[rotorwrench]

Nobody will ever poor as many as FoMoCo did but if the rapid prototyping equipment gets good enough, it may be possible to do affordable low scale production. The old timers made the initial positive blanks out of wood & glue to get something to make the reverse negative molds with. Casting sand feels like clay when you work with it. The sand is very fine and the resin binder holds it together well. FoMoCo used a wire that was soft like baling wire to tie the different cores in the right place so the wire would meld in with the iron during the poor. The core box has to be designed to hold the outer shells just right so the core shift is kept to a minimum.

Rapid prototyping can 3D measure a part from hand made core positives and 3D printing can help some with resizing of positives to get something to make a good quality negative core mold out of. It definitely could speed things up a bit but I don't think it will help with the initial measurement of the inside cavities to make the 3D positives. Core molds are made about the same way that the final product is and they have to be made so that the sand cores can be removed easily without breaking them up. This is not an easy task. It would be a lot easier if someone had the original core molds and core assembly box. No one will give this kind of stuff up unless they get paid for it. Lots of hours go into this kind of stuff.

There are some liquid rubber materials a person could plug and fill cavities with but the block would have to be cut apart to get them out. They might be too flexible to work with after retrieval but it might work. If Ford did it, it can be done again but its not as easy as an overhead valve block. The valve pockets and exhaust runners make sure of that.