What say you, are these good, bad or indifferent? Please give your reasoning. Answers that read like "it isn't babbit" are not helpful.

 

Well, the point of babbit is that if you lose oil pressure
you have something soft to ride on, hopefully chew the
bearing insert but not the crank. Of course that's not a
long term strategy.

Aluminum, you have to expect has or will have a hard
oxide coating and is more likely this will chew the crank
if you ever lose the oil film (or some event pushes you
through it, like a detonation).

That's my take, just from thinking about the materials.
What if any advantage an aluminum bearing offers, I've
never heard. But I think it's not so much about what
happens when things are going well.

 

Interesting thoughts, which align precisely with all that I've learned over the years. Here's what Federal Mogul has to say.
http://www.federalmogul.com/en-US/OE...6#.U9mNlWPQqKI

I also know that the diesels I babysat in the Navy used AL bearings (no steel shell), but the dynamic in a medium speed diesel (8.125" bore x 10" stroke, ~900 RPM) coupled to a 1050kw generator is a whole different animal.

 

OK, now I see why they're pushing this:

"All new Federal-Mogul aluminum bearing alloys are now
free from lead, cadmium and other environmentally harmful
substances."

Same crap as is going on in electronics, get the lead out,
blah blah.

Evidently these are aluminum alloys (but then so is most
aluminum) and they claim they are suitably soft. But I
don't know as I'd trust that to stay that way over time.
Copper, tin, lead oxides are all nice and soft. Not so,
the aluminum oxide. And any wear particles sit in the oil
to extrude-hone the oil path, nice.

 

Oh, I agree. But, tis the way things are going. I bet in 5 years you won't be able to get a babbit bearing for any money.