Hi Mark, the added ring is due to way back when; Gregg Riddle of Rimco offered a wider sealing surface for the type IV cylinders. It was to add a extra sealing area.
These are the cast iron 94's opened up to 96's and with a added sealing ring. I also had the heads and cylinder dual "O" ring grooved.
These 2.0 head were opened up for the extra sealing ring. I also had the 1.7 heads done the same way. But then I got greedy and wanted more bore and stroke.
I have read somewhere the lower side of the cylinder do need air routing, so I'm going to address it some how and when I get to that point. I need to have the heads CC and see how much of my combustion chamber were enlarged in my porting. I want 8 compression, and possibly zero piston to cylinder height; I hope my heads were opened up enough to gain the 8 compression ratio. So now you know why the extra ring on the latest version. and this is it no matter what
