this is a d16a6 (stock 1989 crx si engine)
I have an agrivatting problem with my car using oil, this is what i've done so far to try and fix it:
Completely re-built engine:
-new main and rod bearings (correct size)
-bored cylinder chambers 20 thousandths over
-20 thousandths oversized pistons
-new piston rings (20 thousandths over)
-new piston pins to fit new pistons
-<U>all</U> new oil seals and gaskets in and around the engine
-engine was put back together professionally and correctly
-block was decked to clean up matting surface, 8 thousandths

cylinder head rebuild:
-re-ground valve seats
-new exhaust valve guides
-intake valve guides were checked and good
-head was acid bathed
-new valve stem seals
-head was milled to make perfectly flat

other new engine parts:
-new PCV valve
-new Skunk 2 intake (this shouldn't make a difference)
-new oversized t-body (this shouldn't make a difference)
-new water pump
-cleaned screen on oil pick-up

*Is it going to take some time for the valve guides to set? could this be why my car is using oil sometimes and not other times?
*Could it be because the engine only has 4500 miles on it since the complete rebuild?
*it seems to use oil only sometimes, for instance: I'm in clemson, and i drive 200 miles to columbia and back, sometimes it will use a half quart of oil max, and sometimes it will not use any, what could this be?

thanks for any input