LiquidPiston is currently developing and testing the X Mini, a power-dense, low-vibration, quiet, 70 cubic centimeter gasoline powered rotary four-stroke engine prototype. The compact engine (4-pound core) has only two primary moving parts.
Download X Mini Brochure with Specifications
LiquidPiston’s X Mini is powered by the company’s patented High-Efficiency Hybrid Cycle (HEHC), an improved thermodynamic cycle optimized for fuel efficiency and provides low-noise benefits. The system has been demonstrated operating at 3.5 horsepower (net indicated) / 2.1 horsepower (brake) at 10,000 RPM. The X Mini has the ability to run for 40 minutes at a time and for three hours cumulatively. These demonstrations of the gasoline-powered X Mini proves that LiquidPiston’s innovative engine technology can scale down in size and is multi-fuel capable.
When X Mini fully matures the engine is expected to weigh 3 pounds, produce over 5 horsepower at up to 15,000 RPM, and be over 30 percent smaller and lighter than comparable four-stroke piston engines.
The X Mini will enable many small engine applications to be smaller, lighter, and quieter, including:
Hand-held power equipment
Lawn and garden equipment
Unmanned aerial vehicles
Auxiliary power units for boats, aviation, and other vehicles.
The engine’s improved noise, vibration and harshness (NVH) characteristics will also increase product performance, enhance operator comfort and prolong application life.
This video shows an early X Mini prototype running, in a speed sweep from 1000 to 6,000 RPM.
This high speed video taken at 20,000 frames per second shows the combustion happening inside a LiquidPiston X Mini engine prototype. The engine cover was replaced with a special quartz cover in order to take the video. A spark plug is blocking part of the combustion chamber, but the remainder of the chamber is visible as the rotor expands, and it is clear how the spark-ignited flame propagates in this chamber.
This engine is the size of a grapefruit, weighs 4 pounds, and produces 3+ HP! This video shows the internals of the engine, demonstrates the gas flow and implementation of the SI version of the High Efficiency Hybrid Cycle (HEHC)
This video shows LiquidPiston’s novel 3-chambered rotary engine powering a small vehicle demonstrator (go-kart). This marks the first time an engine has been run outside of the lab, and is a big milestone for the company, as this engine required integrated cooling and control systems.