Got done with the latest step in the High Riser project this evening. I'm working on the upper portion of the manifold now, and the first step is to build the plates that bolt onto the port plates that bolt onto the heads. I started with 1.25" X 4" 6061 aluminum, and again purchased enough of it so that I could test machine a small section to get the CNC program right. I wanted to make these plates thick enough so that they wouldn't warp too much during the welding operation, and also wanted to machine them so that I could use Mario's idea of an extension of the runner that would be easy to weld to. After making the drawings I calculated the CNC toolpaths, using my 1" ball porting tool for contouring the inside of the runner and the outside, where it necks down for the welding. After I cut the piece I bolted it onto one of the port plates, and it looked pretty good:
I had one error in the program that caused the welding flange to be a little thin in the lower left area of the port, but that was easy to find and fix, so I chucked up the real part and set up the machine. It ran for about 8 hours yesterday making the first part, and another 8 hours today making the second one. Tonight I bolted the flanges onto the engine:
I think they look pretty good, and they sure will be a lot easier to weld to than a flat plate would be. Here's a shot looking down the runner. The first 3.25" of the runners are essentially complete now, except for the final smoothing with a sand roll:
Next up I'm working on the plates that the runner will weld into to form the plenum. They present some special machining challenges, so it will probably take me a few days to get a test plate completed and confirm the program works before I do the actual plates. But once they are finished, there is nothing keeping me from forming the runners and starting to do the welding on this intake. This has been a lot of work on the machine side, but I think it is coming together nicely, and hopefully it will be worth it in the end.
