The incredible APRC system is undoubtedly the most significant new feature of this new RSV4 version. However, the RSV4 Factory APRC SE engine sports a platitude of improvements to upgrade its already legendary technical and mechanical characteristics.
Aprilia RSV4 is the only production super sport bike using a narrow 65° V four-cylinder engine with unique features. Extremely compact, as slim as a twin-cylinder to fit in an ultra-compact chassis, the 65° V4 engine was and still is the epitome of Italian engineering ingenuity.
The Aprilia 65° V4 engine specifications in short:
monobloc with integrated crankcase liners
4 valves per cylinder (Titanium and Nymonic) operated directly by a camshaft driven by a mixed chain/gear system, lateral timing chain, central gear train
Electronic injection with 2 injectors per cylinder and integrated independent Ride by Wire system for each bank. Three mappings selectable from handlebar.
6-speed direct-control cassette type gearbox
Multiplate wet clutch with mechanical slipper system
Magneti Marelli control unit managing ignition, injection and Ride by Wire system, and variable length intake ducts
APRC system for dynamic control
The narrow V architecture translates into an engine that is incredibly compact in length, offering advantages in terms of mass centralisation and an extremely high performance chassis (short wheelbase, long swingarm).
The innovative timing system (with the chain camshaft driving only the intake camshaft, which in turn drives the exhaust camshaft via a gear) has made extremely compact heads (just 250 mm at the rear of the engine) especially in the area beneath the frame spars, which are thus much narrower than would otherwise be possible.
A countershaft dampens first and second order vibrations, making the engine even smoother than a 90° V one.
The monobloc crankcase with integrated aluminium cylinder liners ensures maximum rigidity and consistent performance.
The electronic management system is another example of the 65° V4 engine's technological supremacy. Full Ride-by-Wire technology eliminates any direct connection between the throttle grip and the throttle valves, which are entirely controlled by a latest generation Marelli control unit that also controls the ignition and the 8 injectors (the 4 secondary fan pattern injectors come into play at high loads).
Each bank has a dedicated servo unit actuating its own two throttle bodies only. This means that the aperture of the throttle valves and, as a consequence, the quantity of fuel injected, can be controlled independently. This solution, applied here for the first time ever in a production bike, opens up practically infinite possibilities for power delivery control and works hand in hand with the APRC system.
The transmission has also been designed to the meet most advanced criteria to offer the maximum performance possible. To underscore the racing soul of the 65° V4 engine, it is mated to a cassette gearbox with a wet sump lubrication system (with oil in the crankcase). The wet clutch features a mechanical slipper system for optimised engine braking torque control and stability under hard braking.
The 65° V4 was one of the most advanced engines in the world at the time of its debut. The new RSV4 Factory APRC SE underwent a number of refinements and further improvements based on the world superbike racing experience with the factory bike. The new exhaust and engine mappings make for optimal power delivery. Lubrication has been improved at critical points, the countershaft runs in ball bearings rather than plain bushings and the head cooling circuit has been reviewed for optimal operating temperatures and long-term reliability.
Combustion chambers and cylinder-piston fits have also been revised for optimal engine performance. The three lowest gears are spaced closer for extra speed out of bends. The advanced exhaust butterfly valve management system improved delivery in the low rpm band and reduces emissions while preserving the engine's thrilling sound.