Moto Morini’s Gianni Mariani interview

Italian engineer Gianni Mariani’s Milanbased company CGM was founded in 1978, and has since become the leading Italian engine emissions experts – a profitable activity as ever-stricter homologation rules are imposed. But Mariani’s creative passion is harnessed with the design and development of engines of all types, on the basis of which he’s dealt with many Italian and Chinese companies doing design, tuning and development work.

This began in 1980, when Mariani himself designed the rotary-valve two-stroke single which Eugenio Lazzarini took to the 50cc GP World championship under the Iprem name, which in due course became the Garelli 50cc GP racer aboard which he twice finished runner-up for the World title. Forging a close relationship with Yamaha’s Italian subsidiary Belgarda, Mariani’s company prepared all Belgarda’s entries for the Paris-Dakar and other African rallies, while also producing two single-cylinder Supermono road racers which scored successive victories in the major Monza International race for such bikes.

Later on, Mariani worked with the Vertemati brothers on developing their light, powerful four-stroke single-cylinder MX engine which was the forerunner of today’s such bikes produced by all manufacturers. Redesigned by Mariani, this reached production under the VOR name, for whom he also designed a very advanced 250cc four-stroke enduro/MX engine. But VOR functioned on very narrow margins and eventually went bust, so the 14,000rpm twincam four-valve 250cc project went to GasGas in Spain, for whom Mariani also developed a low, compact 350cc sidevalve trials engine. Mariani has also produced several engines for Chinese manufacturers, as well as big bore versions of Moto Guzzi and Ducati V-twin motors. The Moto Morini 750 V-twin brings his talents to the global marketplace for the first time, and speaking to him at the EICMA Show revealed how that came about.

AC: Gianni, when did Moto Morini first contact you to start work on this new engine?

GM: My contact with Moto Morini goes back a long way, because in the early 80s I was involved with development of their Turbo 500 V-twin! I was working at Dell’Orto at the time, and I designed the carburettor for that motor. It made

75bhp, which was a lot of power for a 500 back then, but Morini was underresourced and had to drop the project before it reached production.

I got reintroduced to Moto Morini in 2018 when JD, one of my customers in China, wanted to buy the company. But Mr. Chen Huaneng of Zhongneng was very quick – as soon as he saw another Chinese guy coming, he put a big cheque on the table and said: “It’s sold.” Because they come from the scooter sector I knew Zhongneng would need assistance in developing new Moto Morini products, so I went to see Mr. Chen in his factory, because I understood that all such decisions would be made at that level. We sat down in Mr Chen’s big office, and I said: “Congratulations, you bought Moto Morini – you beat the other company, that’s great.” “Yes,” he said, “It’s very good, I am very happy.

Now, please tell me what I have to do!”

This was in 2018, and so I said: “Be careful, if you want to make Morini motorcycles, you have to do something different from Benelli, not make the same Chinese stuff with an Italian badge.” He didn’t understand at the beginning – he’s a businessman, he doesn’t even ride a scooter himself. But he had understood that to stay in this market, you need a brand, otherwise you’re just one more faceless Chinese company. So I said: “Mr Chen, would you allow me to make some proposals?” “Oh yes, of course, do what you want.” So I said: “The first thing in a bike is the engine – without the engine, you don’t do anything.”

And I made a proposal of a family of small V-twin engines. Ever since the 175 Settebello single in the 1960s, Moto Morini has been a

V-twin brand – Franco Lambertini’s 3½ in 1973 started all that. So I told Mr. Chen that in recent years Morini has always been a twin, so he must do one now. “Ah, but a twin is more expensive.” “Yes, but why is Harley-Davidson making a twin, why is Ducati making a twin, why is Moto Guzzi making a twin? It’s the heritage of the brand.” So it was decided I should design a midsize 750cc V-twin engine. Mr. Chen came to see me in Milan, and said: “Make a big chart, with all the possibilities you see for a modern engine, and I will decide what to keep.” So I included everything I wanted, like a horizontally split crankcase; double overhead cam; cassette gearbox, dry sump with twin pumps; composite chain and gear camdrive; and so on. For each feature I wrote my comment, ‘This is good for that’, ‘This is bad for that’, and sent it to China. One week afterwards the chart came back, and everything was circled in red to go ahead with that – except the crankcase couldn’t be cut horizontally, because their supplier only had facilities to do individual cylinders, not a big crankcase. I said: “It’s a pity, but okay – I proposed 10n solutions, they accepted nine, so I can be satisfied.”

And so, in 2021 we started to develop the complete new Moto Morini engine from scratch. To save some money we used some transmission parts from the CorsaCorta

V-twin, which is very good, but we modified it to have a cassette gearbox, which you can extract from the left without disturbing the clutch, so in Supersport racing this will be helpful. Because, of course, I said to Mr.Chen, if you make such an engine, one day or another, we’ll go on the race track with it.

AC: The Supersport class has been cleverly adapted to accept all types of engine of different capacities and number of cylinders – and after not winning a single race in 2022, Ducati swept the board last year, so obviously a V-twin will be very competitive.

GM: And it’s the perfect opportunity for Morini to compete with the big names at affordable cost, hoping, of course, to be competitive. It’s a challenge, but if you don’t have the basics right in the engine, you can forget it. So, we did a lot of work, particularly to make the engine compact, because I knew that for anybody designing a bike, if you have a small, short crankcase you can have a longer swingarm for better traction and grip. So we were already thinking of the implications of the layout of the complete bike.

So our engine is a 90° vee, double overhead cam, with an intermediate shaft in the middle of the cylinder driven by gear off the crankshaft, and then via a short chain to an idler, and then by other gears to the camshafts. We have a 22° included valve angle, and the valve sizes are 36.5mm inlet, and 28mm exhaust. For the moment we use a 90mm bore with a 58.9mm stroke – I wanted to do 94mm for a shorter stroke and higher revs, but maybe we can do that in the future. In this form we have about 100bhp depending on the tuning, at 9500rpm – but the powertrain is stable up to 14,000rpm, so there is good potential for racing! That’s because we use extremely light finger followers made of steel, as are the valves, for economy reasons. But we have a lot of development in front of us to produce a higher performance version of the engine.

AC: You’ve produced a 750cc engine as instructed – but can this be made bigger, too?

GM: The engine is modular, 750 and 950, exactly like the Panigale V2. Once again, it’s a civil war in Bologna, just like in the 1960s with the Morini Settebello against the Ducati 175 and 250!

AC: So what will be the bore and stroke for the 950?

GM: There I was a bit more daring, so the bore is 100mm and the stroke 61mm for 958cc, with bigger valves - 40mm for the inlet, and 33mm for the exhaust, with two springs per valve, of course, and again set at 22° to each other – and four valves per cylinder, obviously. It’s not a Desmo, but with the lightweight powertrain I think we will have good performance consistently.

AC: So you made your own luck by going directly to China – and this engine is the result.

GM: Yes. I’ve been going to China for 15 years – but this is the most exciting project I’ve done there yet!