I had forgotten about Freedom Motors, thanks KikiLobo. That site certainly highlights one of the advantages of rotary over 2-stroke:
By operating on the 4-stroke principle, a rotary can have very good control over air to fuel ratio, this makes it suitable for the oxidation&reduction catalyst used for the emissions test. If the engine is to run as a diesel (Chevvrons question) then we are back to a "lean" air-to-fuel ratio. This means you cannot run the reduction part of the catalyst, but NOx only suffers if the combustion temperature gets above 2000K. The oxidation catalyst can still be used to remove any unburned hydrocarbons - i'm just oldschool in that i believe in not producing them to begin with.
My main concern then, for diesel or kerosine usage, is the limitation in compression ratio. I am definately convinced that efficiency is the only way forward for a helicopter powerplant...
Mart
Last edited by Graviman; 21st May 2006 at 19:07.