In 1982, our friend Erich Däubler visited the Rossi factory near Brescia in northern Italy. Here is his report with black and white photos. Erich is an enthusiast of Italian model aircraft engines.
Original report: A visit to the Rossi brothers near Brescia/Italy shows that a visit to a model engine factory can be interesting, even or especially for a non-specialist in this field.
For many years, the name Rossi has been synonymous with precision and high performance all over the world, although these qualities have to be paid for at a slightly higher price than average engines. The company was founded 24 years ago by the two Rossi brothers, at that time with just a few employees; since then it has grown steadily and today employs around 40 people in design, production, assembly, dispatch and administration, who have their hands full.
Until a few years ago, only model engines were built and sold worldwide. Many model pilots are probably still familiar with the 10 cc Rossi in the mid-sixties; it was available in RC and speed versions. The engine was given optimum throttle characteristics in 1969 when it was supplied as standard with the Kavan carburettor (the first carburettor with separate full throttle and idle mixture settings).
At this time, Rossi engines were the most powerful standard 10 cc engines in the modelling sector. The 2.5 cc racing engine was also one of the best in its class and was mainly used by free and tethered pilots.
When various manufacturers launched the first 10 cc engines with reverse scavenging on the market at the beginning of the seventies, which equalled or even exceeded the performance of the conventional cross-current scavenged Rossis, these engines became somewhat quieter, especially in aerobatics and competition flying.
The development of a reverse-scavenged 10 cc engine from Rossi was a long time coming, but ultimately paid off in terms of performance and running characteristics. The first competition engines appeared in Italy at the beginning of 1976 and by the end of the year it was possible to buy them there at least. This ‘standard engine’ (10 cc front carburettor – side outlet – ring) developed into such a comprehensive range, especially in the 10 cc class, that hardly any other manufacturer can currently offer it; whether front carburettor with side or rear outlet, rear carburettor with rear outlet, all in ring or ABC version, partly as pure speed engines with Venturi carburettor.
In addition, there are also some versions available as 65 cc, i.e. 11 cc in the aircraft version and, in particular, water-cooled versions for boat models. Apart from various types of 2.5 cc speed motors, for some years now there have also been corresponding flight and boat motors in ring and ABC versions as 80 and 90 cc, i.e. with 13.3 and 15 cc displacement; mainly suitable for large model aircraft in conjunction with corresponding reduction gears due to the speed design.
Many competition victories and national and international records in various classes on water, on land and in the air testify to the good running characteristics and performance of Rossi engines in recent years. In addition to a wide variety of engines, the company also manufactures precision carburettors (with and without adjustable jet needles), many different types of resonance silencers, exhaust manifolds and adapters, engine mounts for model aircraft and boats and, of course, all types of glow plugs and glow heads, which are also sold in different packaging under different names by a number of other companies.
Apart from a few problems caused by material defects or similar (e.g. cracks in the cylinder heads of the 10 cc engines in 1980 and 1981), which can occur with all engine manufacturers, the ‘Rossi’s’ are among the most precisely manufactured and powerful model engines ever.
However, some care is also required when handling and especially when using fuel. You should always use fuel types with an oil content of no less than 18-20%, as the oil not only contributes to lubrication but also to heat dissipation; and high-revving engines also need good cooling.
Rossi housing raw material blocksWith fuel mixtures with synthetic oils of only 8 or 10% oil content, which are now common in some cases, high-performance engines such as Rossi’s can soon suffer a significant drop in performance and even give up the ghost completely. Nitromethane is generally not required, as the well-functioning carburettors ensure that idling and the transition to full throttle leave nothing to be desired and maximum power is normally always sufficient; record hunters have their own recipes anyway.
The latest project from Rossi is a V-belt reduction gearbox for two engines in a V arrangement. It is designed for two 61/65/81 Fi-RC (front carburettor/rear exhaust) with resonance pipes, whose carburettors are supplied via a common, remote-controlled mixture adjustment (jet needle); the two throttle levers are also connected to each other.
The ball-bearing propeller shaft is driven by two V-belts at a ratio of approx. 1:1.8 and, after initial test runs, gives the 20×8 and 20×10 Zinger wooden propellers used for this purpose speeds of 9000 – 10,000 rpm. The relatively low annual production of approx. 30,000 motors guarantees consistent accuracy of all manufactured parts. Apart from the fact that the motors and accessories manufactured by Rossi are sold all over the world, the main customers, apart from the USA and Central Europe, are China, the USSR, Cuba and Jordan – who would have thought it?
In Italy, the average model aeroplane pilot does not use these motors so much; the relatively high purchase price, which has risen considerably in recent years due to the high inflation rate of just under 20% in Italy, is a deterrent. For some time now, the Rossi company has been known not only as a manufacturer of motors, but also as an importer of Japanese remote controls of the “J.R.” brand, various batteries and some model cars for Italy.
Byron products are imported from the USA and Topp and Kavan from Germany. As production and the workload have increased considerably in recent years, a new building is already under construction behind the current production hall. In conclusion, the good impression that the factory makes on the visitor remains; one may perhaps express the hope that, despite increasing production figures, the long-known precision and good performance of the model engines will be maintained, which have made the name Rossi what it has meant for many years: performance and quality.
Text and Images Erich Däubler
Thanks to Modellflug International
