cylinder bore

[centredautomag]

I was gapping my rings yesterday and notice a shadow on top of the cylinder wall,I can catch my fingernail on it.

Do you guys think it is time to put a sleeve in?   Thanks Marc.

[My427stang]

That wouldn't scare me, remnants of a ridge, but how does the bore measure and how tight of clearances are you running?  Are the rings in the same location as the last pistons?

[CaptCobrajet]

I'd be much more concerned with the straightness and roundness.  It looks like a good surface finish from the pics.  That little spot won't ever be an issue if it is otherwise in good shape.  I'd rather buy a piston a few thou over than sleeve one, but I would do neither to that if it is straight and round within .0005. with a plate bolted on it.  Hard to get one better than .0002..........

[centredautomag]

I as been bore and hone with torque plate . I guess the machine shop didn't notice it before ordering the piston.I look like mini rust spot if you look at it carefully.
Clearance are at .0045 to .0047 on all cylinder with Mahle forge piston.

[WerbyFord]

As Ross hinted the only real thing with a ridge is the new ring banging up against it and breaking.
Even if the new rings are at the same height as the old ones, they are new, grooves are new & less forgiving, so it could hit that ridge.
I'd make sure its gone first even if do it with sandpaper (BTDT, cheap way out).

If no risk of the ring hitting it, then it wont hurt anything.

[CaptCobrajet]

All good points.  If the "edge" you reference is only in that small area of the circle, the ring won't bang into it, because the rest of the bore will keep the ring from conforming to that little dip.  If the ridge was in half of the circle..... different story.  The engine will never know that spot is there.  It will not leak much, and will spend a short time of rotation in that spot, on one hole.

[centredautomag]

Thank you everybody for the good news  and have a merry Christmas . Marc.