Just thought I would share with you the results that myself and my good friend got with the steam engine project.
We didn't have castings or access to casting manufacture, so we made the entire engine from billet - thats right, machined the whole thing from bar stock.
This allowed us to change the materials as we saw fit, the final engine is mostly aluminium, but any moving parts (i.e crankshaft) is made from steel and run on phosphor bronze. The expansion chamber is made from billet steel as this is the area which has to contain the steam pressure and temperature changes.
This was the first engine we made and the results speak for themselves! All thanks to vintageprojects.com!
Engine was built by Karl Davies and Stephen Dunstan in 2006.
Beautiful job. I am in the same process, building the steam engine from scratch out of steel. I have been working on it for two years part time and hope to finish it in 2910 in time to enter it in our local county fair.
Ed, Idaho

That thing is awesome! Nice work