Technical Original forged small block Chevy crank versus new

Original ***ertions aside, I thought it was pretty ****ty when GM asked the US government to front the money for them to build a new factory.......and when they got the money they built the factory in Mexico. Kinda makes brand loyalty a thing of the past..........Buy a Chevrolet and see the USA in your multi-national car..........we'll be getting all our batteries and computer chips from China for the new electric vehicles they are pushing on us soon. Nice to know you are doing your part to make it happen............

 

Back to the quality thing. There is something called an "inspection escape" which is bad if you run a formal SPC program or something like it. It can happen to any company anywhere, foreign or domestic.

This is where something gets past the inspection system and gets delivered to the customer as the worst case scenario. Best case, you may have to purge stock and look at anything you have made or bought that may be suspect. This is where lot, date codes and serial numbers come in handy.

If it happens, the company needs to do the due diligence thing, apply the 5 "W" to it, find the root cause or causes.

 

I agree totally with squirrel........you will not see a fatigue failure on these cranks........you can see a dynamic fracture/failure from any serious overload though. (I have a PhD in Fracture mechanics/fatigue, and about 40 years applications experience behind that)

 

With these cranks being virtually indestructible according to our bevy of experts ,I'm surprised anyone has any need for additional aftermarket cranks & the vintage ones arent sold by the ounce .

 

I guess I was in the right place at the right time (with the $200) many years ago when I found the NOS forged small journal crank for my 327.

 

Nice sarcastic remark.......A lot of crank/rod journals get ruined by poor ***embly practices and poor maintenance..........resulting in spun bearings, etc....... to the point that they cannot be turned any further.

 

Yup, there's always gotta be at least one!

 

Several decades ago I worked for a specialty machined shop, and we offered Magnaflux ( wet mag particle ) and Zyglo ( fluorescent dye penetrant) inspection. I bet I magnafluxed 1000s of crankshafts. Found a bunch of "indications" mostly in the rod journal radius. Huge differences in indication length and brightness ( sort of related to depth) .
Just like fatigue cracks are supposed to do in the textbooks. Start out microscopically small, and progress a little bit with each high stress cycle.
I can't swear indications were ever found in non welded OEM SBC forged cranks with proper radius/fillets, but I think there were.

Here's an old 2008 HAMB thread. As I read it, a couple of folks state they've broken forged OEM SBC cranks.
https://www.jalopyjournal.com/forum/threads/crank-broke-350-chevy.262262/
I believe it.

Rare ain't never.

 

Some folks resent expertise, and have a tendency to lash out at it.

It is an unfortunate character trait, and one that is all too common and frequently expressed.