"....a piece of broken compression ring becoming lodged on the edge of a piston and grenading into bits. The cylinder was deeply scored."

Mr Bob, Yeah I had the scoring too. In three cylinders I think. Oil consumption was 1/2 qt to 1 tank of gas. But my real problem was something else. See below.

"Does it run on 4 cylinders? Usually, You need 90 psi minimum before a cylinder will fire. How many miles does it have on it? 110,000 miles is the limit of the original Mahles if you are driving hard.

What compression ratio does it have?"

Paul, Mileage undetermined. Probably a lot more than 110,000. The engine had stopped starting, ever. Compression ratio, I think it started out as a B18D, but the head was not stock, and had B20 intake valves. So I don't know the compression.

When I pulled the head, I found 3 burned exhaust valves and 1 going. My own fault for not recognizing that the head I had put on a year ago was not stock and needed bigger lash settings. So I have gone with another engine, a 69 B20, that might get by with only honing and no new pistons. And a head rebuild on the B20 head. It's not together yet.