| MODEL | HARLEY-DAVIDSON NOVA PROTOTYPE 1981 |
| Year | 1981 |
| Engine Type | Liquid-cooled 60° V4, DOHC (modular V-twin / V4 / V6 family) |
| Displacement / Capacity | 800 - 1000 cc (V4 versions) |
| Bore X Stroke | 66 or 74 x 58 mm |
| Compression Ratio | — |
| Cooling System | Liquid cooled |
| Max Power | 100.7 kW / 135 hp |
| Max Torque | — |
| Ignition | — |
| Induction | — |
| Start System | — |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 5 Speed |
| Clutch | — |
| Final Drive | — |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | — |
| Rear Suspension | — |
| Front Brakes | — |
| Rear Brakes | — |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | — |
| Rear Tyre | — |
| FUEL SYSTEM | |
| Fuel Capacity | — |
| Fuel Consumption | — |
| Top Speed | — |
Nova was Harley-Davidson's secret late-1970s plan for a modern, water-cooled engine family to take on Japanese bikes in the 500-1000 cc market. Porsche engineered a modular, oversquare, high-revving design in V-twin, V4 and V6 forms that shared bore, stroke and many internal parts; the V4 touring and sport machines were to come first. About 30 engines and a dozen running prototypes were built and tested, but the money ran out when AMF lost interest, and the bought-back company bet on the Evolution V-twin instead. The touring fairing and luggage later went onto the FXRT.
