrading other parts of the powertrain that were long overdue for improvement; and the company's need to give people legitimate reasons to buy a new Harley when the one they already have is a perfectly good motor cycle. `~When we put all those elements together," says Metz, "we felt we could implement them and a lot of other detail improvements at the same time." He and his team succeeded, but not quite all at once; the majority of the changes were introduced last year on the Dyna series. Among those many refinements was an all-new six-speed Cruise Drive transmission with helical gearsets on second, third, fourth and fifth gears; redesigned engine and transmission cases with inteinal oil lines between oil reser~oir
and powerplant; a redesigned cam drive; automatic camchain and primary-chain tensioners; and the exclusive use of electronic fuel-injection on all Dynas instead of carburetors.
For 2007, the rest of the Twin Cam line gets those same upgrades, with one exception: To retain the classic look provided by their under-seat oil tanks, the Softails still use external oil lines. But they and all other Big Twins are 96inchers, and all Harleys are now fuel-injected, including Sportsters; from this point onward, carburetors are spoken of only in the past tense by the folks on Juneau Avenue.
The ’07 model year also marks the debut of four new regular-production machines: one Sportster, one Softail and two V-Rods. The Sporty is a 1200 Roadster decked out in 50th anniversary graphics and badging commemorating the original 1957 XL. The Softail Custom takes us back to the
’60s again with “Easy Rider” styling highlighted by an ape hanger handlebar and a thick, heavily stepped king-andqueen seat that includes an integral passenger backrest. The V-Rod Night Rod Special is a standard Night Rod on which everything but the handlebar, fork tubes and muffler wraps is cloaked in dark-as-midnight black. The VRSCX uses replica graphics and the 120cc-larger engine (1250cc vs. 1130) from last year’s CVO V-Rod to pay homage to the Vance & Hines Screamin’ Eagle drag-race team that has won two consecutive NHRA Pro Stock championships.
Otherwise, except for the Softail Springer and Heritage Springer, both of which have been dropped for ’07, the rest of the standard production models are back for another go-round. A long list of detail refinements is spread across the line, including a 30-percent stronger final-drive belt, new gauges,
reduced clutch-lever effort and an optional Smart Security System that uses a proximity sensor to automatically self-arm and disarm when the rider is anywhere near the motorcycle. And two Softail models, the Custom and Fat Boy, have been recipients of considerable redesigns for the coming season. Though the Sportsters did not undergo nearly as many changes as the Big Twins, the 883s received a significant performance upgrade. Thanks to the greater degree of fuelmixture control afforded by the EFI system, the smallest XLs are now able to use more performance-oriented cams, a larger-diameter throttle body (45mm vs. the previous 40mm carburetor) and a more-aggressive spark map. The net result, according to Harley, is 15 percent more torque at 2500 rpm and an 18-percent reduction in 40-to-60-mph topgear roll-on acceleration times. When asked why the company didn’t swing for the fences and pump the ’07 Twin Cam models up to 103 inches by using the Big Bore cylinders with the stroker crank, Metz’s reply was simple and straightforward: “Choices. Not everybody wants the same thing. Just as riders want different
choices in chrome or paint or other accessories, they also like to have choices in engine size and the way displacement is achieved. Besides, if the owner of a TC 96 wants to move up to 103 inches, all he has to do is install a Big Bore kit.” True. But you can bet your inheritance that the huge revenue stream generated by Screamin’ Eagle engine hop-up equipment-the 37/s-inch Big Bore Kits in particular-played a pivotal role in the decision not to go all the way to 103 inches. The same could be said for new Screamin’ Eagle mufflers claimed to deliver a slight bump in performance, enhance the exhaust note and remain 50-state legal. If they meet all those criteria, why aren’t they original equipment? The answer is obvious. There are other displacement options available, however. The company is offering four Screamin’ Eagle CVO models for 2007-a Softail Springer, a Road King, an Ultra Classic Electra Glide and a Dyna. Not only are all priced well above $20 Large, they all have 110-inch engines. They use the >
same 43/s-inch stroker crank as their predecessors, but now have 4-inch bores-a first for Twin Cam engines-instead of the previous 37/s cylinders. And if a really long stroke is on your must-have list, Screamin’ Eagle offers a 45/s-inch stroker crank that can be combined with the 37/s cylinders to deliver 109 inches.
Though none of the CVO models were present at the press conference, most of the entire 2007 regular-production lineup was on hand, and I was able to spend an entire day riding a representative selection of them in the mountains northeast of San Diego. I came away very impressed with the improvements Harley has fashioned.
Most obvious is the added torque (between 13 and 17 percent, according to Harley, depending upon model) hammered out by the larger displacement. The TC 96 accelerates up through the gears more quickly, and its ability to pull harder in any given gear is a distinct improvement over the 88-incher. Taller overall gearing allows the engine to turn about 400 fewer top-gear rpm than the 88 at road speed, yet the roll-on acceleration in sixth is better than it was in fifth with the smaller motor. Overall, I thought the 96’s performance was roughly equivalent to that of a 95-incher fitted with aftermarket mufflers.
What’s more, the combination of more torque and an extra gear allows the ’07 bikes to zip around slower traffic much more easily than before.
Having more ratios spaced closer to one
another means that the revs always remain nearer the torque peak after every gearchange. This will have the most positive impact on fully loaded, two-up FL baggers, which often have struggled to pull long hills or make safe passes because one gear was too low and the next-taller one too high. Metz talked about all the pains the powertrain group went through to make the 96-inchers torquier, quieter and cleanerrunning. "We played forever with the cam specs," he said, "moving the lobe centers around to get the best torque num bers with emissions-legal engines, and we did a lot of work with the mufflers and the injection programming. We ended up being so successful that all the 96-inch motors now are 50-state legal without the need for catalytic convertors. And the reduction in mechanical noise provided by the helical transmission gears allowed us to give the exhaust a deeper, more traditional V-Twin `boom' while still meeting the sound regulations." That's no exaggeration. The new Twin Cammers now own the best-sounding stock exhaust they've had in years. To the rider's ears, the engine almost sounds like it's breath ing through louder, less-restrictive aftermarket pipes, even though the system is perfectly legal. "We got our sound back," is how the exhaust note was enthusiastically described by Bill Davidson, H-D's Director of Motorcycle Product Development. "Harleys now sound like. . . Harleys." All the new engines are smoother, as well, whether it's the rubber-mount Dynas and FLs or the solid-mount, counterbal anced TC 96B motors. "We managed to make the 96's pistons and connecting rods lighter than the 88's," says Metz, "and that reduction in reciprocating mass meant we could reduce engine vibration." So despite bigger displacement, a longer stroke and higher compression (9.2:1 ys. 8.9:1)-three factors that tend to make for more-violent power pulses-the TC 96 engines are noticeably smoother than their 88-inch predecessors. This, then, would indeed seem to be a landmark year for Harley-Davidson. Even if you don't count all the new part numbers.
For more photos of the 2007 Harley-Davidsons, visit www.cycleworld.com
