I thought I'd post this article here as it is an effective means of power-assist and uses plain old diesel fuel. I have recently discovered two implementations of this technique and I offer them up for consideration here.
http://www.moulton-forum.de/viewtopic.php?t=247
http://www.flickr.com/photos/33566986@N03/
The first two pictures of the flickr site show the second implementation I mentioned, along with the intrepid and fearless pilot. This version uses a combination of a model jet and a turbo-charger, but I cannot imagine how they are connected or why. I would have thought the jet was enough.
I understand that the base price for these engines runs around $2K. The article from the moulton-forum explains more. One issue may be the noise, these little engines create the most staggering racket imaginable. But in the interests of technology - these are but small matters.
Lawrence