Cylinder Bore Discoloration

[97gsxIA]

So I have a built 6 bolt block that's been sitting for a year or so awaiting a buyer or a new shell to drop in and I noticed this discoloration at the bottom of the bore. Can anyone tell me what this might be from? She's been sitting a while. Just warm up idle time on it. (8-10) minutes worth.

Upload troubles. Here's the pic.

 

[BogusSVO]

The vertical line is more of a concern. You may have a damaged ring. or a ring that was not deburred after filing.

 

[97gsxIA]

What would be your recommendation bogus? I was going to drop this in mighty max I might be getting. Is the risk too much?

It has no depth to the line.

 

[BogusSVO]

With it out, I would pull the oil pan off and knock the rod out and inspect it.

Now would be the time, a bit easier with the head off and the short block out of the truck.

 

[donniekak]

I would tear it apart, have it honed, and use new rings that have been file fit, and de-burred. When you fit the rings, the outer edge gets a burr on it that must be filed off by hand.

 

[97gsxIA]

Ok so question. This particular block has wossner 8:1s with a .020 over bore. Since its been ran already if I take it out to inspect I'm going to have to refit the rings or get new rings anyway? They should be at .020 on the top and .024 on the bottom. Should i shoot for the same numbers?

 

[donniekak]

It's going to need that big scratch honed out of it no matter what. After a hone, it will need new rings. The .020" .024" rig gap is very common with performance builds. It works fine.

 

[97gsxIA]

Here the thing. For the life of me. I cannot find replacement rings for these pistons... Wossner doesnt even have them listed on their site. Just their pistons sets. They have to be able to get me some replacement rings right?

Even MAP (guys who built the block) don't have them on their site.

Obviously it needs a hone if theyre coming out. But if I can't find new rings, Should/Can I refit the ones I have if theyre not damaged?

 

[donniekak]

Measure the rings, they are probably a common size. Either 1.2mm and 1.5 mm like stock, or 1.0mm and 1.2mm.

 

[JacksonAuto]

Did MAP assemble the shortblock? If so then don't worry yourself with finding new rings and fixing the problem. Call them and tell them they need to fix it.

 

[97gsxIA]

The block was one of two built by MAP for a friend. I bought it off of him on the cheap after he made good power off the first one.

I'll just give it a hone, and some new rings for peace of mind. I didn't like the almost non-existent crosshatch anyways.

Who knows, my buddy could have pulled the pistons to double check gaps and fudged it up and let it go cheap, can't blame MAP unless I knew for sure it wasnt him.

UPDATE:

Got a hold of a Wossner rep and ordered some new rings.

For anyone with Wossner pistons looking for rings, the part number for their rings are based on the following system:

(bore size with no decimals)XTY

So for 85.5mm (.020 over) pistons, the ringset part number is 855XTY

Is there anyway to add a "wossner" tag to this thread?