Inherited a crank w/my house purchase a few months back- it appears to be a SBC unit- but I can't find a casting number anywhere. Been looking on all the counterweights and I understand that forged cranks may not have had the best/most readable numbers to start with- Anyone got any tips or ideas (I really don't want to have to soak this thing in a vat of varsol and scrub it down all over)?

Why not mic the main and rod journals and see what you get? If it is a GM forged crank I believe it will have a wide casting line.

I hope it turns out to be a good find.

Later,

ChevyReb

Small block crank flange info:

If it's round = 283. Round with a notch cut out = 302. Half round with a square section = 327. Half round (with kind of a wing added to it) with a square section = 350.

Thin parting line = casting. Wide parting line = forging.

That is my junkyard/garage sale quick id guide. I've never seen the round with the notch missing, but if I ever do, I'm on it.

Well- it appears the crank is a forged unit, and it has a round rear flange with 6 flexplate/flywheel mount holes, a larger index-type hole and a single cut-out. The crank throw on the #7 and #8 rods is also different than the rest- sort of a crown shape to it.

This sound like a 302 crank? What differentiates an older 2-piece rear main seal crank from a newer single piece rear seal crank? Seems kinda odd someone left me a good crank- although the previous owner apparently did like pre-1973 trucks.

pics would say 1000 words http://www.nastyz28.com/ubb/wink.gif

You said it all coupe400. No hard feelings, but like he said, it's a mystery. Need pics. Just 1 hint. LOL

If the seal flange is larger than the rear main journal you have a small journal crank, Same size is a large journal crank.

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Custom Auto, your source for quality machine work, cores and new parts at competetive pricing right here in British Columbia 1-888-563-4050
A Canadian, EH? (with a 10 second street car)

Yeah, And if the seal flange is smaller, it's a 400. Right? Am I saying this right. Man, If we figure this thing out, I would say we are all pretty damn good. http://www.nastyz28.com/ubb/smile.gif

<font face="Arial,Verdana" size="2">Originally posted by Breese:
Yeah, And if the seal flange is smaller, it's a 400. Right? Am I saying this right. Man, If we figure this thing out, I would say we are all pretty damn good. http://www.nastyz28.com/ubb/smile.gif

</font>


Correct!
The other way to determine a 400 crank is they always came with a dowel in the crank flange to postition the flywheel counterweight correctly.

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Custom Auto, your source for quality machine work, cores and new parts at competetive pricing right here in British Columbia 1-888-563-4050
A Canadian, EH? (with a 10 second street car)

OK, here we go (I'm wondering now if I'm even barking up the right tree on this crank):

http://www.nastyz28.com/~ericf/myscrank/flngtop.jpg

http://www.nastyz28.com/~ericf/myscrank/flangeside.jpg

http://www.nastyz28.com/~ericf/myscrank/headon.jpg

http://www.nastyz28.com/~ericf/myscrank/topdown.jpg


and the 7&8 rod main:

http://www.nastyz28.com/~ericf/myscrank/78main.jpg


Any ideas?

If I had to guess,, I'd say it's an international crank http://www.nastyz28.com/ubb/wink.gif
I think ya got a large size paperweight there Eric

Ditto Marv on this one???????????????????

B/c it sure isn't a Chevy crank that I know of...

pdq67

got a thick piece of flat steel?? build a base and a top and make a table!

Damn, which river was that crank at the bottom of?

Yup- this thing's now loaded in the back of a trailer with 3 rotted out Jeep doors which were left behind by the previous owner of my house- all going to the dump tomorrow.

With all of the jeeps this guy had it could very easliy be a crank to a 290, 304 or even 343 AMC motor.

Yep,
AMC.

Thrust is on the 3rd main, not the rear as a Chevy.

For the hellavit I'd clean it up and Ebay that sucker http://www.nastyz28.com/ubb/wink.gif AMC parts are high!

Don't take it to the dump. Some Scrap dealers are still paying for scap steal/iron.
I know its only like $25-$50/ton, but here if i take something to the dump, I have to pay a dump fee and its farther then the scrap dealer, so I am a double looser that way. Just my .02 worth.

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70 1/2 Camaro Z/28 with 461cu.in. BBC & OD Auto, 3.31 12 bolt posi.

Doh! Too late- it's at the bottom of a dumpster in the town dump. Ebay'ing probably wouldn't work real well anyways- that friggin' thing weighed about 80lbs.

<font face="Arial,Verdana" size="2">Originally posted by wayner:
Some Scrap dealers are still paying for scap steal/iron.
I know its only like $25-$50/ton,

</font>

Here scrap is running anywhere from $130 to $160 a gross ton(2240#). The structural steel fabricator I work for sells scrap to the recycle yards by the tractor trailer loads(a min of two loads/week) and the checks come across my desk for verification, so I keep a pretty good eye on the prices these days.

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John Wright

John,

What's your Boss's Crew's beer-cans going a pound for??

He, He!!

pdq67