Heavy Fuel Spark Ignition engines for UAVs

Here's a research paper on direct injection of spark ignition aircraft engines using jet fuel and diesel fuel. Now that the military's are interested in small aircraft engines that use fuels other than gasoline, we might see some new technology for our use.

Jekyll

http://www.auvsi.org/unmannedscience/newsletter/attachments/52/Cathcart_G.pdf