Metric Piston Rings
Top rings are plasma moly inlaid and barrel lapped for long life and quick seating. All Ross top rings are ductile and can be twisted at least 180 degrees and back numerous times without fracturing. Top rings are symmetrical, can be fitted in the groove either way and are coated with zinc phosphate to improve initial scuff resistance. Radial thickness on all Ross moly top rings in bore sizes from 2.756 through 3.494 (70 mm through 88.75 mm) is .125. All rings above bore size 3.499 (88.9 mm) are SAE “D” wall, except .043 compression rings.
Second rings are cast iron reverse torsion twist. The torsioning is obtained from the bevel on the inner lower edge. Other performance advantages are conformability to cylinder wall, good wear resistance, and a specific OD shape that will encourage downward oil scraping and minimize upward scraping. Ross second rings are also zinc phophate coated. Radial thickness on all Ross moly second rings in bore sizes from 2.756 through 3.494 (70 mm through 88.75mm) is .125. All rings above bore size 3.499 (88.9 mm) are SAE “D” wall.
Gas Nitride Rings
Top rings are gas nitride steel, with a barrel shaped face. Second rings are a modified Napier with the “hook” blending into the face of the ring about .100 from the end gap. Napier rings are the ultimate scraper rings. Having the hook blend into the face of the ring accomplishes two important tasks. First it allows the rings to be oversize for hand gapping without having an extremely fragile area to chip at the end gaps. Second, the sealing and scaping action on the face of the ring is more uniform around the surface of the ring than a regular Napier ring. Ordinarily, unit loading pressure is much higher near the end gap and the Napier design is more active in this area. With the Ross modified Napier rings this problem is greatly mitigated. Oil rings are comprised of two chromium plated carbon steel rails (segments) and a stainless steel expander.
| Bore (Inches) | Bore (MM) | Size | Item Code | Description |
|---|---|---|---|---|
| 2.283 | 58.00 | 1.0,1.2,2.5 | XC58 | Chrome Steel, Taper Face Napier |
| 2.559 | 65.00 | 1.0,1.2,2.8 | XC65 | Chrome Steel, Taper Face Napier |
| 2.598 | 66.00 | .031,.031,1.5 | XA66 | Chrome Steel, Taper Face Napier |
| 2.598 | 66.00 | 1.0,1.2,2.8 | XC66 | Chrome Steel, Taper Face Napier |
| 2.618 | 66.50 | .031,.031,1.5 | XA66.5 | Chrome Steel, Taper Face Napier |
