Blow Hard
Blow Hard
Cyclone with an attitude
WE HERE AT CYCLE WORLD HAVE developed a fondness for the frolic factor of Buell sportbikes. Having gotten our share of kicks aboard the raw-edged S1 Lightning, however, we've come to appreciate the well-rounded versatility of the softer-focused M2 Cyclone. Yet even so, it's easy to understand how an M2 owner might develop a case of S1 performance envy. Fortunately, when it comes to hopping up Harley-Davidson V-Twins, there is a wealth of parts and tuning knowledge.
Don McCaw, an engineer at John Deere (how’s that for irony?), has a penchant for building hot-rod Flarleys. “My first engine job was on a Sportster I bought while in high school,” recalls the 53-year-old Iowa resident. McCaw used the Sporty to set a couple of Bonneville speed records in 1970, before turning his attention to campaigning a Corvette in SCCA roadraces. It was only natural that McCaw’s return to motorcycling would lead him to tinkering with Sportsterpowered Buells.
A decade ago, McCaw hooked up with Erik Buell to build a project bike that was featured in the August, 1990 issue of CW. Since that time, the two have collaborated on various engine-related projects, and decided that the time was ripe to do another project bike.
“The idea was to take the base machine and give it streetable power-no peaky, hard-to-control, hard-toride, hard-to-start condi-
tions,” says McCaw of the M2 featured here. “It’s a configuration that the average guy on the street could do.”
To begin with, McCaw increased the V-Twin’s displacement from 74 to 87 cubic inches (1203 to 1426cc), which he feels is the limit with the stock engine cases. A lightened and mas-
saged set of 7.9mm-oversized JE forged-aluminum pistons yielded square (96.8 x 96.8mm) cylinder dimensions. Because such a bore increase would undesirably thin out the stock liners, however, a pair of Axtel cylinders with high-quality iron liners was used. A set of S&S 7.44-inch forged-steel rods also was deemed necessary, because the new cylinders were taller than stock. The stock crank was lightened and polished, and the compression ratio was bumped up to 11.0:1, still allowing the use of pump gas.
McCaw enlisted the expertise of R&J Performance Enterprises to help with the head work. Although oversized stainless-steel Manley valves were installed, the ports were kept small to retain flow velocity and ensure stout low-end and midrange delivery. Zippers Red Shift #585 cams with fairly mild lobe profiles were selected for the same reasons. Other valve-train essentials included Isky NASCAR-type valve springs and pushrods, Jim’s roller rockers and Zippers lifters, which McCaw modified to prevent lifter collapse at peak revs.
An S&S G-type carburetor with a Thunderjet kit breathes through a custom-built air cleaner employing a K&N filter. A Buell Pro Series competition exhaust system with 2.5-inch collector and free-flowing stainless-steel muffler lets the world know this M2 means business. A Dyna 2000 ignition deals the spark, while a Barnett clutch pack handles the substantial increase in torque load.
Strapped to the CW dyno, McCaw’s massaged M2 churned out 106 peak horsepower at 6900 rpm, a 45 percent gain over stock. Peak torque was similarly increased to 92 foot-pounds at 4600 rpm, with a gain of 20-plus foot-pounds throughout the rev range.
On the road, the engine’s ultra-crisp throttle response and tractorlike bottom-end grunt made the bike wheeliehappy in the lower gears, and a roll-on monster in the upper ones. At the dragstrip, the M2 ran 11.09 seconds at 121.03 mph, and further flexed its muscle with top-gear roll-ons of 3.1 seconds from 40-60 mph, and 3.4 seconds from 60-80.
Top speed, as measured by the CW radar gun, was 144 mph.
Proof positive that a Cyclone can leave a Lightning sucking wind.
-Don Canet
