In my opinion. broaching the deck surface instead of face milling probably has quite a bit to do with the inconsistency of the deck as far as flatness and surface finish are concerned. I've sold to and serviced several engine manufacturers in the area (GM, Nissan, Hyundai) - modern aluminum engine block machining generally (but not always) utilizes large diameters face mills, up to 400 mm, using mostly PCD inserts with wipers - flatness and surface finish are held to very tight tolerances. Most blocks have cast iron liners, so the mill has a bimetallic surface to contend with (some are cast in place, others are frozen and "dropped" in; they require decking to finish). All of the processes add up to why modern engines can last so much longer with decent maintenance than our good ole small and big blocks used to (metallurgy has advanced a lot to boot).
All that said, it makes you wonder where we would be by now if we had the engine and fuel management technologies prior to the horrendous '74 and later emissions dogs. But i'll still stick to my 302's, 350 and 396 equipped cars, any day.
Regards,
Steve