| 2.638 | 67.00 | .031,.031,1.5 | XA67 | Chrome Steel, Taper Face Napier |
| 2.638 | 67.00 | 1.0,1.2,2.8 | XC67 | Chrome Steel, Taper Face Napier |
| 2.658 | 67.50 | .031,.031,1.5 | XA67.5 | Chrome Steel, Taper Face Napier |
| 2.677 | 68.00 | 1.0,1.2,2.8 | XC68 | Chrome Steel, Taper Face Napier |
| 2.736 | 69.50 | 1.0,1.2,2.8 | XC69.5 | Chrome Steel, Taper Face Napier |
| 2.756 | 70.00 | 1.2, 1.5, 2.8 | R2759 | Ductile Moly |
| 2.756 | 70.00 | 1.0,1.2,2.8 | XC70 | Chrome Steel, Taper Face Napier |
| 2.776 | 70.50 | 1.2, 1.5, 2.8 | R2779 | Ductile Moly |
| 2.785 | 70.75 | 1.2, 1.5, 2.8 | R2788 | Ductile Moly |
| 2.795 | 71.00 | 1.2, 1.5, 2.8 | R2798 | Ductile Moly |
| 2.795 | 71.00 | 1.0,1.2,2.8 | XC71 | Chrome Steel, Taper Face Napier |
| 2.815 | 71.50 | 1.2, 1.5, 2.8 | R2818 | Ductile Moly |
| 2.835 | 72.00 | .031,.031,1.5 | XA72 | Chrome Steel, Taper Face Napier |
| 2.835 | 72.00 | 1.0,1.2,2.8 | XC72 | Chrome Steel, Taper Face Napier |
| 2.854 | 72.50 | 1.2, 1.5, 2.8 | R2857 | Ductile Moly |
| 2.864 | 72.75 | 1.2, 1.5, 2.8 | R2867 | Ductile Moly |
| 2.874 | 73.00 | 1.0,1.2,2.8 | XC73 | Chrome Steel, Taper Face Napier |
| 2.894 | 73.50 | 1.2, 1.5, 2.8 | R2897 | Ductile Moly |
| 2.904 | 73.75 | 1.2, 1.5, 2.8 | R2907 | Ductile Moly |
| 2.913 | 74.00 | 1.2, 1.5, 2.8 | R5012 | Ductile Moly |
| 2.943 | 74.75 | 1.2, 1.5, 2.8 | R2946 | Ductile Moly |
| 2.953 | 75.00 | 1.2, 1.5, 2.8 | R5015 | Ductile Moly |
| 3.010 | 76.45 | 1.5, 1.5, 2.8 | 2M6198-10 | Cast Moly |
| 3.010 | 76.45 | 1.5, 1.5, 3.0 | 2M6198-10 | Cast Moly |
| 3.012 | 76.50 | 1.0,1.2,2.8 | XC76.5 | Chrome Steel, Taper Face Napier |
| 3.032 | 77.00 | 1.0,1.0,2.0 | XG77 | Gas Nitride, Taper Face Napier |
| 3.051 | 77.50 | 1.5, 1.5, 3.0 | R3054 | Ductile Moly |
| 3.051 | 77.50 | 1.0,1.2,2.8 | XC77.5 | Chrome Steel, Taper Face Napier |
| 3.061 | 77.75 | 1.5, 1.5, 3.0 | R3064 | Ductile Moly |
| 3.071 | 78.00 | 1.0,1.2,2.8 | XC78 | Chrome Steel, Taper Face Napier |
| 3.071 | 78.00 | 1.0,1.0,2.0 | XG78 | Gas Nitride, Taper Face Napier |
| 3.100 | 78.75 | 1.5, 1.5, 3.0 | R3103 | Ductile Moly |
| 3.110 | 79.00 | 1.0,1.2,2.8 | XC79 | Chrome Steel, Taper Face Napier |
| 3.110 | 79.00 | 1.0,1.0,2.0 | XG79 | Gas Nitride, Taper Face Napier |
| 3.130 | 79.50 | 1.0,1.0,2.0 | XG79.5 | Gas Nitride, Taper Face Napier |
| 3.140 | 79.75 | 1.5, 1.5, 3.0 | R3143 | Ductile Moly |
| 3.150 | 80.00 | 1.5, 1.5, 3.0 | R5030 | Ductile Moly |
