Ring End Gap

Does anyone sell rings with over length gap?

     "" shim the rings for side play ""
HMmmmm,,,,? what youse talkin bout,,Leon,,,???
You might could use automotive rings "IF" the ring thickness is of the size to properly fit in the piston lands, which is not adjustable , and THEN file fit the ends in the cylinder they are goin into for optimum end gaps.
In these low compression, low RPM engines, I'm not too sure you would be able to tell any difference in HP whether you file fit or not. MY SOP is to always fit every ring in the cylinder it is goin into, just to be sure there will not be any interference of end gaps. Hope this helps.

Edited by desertjoe - 04 Jun 2016 at 4:03am

Would it be possible to use rings for a 4.125 piston and file off the ends?

If my math is correct, the (outside) circumference of a 4" piston is 12.5663" and a 4.125" piston id 12.9590.

I know the "arch" of the ring would be slightly different, but very little.

Doesn't a 350 chevy piston have a 4" bore? Are the rings the same thickness? I'm guessing they aren't.

I guess a .020 overbore ring wouldn't work either?

your talking two different things here. If the ring is not thick enough for the ring groove, that is a big problem.......What Charlie is talking about is taking a stock piston which has a .007 ring end gap and putting into a worn sleeve that has a bigger bore and now has a .015 end gap  ( I think this is what he is saying).

Hey Charlie,,,I know at one time,,you used to could buy automotive "oversize" rings in .010, .020 oversize that might let you do what you're thinkin about,,,?? You would have to go to a MOM and POP type parts store that would have that knowledge cause I doubt you will find that out in a Oreillys or autozone store. Rings for a 4" bore are rings for a 4" bore and the difference will be the thickness of the rings their selves relative to the piston lands. The differences will be the specialized rings of exotic metallurgy for HIGH RPM engines that would be overkill in these AC's.
I think you could still do what you want IF your friendly parts store manager has the right BOOKS to will let you "browse" thru the ring sets available in small oversizes, to hopefully find a set with the right oversize to fit in the cylinders.
I doubt the 4.125 rings can be made to fit in a 4" bore without breakin most of them during installation or on startup.

   "" Use two identical thin automotive rings stacked in the same groove with the end gaps 180 degrees from each other. This might require widening the piston groove a bit to accommodate the two new thin rings. Done this dozens of times on puller engines. """

WOW,,,!!! this is a very GOOD idea,,,,and talk about gas sealing touching on the upper 99% if not over 100%,,,!!! HMmmmm,,,now I'm thinkin bout my 406 maybe needin some lookin into,,,,,Dang,,,thas a great idea,,,,,!!!
   

Then get the 020 over, and file fit them down. That is what gives the extra length to tighten up the end gaps. I personally don't obsess with end gaps, but I'm not looking for every last hp I can get either. I just make sure they are wide enough, and a good stagger, and go! Also, if you have .015" now, that's really only .003 more than you need anyway, right? Isn't it .003" per inch of bore? So really would be a lot of unnecessary work to tighten the gap up .003"!

Edited by injpumpEd - 05 Jun 2016 at 11:17am