Thanks for the correction Paul, that is correct the Arma is a trade name of nodular steel by GM. I just used it as an example because I consider it among the best of Nodular irons, kind of a bench mark.
I did mention the grain structure of the offshore cast cranks was pretty crappy. The metal is also softer. There is more too it that just yield numbers. Versus watching a big HP engine using a Pontiac OEM crank, I would place to hide if an off shore cast crank was used in a 800 HP+ engine dyno session!
The factory Nodular cranks Pontiac used are very tough, but not compared to a non twist 4340, that was my point, it was not too talk down Pontiac’s factory cranks. It probably sound like it the way I worded that statement. I have almost all N cranks, and one 4340 in my Pontiac cars. Like I mentioned or inferred in a couple other posts, I think the harmonic balancer destroys more factory cranks than over loading them.
Thanks Shiny, good catch, elasticity was not the correct wording, should have use resilience or toughness. Good thoughts.
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