| 3.150 | 80.00 | 1.0,1.2,2.8 | XC80 | Chrome Steel, Taper Face Napier |
| 3.150 | 80.00 | 1.0,1.0,2.0 | XG80 | Gas Nitride, Taper Face Napier |
| 3.179 | 80.75 | 1.5, 1.5, 3.0 | R3182 | Ductile Moly |
| 3.189 | 81.00 | 1.5, 1.5, 3.0 | R5033 | Ductile Moly |
| 3.189 | 81.00 | 1.0, 1.2, 2.8 | RN3192 | Gas Nitride, Taper Face Napier |
| 3.189 | 81.00 | 1.0,1.2,2.8 | XC81 | Chrome Steel, Taper Face Napier |
| 3.208 | 81.50 | 1.0,1.2,2.8 | XC81.5 | Chrome Steel, Taper Face Napier |
| 3.209 | 81.50 | 1.5, 1.5, 3.0 | R5034 | Ductile Moly |
| 3.209 | 81.00 | 1.0, 1.2, 2.8 | RN3212 | Gas Nitride, Taper Face Napier |
| 3.218 | 81.75 | 1.5, 1.5, 3.0 | R3221 | Ductile Moly |
| 3.228 | 82.00 | 1.5, 1.5, 3.0 | R3231 | Ductile Moly |
| 3.228 | 82.00 | 1.0, 1.2, 2.8 | RN3231 | Gas Nitride, Taper Face Napier |
| 3.228 | 82.00 | 1.0,1.2,2.8 | XC82 | Chrome Steel, Taper Face Napier |
| 3.248 | 82.50 | 1.5, 1.5, 3.0 | 2M4745-20 | Cast Moly |
| 3.248 | 82.50 | 1.5, 1.5, 3.0 | 2M4745-20 | Cast Moly |
| 3.248 | 82.50 | 1.0, 1.2, 2.8 | XX82.5 | Gas Nitride, Taper Face Napier |
| 3.258 | 82.75 | 1.5, 1.5, 3.0 | R3261 | Ductile Moly |
| 3.268 | 83.00 | 1.5, 1.5, 3.0 | R5039 | Ductile Moly |
| 3.268 | 83.00 | 1.0, 1.2, 2.8 | RN3271 | Gas Nitride, Taper Face Napier |
| 3.268 | 83.00 | 1.0,1.2,2.8 | XC83 | Chrome Steel, Taper Face Napier |
| 3.297 | 83.75 | 1.5, 1.5, 3.0 | R3300 | Ductile Moly |
| 3.307 | 84.00 | 1.5, 1.5, 3.0 | R5142 | Ductile Moly |
| 3.307 | 84.00 | 1.0, 1.2, 2.8 | RN3310 | Gas Nitride, Taper Face Napier |
| 3.307 | 84.00 | 1.0,1.2,2.8 | XC84 | Chrome Steel, Taper Face Napier |
| 3.312 | 84.12 | 1.5, 1.5, 3.0 | RS-1001 | Ductile Moly |
| 3.327 | 84.50 | 1.5, 1.5, 3.0 | R5044 | Ductile Moly |
| 3.327 | 84.50 | 1.0, 1.2, 2.8 | RN3330 | Gas Nitride, Taper Face Napier |
| 3.346 | 85.00 | 1.0,1.2,2.8 | XC85 | Chrome Steel, Taper Face Napier |
| 3.347 | 85.00 | 1.0, 1.2, 2.8 | RN3350 | Gas Nitride, Taper Face Napier |
| 3.366 | 85.50 | 1.5, 1.5, 3.0 | R5047 | Ductile Moly |
| 3.366 | 85.50 | 1.0, 1.2, 2.8 | RN3369 | Gas Nitride, Taper Face Napier |
| 3.376 | 85.75 | 1.5, 1.5, 3.0 | R5148 | Ductile Moly |
| 3.376 | 85.75 | 1.0, 1.2, 2.8 | RN3379 | Gas Nitride, Taper Face Napier |
| 3.386 | 86.00 | 1.5, 1.5, 3.0 | R5049 | Ductile Moly |
| 3.386 | 86.00 | 1.0, 1.2, 2.8 | RN3389 | Gas Nitride, Taper Face Napier |
| 3.386 | 86.00 | 1.0,1.2,2.8 | XC86 | Chrome Steel, Taper Face Napier |
