Although HD are known to produce stylish lazy ‘Life Style’ bikes, its not very famous for ‘technologically’ advanced bikes until the VRSCA or V-Rod came in the picture. Even The V-Rod breaks very little technological ground compared to bikes from its competitors overseas. But for a brief, shining moment in the 70s, Harley sat poised to blow the roof off the motorcycle market-and its own reputation as a manufacturer of stodgy, technically unsophisticated products-with a dazzling new model powered by a water-cooled V-4, code-named Nova. That it never got passed the prototype stage is another matter altogether, but HD was and still is very reluctant to discuss about the Nova until after years of constant, good-natured badgering by American Rider, the story came to the world. Five Nova prototypes are still gathered together in one place in the Milwaukee factory. At the time of the Nova's conception, Harleys were powered by big-bore, long-stroke, slow-revving pushrod engines. A healthy Harley in a good state of tune might register 50 horsepower on a rear-wheel dynamometer. The plethora of short-stroke, water-cooled, overhead-cam engines that the overseas competition would eventually usher in were still just a gleam in their designers' eyes. But in 1976 Harley put into motion a plan to design and produce a radically new family of motorcycles powered by a series of engines that would incorporate all those modern features...and produce up to 135 horsepower.
Left picture courtesy - Lee A. Wood, Source - Bearspage
What happened?
The Nova grew out of a series of meetings held in mid-1976 that is still referred to in Harley executive's lingo as the Pinehurst meetings. There it was decided that due to the proliferation at the time of high-tech motorcycles from other countries, and their wide acceptance by American motorcyclists, a redesign of the current 74 (1,200cc) shovelhead engine would be insufficient to guarantee the company's long-term growth. So planners proposed a two-pronged strategy to ensuring Harley's future. First, because of the established product line's loyal following, they set into motion an advanced V-twin project with the goal of updating the shovelhead Big Twin and Ironhead Sportster. The eventual result was the Evolution engine. At the same time, an all-new machine with advanced technology would be developed to appeal to riders who wanted more contemporary performance. Harley's engineers laid out a number of concepts including a series of motorcycles powered by three basic multicylinder, water-cooled engines in six displacements-the Nova family-all incorporating the latest technology. Subsequently, the planners had mapped out Harley's future as a manufacturer of both traditional and cutting-edge motorcycles. The Nova's mission was to penetrate the 500cc to 1,000cc market-Harley's smallest air-cooled V-twin engine was 1,000cc (the Sportster)-and attract the growing population of performance-hungry riders.
The Nova family, which perfectly bracketed the most popular segments of the world market, could both fill voids in the American market and give Harley a presence on the international scene. But Harley's engineering resources would be severely stretched with both programs. While most of the designers were motorcycle enthusiasts, not all were card-carrying engineers. The task of developing the Evo, in both Sportster and Big Twin iterations, was daunting enough-the Nova would overload H-D's engineering capacity. The solution was to farm out the powertrain's design and development. Harley solicited detailed design proposals from three companies, Porsche was eventually selected and subcontracted at the end of 1979 to design and develop the Nova engine and transmission. All chassis development and testing would be done in Milwaukee. To cover the desired range of displacements, the Nova family would share many common, interchangeable components. The basic concept revolved around a 60-degree V-cylinder arrangement of two, four and six cylinders. Other requirements included liquid cooling, double overhead camshafts, a balance shaft to reduce vibration and a five-speed gearbox. The valve gear and even the gearbox were to be interchangeable. In addition to carbureted models, a fuel-injected version would also be developed. All the engines were designed to use either 200cc or 250cc "wet" cylinder liners and pistons. 
These would interchange between the V-twin, V-4 and V-6 engines. So the 800cc and 1,000cc fours are basically made of two 400/500cc twins, and the 1,200cc and 1,500cc six-cylinder versions consist of three banks of twins. The bore sizes were set at 66mm and 74mm (2.60 and 2.91 inches) for the 200cc and 250cc cylinder displacements, respectively, with a common stroke of 58mm (2.28 inches). This gave a very modern oversquare bore/stroke ratio of 1.14:1 for the smaller engine and 1.28:1 for the larger size. The short stroke would allow these engines to rev safely to nearly 10,000 rpm, an impossible speed for a 5,000-rpm Big Twin with its long stroke of nearly 4 inches. The cylinder heads feature two valves with bucket tappets actuated directly by overhead cams. Harley looked seriously at a four-valve head, but staying close to its conservative philosophies, chose the least complicated configuration while not ruling out a change later on-the production two-valve heads were designed to be adaptable to a four-valve layout. Harley engineers had developed a preliminary design for the entire family before the detail design of the first engine-the 800cc Nova 8-was started. This size was considered the middle ground of displacement ranges thought to be the most promising. The cylinder bore and stroke were also based on engineering analysis of noise management, something Porsche had considerable experience with. As engine development proceeded, the chassis designers weighed the final-drive options. Belt final drive was not perfected then, and they chose not to trust it for the high-performance Nova. That left either shaft drive and chain drive. Despite its advantages in terms of cleanliness and low maintenance, shaft drive was seen as too complex, too heavy, and too costly to repair or replace. It also absorbed about three percent of the engine's power every time the drive changed direction, twice in the Nova's case. Despite Harley engineering's reluctance to adopt the shaft, it proceeded with that alternative. In fact, there was even open discussion of turning the engine 90 degrees in the frame, with the cylinders protruding sideways in an arrangement similar to Moto Guzzi's; this would eliminate one of the two right-angle drives in the shaft. That discussion was quickly dropped. By the time the FLT hit the market in the fall of 1979, belts had been proven and the shaft lost what little appeal it had for Harley engineers. The final drive of choice became the belt, with a chain option. Besides, if needed, the shaft could always be resurrected in the future.
