Not the inside diameter of the bore, it is on the top of the flange and we noticed it when we were measuring liner protrusion. We are a school and last year we overhauled the engine and put in new parts from YT including new liners, pistons, etc... Almost immediatly following startup the cooling system built pressure and eventually we noticed some coolant was also getting into the combustion chambers. This school year we took the engine apart and we are trying to determine the problem.
All looks ok, except we noticed that the tops of the liner flanges are not flat. We were measuring liner protrusion after clamping the liner down with a hold down tool and we had about .0035" protrusion on the outermost part of the flange, but the protrusion gets progressively less as you move in towards the centermost or inner edge of the liner. Again the outermost part was between .003 and .004", the center part of the flange where the fire-ring sits is about .000", and the inner most part is recessed about .002".
I know that the innermost part doesn't matter because the gasket doesn't seal there, but I do not get why the liner flange top wouldn't be flat. It seems like this could be contributing to our problem. Thanks.