| 3.396 | 86.25 | 1.0, 1.2, 2.8 | RN3399 | Gas Nitride, Taper Face Napier |
| 3.406 | 86.50 | 1.5, 1.5, 3.0 | R5150 | Ductile Moly |
| 3.406 | 86.50 | 1.0, 1.2, 2.8 | RN3409 | Gas Nitride, Taper Face Napier |
| 3.425 | 87.00 | 1.5, 1.5, 3.0 | R5152 | Ductile Moly |
| 3.425 | 87.00 | 1.0, 1.2, 2.8 | RN3428 | Gas Nitride, Taper Face Napier |
| 3.425 | 87.00 | 1.0,1.2,2.8 | XC87 | Chrome Steel, Taper Face Napier |
| 3.445 | 87.50 | 1.5, 1.5, 3.0 | R3448 | Ductile Moly |
| 3.445 | 87.50 | 1.0, 1.2, 2.8 | RN3448 | Gas Nitride, Taper Face Napier |
| 3.445 | 87.50 | 1.0,1.2,2.8 | XC87.5 | Chrome Steel, Taper Face Napier |
| 3.465 | 88.00 | 1.5, 1.5, 3.0 | R5055 | Ductile Moly |
| 3.465 | 88.00 | 1.0,1.2,2.8 | XC88 | Chrome Steel, Taper Face Napier |
| 3.484 | 88.50 | 1.5, 1.5, 3.0 | R5056 | Ductile Moly |
| 3.494 | 88.75 | 1.5, 1.5, 3.0 | R3497 | Ductile Moly |
| 3.504 | 89.00 | 1.0,1.2,2.8 | XC89 | Chrome Steel, Taper Face Napier |
| 3.524 | 89.50 | 1.0, 1.2, 2.8 | RN3527 | Gas Nitride, Taper Face Napier |
| 3.533 | 89.75 | 1.5, 1.5, 3.0 | R5061 | Ductile Moly |
| 3.543 | 90.00 | 1.0,1.2,2.8 | XC90 | Chrome Steel, Taper Face Napier |
| 3.543 | 90.00 | 1.0, 1.2, 2.8 | XX90 | Gas Nitride, Taper Face Napier |
| 3.552 | 90.20 | 1.5, 1.5, 3.0 | R5062 | Ductile Moly |
| 3.572 | 90.70 | 1.5, 1.5, 3.0 | R5163 | Ductile Moly |
| 3.607 | 91.60 | 1.0, 1.2, 2.8 | RN3610 | Gas Nitride, Taper Face Napier |
| 3.617 | 91.80 | 1.0, 1.2, 2.8 | RN3620 | Gas Nitride, Taper Face Napier |
| 3.622 | 92.00 | 1.0,1.2,2.8 | XC92 | Chrome Steel, Taper Face Napier |
| 3.625 | 92.00 | 1.5, 1.5, 3.0 | R3627 | Ductile Moly |
| 3.632 | 92.25 | 1.2, 1.2, 3.0 | RS-1003 | Ductile Moly |
| 3.642 | 92.50 | 1.0, 1.2, 2.8 | RN3645 | Gas Nitride, Taper Face Napier |
| 3.642 | 92.50 | 1.2, 1.2, 3.0 | RS-1004 | Ductile Moly |
| 3.661 | 93.00 | 1.0,1.2,2.8 | XC93 | Chrome Steel, Taper Face Napier |
| 3.662 | 93.01 | 1.5, 1.5, 3.0 | ROSS3662 | Ductile Moly |
| 3.662 | 93.01 | 1.5, 1.5, 3.0 | ROSS3662 | Ductile Moly |
| 3.740 | 95.00 | 1.5, 1.5, 3.0 | R3745 | Ductile Moly |
| 3.750 | 92.25 | 1.5, 1.5, 3.0 | 2M4942-STD | Cast Moly |
| 3.750 | 95.25 | 1.5, 1.5, 3.0 | 2M4942-STD | Cast Moly |
| 3.760 | 95.50 | 1.0, 1.2, 2.8 | RN3763 | Gas Nitride, Taper Face Napier |
| 3.780 | 96.00 | 1.0, 1.2, 2.8 | RN3783 | Gas Nitride, Taper Face Napier |
| 3.812 | 97.00 | 1.5, 1.5, 3.0 | R3816 | Ductile Moly |
| 3.818 | 97.00 | 1.2,1.5,4.0 | XH97 | Ductile Moly |
