Jim Lonzo enjoys cruising on his 1998 Harley-Davidson Heritage Softtail.

When lifelong motorcyclist, Jim Lonzo, tracked down his dream bike, he made it his own unique ride. He personalized the bike's looks and, with the help of Extrude Hone Powerflow Abrasive Flow Machining (AFM) process, boosted its performance while maintaining maximum drivability and reliability. The result is an attention-getting bike with strong, smooth, reliable cruising power.

Lonzo, general manager at the Brooks Automotive Group GM dealership in Connellsville, PA. said, "I had my first bike when I was four. I don't think there's ever been a time that I haven't had some type of motorcycle, be it dirt or street or quad." Among the bikes were five Harley-Davidson machines. In 2000 he set his sights on a 1998 Heritage Softail, built in recognition of Harley's 95th anniversary year. The bike he found was a chrome-accented turquoise and cream. "I hunted this bike down," he said, "then I changed everything on it!" Lonzo painted the bike a deep, rich red and stripped it down to give it what he calls a "60s hotrod" appearance.

Originally turquoise and cream, Lonzo stripped his machine down and painted it a bold, deep red. but the modifications run deeper than just the color.

Modifying Harleys is the rule rather than the exception, according to Rick Clemence, service manager at Cerini's National Road Harley-Davidson in Uniontown, PA., "All the bikes get something to personalize them," he said.

Mechanical upgrades are extremely popular. "Just about every bike that leaves here gets pipes on it at some point in time," he said, "they make it sound like a Harley!"

Clemence said about 30 percent of the bikes that go through his shop get more extensive performance upgrades. The shop most often modifies Harley's newer, higher-revving Twin Cam engines. Lonzo's bike has the longer-stroke EVO motor (the Twin Cam's predecessor) which, Clemence said, "just wasn't designed to handle a whole lot" of performance modifications. So to maintain reliability while upgrading performance, Clemence bored the cylinders on Lonzo's 1340 cc (80 c.i.) twin to 0.005" oversize and put in higher compression forged pistons, increasing the compression ratio from 9.5:1 to 10.2:1. At the same time, he installed a camshaft engineered to provide moderately higher output. "We upped it a little bit but not out of this world," Clemence said, "We were looking for performance and dependability. We didn't want to make it a drag bike."

Rick Clemence of Cerini's National Road Harley-Davidson discusses Lonzo's cylinder heads with Rick Miller of Extrude Hone.

To further improve his bike's output, Lonzo had the engine heads' intake and exhaust passages, along with the intake manifold, polished via the Powerflow Abrasive Flow Machining (AFM) process. Used for years to enhance performance on automotive components, AFM involves forcing an abrasive-laden medium through the engine parts at rates and pressures calculated to thoroughly polish the airflow passages while removing minimal amounts of material. Rick Miller, Extrude Hone Automotive Project Manager, said other polishing methods improve flow volume at high engine speeds, but remove so much material that flow velocity falls off at lower engine speeds. The other methods may improve high-end horsepower, but low-end torque suffers. "AFM increases airflow and air velocity without removing a lot of material, so we maintain the higher velocities at low rpm, which in turn make more power and torque at lower rpm," Miller said, "which is where you want it."

The heads were removed to be processed with the Powerflow AFM process and new high compression forged pistons were installed after the cylinders were bored.

Lonzo's bike was Rick Clemence's first exposure to AFM. He said he was "very impressed. We got some really good numbers out of the bike, and we didn't do that much of a modification. We saw a 25 percent increase in power, and torque came up too. It was still a nice curve, start to finish, just higher."

On National Road Harley-Davidson's Dynojet model 250 dynamometer, Lonzo's Softail put out a maximum of nearly 60 hp and 68 lb/ft of torque before modifications. After completion of the AFM process and installation of the pistons and cam, the engine made over 76 hp and nearly 85 lb/ft of torque.

In addition, post-modification emission numbers showed a reduction of hydrocarbon particulate emissions of more than 60 percent, as well as a nearly 30 percent reduction in emission of carbon monoxide.

The Powerflow AFM process was performed to the intake and exhaust ports of the cylinder heads as well as the intake manifold.

Rick Miller said, "Our goal was to take a stock bike that runs decent and make it run better and still be very driveable without spending a lot of money." Jim Lonzo said he appreciates the reliability of the upgrades. "We could have made it very radical, but the dependability would be gone. I'm not afraid to get on my bike and run where we've got to go." He said the power improvement feels like the difference between a torquey V-8 and a high-revving four. He said he and his cyclist friends do "fifth gear rollouts -- side by side at 40 mph, then crack the throttle open" – that prove his bike has "plenty of midrange torque." Lonzo said he's seen indications that the bikes' fuel economy has improved. "Before, I would fill up my tank at about 100 miles; now I'm getting almost 150 miles with a tank of fuel." He also claims it sounds better. "A guy who had the same bike, same pipes as mine, said 'why does your bike sound so different?' "Rick Miller said he's heard that before; "It's something about our process. I don't know if it's the torque curve, or better airflow, they sound throatier they have that."

Reflecting on the significant power, sound, and other effects of the AFM process, Lonzo concluded, "I thought the Extrude Hone process could make a big difference. Obviously it did."

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