X2 rotary diesel engine offers 75% thermal efficiency

LiquidPiston has announced the X2, a 40hp rotary engine that requires no valves, cooling systems, radiators, mufflers or other components.

The innovative design operates on the company's patent pending High Efficiency Hybrid Cycle (HEHC), which is optimised to increase average efficiency over conventional diesel engines from less than 20% to more than 50% under typical operating modes. According to LiquidPiston, the cycle reduces fuel consumption by as much as threefold over conventional diesel engines, and when working in combination with the rotary engine architecture, enables an engine that is up to ten times lighter, significantly quieter and two to three times more efficient at part-load than conventional engines. Additional features include a fixed volume combustion chamber that permits very high temperatures and pressures; a theoretical thermal cycle efficiency of 75%; and an expected brake efficiency of 58% (peak) and 50% (partial load). The company is currently test firing an alpha prototype of the X-series engine called the X1. The X2 engine is expected to be available as a beta prototype for outside testing by the first quarter of 2013.