Ritorno Vee Two Imola Evo
With Phil Aynsley
By 1978 Ducati was looking to modernise its V-twin range of engines. An updated version was designed, and prototypes of the new engine were then used in the 900F1 race bikes (commonly known as an NCR), and powered Mike Hailwood to his famous 1978 Isle of Man victory.
Despite the success of the engine in subsequent endurance races, Ducati dropped the design for what became the last production version of the bevel V-twin, the Mille. The Pantah and its derivatives then superseded the bevel designs.
Fast forward 25 years… Guiseppe Ioanonne, a well-known Italian pattern maker obtained the old patterns for the race motor, and after repairing and making new ones as required, made himself a new motor! The factory then supplied the engineering drawings to him in exchange for two more motors.
Ioanonne also produced another five motors. However the small market for such a design, plus the effort involved, resulted in extremely high costs, so when Brook Henry of Vee Two fame approached him for ten sets of blank castings, he offered to sell Brook the drawings and all associated patterns.
Taking the bull by the horns, Brook decided to apply his near 40 years of Ducati bevel experience to modernise the venerable bevel motor. The Western Australian employed current day materials and knowledge – while at the same time retaining its unique exterior appearance. So was born the Ritorno (Return), motor!
The motor features a 94 x 71.5 mm bore/stroke giving a capacity of 992cc. Titanium 45 mm inlet/40 mm exhaust valves are used at a 56º angle in ported and polished heads that use a ‘bathtub’ combustion chamber with a 13.5:1 compression ratio.
Forged billet slipper pistons operate in one-piece cylinders with Nikasil bores. A plain bearing crankshaft, high pressure oil system with spray bars/nozzles in the heads and gearbox are among many other internal modifications.
Keihin FCR 41mm flat slide racing carburettors are fitted. The twin plug heads use a Sache ignition and a Motogadget m-unit controls the electronic speedo/tacho and LED bar-end indicators.
The chassis is from a 1981 Mike Hailwood Replica, that has been modified with a steeper head angle, repositioned engine mounts, and a shorter seat loop. 17 inch wheels are fitted along with Öhlins suspension, front and rear.
Output is 122 hp at 8500 rpm (rear wheel) with a half wet weight of 168 kg.
For those bevel owners who don’t want to go the whole hog for a full $40,000 motor, Vee Two can supply the heads, cylinders, engine covers, or dry clutch, for owners to fit to their existing bevel engines.
This was the first Vee Two Imola Evo and was built to showcase the Ritorno motor for the US market. Video of it in action can be viewed here:
Source: MCNews.com.au