I got a sears free spirit bike engine (you've seen them, also called tas spitz or bike bug) It wasn't a basket case but you can tell it hadn't been run in years. after a bunch of emails to msamigo and I lot of hair pulling I got her running. I must say this is a great little engine and a good design for a friction drive. It is beautiful in it's awkwardness.
I don't really trust my old schwinn speedo but I think my top speed is 20 with out pedaling. These were designed to be pedaled a little and I could use the exercise.