Hi Mr. Fluffy, I will try to help out as much as I can, I've got an old Storm boring bar, motor driven, not hydraulic, but the main difference should only be the feed. That block with three different angles is most likely for holding the cutter, which is probably supposed to be a bit of carbide brazed to a round bit of tool steel, probably with a flat to establish a fixed placement in each hole, to get three cuts leaving a designed in cutting angle and center for repeatability when boring. From the looks of it, your machine was intended for radial cylinders with the half rounds to provide spacing as "parallels", from the bottom of the cylinder flange. The diamond wheel should go on the non-drive end of the motor turning the spindle, and there should be a post for the three holes in the casting to slip on, so you get three different angles on the cutter installed in a cutter holder, which would probably be your steel bars with holes in the center. If they are, there should be a place in the funny casting that they fit into rather specifically, and repeatably.
My machine is made for boring in regular engine blocks, sitting on top, and boring each hole in turn, using a scroll and three jaws which come out, to center the bar over the cylinder to be bored. Most radial engine cylinders are mounted to heads one time and remain with the head to the end. I suspect that hardened center is a means of centering the boring bar relative to the center of the head, if you don't have jaws or legs which can be scrolled out to center on the bore its self. I have almost no information about my boring bar, it was given to me after some dissassembly, and most of the removed parts arrived one at a time later, so I've worked on it since I've got it, and made parts along the way. I made a holder for triangular inserts, and got it working, but the cutting angle was wrong and I got lots of chatter. I've made different tool holders, but all have had their problems. I've never used the diamond lapping wheel since the very beginning, I had two tools in holders, both which has a round cutter bar with a top flat for a set screw, held into rectangular blocks with a ball detent pop in place, and repeatable accuracy, but had only a tiny bit of carbide left on the tip of each tool. I believe I will be brazing carbide bits onto some new holders, and getting some diamond lapping compound in oil, as I know from experience, a boring bar with its cutter in exactly the right place, ground/lapped to the three specific relief angles, cuts cleanly, reliably, and on size, and while I've tried to duplicate the angles of incident with my tool blocks made for indexable bits, I have failed to get it exactly right, and don't get decent cutter life. Since the machine was made in 1937, found that etched on a Timken bearing when I rebuilt the bar, and it had two cutters in holders with it, and the original sample bottle of diamond lapping oil, I suspect it lasted all its previous cutting life with just the two cutters, lapped each bore so they never got dull, and it was set aside when the cutters got small, parts no longer available, and a new one brought in. I suspect I will get better results with brazed bits matching the originals, and using the odd castings for the proper cutting angles on the carbide, as it was in full use for about fifty years before it was set aside.
I would try to find a way to mount the diamond wheel on the drive motor end which spins the bar through gearing, and see if the blocks with holes fit and clamp into the funny shaped casting with the odd holes, and then the casting with the block, fitting over a fixed post on the motor drive unit which should be somewhere next to the end of the motor drive shaft. My boring bar is all mechanical drive, because it is to set on the block of the engine being bored, but to bore in situ in a radial engine, it would take a hydraulic feed and odd set up to make it feed evenly, and accurately while at odd and different angles. If the cylinder to be bored were hanging beneath the boring bar, the cutter holder should fit in a solid mount in the boring head, the cutter holder bar with the carbide tip should stick out and be setable with the micrometer setting devise, the carbide tip should be essentially parallel to the axis of the boring bar, and the casting, if it is to hold cutter holders for lapping, should slip on a post which would give you a lap for back clearance on the leading cutting edge, side clearance to clear the tangent of the bore, and face lapping to sharpen the cutter hence three funny angled holes. My machine has two different castings with slightly different angles, I suspect for different bores, as it has a wide range, but possibly for different material, as iron is cut with far different angles than heat treated steel, which most aircraft engines use for cylinders. I thought I had a diamond lapping wheel on my machine, but time and experience showed it is a cast iron wheel, used with diamond paste, for lapping, as it quit cutting as I scraped the last of the lapping compound out with a tooth pick, right before I went to my own made holders and still don't equal the quality of cut I got originally, with the lapped cutters, but now are absent any discernable carbide left. I hope this helps out your figuring out your machine, I took a long time getting mine going, but it's cut enough cylinders since then to make rebuilding the machine entirely worthwhile. Mad Jack
