Test success for Lotus engine
The first testing phase of Lotus Engineering's Omnivore variable compression ratio, flex-fuel direct injection two-stroke engine has been successfully completed on gasoline.
In addition to exceptional fuel consumption results, the engine has successfully demonstrated homogenous charge compression ignition (HCCI) - where the engine operates without the need for the spark plug to ignite the fuel and air mixture in the cylinder - down to extremely light loads. Traditionally, this has been challenging but this combustion process results in ultra low emissions and has been achieved over a wide range of engine operating conditions, even from cold start.The detailed research has so far focused on lower speed and load conditions that represent a major proportion of an engine's operation in a real world environment.At 2000rpm and up to approximately 2.7 bar IMEP (Indicated Mean Effective Pressure), the ISFC (Indicated Specific Fuel Consumption) achieved is around 10 per cent better than current spray-guided direct injection, spark ignition engines. Emissions results are an impressive 20 ppm NOx at less than 2.3 bar load and has four-stroke-equivalent hydrocarbons and carbon monoxide emissions.Simon Wood, technical director of Lotus Engineering said: "Omnivore lays the foundations for a novel and pragmatic vision of a variable compression ratio engine concept suitable for production."A multi-cylinder version is practical for a wide variety of vehicles and offers greatest benefit to C and D class passenger cars which can take advantage of the low cost architecture and significantly improved fuel economy and emissions."We are continuing our discussions with other manufacturers and eagerly anticipate the development of multi-cylinder demonstrations of this revolutionary engine configuration."