Ideal for all high performance applications including turbo charging with boost up to 16 lbs. sq. in.
Top rings which fit bore sizes of 3.939 and smaller are symmetrical and can be fitted in the groove either way. Top rings which fit bore sizes 3.940 and larger are torsional in design. The torsioning is obtained from the bevel on the inner upper edge. All top rings are zinc phosphate coated to improve initial scuff resistance and to add corrosion resistance.
Second rings are cast iron reverse torsional twist. The torsioning is obtained from the bevel on the inner lower edge. Other performance advantages are conformability to cylinder walls, good wear resistance, and a specific O.D. shape that will encourage downward oil scraping and minimize upward scraping. Ross second rings are also zinc phosphate coated. Radial thickness on all Ross second rings in bore sizes from 3.051 through 3.494 (70 mm though 88.75 mm) is .125. All rings above bore size 3.499 (88.9 mm) are SAE "D" wall.
Oil rings are three piece circumferential type. They are comprised of a stainless steel expander and two chromium plated carbon steel rails (segments). Ross rails are narrower than rails made by other manufacturers and are also of less radial depth. The radial depth of the rail greatly influences conformability, i.e., the ability to conform to the shape of a distorted bore. The conformability is related to the section module of the rail. This is inversely proportional to the cube of the radial thickness so it can be seen that a small reduction in radial will have a big impact on conformability. Oil can escape past the oil ring assembly via the upper side of the upper rail. By having a 15 degree angle on the rail support there is a component of the radial force applied in pressing the rail sides against the groove. Side width control of the Ross oil rings is further enhanced by means of the rail support pads which are rolled into the outer section of the expander. These pads prevent undue rail side movement which can effectively pump oil and increase oil consumption.
1. All part numbers are for one cylinder only
(For a Four cylinder set order quantity of Four)
2. All ring sets listed on this page are made to a diameter larger then the bore
diameter. This means the gaps must be filed to get the correct gap.