WHEN GUZZI GOT TEETH
Thirty years ago an American dentist built the most successful Moto Guzzi racers since their 1950s glory days. This is the story of Dr John
American dentist Dr John Wittner and his championship-winning Moto Guzzis – the most successful Guzzi racers since the ’50s
American racing got a boot up the bum in the 1980s. A dentist from Philadelphia used ageing Italian pushrod V-twins to win the US Endurance series and popular Protwins championship, making them the most successful Moto Guzzis since the factory stopped Grand Prix racing in 1957. And by developing an eightvalve engine that finished on the podium first time out at Daytona, he played a key part in the most desirable Guzzi of modern times.
Dr John Wittner tuned Harley-davidsons when he wasn’t fixing teeth. But in 1983 he bought a Moto Guzzi Le Mans, because it had a pushrod motor like the Harleys, and was rugged. “I bought it to go endurance racing,” says John. “I’d worked on and ridden a number of Guzzis, and knew they were extraordinarily reliable.” In just its first year, Wittner’s team won the 1984 US Endurance Championship’s Middleweight class, with a 100% finishing record. Having sold his dental practice to concentrate on racing, the next season Dr John’s squad won the 13-race US Endurance title outright, ahead of Japanese fours which were often slower and always more thirsty than his two-valve V-twin. Heroic stuff.
Wittner’s fortunes slumped in 1986. He didn’t want his team to defend the endurance title because he thought it would get them in a rut, but a lack of events outside the US where John could race his Guzzi was a problem, so the bike hardly raced. Almost broke, Wittner gambled everything on an air ticket to Italy and camped on the step of Moto Guzzi’s boss, Alessandro de Tomaso. And he got lucky. “I got so involved I didn’t return for two months,” he recalls. “Then one morning I woke up and remembered I’d left my car in airport long-term parking...”
De Tomaso recognised Wittner could rejuvenate Guzzi’s staid image, and sent him home with business cards saying ‘Engineering Development Consultant, North America’ and the money to build a Stage 3 racer. With a new frame, cantilever swingarm and Georgia rider Doug Brauneck onboard, Dr John’s new V-twin broke Ducati and Harley’s six-year hold on US Protwins to win
the 1987 AMA Championship – making it the most successful Guzzi in decades. De Tomaso was so delighted he gave Wittner a prototype engine. Designed by Umberto Todero (who was involved with the legendary 500cc V8 and the 350s that ruled 1950s Grands Prix), the overheadcam V-twin had four-valve heads and was a cost-efficient option for Guzzi’s future. The 90 x 78mm, 992cc motor made 92bhp with road silencing, and it was hoped racing would get it productionready. In March 1988, Wittner took his barely-finished bike to Daytona with the engine still in prototype form, apart from open exhausts, Crane cams and flatslide carbs. It didn’t turn a wheel until the second day of practice – yet Brauneck was third in the world’s premier twins race, behind Roger Marshall’s Quantel Cosworth and Stefano Caracchi’s NCR Ducati 851. Suddenly the world was paying attention to Moto Guzzi.
Wittner short-stroked the V-twin after Daytona with three-ring pistons in bored-out cylinders and a rebalanced V7 Sport crank. With 95.25 x 70mm giving 999cc, compression up from 10:1 to 11.25:1 and larger carbs, power went up to 115bhp at 9300rpm. They encountered R&D problems with the new engine over the season, as expected, yet still placed fifth at the end of the year.
I was invited to ride this Guzzi – a bike capable of troubling the fastest twins in the world and destined to form the backbone of the brand’s road range – at Loudon in August 1988. By now it had the Daytona name, an indication of the road bike moniker to come.
The most noticeable thing was how freely it revved – the tacho needle flew round the dial almost as eagerly as a two-stroke. Previous Guzzi racers were mega-tractors, so it was a surprise to find an easyrevving, light-feeling bike. Midrange performance was its strong point, coming alive at 5200rpm with a build of power as it rushed to 9000rpm. I found the motor reluctant to rev as high as the claimed 10,000rpm peak, though. At just over 9000 it ran out of breath, so the benefit of four-valve heads and the reduced inertia and friction of paired valves and an overhead cam wasn’t as big as it could have been. “We’re only at the beginning,” Wittner told me. “I see over 120bhp at the wheel as a target.” His forecast was right – the following year’s fuel-injected version made 128bhp and hit 167mph at Daytona...
The 8v engine was 12lb (5.5kg) heavier than the 2v design, yet compared to the 1987 racer with essentially the same chassis it seemed more agile. The Daytona was easier to lay into a turn, or swing from side to side. Front weight bias was 55/45%, promoting front grip in turns, with compacted mass aiding direction changes. Though a 1460mm wheelbase wasn’t short, the bike was much smaller than looks suggested. Its frame was a rectangular-section chromoly steel backbone, attached to round tube carrying thick aluminium plates. These held the gearbox as well as providing a swingarm pivot. The engine was tipped back two degrees from
horizontal to rationalise driveshaft angles, and offset to the right to allow a fat Marvic rear wheel. Marzocchi M1R forks only had springs inside; damping was by a Koni F1 shock mounted ahead of the headstock, where it was quickly and easily adjustable.
Weighing 158kg with oil (but no fuel), the eight-valve Guzzi handled excellently, especially when taking bumps at lean. Dr John had resolved a shaft-drive twin’s traditional Achilles heel, its transmission, with a Swiss-made clutch/flywheel unit and his own floating rear end to eliminate torque reaction. This parallelogram principle, as used on Magni Guzzi streetbikes, removed torqueinduced rise and fall, and the racer felt like an across-the-frame twin with chain drive. On track it was neutral, with no understeer on a closed throttle, or wheel hop under engine braking. It put the power down impressively – the cantilever rear soaked up all but the most obscene bumps, with a just-so amount of anti-squat.
It stopped superbly too, thanks to linked brakes, although they took some getting used to; you needed to brake in a straight line and pitch into the corner under power, rather than trail-brake into turns. The Guzzi responded to a firm throttle hand, powering out of bends with a glorious thunder from its open meggas.
Three similar bikes to Dr John’s Guzzi were built by the factory for European Battle of the Twins racing by various European distributors, but fitted with pushrod engines based on his 1987 motor. However, Wittner retired from racing at the end of 1989 and moved to Italy to work full time on developing the Daytona 1000 street bike first seen in November 1989 at the Milan Show.
His racer is now on display in final development form in the Moto Guzzi factory museum, and Wittner is restoring the 1987 two-valve AMA championship-winning bike, to ride it in demo events, to record the contribution of the people he worked with at the factory. “I loved my time with Guzzi and miss the wonderful people I was privileged to work with,” he says. “They kept Moto Guzzi alive through difficult times, with hard work and faith.”
‘DR JOHN HAD RESOLVED A SHAFT-DRIVE TWIN’S TRADITIONAL ACHILLES HEEL, ITS TRANSMISSION’