Gap no gap; gees it makes my head hurt. Reminds me of last yrs " what'a the definition of sex". Rings must have "clearance" because they expand at .00000065 in/in/deg = about .008 inch for a 4 in piston. ERA535 is right on; the leak down is hardly measurable; it's even less that that; why, where does the 2% leakdown go? to the second ring. Now you have .02x.02 for a whole ..0004 or .04% leakdown. Now where does that go? to the
oil ring which is designed to have an
oil sealing feature and is very effective at stopping any leakage that gets that far.
However; the the most important factor is: the bridge has 2 90 deg edges per ring side, these are "stress risers" that are cyclic fatique failure sites. Now you have 4 per ring, one bridge piece, x2 ringsx8 cylinders; you have just increased the odds of a material failure by 80 times. Granted the probablity of a ring failure is low; but why increase any odds 80X. In dirt farmer language, the odds of getting hit by lighting is very small, but you don't walk around a golf course swing a club in a lighting storm.
No production engine used these kind of rings because they are not as reliable. Stick with a properly end gapped std ring. They have stood the test of fire and time for good reasons.
gn