Hot on the heels of patent documents showing that China’s CFMoto is working on a 200-plus horsepower 1,000cc V-4 superbike engine, another patent application shows the company is also developing an inline-triple of around 675cc.
It’s an interesting move, showing that despite its close ties with KTM and the widespread belief through much of the industry that the internal combustion engine is entering its final act, CFMoto is interested in creating its own engines in a wide array of capacities and layouts. It also hints that there is still a future for internal combustion. CFMoto and the wider Chinese motorcycle industry already have extensive experience with battery-powered motorcycles—not to mention vast battery-production facilities on their doorstep—and yet they’re still putting development resources into traditional gasoline engines.
The triple shown in the new patent application appears to be part of the same family as the 449cc parallel twin that’s hitting showrooms in this year’s 450SS sportbike (sold as the 450SR outside the US). That bike is already expected to lead to an entire range of models, including a naked 450NK roadster and a higher-spec 450SR-S with a single-sided swingarm—both have been spotted testing already. Now it appears the engine is also part of a modular family that will expand to three-cylinders. The 450SR’s twin is CFMoto’s first with a 270-degree crankshaft and promises to be a huge step forward compared to the company’s other ICE engines.
It’s clear from the patent images that the new three-cylinder engine shares the same design themes as the 449cc twin. The cylinder head and cam-cover design look all but identical, simply stretched to add an additional cylinder to the mix. If the 72mm bore and 55.1mm stroke of the 450 are carried over to the triple, the result will be a total of almost exactly 673cc. It’s a slightly longer stroke and narrower bore than the old 675cc Triumph triple, which used a 74mm bore and 52.3mm stroke, while the other 675cc three-cylinder that springs to mind—MV Agusta’s F3 675 engine—is a much more over-square design with a 79mm bore and 45.9mm stroke.
The implication would be that the CFMoto engine is focused more on low-to-midrange torque and less on outright revs and peak power. However, just as both MV Agusta and Triumph have tweaked their engines to push them toward 800cc, CFMoto could easily change the bore and stroke to give the triple more displacement and performance if required.
The design clearly shows that the engine has a balancer shaft mounted at the front, as is the norm for triples, and it appears the water pump is driven from the same shaft. The engine is mated to a conventional six-speed transmission, but the patent application itself is focused on rather mundane details of the oil-pump drive, so doesn’t reveal much information that’s specific to the triple. The drawings that accompany the patent, however, include images of the camshafts and valves—confirming it’s a 12-valve triple with two chain-driven overhead camshafts.
In recent months we’ve seen an explosion in large, multicylinder engines from China, with brands like QJMotor, Benda, Loncin, and CFMoto developing a variety of inline and V-configured four-cylinder designs. Meanwhile, Zontes is on the verge of launching a three-cylinder sportbike and QJMotor has adopted Benelli’s 899cc three-cylinder and started to manufacture it in China for the reborn TNT 899. Given that the majority of two-wheeler sales in China are electric scooters, and the Chinese government has been supporting the development of EVs in an effort to secure a position at the front of the global industry making such machines, it’s intriguing to see so much combustion engine development underway.