Quote:
Originally Posted by DanEC
Well - a follow up question. I've always heard of "stuck rings" and efforts people will go through to free them up. Never had a situation I could relate to that problem or completely understood the issue. Is this typically in relationship to the rings being carbon gummed up and no longer able to rotate??
Dan
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There are a number of things that can cause sticky rings. You are correct in that they are mostly in older engines or ones that sat for an extended period. If they are stuck, the big problem is they can't seal the cylinder or worse they gouge one. Gummy rings from excess
oil, corrosion from setting too long with a valve open allowing atmosphere to eneter with mosture, those are the most common ones I've seen.. I have also seen, though more rarely, damage to the top of the piston, whether detonation or FOD, that pinches the top ring and causes it to not function properly. Those are usually pinched at one point,though I have seen one that the whole circumference of the piston top had melted from lean/detonation and the complete top ring land was pinched.
While I have known for many years about ring movement, I doubt they actually "rotate completely around the cylinder. I would suggest that they work back and forth as they move up and down. Pulled a lot of engines apart and never saw rings too far from their point of installation. The rings are usualy still close to the installed phasing as well, so I'd have to see some that "spin" completely before I'd buy it. Of course just a little movement within a 2 stroke engine can get a ring hooked in a port and ...well I'll save the description.