New piston in old liped cylinder?

[Vintage Engine Repairs]

Lol, even huskihl spelled it wrong so you are not alone, its Kolbenschmidt.

Oh did he I wouldn’t have known! LOL

 

[pioneerguy600]

Oh did he I wouldn’t have known! LOL

You are not German, right.Richt!

 

[huskihl]

Lol, even huskihl spelled it wrong so you are not alone, its Kolbenschmidt.

Oh it was in there at one time, I promise. It had auto corrected to 2 t’s at the end and I changed one of those to a d. Apparently in the process it lost the s LOL

 

[bwalker]

No kidding. I have never seen that in 5-600 cylinders that I’ve been into.

To me it kooks like the plating ended where the "ridge" is.
I have seen dirt bike cylinders wear and it never happens in a perfectly straight line around the circumference. Plating varies in thickness and is diamond honed to size. It also usually happens on the fore and after around the intake and exhaust ports.

 

[bwalker]

Here is a good example of what worn plating looks like.

 

[pioneerguy600]

Oh it was in there at one time, I promise. It had auto corrected to 2 t’s at the end and I changed one of those to a d. Apparently in the process it lost the s LOL

Oh it was in there at one time, I promise. It had auto corrected to 2 t’s at the end and I changed one of those to a d. Apparently in the process it lost the s LOL

Darn auto correct, I disabled it just cause it is a big nuisance. I leave my spelling mistakes as is, just to prove how illiterate I am. I also have little patience these days to fight with something I cannot overcome, no auto correct, no problems.

 

[Mcfly49]

To me it kooks like the plating ended where the "ridge" is.
I have seen dirt bike cylinders wear and it never happens in a perfectly straight line around the circumference. Plating varies in thickness and is diamond honed to size. It also usually happens on the fore and after around the intake and exhaust ports.

Are you saying the lip isn't from wear?

 

[pioneerguy600]

Here is a good example of what worn plating looks like.View attachment 976983

That`s a typical wear problem, seen that so many times on all manufacturers cylinders but the op has a totally different problem, its not a worn off plating issue.

 

[ballisticdoughnut]

That cylinder can be honed and reused. that "lip" is just a part of the cylinder where the rings don't make contact at TDC.

 

[Mcfly49]

That cylinder can be honed and reused. that "lip" is just a part of the cylinder where the rings don't make contact at TDC.

My original question still stands then. Would I just slap it back together and see if it lives? It would be a shame to tear up a piston just to see if it works, no?

 

[ballisticdoughnut]

My original question still stands then. Would I just slap it back together and see if it lives? It would be a shame to tear up a piston just to see if it works, no?

If it's an abrupt sharp edge then no, I wouldn't run it. If it's smooth and can barely be felt with your finger it'll be fine.

 

[cookies]

either the plating below the ridge is worn off or the cylinder was cut much deeper creating a soft uncoated spot that will wear quickly being its bare aluminum..vega...vega..vega

 

[bwalker]

That`s a typical wear problem, seen that so many times on all manufacturers cylinders but the op has a totally different problem, its not a worn off plating issue.

Which is why I don't think it's caused by wear.

 

[bwalker]

My original question still stands then. Would I just slap it back together and see if it lives? It would be a shame to tear up a piston just to see if it works, no?

I am not 100% certain,but I don't think what your seeing is caused by wear. I believe that ridge has been there since day one. I would mount the cylinder, take a squish measurement, the measure the top of the ring groove, add those two together and determine if the ring passes over the ridge. If it doesn't I would run that cylinder. It appears to be in decent shape and I would as soon piss on an electric fence than put Chinese junknin a fine old saw like the 028.

 

[pioneerguy600]

Which is why I don't think it's caused by wear.

Exactly, I doubt its wear at that point in the cylinder.

 

[Mcfly49]

How about now?

 

[bwalker]

How about now?

View attachment 977103

View attachment 977104

Ok, that's for certain wear. Cylinder is shot.

 

[huskihl]

I bet that cylinder has several thousand hours on it. I’ve never seen one damaged up there, only around the intake port

 

[CJ1]

That would be one you would like to find out the history on. [Or maybe not!] cj

 

[BrettS]

Which is why I don't think it's caused by wear.

Ok, that's for certain wear. Cylinder is shot.

So which is it then?, is it worn or not in your 'expert' opinion