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?

 

I would put some Lucas engine oil additive in it and keep an eye on the oil level. Worse its gonna do is smoke. Sounds like the cylinder walls are scored from the head gasket failure. It may just be a stuck oil control ring.
Is it blowing oil out of the exhaust?

 

Thanks, JetA.
No oil in exhaust. But just burning a lot.

 

I have a Cat 247b that was smoking a lot while it was cold once it warmed up no problem. I used about 1/2 quart of Lucas in the oil and it quit smoking after a couple runs. I think maybe it was a ring sticking. I use the Lucas fuel treatment or a two stroke oil to clean the pistons and lube the cylinders with this low sulfur diesel my old Cat wasn't made to burn the crap they sell as diesel today. Hope it works for you!!