This looks like a great site! I am not a accomplished machinist. All that I know I have learned from sites like this one and a lot of reading on the Internet. In the past couple of years that I have been messing with this sort of thing I have made three little engines that where fun and challenging for someone like me. The latest is the Finger engine I had no plans just photos and it took a few tries to get the proper linkage lengths, but it works well and runs very smooth. The other two engines are run on compressed air and very much fun to build. I think I found some drawing of them on the Internet some where.
Mel
Mel