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On Tue, 2003-04-22 at 19:19, Mark Seaton wrote: > > ----- Original Message ----- > From: "Russ wolfe" <russella@prairieinet.net> > > > > > Well they were all lined up but I moved them round so they were 120deg > > > Piston rings rotate as the engine runs. That is what the 60 degree cross > > hatch in the cylinder walls is for when you hone the cylinders. I space > > the rings on a new assembly, but don't really worry about it. > > One thing you do want to do, is make sure that the rings are free on the > > pistons, with no carbon or varnish under them. > > So does this mean that they will all tend to end up with their gaps aligned > due to this being the line of least resistance to the expanding compression > gases? I blamed the engine builder but perhaps it was just natures course? I > had always thought the cross-hatch was to promote controlled initial wear > (bedding in) and a good ultimate seal whilst providing some oil trapping for > lubrication? > They won't end up lining up, as they will keep rotating, and end up mis-aligned again sooner or later. With 3 piece oil rings, you don't have a gap in the oil ring, as such. They are assembled so as the 3 gaps/ends are not together. As for the cross hatch being for intial break-in, Have you ever seen orginal factory cylinders? 100K miles and the marks of the cross hatch is still there. -- Russ Wolfe '66 FB MT '71 FB AT '65 Bug (not running) russw@classicvw.org http://www.classicvw.org ------------------------------------------------------------------- List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org