my story: Cat 311b excavator with about 10,000 hrs on the machine. Had a lot of blow-by and the head gasket finally failed. Milled the head. found no cracks, put it back together and it ran great for 40 or 50 hours then it began to smoke. Smokes worse every time I run it. Question; I'd like to do one more little job with it before I sell it, but it would be cool if the machine was running when we want to load it. . .You guys guess the problem is rings? Can I run it ten or twenty hours without it blowing up?

PS: Is blowing some oil out the exhaust. . .

 

PS: I did add a quart of Lucas and let it run for about 15 minutes and watched. No change yet.

 

How's the 311b doing these days? did you try and run it with a good load on it? Still smoking?