The Engine; The Countershafts - APRILIA RSV Mille 1000 1999 Technical Training Course

Aprilia Consumer Service Spa
Technical Service and Training
Release 4 july 99

THE ENGINE

The engine fitted on the RSV Mille is a completely
new type, conceived and developed by Aprilia's
engineers. It is a 60°V-formation longitudinal two
cylinder engine, with 4 distribution valves per cylinder
and a double camshaft at the head, controlled by a
mixed chain and gear system. lt is fed by electronic
ignition with air input through a system of dynamic
air intakes. lgnition is of the CDI type, where the load
of air and petrol is fired by the TSI system (Twin
Spark lgnition) which uses two spark plugs per
cylinder. lgnition is controlled by the integrate engine
management system, which also controls injection.
While it is true that the 90' V engine is itrinsically balanced (the first order forces generated during
the movement of the internal organs automatically cancel one another), it is equally true that the
dimensione of the engine are penalized by the size of the angle between the cilinders.
The decision to use a 60° V-formation two-cylinder engine responds perfectly to the need for a
lightweight, compact engine, so as not to sacrifica the design of the cycle parts with tecnical
solutions and weight distribution that are not optimum.

The countershafts

The problem of the vibrations which are created
inside a 60 V engine gave the designers a lot of
work. The possibility of offsetting the pins of the
connecting rod was discarded, as it would have
required excessive widening of the dimension of the
motor crankcase.
The solution found was the use of the exclusive
AVDC patent (Anti-Vibration Double
Countershaft).This system uses an anti-vibration by
turning countershaft which, in the opposite direction
to the engine shaft, balances the first order forces.
The moment generated by the countershaft is, in
turn, balanced by fitting a second countershaft
(Smaller than the main one) inside the head of the
rear cylinder. The result of adopting this technology
is an engine with excellent characteristics of power,
torque, with extremeily reduced vibrations.
This material is didactic and
may be changed following the technical
development of the product