Re-hashing re-ground cranks

["Jay Mackro" <jmackro@domain.elided>]

Watry, Andrew <Andrew.Watry@domain.elided> had commented:
> Subject: 2000 cranks
>
> Just by way of clarification, on the 4-cylinder cars, only the 2000 cranks
> are nitrided. 1300, 1600, and 1750 cranks are not (at least from the
> factory), and can and are ground to new sizes all the time.

OK, I agree with the above statement.  Now, here's my question:

  Why can the 1750/1600/1300 cranks be reground, but some
  people advise against re-grinding the 2000 cranks?

Are they suggesting that the 1750/1600/1300 cranks are made out
of some sort of "good" steel, but that 2000 cranks consist of an
outer layer of hardened nitrided steel, with interiors made from
recycled pressboard?  So, if you grind off the nitrided part, the
surface you have now exposed is somehow inferior to the
corresponding surface on a reground 1750/1600/1300 crank??
Given that all 105/115 Alfas use the same bearings and the same
oil pumps, I am sort of skeptical that the 2L's really need to
have a nitrided surface exposed to the bearings, while their
smaller displacement cousins do not.

OK, sure, the nitriding was a nice feature, and one that probably
extended the life of the 2L crankshafts.  And, yea, if you are
racing a turbocharged 2L with 11 : 1 compression, nitrided
bearing surfaces might be nice.  But, for street and light
competition use, I am at a loss as to why the 2L cranks can't
be reground the same as the 1750/1600/1300 's.

Jay Mackro
San Juan Capistrano, Calif.

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