Saw these and thought it would provide some great discussion here. Sounds great, but wonder how long they'd last??? Metalurgists...chime in.
Eddie

Clevite 77 COATED race main bearings for Chevy SB 400 1970-80

Industry's first moly/graphite coated engine bearings

Armored with a blend of molybdenum disulfide (moly) and graphite in a polymer substrate
Armor is applied to the proven Clevite 77® TriMetal bearings
Parting lines are uncoated for proper bearing crush
Coverage will include popular Ford, GM and Chrysler models as well as popular Sport Compact applications.

Features, Advantages and Benefits

Feature Advantage Benefit
MoS2 in polymer base Low friction Reduces drag & increases HP
MoS2 in polymer base Self lubricating Helps fight dry starts
MoS2 in polymer base High strength Good support for oil film
MoS2 in polymer base Resists wear Helps preserve surface finishes
Graphite Not temperature sensative Protects hot or cold
Graphite Self-lubricating Protects during start-up
Graphite Reduces friction Increased power
Rated for 500° F (continuous) Resists breakdown Welcomes tough racing applications
Rated for 600° F Extra margin Defends against severe (intermittent) conditions
Low Temp Cure Bearing friendly Protects metallurgical integrity of bearing
Inert Wear Layer Conformability Adapts as needed to thereal engine
Inert Wear Layer Chemically friendly Wont contaminate lubrication system
OEM Caliber processes Superior quality Tightest controls of thickness and curing temps
Bare Parting Line No sanding needed Proper crush without reworking bearing

 

Calico and others have been offering coated bearings, etc for years, so it's no surprise the actual manufacturers are now offering it themselves. I don't know what the composition of Calico's coatings are but they are pretty durable and I would expect that Clevitte is using something similar. Although there should theoretically be no direct contact between the crank and bearings, for instance, we all know that metal to metal contact does occur during startup, etc. These coatings are 'sacrificial' and do wear out but for the people that use these types of products, they generally are not expecting it to last 100k miles until the next rebuild.

I used coated bearings in a SBC 427 I built a couple of years ago and had to change pistons to lower the compression ratio due to the addition of a twin turbo system. The engine had about 3-4k miles on it and about 20 dyno pulls. The bearings looked brand new and there was no visible scoring or wear to the coating.

 

I am using these bearings in my current engine
upon plastigaging I discovered the coating decreased
clearance by almost .001
a minor crank polishing corrected this
other than that I have had no problems with them

 

Hmmmmmm .001

 

I have seen cranks before that guys have tried to polish some extra off for clearance and from what I have seen the journals are not very flat after that process is done.

 

its a good thing I work at a machine shop
I look for about .002 on the rods and mains
it wound up .0018 on the rods and .0015 on the mains
the oil pressure is 80psi cold and 45 hot
oh yea too much oil pressure I know
a friend of mine ran a super stock 283 he turned 10k in the
bleach box with 10psi oil pressure
I'll stick with the 45psi of LE 15w40 oil