I bought a set of NOS Federal Mogul 1526/1527CA .010 undersize main bearings for my 226 I6 flathead and the new bearing faces are copper colored instead of the silver.white babbitt face I am used to seeing. Has anyone else seen these type of bearings before? Are they OK to use?

 

I've seen and heard of that. It might be worth a call to Federal, if you think there is any chance these are used bearings? I think the copper facing is used on specific types of cranks -- forged? I don't know. Is the copper very uniform?

 

Yes, the copper is very uniform. I definitely believe it is new as the surface is not shiny (its a dull copper color) and is consistent across the face of all the bearing shells. I saw a set of "Michigan Bearings" on Ebay that look like mine. Here is the link:
1947 51 Ford 226 Crestliner Custom Deluxe Rod Bearing Set 8 Cyl Nors 060 | eBay

I am just curious what the advantage and/or disadvantage there is to this type of bearing versus the regular babbitt type.

 

Wow, 60 under, you'd have to be desperate to try those!

As I recall, the copper coating gives higher load bearing capacity at the expense of lower embedability (for particulates). The 226 only has 4 mains, right? That's a pretty heavily loaded bearing on a shaft that long and heavy.

 

That's true, only 4 mains. Well, I guess I'll use them and hope for the best. Thanks for your help.

 

You had your crank turned/polished, right?

 

Sure did. It's now at .010" undersized according to the machinist.