I figured it was gray iron so I used gray iron for what I was doing. I had a thin flat style oil pump that was cracked from the outside into the rotor chamber. I have an idea about making the pump push more oil so it was a prime candidate for trying it out on. I bored out the pump and made an insert out of gray iron that pressed it in and machined it. Now I can try some ideas to increase the volume and still using just the 2 vanes. Still need to make a few things and test it to see if it made any difference. Just can't seem to find enough time to get into it the way I want. Hope to try it out soon.