507OLDS

The N-crank and the CN crank are the same thing,same material,thus having the same casting number.
When I ship cranks,I use 2x10 lumber,and make a small box or crate,with screws,and use some good 3/4" plywood for the ends. Total weight will be roughly 85lbs,but nice and sturdy.The crank slides in there nice & snug.You make a spiral shape with the planks,if looking down at the opening.Hope that makes sense.

507OLDS

Has anyone actually seen a cast iron crank? What is the casting number. The N and CN are the same material,same content. 397363

2blu442

Hello Brian
I've got a couple cranks that don't have the CN or N cast into them. They have the same casting numbers though. One came from a boat motor, the other came from a mid-1970's 455 and it had a pilot bearing with the c-clip retainer. Here's a couple pictures, one of the N crank and one without showing the same location and casting number. John

P4260187.jpg

P4260186.jpg

507OLDS

I say they are the same.Otherwise they would have a different casting number,like the forged 68 cranks. I would run any/all of those.

Tallpaul67

In re: to the "N" and "NC" they are a stronger crank than a regular forged crank a I had stated earlier. Go to the following website and scroll down to number 6.
http://www.442.com/oldsfaq/ofcrk.htm

Octania

"if it's on the internet, it must be true" right?

I have seen many cranks with '363 but lacking the N or CN designation.

It's been a while since metallurgical classes, but I recall maybe the addition of a tiny amount of carbon changing the molecular structure of the material as the difference between plain cast iron and nodular CI.

Anyone got time to find info from a reputable scientific source?

Hey Mr. "1bad75442" from Charlotte- is that a bright green car maybe with no hood? I saw such a thing in Lansing a week or so ago.

2blu442

Guys, we were getting way off topic with the OP crank for sale thread so I moved these posts to a new one.

Brian, I agree with you that I'm fine running any of these cranks in my cars. I'm not sure what to think about the same casting number.

Brian, maybe I should have left the shipping one there, but I really need to try your method. I've been hesitant to ship a crank just because I'd hate for it to get bent or damaged in route.



John

Tallpaul67

Alright octania i understand that the internet is not always 100% accurate with information but I have read that in more than one place. It just seems obvious to me that the casting numbers would be the same except for the obvious "N" stamped on the counter weight because they are both the same stroke. The "N" is what distinguishes one from the other. Anyway no hard feelings. Lets just agree to disagree. Here is some interesting reading on nodular iron and why it would make for a good composition metal for a crank.

http://www.iron-foundry.com/grey-iro...ular-iron.html

Octania

Well, not just ripping on you, ya know
the 442.com FAQ is notoriously riddled with errors

nice article you found... yeah, 2.5x the tensile strength [90/35] is a pretty strong argument for Nodular over Gray CI.

"Compared with grey iron, nodular iron has an absolute advantage in intensity. The max tensile strength of nodular iron is 90k psi, while the max tensile strength of grey iron is only 35k psi.

Nodular Irons are generally superior to grey irons, regarding their yield strength. The max yield strength of ductile iron is 40k psi; Grey iron is not very malleable or strong, it fractures easily.

Nodular iron is more flexible and elastic than other cast irons. Nodular iron has higher strengths, greater elongation and better resistance to impact than grey iron.

The nodular iron family offers the design engineer a unique combination of strength, wear and fatigue resistance and toughness as well as excellent ductility characteristics. In all its grades, nodular iron exhibits mechanical properties that make it an ideal materials for mechanical and automotive parts.
Gray iron is the most versatile of all foundry metals. With the exception of wrought steel, grey iron is the most widely used metal for engineering purposes. Grey iron is an extremely inexpensive metallic material and is readily available in large quantities at almost any foundry."

J-(Chicago)

The difference between N and CN cranks is in the journals.

If you look at a CN, it has press rolled fillets on the ends, instead of a gradual chamfer. The CN cranks are a little stronger in my opinion because of this process. Same material though.

Smitty275

ALL Oldsmobile cast crankshafts for the 455 are the same nodular iron. There have been designations of N, CN, Cn, AN, An, and a few that don't come to mind right now.
In no way is ANY nodular iron crank stronger than one of the factory forged cranks.
The undercuts at the rod journal ends appear to be just that, undercuts from machining the casting before went to the grind process.. They do not appear to be pressure rolled reliefs and considering the material I highly doubt that they are pressure rolled reliefs. I will also say this is absolutly the first time I have even heard of that idea on those cranks.

Tallpaul67

Hey smitty thanks for clearing things up.