Its certainly been a while but work is still progressing.
OK. The casting turned out to be a complete disaster, bull at a gate time.
I first machined the top flat straight out of the box without actually checking the casting
When I checked the thickness of the saddle it was already below what I needed as a finished size.
Consigned to the bin.
Not even comtemplating another casting I bought some thick walled steel tube and set about machining, boring out the centre to req'd size then the outside for the thickness. That done I bought a 100 x 100 steel block for the cylinder ,this was cut on the mill to fit the saddle. As the block was undersize on the width I milled it flat and silver soldered extra steel to give me the width I needed. This was then set up in the mill and both ends milled so I could place on one end and bore out for the cylinder. Following this I turned a wooden plug to fit in the cylinder so I could place in the vice and roll the block taking light cuts to shape to the radius req'd. The cylinder proper was machined from cast iron to a shrink fit and placed in the freezer over night, then heating the steel block the cylinder was quickly fitted
The ports were milled into the port face as usual practice and the cylinder was then placed in a tilting vice to drill the ways from the cylinder ends. This was setup using a simple jig with 2 equal length adjustable arms so the end of one touched the inside of the cylinder edge and the other inside the top of the milled port. Perfect on 3 ,on the last managed to move slightly and just caught the edge of the milled port but I think should be ok.
will post some images tomorrow
