Chrome Moly Rings

Moly has a very high resistance to scuff.

Chrome moly rings.

When hastings introduced the revolutionary flex vent oil ring to the world in 1956 a new era in automotive engine technology began. This actually requires that during break in the ring come in contact with the cylinder wall. Hastings compression rings together with the flex vent oil ring provide the ultimate in piston ring set performance. They are designed so that the final finishing is in the cylinder.

These rings are not lapped round and true at the factory. The base material and design are the same as used in speed pro plasma moly ring sets only the face coating is changed. Just wondering if anyone has used the sealed power speed pro federal mogul r9771035 plasma moly rings if so any trouble with them seating about how long did it take for them to fully seat i have about 300miles on my new 347 build have a little bit of a problem with crankcase pressure did the v c breather thing helped out a bunch now going back and putting in another pcv on drivers. 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.

American cars made before the mid 50s used plain cast rings 90 of them needed. Chrome has good resistance to scuff but does not exhibit moly s oil retention capabilities. When rings are discussed it usually concerns the top ring only. Plain cast iron is a durable wear surface in normal operating conditions and is less costly than the moly or chrome faced ring.

In addition the second rings are reversed twist taper faced cast iron. Moly rings have a groove cut in them filled with molybendum a soft metal that does magic stuff while regular cast iron rings are just the cast iron material that the whole ring is made of. Basic machine design do not run 2 simular hardness materials together ie steel shaft with brass bronze bushings not steel to steel. 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. 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. And the aterials typically used are cast iron moly chrome or ceramic. Chrome file fit ring sets are listed by bore diameter and list available over sizes.

But all top rings are cast iron either plain or ductile. The face of the top rings in these sets are electroplated with chromium to provide a surface that is resistant to abrasive wear. A steel napier second ring and industry leading cp 20 oil ring round out the package. Also a reason engines with chrome rings burn more oil than iron moly combos.

The material that s referred to the ring facing or the portion of the ring that runs against the cylinder wall. Modern engine with moly rings and proper plateau finishes on the bores are for all practical purposes broken in within a.