assuming that you have new cylinder liners and pistons or old pistons with good ring groove conditions, piston rings come with the correct/specified clearance when bought new.
Piston ring gap.
There is no clearance of the ring to the block. The ring works in contact with the block to seal the combustion chamber and provide oil control.
To measure the piston ring side clearance, first, install the piston ring onto the piston and place them in the cylinder bore. Use a feeler gauge to measure the gap between the ends of the ring when it is positioned in the bore. The thickness of the feeler gauge that fits snugly in the gap indicates the side clearance. Ensure that the measurements are taken at multiple points for accuracy, as the clearance can vary due to wear or manufacturing tolerances.
As the piston moves up and down in the cylinder it also moves the piston rings up and down in the grooves. With the rings moving up and down it gradually increases the side clearence. Material is taken off from both the piston groove and the ring.
Any marking on the piston ring goes UP towards the top of the piston. Only the first 2 will have any marks and I believe they have the letter N on them so have the letter N facing up when installing the rings. Good luck.
Slide one of the compression rings down into the cylinder and measure the gap with a feeler gauge.
The way the question is phrased the answer is zero. But I suspect that you mean ring gap, and rule of thumb is .002 inches per inch of bore.
You have to disassemble the entire engine, remove the piston and check the rubber ring around that piston.
The DNJ ring spec. information, printed on each compression ring (located next to the piston ring gap), is installed facing the top of the piston for both the top (#1) and middle (#2) compression piston ring slots. The oil control ring can be installed just like any other oil control ring in the bottom (#3) piston ring slot.
a piston ring is not calibrated. You just slide the new one in place
The DNJ ring spec. information, printed on each compression ring (located next to the piston ring gap), is installed facing the top of the piston for both the top (#1) and middle (#2) compression piston ring slots. The oil control ring can be installed just like any other oil control ring in the bottom (#3) piston ring slot.
one ring per piston, the pistons have a groove in it where the ring fits on.