Single cilinder IC engines
I'm wondering whether that the conversion of a single cilinder engine would be any different than with a IC engine with several cilinders ? See http://en.wikipedia.org/wiki/Single_cylinder_engine
Also, I'm wondering whether the 1-stroke engine is useful for AT purposes (http://answers.yahoo.com/question/index?qid=20080110094133AAufsNT ) It might be more durable from what I can tell, dough not more efficient.
HHO production
a simple article with schematics (perhaps you can make one based on my http://en.wikipedia.org/wiki/File:Oxyhydrogen_booster.JPG ) and parts list (+ price) would be simpler. At the moment, there are also allot of devices to make both hydrogen, oxyhydrogen, ... A single, simple method to make the emissionless fuel is advisable, ideally using a technique that uses as little as possible ingredients (ie baking soda too needs to be made, see http://www.answerbag.com/q_view/12489) Perhaps you can make an article lining up the differences between the various techniques (see links at appropedia articles, and http://peswiki.com/index.php/Directory:Fuel_Efficiency_Hydrogen_Injection ; perhaps that the hydroxy scooter method is one of the best methods, but a good article should be made)