Once again it’s McMaster-Carr to the rescue. I ordered a sheet of 1/64″ +400°F aramid fiber gasket (McMaster P/N 9470K36). Now the only problem was how to cut the gaskets.
Hodgson Part 074, Intake Crankcase Mount
I rough sawed some 0.5″x0.9″ blanks from some 1/8″ 7075-T6 aluminum plate for the mounts. I decided to go with aluminum instead of brass since the intake pipe does not get soldered to this and I thought aluminum would look better next to the aluminum crankcase.
Hodgson Part 073, Header Flange
I clamped up a scrap tooling plate in the mill vise and used a couple of small clamps to hold a 3/32″ sheet of yellow brass on it. I then laid out a 1.375″x0.600″ grid of 15 flanges, drilling a clearance 
hole in the brass, and tapping the tooling plate below with a #6-32 tap. Once some #6 screws were tightened down, I was ready to roll.
Hodgson Part 067, Rocker Pivots
The material I used for the rocker pivots was purchased from McMaster-Carr. I chose some 3/32″ precision ground 316 stainless shafting, P/N 1263K37, that was 0.0002″ undersize. Two 36″ pieces should be enough to make the pivot pins and all of the pushrods.
Hodgson Part 066, Rocker Arms
I had some 10mm diameter 416 Stainless heat treated to HRC35 left over from a previous job. Even though most of the time was spent converting it from round to square, overall it was not very hard. However, don’t underestimate the added complexity such small parts can add to fixturing.
Hodgson Part 065, Rocker Bases
The bases are fairly small parts, so I’ve attempted to work in as many pieces as I can at one time. The CAD file 065 Base Setup (AutoCAD 2010) includes my layout as well as some other layers with sketches of the milling and turning fixtures I made as well.
Hodgson Part 064, Cylinders
One of the biggest problems with trying to do something like the Hodgson Radial here in China is finding quality materials. I’ve been lucky with my aluminum products since there is a big Alcoa plant in Kunshan not far from where I live that supplies materials for both the China and worldwide aerospace market. Unfortunately I’ve not been as lucky finding a supplier of quality ferrous materials, and the purported 12L14 material I procured for my cylinders is a case in point. While I was assured this material was “equivalent” to 12L14, it was very gummy to machine and did not act at all like a free-machining leaded steel.
Hodgson Part 061, Valve Spring Retainers
Once again my laziness shows through. Instead of making these retainers from scratch, I started with some 1mm stainless dowel pins from McMaster-Carr.
Hodgson Part 059, Valve Spring Cups
The valve spring cups began life as a length of 10mm 416 stainless steel heat treated to HRC32-35. These parts get beat on by the valve spring retainer many times a second and I didn’t want any deformation occurring. Besides, heat treated material machines to a beautiful surface finish.
Hodgson Part 058, Valves
Once again, the problem of obtaining high quality materials here in China made for a little more work in creating the valves. To obtain the necessary material, I used heat-treated stainless bolts sourced from McMaster-Carr in the US as my base material.