Technical Original forged small block Chevy crank versus new

Does anybody have fact based opinion if a 60 year old Chevy forged crank is a wise choice versus a new aftermarket forging? It seems unless you spend three grand plus, it’ll be a Chi comm forging. I’ve cut China metal and it is not the same as an American Forging. For that money I could take my chances with the senior citizen crank and hope for the best. I’m still an ABC shopper when I can. (Anybody But China). Am I not shopping at the right place?
Thanks all,

 

The guys are likely going to want to know more about what engine it is and what your goal is for the engine and whether you have the factory crank already or are starting from scratch before offering up info..

Generally speaking, unless its a rocket ship, it may be difficult to tell the difference as long as either are straight, balanced, journals are round and not tapered, have the correct fillet radius for the application etc.. it could just be the money spent to get there.
Nothing wrong with liberty/compstar/molnar/scat etc,

 

Yes more info would help. But if it were me and the cost to have the old forged crank brought to spec (magnaflux ,grind and polish) was less or probably even a little more I would use it over a new offshore piece. I’ve had low budget offshore cranks come through that needed to be straightened so that adds to cost. If in fact it’s going to be a rocket ship then maybe the high end unit is in order.

 

I thought Callie’s was a US company? I seem to recall them being under a grand for a 4inch stroke crank.

Edit: Just googled them, seems that have some made overseas and finished here, others made and finished here (if what I read is current).

 

The guy who built my engine drag raced all his life and he told me that he never had a forged Chevy crank break.

 

I had one from an early LT1 snap . Not in the engine , machine shop trying to straighten it to true . He said it was .002 out of straight and it snapped . I truly believe , he was not being honest and wanted my crankshaft .

 

I have been using stock cast cranks for up to 450 HP builds with good luck. I ran stock cars in a claimer class and they turned 7000 RPMs all night. I took many apart to freshen up and the cranks were always good. Watch the eBay re-box specials that come from China, avoid those like the clap.

 

Id just also like to point out that just because something is from china it doesnt mean its automatically junk. There ARE morally sound companies like the ones listed above who CARE about the blanks theyre given to finish off, you know, they keep an eye on it making sure theyre giving us the best possible product at the best price, because we cant all afford winberg stuff, we still all get to play hotrods. Its also not pushing american jobs out, there are still tons of american people along that chain employed, right down to the delivery guys on a local level.

 

There are too many good reasons to use a new crank in my opinion.. the old guys who designed and developed this stuff done a FANTASTIC job for all of us, full respect! And we are greatful. But time marches on and we know more now..
for every guy out there not stressing old gear and calling it luck, theres likely another guy who wasnt so lucky using old stuff...

new cranks might have different material compositions to get the properties you want in a crank..
Theyre already bull nosed..
The overlap in the journal looking at the crank head on is better..
Material is where it needs to be where it wasnt in every old crank thats broken..
You get your choice of journal and stroke sizes..
You get a clean slate to work with and balance..
You can have anything fully custom...

my latest engine has a liberty crank, PERFECT drop in ready (sans balancing) journals all on size, no taper, no egg shape, perfectly straight to the tenth.. you really cant argue with the accuracy of cnc manufacturing nowadays...

also.. we havnt even begun this same question yet in regards to connecting rods! i hope you arent using old ones..
nowadays its really accessable to get a complete matched rotating assembly.. that way you dont haveto juggle rods and bob weight etc issues with your old 350 crank.
Pistons are all on size down to the tenth too thanks to cnc (well my mahle ones were on the cmm anyway)

 

Again, if you have an old forged crank already, use it and spend the money you save on decent modern chinese rods, if you have a clean slate, get a modern rotating kit....

Still depending of course on the engines goal

 

This.
Intellectual property isnt a thing in china, everything belongs to everyone, so this is when the cheap chinese stuff happens..
When the american guy isnt there overseeing what is being sent and its after hours, thats when they run batches of quick crap just to get out the door and make a quick buck since theyre already tooled up.

 

Why would you want to replace a good old original crankshaft? Get it checked for cracks and straightness, turned if needed, and balance to work with the rods and pistons, and it'll be fine. Make sure the snout is not messed up, and you might want to get it drilled and tapped if it's not already, and you plan to use it at high rpm, or hang some extra pulleys off it to drive AC or a blower.

I'd use the original rods too, with good bolts installed, and resized and balanced.

