LiquidPiston develops compact, powerful, quiet, efficient, low-vibration, multi-fuel capable combustion engines that are scalable from 1 HP to over 1000 HP. Their X engine is a landmark, non-Wankel rotary engine that has few parts and uses three combustion events per rotor revolution for significant power density.

LiquidPiston’s efficient, powerful engines are developed using their patented High Efficiency Hybrid Cycle (HEHC) technology, which is 30% more efficient than the gasoline and diesel cycles used in most internal combustion engines. The cycle includes the following elements:

·     Compression: For maximum efficiency, air is compressed to a high compression ratio. Fuel is injected and compression ignited(CI-HEHC).

·     A dwell near top-dead-center forces combustion to occur at nearly constant-volume conditions.

·     Combustion products are over-expanded using a larger expansion volume than compression volume, as in the Atkinson Cycle.

·     Cycle-skipping power modulation allows high efficiencies at low power settings while simultaneously cooling the engine’s walls internally and providing partial heat recovery.

·     Water may be injected to internally cool the engine. Some of this cooling energy is recuperated as the water turns to steam, increasing the chamber pressure.