Diesel Engines 1.6 NA CS ring gaps
HM: You must get the bores cross-hatch honed before fitting new rings or pistons and rings
Many experienced garage mechanics can do this for you. Wash the bores out throughly afterwards with petrol and wipe spotless.
After honing and cleaning:
From Bentley (Section 13.29)
Push ring squarely down into cylinder until it is about 15mm from top edge (an old piston is goof for this, be careful!)
Upper & lower rings
Ring Gap (Wear Limit)
0.3~0.5 mm (1 mm)
Oil scraper rings
0.25~0.4mm (1 mm)
Use feeler gauges to determine gap, keep ring square in bore, don't force the feelers, but find the max. gap where feeler can be pulled back out steadily but is not jammed in gap.