The Nova was never intended to look like any of the traditional Harley V-twins, since its target market consisted of performance-oriented riders accustomed to the styling of Harley's overseas competition. But Willie G. Davidson, who oversaw the Nova's appearance, refused to buy into the function-over-form philosophy prevalent in the styling of high-performance bikes of the day, insisting that a large, flat radiator stuck on the front of the bike was an affront to the eye. It was his insistence on a concealed radiator that led to one of the Nova's most unusual-and patented-features, an underseat radiator. The radiator lies almost horizontally, with two large forward-facing scoops protruding forward from what normally would be the fuel tank, funneling air into a plenum chamber above the radiator. A fan under the radiator pulls air through it, down and rearward, away from the rider and passenger. What began as a styling imperative offered inherent advantages. The air intake is mounted well above ground level, preventing debris from being sucked into the radiator. Because the airflow is channeled and controlled, a smaller radiator can be used with greater efficiency. And almost as important at the time, the "invisible" radiator kept Willie G. and his stylists happy. A pressed-steel backbone-style frame-strong, light, and easy to manufacture-has a rear subframe welded to it, and uses the engine as a structural member. With no front downtubes or radiator, the engine bay has a clean look, and the cylinders' "cooling fins" give the engine an appearance of being air-cooled. With the fuel tank displaced from its traditional location by the cooling system, H-D engineers designed a saddlebag-style tank that straddles the radiator. There is a distinct advantage in this location: a lower center of gravity. Engineers had minor concerns about the possibility of vapor lock caused by radiator heat, and the problems associated with the fuel pump and plumbing-required by the tank's low position-but these issues were considered easily surmountable. The tank's placement also limits fuel capacity, and therefore range.
The solution, though not elegant, is huge side panels, perhaps the Nova's single styling blemish. As dyno rooms hummed and prototypes logged test mileage, the Nova appeared close to launch. A project of the Nova's scope, however, required solid backing from the check-writers at the corporate level, and Harley's parent company at the time, American Machine and Foundry (AMF) not only backed the Nova, but supported Harley's overall growth. Under the direction of AMF president Rodney C. Gott, who was a motorcycle enthusiast, Harley acquired the York final-assembly plant. The company grew with the influx of capital, and new people were brought in. In the years of 1978 through 1980, the motorcycle division was perhaps AMF's largest profit center.Then Gott retired, Tom York took over AMF, and the outlook suddenly changed. Previously AMF's business was roughly half industrial and half leisure, Harley being part of the latter group. In a major shift in strategy, York ordered the expansion of the industrial side, and financed it with profits from the leisure side. Under this plan Harley-Davidson, AMF's largest profit generator, would become the cash cow, milked of capital to feed other business interests. The Nova project, ultimately considered expensive and risky, fell victim to the bottom line, and was terminated.
In a way, however, the Nova's demise sparked Harley-Davidson's resurgence. Cutting Nova funds was one of the reasons Beals led the so-called "gang of 13" to propose buying the company back from AMF. AMF agreed, and by mid-1981 Harley-Davidson became a privately held company. Highly leveraged with an enormous bank debt, Harley's future options boiled down to just two-either continue development of the Evolution V-twin, or build the Nova. The Nova was the long-range hope, the 10-year promise. But air-cooled twins promised the most immediate cash flow. And so the Nova died yet another death. Even so, Harley execs continued searching for investors to fund a manufacturing plant for the Nova. As late as 1984 Beals made presentations to many companies in the United States and Europe, but had no success. Among the what-ifs that inevitably attend a story of shattered dreams are these: What if Harley-Davidson had gone ahead with the Nova? What would it look like today, and how would it compare to its competition? And there's another question that's just as intriguing; what if Harley had chosen the other path, and dropped the Evolution altogether in favor of the Nova?
Another Harley Davidson prototype was the VR-1000 (picture below). The story... here
