Honda Repair: blue smoke, 89 honda civic, plug holes

Question
'89 honda civic, 1.5L, SOHC 4cyl auto.

Replaced two burned exhaust valves in #1 and all 16 stem seals.  Car ran fine for 20 min.  Changed oil.  Accidentally bent dust cover on clutch/tq. converter housing not knowingly.  Thought high pitched rubbing noise was a main bearing that possibly got dirt in it and spun.  Frantically removed cam cover to inspect and listen to cam to rule out the possibility that the noise was coming from the cam.  Realized that the noise was the bent dust cover, bent it back.  Got two plug wires switched putting it all back together.  Backfired through the intake.  Got wires back on right and the car runs great now but burns oil.  Burns lots of oil.  Something happened when it backfired. Compression is 180, 180, 180, and 210psi.  Oh, the pistons have dime shaped circular patterns in the centers that can be seen through the spark plug holes.  They look like small crop circles.  I have never seen this before.  Did I ruin this lady's car switching her wires around?  Let me know what you think or if you need any more info.  Thanks!

Mike Hughes  

Answer
Mike,

With you reversing the plug wires, that should not and would not have caused your oil burning problem. If it took that little to damage engines, we would be rebuilding them all the time.
As far as the crop circles go, it is one of 2 things.
1: Those pistons have that marking from the factory. Its a good way of explaining it. (crop circles)
2: You may be looking at a part of the piston where the valves hit. Caused by incorrect cam timing. The timing may have went off from either incorrect installation, or some other reason. Check the cam timing. If it is off, you may have damaged the valves and pistons. Maybe a cracked valve guide.
The most logical reason why this car is suddenly burning oil is this:
When you remove the head and rebuild it, you have much better sealing on the top part of the engine. This puts more stress on the lower end. (rings) Causing oil to pass the rings much eaiser than before. That is most likley the reason. Thats why whenever I rebuild the top end, I always do the bottom end also.
Also you may have some of the old head gasket material stuck between the piston wall and rings. That will cause it to smoke also. Did you tape off the cylinder walls so no depris gets down there? I always do. I think this is your real problem.
Gene