The Société Viale et Cie of Boulogne-sur-Seine built an engine that was exhibited at the 2nd Salon de la Locomotion Aerienne and that differed slightly from existing engines.

- It had fan-shaped cylinders and a shell-shaped aluminum crankcase, minimizing penetration resistance.

“The fan-shaped Viale engine”

- The bearings were ball bearings, and the crankshaft was a single piece of nickel-chromium steel.

- The cylinders had bronze heads, and the angle between cylinders was 65°.

- Note that to produce ignition in the 3-cylinder engines of the time, the theoretical angle should be 72°, otherwise an irregular ignition would occur.

The Viale Company reduced this difficulty by adopting a special arrangement of the main connecting rod and connecting rods, with a carefully calculated phase shift so that at 65°, the explosions occurred at 144°, 288°, and 288°, as if the cylinders were at 72°.

All of this was done in the 32/35 hp Type A engines, which consumed 15 lb of fuel per hour, rotating at 1,500 rpm.

The pistons had a bore of 105 mm and a stroke of 130 mm. There were two exhaust valves per cylinder, of different diameters.

The exhaust holes at the end of the piston, common at the time, were eliminated.

But perhaps the most interesting aspect of this engine was the valve control without the classic spring, as the cam plate didn't have any springs, but rather a groove through which a pivot transmitted the lifting and closing of the valves, pushing and pulling the rods.

"Valve Control"

This valve control system was later called (for example, on Ducatti motorcycles) by the strange name "Desmodromic."

Proposed as an advancement of the much later racing bikes mentioned above, it turns out that the system was already in use by 1910.

The Viale type B engine was a 5-cylinder radial engine with 50/60 hp, weighing 85 kg.

"5-cylinder Viale engine"

However, it is known that a 5-cylinder radial engine was the one used on the Avro F in 1912, with only 35 hp.

"Viale 35 HP on an Avro F"

-The truth is that Viale was actually Italian; the founder's name was Spirito Mario Viale, a mathematician and engineer, he moved to France.

-Together with a fellow countryman named F. Santarini, who worked at Anzani and with whom Viale established several collaborations.

-In fact, he influenced many details, even Anzani's engines.

-It turns out that a five-cylinder engine that had to be repaired in England on a Bleriot trip was acquired by Avro and was installed oin at least three prototypes for their first flights.

“Viale three-cylinder fan-shaped engine"

-Below is an enlarged detail of the rod control follower. This system pushes and pulls the rods.

“Better view of the disc with a looped track”

-Other engines would be those advertised in the following illustration. It refers to a 50 HP 5-cylinder and a 70 HP 7-cylinder.

-This is the ad placed by a representative based in England for the British Empire market.

“Viale ad in the UK”

From Appendix 6: Below a better view of the 5-cylinder rotary engine, 55-60 HP and weighing 85 kg.

"Viale 5-cylinder rotary engine"

From Appendix 10: A three-cylinder engine easily confused with the Anzani and countless similar models from other makes,

"Viale with springless valve control"

The main characteristic of this engine is that the valves are lifted and returned mechanically directly by rocker rods that both push and pull.

At the rear end of the crankshaft, there is a disc with slots along which a shoe attached to the lower rocker arm travels. This type of control is still called "Desmodromic."

“Slotted plate instead of camshaft”

From Appendix 12: Below we show more photographs of this three-cylinder fan-shaped engine, considered one of the first “desmodromic” engines, meaning that valve controls were connected through all the linkages, thus eliminating the need for valve return springs.

“Engine view from behind”

The rear view is precisely the most interesting because it shows us the slotted disc, like a budding “turntable,” on which a sort of needle slides, rigidly moving a rocker arm in both directions, pushing and pulling the control rod and, therefore, the valve attached to the mechanism.

“Viale diagram for interpretation”