396/427 Crankshafts

[William Holder]

Re: 396/427 Crankshafts

Gentlemen, I have seen several of these cranks at swapmeets and I belive they are made in china as the machine work was very poor. there were voids in the fillet radi from the journal to the counterweight and as you said the casting number is raised instead of embosed I do not belive that these are real GM cranks. I would take one to a machine shop that grinds cranks and have it magnafluxed and checked for proper stroke and indexing (throws 90deg apart).
As far as it being illegal for people to use that number I do not belive that is a deterant. You can buy anything these days that is a copy. havent you seen 100.00 rolexes in NYC? Levis jeans , Nike's t shirts and sweats, cosmetics etc..all have knock offs or copys around. Anyway this is all just my humble opinion. Let me know if you get the cranks checked out how they look. I figured that the people making Carillo rod copies and scat and cat cranks were jsut making these cranks and putting the casting number on them?

[Joe L.]

Re: 396/427 Crankshafts

William-----

The forging number on this crankshaft is embossed, not raised. It is EXACTLY in the same size, font, and configuration as the 454 forged crank that I purchased from GM. Older GM forged cranks are the ones that usually have the raised forging number.

The machining on the cranks that I purchased looks to be outstanding; I didn't detect a single flaw of any kind.

It is very possible that GM has had forged crankshafts made in China and I don't dispute the possibility that it's possible that's where this crank core was forged. As I mentioned, GM no longer has ANY in-house forging capability, so the forged pieces have to come from somewhere else. Nevertheless, I'm sure that GM insists on the same quality from foreign suppliers, wherever they may be, as they do from US suppliers.

China is an expanding source of automotive parts for BOTH the aftermarket AND the OEM markets. I'll bet that you'll find more than a few PRODUCTION parts in brand new Corvettes that are sourced from China. Not the crankshafts, though. LS1 and LS6 crankshafts are nodular cast iron and GM does have in-house capability to manufacture those. I believe that those are manufactured at the nodular iron foundry in Defiance, OH.

With one exception, GM does not use any forged cranks in current PRODUCTION engines. The one exception is the new 3.6L DOHC V-6 used in the Cadillac CTS and Buick Ranier. Also, next generation Northstar engines will have forged cranks.

Forged cranks are used in several SERVICE engines, including the ZZ-4 (and derivatives) and all 454/502 SERVICE engine assemblies. However, contrary to popular belief, forged cranks are NOT used in the new Gen VII 8.1 L big block engines used in trucks and marine applications. ALL of those engines currently use a nodular cast iron crankshaft.

So, where do the forged crankshafts for the above-referenced applications that use them come from? I don't know, but I wouldn't be surprised, at all, if it was China. Which would you rather have in your car----a nodular cast iron crankshaft from Defiance, OH or a forged crankshaft from China?

[John H.]

Re: 396/427 Crankshafts

DCX doesn't have in-house forging capability any more either, but has always bought forged cranks from Tier I suppliers anyway; the forged 4340 alloy Viper V-10 crank is purchased from Ohio Crankshaft, where it's forged, fully-machined on all surfaces (including the weight cheeks), fillet-radiused, cross-drilled, chamfered, and internally-balanced with Mallory-metal slugs. It ain't cheap, but it's bulletproof

[Joe L.]

Re: 396/427 Crankshafts

John-----

That's a NICE piece! No GM crankshafts look anything like it.

[Clem Z.]

Re: 396/427 Crankshafts

john,what kind of crank is used in the V-10 dodge truck engines,forged or nodular iron?