Originally Posted by
DmaxMaverick
Is the firing ring impression consistent all the way around, and consistent with other cylinders? If they are all typical, and the manual and other technical sources don't hint at milling, would they all consider that condition normal, and not need a correction? I'm wondering if it's a product of aluminum vs. steel under high loading/torque or perhaps 20 years of high, sustained pressure. Or, is it a condition involving erosion or corrosion? I suppose it could be calculated, considering the force PSI, effected area, and hardness of the aluminum, exactly how much of an impression it should have. Even if you had them milled, would torquing a new gasket result in the same? If milled, would you be repeating exactly what you're seeing now? I don't know of anyone who's immediately removed a freshly torqued aluminum head for a look. I know it sounds skeptical (I am, a little), but mostly just thinking out loud. This is essentially a new territory for me, and something I'll likely be visiting in the near future. I've done dozens of aluminum head jobs, but those were almost entirely smaller engines, V6's, I4's, and boxers in compact/mid cars. I did assist with an LS V8, but wasn't present for the whole job and don't recall anything remarkable. Fire ring impressions were somewhat, albeit much less pronounced, typical, and often were at least minimally, still present after machining. It never became an issue, after the fact.