yes cylinder is honed, rings are oposite and it's not gasket all gaskets are new and its not OHV engine. This is not first engine I rebuilt but first time I face with this kind of problem. One thing come to my mind as you said ''cylinder walls''. Engine was rebuilded because he had no oil and camshaft broke. Is there some kind of test to determine whethever it spore oil through intake valve or cylinder
thanks