Motorcycle with an Upside-Down Engine- NEMBO 32

Hello dear viewers, you are on the CrossMotor channel. Which parameter is the same for the overwhelming majority of motorcycle engines? At this moment? I'm speaking in the context of the internal combustion unit. Take a close look at all the variety of engines. Nothing stands out. If you set aside a small number of designs, the so-called flat engines like the NA and so on, you'll notice that relative to the engine's crankcase and accordingly the crankshaft, the cylinders or cylinder will be positioned higher. It doesn't matter whether it goes vertically upward or has a certain angle relative to the horizontal plane. That's how it turned out over more than a century of motorcycle design development. This is explained by several reasons, primarily the engine lubrication system. Most internal combustion engines have a relatively simple lubrication system. The oil is located at the bottom in the crankcase, and as the crankshaft rotates, it creates an oil mist that lubricates the piston pins, their rings, and the inner part of the cylinder. An oil gets to the other parts of the engine thanks to the pump, and then it flows back to the oil pan by gravity. A more complex design is the dry sump system with a more advanced network of channels. In two-stroke engines, oil reaches the connecting rods and the crankshaft together with the fuel. Secondly, what do we have on the cylinder? The spark plug, the wire going to it, and also nearby is the fuel system, either a carburetor or an injector. Since a motorcycle is a fairly open design and exposed to external influences, it makes sense to place all these parts as far away as possible from water, dirt, and other unwanted things. However, there is a unique motorcycle in the world that literally turns the idea of traditional engine design upside down. This is the Italian Tritsat Diva. And about it, and not only about it, I'm going to tell you about it now. Enjoy watching! To turn the engine upside down, they came up with this quite a long time ago. The prototype, the Prototype 32, is not a pioneer in this niche. Inverted engines, both inline and V-type, found quite wide application in piston aviation in the 1930s and 1940s of the last century. An engine of this configuration gave the following advantage. It allowed the pilot to have better visibility, and it also made it possible to mount the weapon closer to the pilot's line of sight, which helped with aiming. Such an engine had a low center of gravity, especially the V-type, and fit well into the aircraft design concept of that time. Also, ground maintenance of such an engine on the aircraft was somewhat simpler. A notable disadvantage of inverted engines is their complex design. Such a power unit, by default, has a dry sump lubrication system with a complex arrangement of channels, pumps, and oil collectors. There is also a risk of engine damage when starting after a long period of inactivity due to oil accumulating in the cylinders. By the way, this negative aspect also exists in radial engines. The first inverted engine appeared in the early 30s, and it was developed by Hugo Junkers. This V-12 underwent bench tests in 32, and in 33 it received its own name, 210. In 34, after successful tests, it goes into Series B production. In the following decades, the development of inverted engines was carried out in Germany, the United States of America, Britain, Italy, France, the Union of Soviet Socialist Republics, and Czechoslovakia. In aviation, the inverted engine proved to be quite good in its time. However, what was the situation with ground vehicles? On motorcycles, engineers were in no hurry to invert the engine due to the reasons already mentioned in the introduction. But that doesn't mean that such motorcycle designs didn't exist. In 1938, the Frenchman Marcel Guiguet, owner of a small French brand, built the 600 motorcycle with an inverted four-stroke inline-four engine. Marcel, since 1923, he had been building motorcycles and gradually moved towards creating, in his view, the ideal two-wheeled machine. At the end of 1935, they officially abandoned motorcycle production in favor of automobile manufacturing. But the dream did not leave Guiguet alone, and he built a unique motorcycle. Since Marcel was an aviation enthusiast, it's not at all surprising that he chose an inverted engine. In fact, his 600 is a scaled-down copy of the Renault-Bengali 4P aircraft engine. The crankshaft was on top, the valves were below, and the valve cover served as the oil pan, from where the oil was collected into a separate oil tank. The maximum power was 30 horsepower at 5000 revolutions per minute. It was planned to build about 200 units of the MG C600 with a sidecar for military needs. However, the military was not interested in the vehicle, and the outbreak of World War II soon put an end to the interesting prototype. However, in France during that time, another motorcycle with an inverted engine intrigued the military. It was a lightweight off-road designed motorcycle. Marcel Viollet developed this machine. The first prototype appeared in 1937 and was equipped with an inverted two-stroke two-cylinder engine with a displacement of 280 cubic centimeters. For the production motorcycle, they settled on a 330 displacement. In the case of EVITA, the use of the inverted layout was dictated by the optimization of the engine and gearbox arrangement in a single parallelogram block. In a two-stroke engine, lubricating the crankshaft, connecting rod and piston rings is much easier. Three transmission gears were intended for driving, and the fourth, the so-called winch gear, had an extremely high gear ratio of 43 to 1. In addition to the driveshaft to the wheel, this suitcase had an extra power take-off shaft. If you want, you can attach a winch, or if you want, a bow propeller. Although the engine was air-cooled, it was only indirectly so. The entire aluminum crankcase was thoroughly washed from the inside with oil, which passed through numerous channels, and the total oil volume in the engine was 8 liters. The military successfully tested and approved the motorcycle for production. The company received an order to produce 3,000 units. However, by the end of 1939, only about 12 to 15 units had been produced, according to some sources, around 100. And now we have reached the Nimbo Motociclite and its three-cylinder inverted engine Super 32 Rove show. The last name stands for the following. 