More progress this week, and in fact the machining operations are done, save the CNC port work. Also this week I had to develop a machining program to cut the bottom of the 351C intake, so that it would fit on my adapter. Here's a photo of the Edelbrock RPM intake in my smaller CNC machine, in the process of being cut, and another photo showing the modified manifold from a top view:
And here's a picture of the nearly completed intake adapter bolted by itself on the engine, and also a couple of shots of the 351C intake on top:
I still haven't finish machined the intake adapter flanges; I've been having some trouble getting the face mill to give me the right finish, so I have to work on that this week. Also I need to write the CNC porting programs and try them out; there will likely be some adjustments required there, after this first manifold is completed. But overall things are going reasonably well. Also this week I got together with a friend of mine who happened to have several different types of blasting media available, and also some of that Alumi-brite chemical, and we ran some tests on one of the manifolds. The Alumi-brite gave the same finish as the manifold I had previously had dipped, so I'm not going to go that route. For blasting we used some media called Black Diamond, which got the aluminum color back to the manifolds but left them looking more stockish rather than bright like the Edelbrock manifolds. We also tried something he had there called cut glass, and that got a little brighter, but the medium glass beads he had gave the best results. I have ordered some #4 glass beads from a blasting supplier and those should be here this week; we'll see how the manifolds look after that. I also got some stainless steel shot this week to try out, but it turns out that it is too heavy to be used in my siphon type blast cabinet, so I will have to find someone with a pressure pot cabinet to try that out. But based on the results from these tests, I'm confident that I can get a good finish on the manifolds with some blasting work. I also think I have a local guy lined up who can do it; it will add some cost to the manifolds, but probably only $20 or so.
At this point I am hopeful that by the end of next weekend I will have the machining procedures finished for the base casting, and can start machining a second manifold that will be usable on an engine. Also I need to get the machining programs written for the access hole cover, and for the road draft hole cover. At this point I think I can have the first usable intake finished in two more weeks. I'm looking forward to some dyno testing with one of these things