| 3.937 | 100.00 | 1.5, 1.5, 3.0 | R5068 | Ductile Moly |
| 3.937 | 100.00 | 1.5, 1.5, 3.0 | R5168 | Ductile Moly |
| 3.937 | 100.00 | 1.2,1.5,4.0 | XH100 | Ductile Moly |
| 3.976 | 101.00 | 1.2,1.5,4.0 | XH101 | Ductile Moly |
| 3.977 | 101.00 | 1.5, 1.5, 3.0 | R3980 | Ductile Moly |
| 4.000 | 101.60 | 1.5, 1.5, 3.0 | R5070 | Ductile Moly |
| 4.000 | 101.60 | 1.2, 1.2, 3.0 | RGN4042 | Gas Nitride, Taper Face Napier |
| 4.000 | 101.60 | 1.5, 1.5, 3.0 | RS4003 | Ductile Moly |
| 4.000 | 101.60 | 1.2, 1.2, 3.0 | RGN4007 | Gas Nitride, Taper Face Napier |
| 4.010 | 101.85 | 1.2, 1.2, 3.0 | RGN4014 | Gas Nitride, Taper Face Napier |
| 4.015 | 102.00 | 1.2,1.5,4.0 | XH102 | Ductile Moly |
| 4.020 | 102.10 | 1.5, 1.5, 3.0 | R4025 | Ductile Moly |
| 4.030 | 102.40 | 1.5, 1.5, 3.0 | R4035 | Ductile Moly |
| 4.030 | 102.40 | 1.5, 1.5, 3.0 | R5073 | Ductile Moly |
| 4.030 | 102.40 | 1.2, 1.2, 3.0 | RGN4032 | Gas Nitride, Taper Face Napier |
| 4.030 | 102.40 | 1.5, 1.5, 3.0 | RS4035 | Ductile Moly |
| 4.035 | 102.49 | 1.2, 1.2, 3.0 | RGN4037 | Gas Nitride, Taper Face Napier |
| 4.040 | 102.60 | 1.5, 1.5, 3.0 | R4045 | Ductile Moly |
| 4.040 | 102.61 | 1.2, 1.2, 3.0 | RGN4047 | Gas Nitride, Taper Face Napier |
| 4.040 | 102.60 | 1.5, 1.5, 3.0 | RS4045 | Ductile Moly |
| 4.060 | 103.10 | 1.5, 1.5, 3.0 | R4065 | Ductile Moly |
| 4.060 | 103.12 | 1.2, 1.2, 3.0 | RGN4062 | Gas Nitride, Taper Face Napier |
| 4.060 | 103.10 | 1.5, 1.5, 3.0 | RS4065 | Ductile Moly |
| 4.065 | 103.25 | 1.2, 1.2, 3.0 | RGN4067 | Gas Nitride, Taper Face Napier |
| 4.070 | 103.38 | 1.2, 1.2, 3.0 | RS-1008 | Ductile Moly |
| 4.070 | 103.38 | 1.2, 1.2, 3.0 | RGN4072 | Gas Nitride, Taper Face Napier |
| 4.080 | 103.63 | 1.2, 1.2, 3.0 | RS-1009 | Ductile Moly |
| 4.080 | 103.63 | 1.2, 1.2, 3.0 | RGN4082 | Gas Nitride, Taper Face Napier |
| 4.125 | 104.77 | 1.2, 1.2, 3.0 | RGN4127 | Gas Nitride, Taper Face Napier |
| 4.130 | 104.90 | 1.5, 1.5, 3.0 | RS-1010 | Ductile Moly |
| 4.130 | 104.90 | 1.2, 1.2, 3.0 | RGN4132 | Gas Nitride, Taper Face Napier |
| 4.135 | 105.03 | 1.2, 1.2, 3.0 | RGN4137 | Gas Nitride, Taper Face Napier |
| 4.145 | 105.28 | 1.2, 1.2, 3.0 | RGN4147 | Gas Nitride, Taper Face Napier |
| 4.155 | 105.54 | 1.2, 1.2, 3.0 | RGN4158 | Gas Nitride, Taper Face Napier |
| 4.160 | 105.66 | 1.5, 1.5, 3.0 | RS-1011 | Ductile Moly |
| 4.160 | 105.79 | 1.2, 1.2, 3.0 | RGN4168 | Gas Nitride, Taper Face Napier |