@Pᴀᴜʟsᴛᴇʀ2 -- I ground my valves and they seated perfectly no leak BEFORE i started opening them. I tested leakdown. But once I installed camshafts and went through a few open and shut cycles, they lost the seal and started leaking again. Do you have any idea why valves seal before being opened but then when you open and shut them a few times, they lose the seal?