I made Jerry Howell's "Miser" engine. http://www.jerry-howell.com/
Think "low friction!" I found the construction to be quite a challenge because there is NO extra power. Everything has to be just right or it won't run. Assembly is finicky, too -- all part of the "no extra power so everything has to be just right" syndrome. Lay in an extra supply of patience.
Try to make a living, not a killing. -- Utah Phillips
Don't believe everything you know. -- Bumper sticker
Everybody is ignorant, only on different subjects. -- Will Rogers
Law of Logical Argument - Anything is possible if you don't know what you are talking about.