 

I don't have an answer for you but I do have this completely useless bit of hearsay ... the brother of a guy I used to work with built up a Pontiac engine for his slightly off topic street/strip car. My understanding is he used an aftermarket crank from a very well known company. Not long after completing the car, he blew the engine. My understanding is the crank broke. He sold the car as a roller shortly after. I do not know if the crank broke due to something else failing or if the engine failed due to the crank breaking ... either way, I was very surprised to hear this big buck crank broke. I won't mention the name of the crank company as I truly do not know the exact details of the engine failure.

As stated earlier ... completely useless info

 

Why , fatigue .

 

Some folks can break an anvil !

 

Fortunately old Chevy engines have a built in fatigue prevention device...the bores and rings wear out long before the crankshaft gets tired, so the engine is taken out of service.

Really, it's not a problem. If you're really concerned, start with a crank that is still standard size.

 

I totally agree.....I have never had an issue with a GM forged crank and have revved them to 8k.
Whenever I find a good 283" forged crank I pick it up for future use. Make sure the thrust bearing is
good.

 

Coming from the nations leading metallurgist that would be comforting ,( somewhat) however....

 

Personally I would not worry about it. I'd run either if it machines up right.
Joe Sherman said a stock SBC bottom end with a cast crank is good to 8,000 rpm.

 

You probably don't want a .030 under crank from a dump truck....but a normal car crank will have led a sheltered life. I'm not a leading metallurgist, but I did take a few classes in engineering school. Steel lasts a very long time if it's not loaded too much.

 

If you use an early forged crankshaft, I recommend that you have the snout drilled and tapped for a damper/balancer retaining bolt, especially if you are going to spin it.

 

Thank all of you for the input and knowledge.
To clear up the vague, I am rebuilding a 56 Chevy than ran in Modified Production C class in the late 60s. There’s not much left, so it’s a rebuild versus a resto.
I want to replicate the car as ran so I’m copying the drivetrain with a few exceptions.
It had an Pontiac rear.
Muncie with straight cut gears.
327 with tunnel ram, Isky gear drive and a magneto. All per the 60s heyday driver and pictures I have received.
So, I’m not points/class racing it but I will run it. I’d like to see how close I can get to their ETs. Minus the Isky gear drive, (which I don’t have anyway) and no magneto, it’ll be locally driven so I’d like to charge the battery with an alternator.
It’s history.
It took runner up in its class in Pomona 68, and class winner Pomona 69. Winternats.
These guys had a helluva car.
Sold in 70 or 71 and became a bracket car or street car and resold up to the 90s. Then sold to a guy for his son, and that’s when the rest of the good stuff was sold off and replaced with stock stuff and either abused or left out in the rain.
But, I had to have it. I finally do. It’s a mess.
What I’ve collected so far.
A ready to go Olds/Pontiac 488 rear.
A dofornow muncie.
I’ve got the right tunnel ram. Core 64 461 heads. I’ve got a line on a 327 block. Actually I’m getting ready to tackle the body but I do want to get the right stuff to put a 327 together I can run and it will live.
For the crank, so far, I do know I’d need a bolt on balancer.
New rods seem money well spent.
Forged pistons too.
The short block I can get, I have not tore into it to see what there is to use.
Without adding several pages of pictures, here’s a few of the better ones.
The car looks nothing like this today but the lettering is allegedly under the Maaco paint. We will find out this fall.
Again, thanks all!
Dave

 

Too bad you didn't stay at a holiday inn last night , then you'd have something!

 

Short stroke steel crank should lead a pretty long life. I buzzed a non-twist BBC forging 7600 for over 450 rounds. To the best of my knowledge that same crank is still at it some 30+ years later in bracket duty. Yes, a GM part. Flux it, cut it, run it.

 

There’s not a lot of Small Journal stuff available.

 

^^^^
True enuff root, but still worth saving $$$$ based on what the end game is. Once it's in there floppin around my guess is it'll swing 7K with few worries if the rods and pistons are up to it. Car ran high 11s 12 flat, that's not a really hard target, but not necessarily a fast food level cheap date either. I wanna hear it when its done!

 

Neat car! Nothing wrong with a GM crankshaft properly prepared.

 

Beautiful. Happy crusade.

 

I have been pondering using the Dart SHP and an aftermarket crank and building the indestructible 327.

 

yeah, too bad. I got nothin' now.