Chrome Moly Rings

Plain cast iron is a durable wear surface in normal operating conditions and is less costly than the moly or chrome faced ring.

Chrome moly rings. The face of the top rings in these sets are electroplated with chromium to provide a surface that is resistant to abrasive wear. Hastings compression rings together with the flex vent oil ring provide the ultimate in piston ring set performance. The base material and design are the same as used in speed pro plasma moly ring sets only the face coating is changed. Modern engine with moly rings and proper plateau finishes on the bores are for all practical purposes broken in within a.

These rings are not lapped round and true at the factory. The material that s referred to the ring facing or the portion of the ring that runs against the cylinder wall. There hasn t been a us made engine made since 60 or a bit earlier that did not come from the factory with either chrome or moly rings. Basic machine design do not run 2 simular hardness materials together ie steel shaft with brass bronze bushings not steel to steel.

A steel napier second ring and industry leading cp 20 oil ring round out the package. Thus they require a coarser cylinder finish than a modern ring. For 1 5mm and 1 16 ring sets the top rings are positive twist ductile iron barrel faced plasma moly inlaid. Also a reason engines with chrome rings burn more oil than iron moly combos.

Chrome rings neccessitate rough bore finishes to hold enough oil to lube the rings as chrome rings hold zilch for oil unlike moly coated rings. Moly has a very high resistance to scuff. Chrome has good resistance to scuff but does not exhibit moly s oil retention capabilities. And the aterials typically used are cast iron moly chrome or ceramic.

Most grey cast iron rings specify a 150 to 220 grit with 180. They are designed so that the final finishing is in the cylinder. But all top rings are cast iron either plain or ductile. In addition the second rings are reversed twist taper faced cast iron.

This actually requires that during break in the ring come in contact with the cylinder wall. Chrome file fit ring sets are listed by bore diameter and list available over sizes. American cars made before the mid 50s used plain cast rings 90 of them needed. When rings are discussed it usually concerns the top ring only.

The difference betwen a standard cast iron ring and an entry level moly ring is just the moly coating on the edge of the ring where it touches the bore. 8 cyl moly ring set 4 060 size.