I came across a question about hydro forming two stroke exhaust pipes on a motorcycle forum the other day. http://www.usa2strokers.com/forum/forum_posts.asp?TID=37366&title=hydroforming-stamped-pipes-school
One of the guys replies got me thinking about casting a die mold to help form the pipe. Man, I was up all night last Sunday thinking about this. By using a die, you could make the parts come out identical to one another no problem. At the moment, I'm thinking a bronze die with an aluminum backing cast on to it. Just another thing I want to do. I better live a long time so I can get half the stuff I want to do done!
Heres a link to a set of pipes being hydro formed. Neat stuff!
Haha! When I started a thread over on the metal casting site about the idea, all the replies had to do with one guys avatar.