[gonejunking]

I'll throw my 2c worth into this, as I am making a few repoductions of Riley heads.
You can use the head that you have to pull a mold from to learn the basic's of mold making. I was given a head to pull a mold off of, but I could not cut it apart, to see how the water jacket's were shaped. So I waxed up the head, and used RTV silicone to make a mold of the head. I made a mold of all 6 sides, then put the 6 sides together and filled the cavity full of wax. Now I had a wax cast of the head. With the wax cast, you now have the locations of the valves, sparkplugs, intake/exhaust ports, waterjackets at the parting surface, and combustion chamber. From here, I get a head gasket, glue it to my surface plate, take a plaster mold of the combustion chamber's, place them in the gasket, then start building the waterjacket, and the runners for intake/exhaust, valve guides.

When you get everything to fit, you put the 5 sides of your mold over your core build up, then pour more wax into the mold. When the wax set's up, remove the head from the mold. Look for defect's, then cut it up to see if your matl is thick enough around the waterjackets. From here, you have to scale it up, to offset the shrinkage in aluminun. It's alot of work, but it can be done!

I joined this group so I could get the info to build a 3 axes router to make moldmaking easier for myself. I just started ordering parts, and will post my build, and the moldmaking for the first head that I do.

Jeffrey