Lucky Ducati

LUCKY DUCATI

This motorcycle holds Ducati's 8-valve future

STEVE ANDERSON

IF...IF IT HAD BEEN ELIGIBLE FOR THE DAYTONA 200, IT would have qualified sixth, behind Honda's Bubba Shobert but ahead of Yamaha's Jimmy Filice. If it had been in the Superbike class, its trap speed of 165.44 mph would have made it Daytona's seventh-fastest Superbike, as fast as the Yoshimura GSX-R750 of eventual second-place finisher Satoshi Tsujimoto, and only six mph down on Wayne Rainey's winning VFR750. If it could have run in Sunday's main event, it would have been tested against more-equal competition. Its rider, Marco

Luchinelli, said that it came out of corners as “strong as an FZ Yamaha Superbike.’’ And all from a pair of four-stroke cylinders-the ones that propelled this latest Ducati to victory in Daytona’s Battle of the Twins event.

Like so many past Ducati racers, this new one has one foot in Ducati’s future, the other in Ducati’s past. Its VTwin engine uses Pantah crankcases (the same as on all current Ducati 650 and 750 engines) with a wider cylinder-stud pattern, carrying all-new liquid-cooled top ends. Two 92mm pistons sweep through short, 64mm strokes to displace a very oversquare 850cc.

Above those pistons are the heart of this engine: two compact cylinder heads, each containing two camshafts, four valves, and eight rocker arms, incorporating Ducati’s all-mechanical desmodromic valve actuation into a Cosworth-look head. One rocker pushes each valve open, and another rocker closes it. The only springs seen are small torsion items that insure proper valve sealing at idle. These new four-valve heads bring Ducati into the 1 980s, with a narrow, 40-degree angle between the valves that provides a compact combustion chamber. With

desmodromic actuation and no large coil-spring pockets to wrap around the valve stems, the intake ports are free to take a straight run down to the valve heads. A Weber Marelli electronic fuel-injection system (very loosely based on the unit used on Ft Ferraris) eliminates any problems with making carburetors work at strange angles of downdraft. Each throttle body is 47mm in diameter, and fed by no less than two fuel injectors, probably because no standard automotive injector can flow enough fuel for this engine’s powerful cylinders.

But the proof of this complex new Twin is its performance. According to Franco Farne, Development Chief of Ducati racing, this engine produces 120 horsepower at the rear wheel, at an engine speed astounding for an 850 Twin: 11,500 rpm. And the engine is safe to 12,000 rpm. But even more impressive is the spread of power. According to Luccinelli, “Power begins at 4000 rpm, and by 6000 rpm it is strong.” Farne confirms this; he says that the engine’s torque peak is at 7000 rpm, fully 4500 rpm below its power peak. This is no peaky screamer; this engine is a torque master.

Of course, in a project this new, not everything is perfect. At Daytona the fuel injection gave some problems, causing poor throttle response in the mid-range, and leaving the Ducati mechanics and Weber technician scratching their heads, wondering whether to make the injection leaner or richer. But Luccinelli is confident, knowing that

this is the beginning, and that there are “many changes required. The fuel injection is new, but in one or two months it will be perfect.”

Right now, the Ducati eight-valve is truly unique, the only one of its kind—but not for long. By May, it will have been followed by 25 replicas, replicas that will become eligible for Europe’s Superbike class, replicas that will include some important improvements. New crankcases will incorporate six-speed gearboxes, and more metal around the cylinder bores, giving strength to grow even larger—to 920cc with just a bore enlargement, and perhaps to a full lOOOcc with a stroke increase.

Later, after a season of racetrack testing, the eight-valve engine design will find its way into Cagiva/Ducati streetbikes. This engine is Ducati’s future, and the people there are clearly excited by it. Perhaps Luccinelli tells it best: “We are developing this bike. Now we prefer this race (the Daytona Battle of the Twins)—the competition is not too strong. But later . . ..”

And he smiles.