[IdahoDoug]

Here's my thought on rings. They are a wear item like the bearing shells you are thinking of replacing. It's also likely they lose a bit of the elasticity that springs them against the cylinder walls. The pressure against the cylinder walls is critical to having the compression forces contained, yet leaving the proper oil film there. As the rings shrink with wear, both change, and the sliding side surfaces of the rings also change width and possibly don't move freely in the piston as designed. Add these up and as cheap as they are, they're a no brainer to replace.

Add to that the low odds you will hyper expand them (vs their daily routine in the engine) to remove them without damaging them in order to measure their end gaps. Keep in mind you'll want to remove them in any case as another thing to clean are the piston ring grooves and lands on the pistons so they properly move and rotate in operation. I've removed rings with a proper ring removal tool and had them snap on me, and I assume that was from decades of heat cycles causing some metallurgical property to change. More brittle? Dunno.

On a normal engine you would not replace rings without deglazing the cylinder walls. Same as honing - it just creates a slight texture that the rings immediately wear off to cause the parts to match nicely - called breakin. The stone honing also renews the texture that holds the oil film. If you can establish from an expert (!) that the Alusil cylinder walls do not need that retexturing for new rings, then definitely replace the rings, right? The descriptions of things indicate there are silica crystals embedded in the aluminum walls and they essentially are what holds the oil film and if there is contact between the ring and wall the rings are not wearing on the aluminum, but only on the protruding crystals. An oversimplification, I'm sure.

So it seems to me the comment its OK to put new rings in without touching the cylinder walls make sense. After all, a conventional cylinder wall needs the new texture for the reasons above, but it seems the Alusil engine doesn't even have metal that comes in contact with the rings. I would think (and some described) a mere cleaning process that removed the carbon, deposits, and crud in the spaces between the crystals and restored the oil film space. If I were you and I could get an expert to read my take on it, nod and say - "yep, he's exactly right - its OK just to put new rings in because the texture is 'built in' to the walls permanently unless they're so badly worn they need a rebore" then I'd put new rings in there in a NY minute.

I think the innovation here is the cylinder walls. Meaning the rings are conventional and get their breaking from the innovative cylinder walls. My opinion on this basis is again that the folks who say "just put new rings in" are correct. So measure the cylinders, and bring an expert into the ring/cylinder wall question. That's probably the only data point they need - good cylinder dimensions - in order to help you make this call.