sounds like an experiment waiting to be done by you . I can't remember if it was on this site or another but 3:1 (rise over run) was better than 2:1 and 2.5:1, so I guess your starting point can be from there.
Location: woodland, washington
posted 8 years ago
current project is close to 4:1. seems to be working well, but I didn't try any other arrangements. that probably doesn't add much to the stove discussion, but it's one data point anyway.
unfortunately, I don't have a lot of material around for experimenting. or time. maybe someday.