This running, prototype Nova engine features a large, bolt-on external
flywheel under the left engine sidecover. The sight glass for checking the
wet-sump oil level is visible at the lower front corner of the sidecase. The
water-cooled engine is fuel injected, with injectors visible between the
46°-offset cylinder banks. Each exhaust head pipe is fitted with reedvalve-type air injectors to reduce emissions. A bolt-on gearcase connects
the transmission output shaft with the driveshaft; the left footpeg and
controls mount on an aluminum bridge which fits over and around the
driveshaft. Note lack of frame downtubes; the engine is a stressed
member of the frame.
Nova combustion chambers are conventional two-valve hemispheres,
with one spark plug. Considering the side-squish design used in the
Harley-Davidson Evolution V-twin engine, the use of the plain hemispherical combustion chamber is a surprise. Note coolant passageways.
At first glance the Nova engine appears to be air-cooled, with fins on the
cylinders and cylinder heads. But it's actually water-cooled with the radiator hidden in the frame backbone, underneath a false tank.
The Nova engine is a wet-sump, unit-construction design; the crankcases
are split horizontally. The fuel-injection flow meter sits between the
cylinders, with injector bodies installed on each side; in this view it
appears that one injector serves two cylinders, with one manifold feeding
two intake ports. A counterbalancer shaft rides in the front of the cases.
The dual camshafts in each cylinder head are driven by a roller chain off the
crankshaft; it's unclear from these photos whether or not the heads are
interchangeable with one set of cams driven off each end of the crank.
Each cam is supported by three bearing towers, and runs directly in the
casting aluminum.
The long swingarm and rear-wheel gearcasing for the shaft drive system
are visible in this view of the Nova. The frame backbone is built up of steel
plates and the radiator is built-in and fed cooling air through ducts in the
sides of the backbone; and the engine is suspended without the use of
downtubes. A collector for the four head pipes is seen ahead of the rear
wheel; the muffler or mufflers are removed in this photo. Instruments
used in prototype testing are mounted above the rear wheel.
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