Hi Bob,
It might indeed, but haven't tried it yet...This does present an idea... If you silicon rubber coat a master positive, then peel off carefully, use that silicon mold with spray foam to make multiple foam positives for casting....
Milling machines are the best thing since canned beer....except for my lathe of course...or beer....or rum and coke....or....
You need to build one of these things (see pic below) all the pulleys and wheels etc I cast in ali as blanks and machined them to size (beer cans for the small wheels, coffee tin for the drive wheel mold)... You will hardly touch a file after that...
Incidentally, I did exactly what you are doing a while back... The big end on a Honda 340 petrol if I remember...only thing I did differently was to squash it oval on the fly press while bolted together, then separate and sand the half shell a bit smaller and undersized, re-assemble, then bore to correct spec on the lathe using a face-plate... About 50c worth of raw material costs/electricity, 1hr of hobby time, and a more than happy friend who had his genset up and going again....
Every bit achieved is a step in the right direction!!
Cheers
Ed