Mike and the list 

while its not uncommon for new rings to take there time seating I asked myself a couple of questions as I read this thread. First did this rebuild include new pistons and cylinders or just rings. what brand rings ? and did the cylinders get straightened with a ridged honed and measured or did they only have the a light hone to brake the glaze in hopes of the rings sealing. 800 miles to a quart of oil is not a reason to take the engine apart but you need to keep a eye on the oil level.
    The idea of revving the engine with no load on it at 5K and holding it there is foolishness even if you had a load on it  that's no way to treat an engine. 
    The clearance of the piston to the cylinder cold is approximately one 1/3 the thickness of a dollar bill and in all my engines I remove the pistons rehone the cylinders and add .001th at least to fit clearance this also gives me a chance check the rings and insure the cylinder is round. 
     The 2.1 engines originally had a stretch to yield con rod bolts and that is a problem that develops over time not due to the RPM.  On my rebuilt engines I use the 1.9 rod bolts when I rebuild the con rods because I fell that is a better bolt over the long run based on the measurements of the countless used 1.9 and 2.1 rods I have inspected. 
The fuel mixture if set to rich can dilute the oil and this could increase the oil consumption and prevent the rings from sealing 
Bob Donalds 
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