I am forever confused about the valve setting of 'two turns'.  The two turns meant to be two more once there is resistance, as far as I know.  I am not getting good readings after that.  

I got the head gaskets renewed on this engine and set the valves one by one with 1 1/2 turns.  Now that it has been running for a few days and the lifters got quiet, I'm setting them again to make sure they are correct.  But now I'm getting lower readings.  

I never understood why two turns.  Does not that make the valve open that much more?  Or the lifter would compress that much?  In that case it can be anything, if the lifters would compress under pressure of the springs.  
Some of the lifters are soft and those have no resistance like the others.  I guess, they get pumped up later and would lift better.

But how do I know, the valves open enough or they close fully?  Somehow it is foggy for me why to do two turns, or any for that matter.  

There must be a professional explanation of this.  Some of you know this, I think.  Let me know please.  This is one item that is not making sense.

Best wishes to all,
Zoltan