3 is the number of cylinders, 2 is the engine displacement in liters, and Rove show literally means inverted. The idea to build a motorcycle of unusual design came to the Italian Daniele Sabotini in the second half of the 2000s. The Nimba 32 motorcycle turned out exactly like this, thanks to the worldview of its creator. Sabotini is a big fan of the aesthetics of old engines. Air cooling, abundant finning on the cylinders, and meticulous attention to every detail of the engine. Daniel is not a fan of modern sport motorcycles, where sometimes you can barely even see the engine because of all the plastic. Sabotini also adhered to the concept of mass centralization for both the motorcycle and the rider, and he wanted to use the engine as a stressed member. That's why the Nimba 32 is made as a roadster, or if you prefer, a naked bike. The engine lies at the very heart of the design. News about this interesting project first appeared in 2010, and the first motorcycle prototype was ready by 2013. The engine is an inline, three-cylinder, four-stroke, air-cooled type. It has a single overhead camshaft and two valves per cylinder. Fuel is supplied by a single injector, and the gearbox is a six-speed. There are at least three engine variants based on displacement. The 1,814cc variant has a 3.937-inch cylinder bore and 3-inch piston stroke. The maximum power is 160hp at 7000rpm and the torque is 162Nm at 5200rpm. The second one is 1,925cc. The displacement increased because the cylinder diameter was enlarged to 4 inches. Also, this engine's compression ratio was increased from 10.5 to 1 to 11.5 to 1. The power is at the level of 200hp at 7500rpm with a torque of 186Nm. The third one has the largest displacement at 1,997cc. The cylinder diameter increased to 4.223 inches and the compression ratio was raised to 12.5 to 1. The power of this engine is 250hp. The maximum torque is 240Nm at 8000rpm. These are very respectable figures, especially in terms of torque, and considering that the inverted 32 is not exactly the pinnacle of engine design from a technical standpoint. Two valves per cylinder, air cooling and single point injection are relatively basic technologies. The engine's potential turned out to be excellent thanks to the large displacement and also due to its very low weight. The motorcycle is capable of boasting a very bold character. The 32 can provide a totally unique track riding experience. Most sport bikes reveal their potential in a rather narrow rev range, closer to the red zone on the tachometer. Incredibly light, it has tremendous torque, starting almost from idle engine speed. Also, riders who were lucky enough to ride the 32 spoke highly of the motorcycle's quality handling. The compact engine crankcase is a load-bearing component in the motorcycle's design. At the same time, the load is concentrated exclusively on the crankcase and does not affect the cylinders in any way. Two small subframes and a carbon swingarm for the rear wheel are attached to it. Thanks to the use of modern lightweight materials, it was possible to achieve an extremely low weight for the Nimba 32 motorcycle. In dry condition, it weighs only 160 kilograms. Meanwhile, the power unit accounts for most of the weight at around 90. Thanks to the engine being inverted, it is well cooled by the incoming airflow. However, I, like most of you, have a perfectly logical question. How will the spark plugs, high voltage wires and other electronics feel after a few good puddles? Look at this photo. Yes, everything there will be exposed to dirt and water. The answer that came to my mind is the following. Nimba 32 is definitely a cool and interesting motorcycle with an unusual engine, but it is designed for riding, whether on the track or on the street, let's say, in greenhouse conditions. And the rich man who deigns to acquire this marvel won't be riding it every day. This motorcycle is a showstopper. Such machines are bought for collections, to ride through exhibition halls and maybe a couple of times a year to drive under their own power at some motorcycle parade or on the track in sunny dry warm weather. If you look at it from this perspective, the design is excellent. It doesn't need any fenders, mudguards or safety bars. As Daniele Sabotini said in his interviews in the 2010's Loving Motorcycles as the highest dynamic expression of the fusion between rider and machine, I have a concept where the engine comes first. I wanted to build a motorcycle with an extreme appearance, whose engine would be beautiful in its original form. And you know what, Sabotini succeeded in this. For a long time, specifically throughout the entire 2010's, Sabotini and a team of talented engineers, designers and mechanics worked on refining the power unit, designing the motorcycle and building prototypes. In January 2019, Nimba Motorcycles announced that the project was ready to go into production. They even planned to release a small series of 200 motorcycles. For the production motorcycle, the 4th engine option was chosen, with a displacement of 1,962 cubic centimeters, a power output of 200 horsepower at 8,300 rpm and a maximum torque of 210 newton meters. The price of the production motorcycle was announced at 68,000 dollars. The company also announced that it lacked the funds to launch production and turned to a crowdfunding platform. To raise the budget, the Italians wanted 3.6 million dollars, but very few people responded to the call for help. As of early 2024, there has been no news about the serial production of the 32 nor about the future of the project. It's possible that the story will end with just the creation of a few prototypes, which happens quite often. But no matter how things turn out, Daniel Sabotini has already made his mark in the history of motorcycle engineering, as has the name of his unique motorcycle. At this point, my story comes to an end. As always, this was the CrossMoto channel. Thanks for watching. Don't forget to stay active on the channel. Comments, reposts and subscriptions are all welcome. Special thanks to everyone who supports the channel financially using the details provided in the description. See you next time.