When talking about rotary engines, the first thing that comes to mind is the Wankel engine, which despite its direct advantages never managed to escape certain technical details, thus affecting its general adoption. However, today we are gathered here by the LiquidPiston X-Mini rotary engine, which after eight years of development had its first proof-of-concept in a go-kart, replacing an 18-kilogram engine.
The Wankel Legacy and Its Alternatives
We all agree that the traditional internal combustion engine can be optimized, but we have reached a point where the option of its direct replacement is becoming more interesting, at least in the case of conventional cars. Leaving aside the electric element, one of the first alternatives on our list is the Wankel engine. By far, Mazda has had the most success in developing Wankel engines, both in general use and in high competition (their 787B won the 24 Hours of Le Mans in 1991). Still, we must admit that Wankel engines are the exception rather than the rule. What do we find beyond?
The First Proof-of-Concept
The video is the first proof-of-concept of the LiquidPiston X-Mini rotary engine, mounted on a go-kart and replacing its original 18-kilogram engine. This little devil weighs just 1.8 kilograms, and can develop five horsepower at 15,000 revolutions per minute. In the video, we observe a three-horsepower version with a limit of 10,000 rpm, and if we think about it for a moment, getting nearly 50 percent of the performance of the previous engine with a weight ten times less is not bad at all. Furthermore, the LiquidPiston X-Mini notably optimizes engine sealing, an aspect that has always been problematic and very delicate in Wankel engines.
Possible applications? Small-scale competitions, lawn mowers, generators, boats, robots, drones... the list goes on. There is still a long way to go before LiquidPiston can bring this technology to market, but we will close this article by saying that the company has good friends (the name starts with 'D' and ends with 'ARPA'), and the next phase will aim at extended tests of efficiency and mileage.
