I have come across something while doing an in frame on my '88 E9 that i have never seen before. The counterbore on the #6 cylinder is nearly two thousandths out of parallel with the deck from the front of engine to the back. Rather the 2 o'clock position is the highest point at almost .002 over the ten o'clock and 8 o'clock measurements. this is translated to the fire ring channel as well. I cleaned up the old liner and dropped it back in and it was the same. This made me concerned for the sleeve flange breaking or the piston running crooked and eating up the rod bearings. But I plastigaged them on disassembly and every single clearance was perfect at .002. Bearings where not undersized. There are many parts like injectors, rods, and such that are signed and dated '98, and as far as i can tell, it has been a very long time since this engine was opened up. Also the head gaskets where beautiful when I removed the heads no sign of anything leaking or loosing seal in anyway. Has anyone come across this before? And anyone have any ideas what to do about it? I don't know if it is the counterbore cut crooked or the whole sleeve bore milled at the wrong angle. I am concerned about breaking the flange or wasting the bearing, and yet the old stuff was good. The only other thing to note was I started to drop the exhaust valve seats on that cylinder. Which is what started this whole process. Any info, experience, or ideas how to move forward would be greatly appreciated.
Thanks