340 CRANK?

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Franko

Franko

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I purchased a 340 dated December 1968. It appears to be completely stock and doesn't appear to have ever been apart. The pistons and rods have original casting numbers. But I can't find any casting number on the crank. The crank is a steel one and the first and last rod journals were drilled for balancing, I believe. I am attaching pictures of the crank. If you zoom in on them you can see thin metal left over from being drilled.

Has anybody ever heard of a 340 crank that had no casting number? And would you agree that this appears to be a stock 340 crank?

Thanks for you help.

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Definitely a forged crank. Those holes are punched out on all cranks for the front and rear throws. Surprised you don't see a number but maybe on cast only?
 
That is definetly a forged crank , looks stock too , could have been a warranty replacement , me too donno if forged cranks had # (cant be casting # since it is not a casting , maybe look for a forging #) , Ok puns aside I am going to a friends place on the weekend and he has many in stock , I will look if they have #s.
 
W-Edge said:
That is definetly a forged crank , looks stock too , could have been a warranty replacement , me too donno if forged cranks had # (cant be casting # since it is not a casting , maybe look for a forging #) , Ok puns aside I am going to a friends place on the weekend and he has many in stock , I will look if they have #s.
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Yep. most forged pieces have a machined pad with stamped numbers.
 
I have 2 other stock 340 forged crankshafts. They both have the casting number 2532457. So that is number I was looking for. Maybe this was produced on a Monday morning.
 
Franko said:
I have 2 other stock 340 forged crankshafts. They both have the casting number 2532457. So that is number I was looking for. Maybe this was produced on a Monday morning.
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if it has casting # it could be a late 340 crank like mid 72 or 73 (they were cast)look at the parting line in middle , in your pics you see it , its like 7/16in wide where on a casting it will be thinner like 1/16th...
 
The holes in the front and rear throws are standard on forged 340's; yes, they are there to help the crank balance with the heavier pistons in that engine. That rear main journal looks pretty oddly etched or stained.
 
Too rounded in the throws to be cast. I have a cast crank 340 and the corners are sharper with a small chamfer. The cast finish is not matte/granular too.
 
W-Edge said:
if it has casting # it could be a late 340 crank like mid 72 or 73 (they were cast)look at the parting line in middle , in your pics you see it , its like 7/16in wide where on a casting it will be thinner like 1/16th...
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Sorry just assumed it maybe was cast but reread your post and saw you mentionned FORGED , checked those #s too and cast cranks would have different # cast in them. my bad...
 
W-Edge said:
Sorry just assumed it maybe was cast but reread your post and saw you mentionned FORGED , checked those #s too and cast cranks would have different # cast in them. my bad...
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I have the same problem with my 69 340 has stock pistons and rods but cant find any casting numbers either! hmmmm!
 
Funny you should mention that, I have been trying to read "casting" numbers on my forged 340 crank and have not been able to make out anything, anywhere. It would seem if all of us can't find any numbers, that is the way the 340 forgings came. But I guess none of us are experienced enough to state that as fact.
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I have a collection of 340 forged cranks, and several forged teener cranks and a 273 forged crank. Not a one of them has a number on it. But each group scales a little differently.Which is how I ID them.
 
Franko said:
I purchased a 340 dated December 1968. It appears to be completely stock and doesn't appear to have ever been apart. The pistons and rods have original casting numbers. But I can't find any casting number on the crank. The crank is a steel one and the first and last rod journals were drilled for balancing, I believe. I am attaching pictures of the crank. If you zoom in on them you can see thin metal left over from being drilled.

Has anybody ever heard of a 340 crank that had no casting number? And would you agree that this appears to be a stock 340 crank?

Thanks for you help.

View attachment 1715068799

View attachment 1715068800

View attachment 1715068801

View attachment 1715068802
Click to expand...
Franko said:
I purchased a 340 dated December 1968. It appears to be completely stock and doesn't appear to have ever been apart. The pistons and rods have original casting numbers. But I can't find any casting number on the crank. The crank is a steel one and the first and last rod journals were drilled for balancing, I believe. I am attaching pictures of the crank. If you zoom in on them you can see thin metal left over from being drilled.

Has anybody ever heard of a 340 crank that had no casting number? And would you agree that this appears to be a stock 340 crank?

Thanks for you help.

View attachment 1715068799

View attachment 1715068800

View attachment 1715068801

View attachment 1715068802
Click to expand...
 
Franko! Just curious. Did get the engine w/a GTS dart
or just purchase the motor separate? As I purchased my
GTS Dec. 28 68 Phelps Dodge E. Lansing Mi. Sold it in
1975 then seen again as a complete car Edmore Mi.
in 1992 but didn't purchase it. I seen it on M-46 again
1997 then the guy sold it. Never seen again! Just
curious. Ddog!
 
On my other 2 stock 340 forged cranks - 1 has the notch in the flywheel flange, like the above picture shows, and the other one has no notch. Any ideas on why the difference?

AJ/FormS- Do any of your forged cranks not have a notch?

D.Dog- I bought this mostly complete 340 from a guy in Monroe, Michigan. He didn't know what 69 it was out of (Dart or Barracuda). The block is dated 12/9/68. Sorry I don't know more history on this engine.
 
Quote from above:
"On my other 2 stock 340 forged cranks - 1 has the notch in the flywheel flange, like the above picture shows, and the other one has no notch. Any ideas on why the difference?

AJ/FormS- Do any of your forged cranks not have a notch?"

I am looking at a "Crankshaft Quote/Work Order Form" and under the section "Flange" there is a question: "Scalloped Yes or No". Does anyone know what a "scalloped flange" would be? Thank you.
 
I *THINK* but I wouldn't bet more than 98% of what you have on it, but I *THINK* the flanges that are NOT notched are 318 poly cranks.

I used to buy them for $25.00 each.


Edit: and that 318 poly crank drops right into an LA block.
 
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I can't remember seeing any numbers on 340 cranks. They are shot peened if original forged cranks 70-72 from what I have seen. Not as familiar with earlier 340's.
 
PAW used to sell 340 forged cranks that were 318 poly cores. They just drilled the 2 throws and balanced them to 340 specs.
 
Franko; other than random two digit numbers, I've haven't seen any identifying numbers on a forged 340 crank. The 13/16" drilled holes in the [two] end crank journals are to help compensate for the extra weight of the HD rods in a 340. The notch in the flange is for clearance for the drill, and it helps a little for balance.
 
The crank I pictured in post #12 was taken from a complete 340 (not running) and the rod journals are not drilled, which leads me to believe it is a 273/318 crank. Who knows if the motor could actually work like that because I don't see any Mallory metal for re-balancing or anything.
 
I have balanced a few 340 (possibly 318) cranks, with and without the 'drilled crank' throws.
Most don't have any numbers to check for application.

They all have balanced up fine with stock 340 rods and pistons?

I always like to polish the beams and lighten the rods as much as possible anyways...
Then the crankshafts will need the counterbalances drilled when either crank is used lol.
 
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