RE: what kind of engine is this?
DO NOT PUT GASOLINE IN THIS ENGINE!
That engine runs on GLO fuel...Alcohol-nito-oil mix. Not sure who built that one. .061 is the cubic inches or displacement. You will need a battery to heat the gloplug...to start it.
OS sells a .30 sized wankel rotory engine.
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXBY72&P=7]click for rotory[/link]