[QUOTE] the silicon relief etching is what was tried on the porsche. it worked fine in the lab, but was not good in practice.[/QUOTE] I will swear that some car magazine said Honda was using this on their mainline engines at some point around ten years ago. Maybe it came and went. But Googling around ... seems to show you are correct about now. Well hey, maybe I misunderstood whatever back when. Glad to hear it, actually, never did think anyone had the technology to do without it and deliver real realiability. So, well, thanks! J.