340 crankshaft value

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72dustervs said:
This seller says this is a 1968 69 70 71 72 Dodge Plymouth Nice Original Mopar 340 Forged Steel Crankshaft ,,I am looking at buying this , I just acquired a 73 340 engine and want a forged steel crank , says its been polished an ready a few years back but never installed , .010 mains .030 rods
Price is $350 ,, any opinions about condition an price compared to buying new ? Should I pass and buy a new one ?
I have torn down the 340 and getting ready to send to machine shop

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What the hell is that big notch milled out of the flywheel flange for? That looks strange.
 
Have not seen the sellers description, but I would not trust that crankshaft. Why did they do such excessive machine work on it? How long did it run after the machine work? Any grantee, that it didn't fell 3 times from a storage shelf? Nope, no way too much risk. If you like it original, I am sure there are better cranks with less eventful history out there.

Wolfgang
 
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rumblefish360 said:
That is not in dispute.
Again, I read it as a cast 340 crank is better than a 318 or 360 cast crank.

IDGAF about any other brand.
If the above is true, how so?

AKA - Educate me.
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I did try to educate you. You didn't want the article. You don't want comparisons to other brands. The cast 340 cranks weren't any different than any of the rest of the cast Chrysler cranks other than they "may have" been shot peened. That seems to be the rumor with the heavy duty 318 cast truck cranks too, although I've never seen one that I could tell 100% was shot peened. Either a cast 340 or otherwise.

What more are you asking for here? I'm not sure I understand.
 
512Stroker said:
What the hell is that big notch milled out of the flywheel flange for? That looks strange.
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340 Cranks and other cranks have the 1-2 and 7-8 throw/journal lightened with a hole drilled in or through it. The notch is needed for access for the drill to create this lightning hole.
To the OP, what con rod and what piston do you intend on using? If your changing away from a piston that weighs 880 grams and a likewise porky con rod, a forged 318 crank would be more in-line for when it comes to having the stuff ballanced, (no lightning hole, and more plentiful, more suited to a match in bob-weight requirement with lighter components). If you had no intentions on new rods, pistons and ballance, then disregard the forged 318 idea.
 
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One good the about the 340 I acquired , it appears to be the first time its been apart , I know it was sitting for last 20 to 30 years in my friend's garage , so if it is indeed STD and the crankshaft is in good shape I may use it , going to wait and see what the shop tells me about the crank as far as cost and condition , if I don't like what shop says then I will by a new forged steel crank and not the $350 , the seller did say it had not been used since the work was done but few things about it I don't like that some already pointed out , the difference in the rods to main bothered me as well , I appreciate all the feedback
 
Yes, the 340 cast crank used a specially weighted flywheel. A forged crank version can be converted however, or you can have the crank zero balanced.
 
rumblefish360 said:
Pfst! Let’s keep the comparo in house, da MoPar house, screw the other guys. How is this better than a 318 or 360 cast crank? That’s the way I read it.
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Because it’s shot peened. The balls of shot are blasted at the crank to compress the metal to make it stronger. Some 360 hp engine hp motors have shot peened cranks also. 74/75 but I’m not sure about 1976. Kim
 
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Max1196 said:
340 Cranks and other cranks have the 1-2 and 7-8 throw/journal lightened with a hole drilled in or through it. The notch is needed for access for the drill to create this lightning hole.
To the OP, what con rod and what piston do you intend on using? If your changing away from a piston that weighs 880 grams and a likewise porky con rod, a forged 318 crank would be more in-line for when it comes to having the stuff ballanced, (no lightning hole, and more plentiful, more suited to a match in bob-weight requirement with lighter components). If you had no intentions on new rods, pistons and ballance, then disregard the forged 318 idea.
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Interesting, the forged 340 4 speed crank that I now run in front of a 727 setup I dont recall it being notched like that.
 
If this notch is the one your asking about the cast crank has it as well

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I had my 340 crank machined .010 under mains, .020 under rods for $250. I would say $350 is "in the ball park" especially if it is drop in ready. I think if you start getting above $500-$600 start looking at new. However the new ones may not be USA steel for example:)
 
K1 is good stuff. He used to be Molnar, sold it then started up again. Or I got it backwards but in any case u can’t go wrong with their products. Kim
 
If you want 340 cubes then ok, go stock. If you are replacing the rods/crank I would go with a 4” rotating assembly from Molnar or K1.
 
72dustervs said:
Question , since going 4 spd is there a difference in flywheel for balance if I use the cast crank ?
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Yes, I would buy a McLeod flywheel, that accepts the bolt on weights, it will work with any small block, just change the weight for balance.
I have one in my Duster, no balance issues with a cast crank 340.
I also used the larger 143 tooth one in my power wagon with a 360 mag, again no balance issues, just bolt on the correct weight.
 
Cast is fine... Chrysler was always know for superior metalurgy compared to GM bits. GM reserved their better metals for the Cadillacs and Buicks... Pontiac and Olds got OK stuff but Chevy always for the poorest quality steels. Ask any machinist what cranks and blocks are the toughest to machine.

My last early Hemi build went to a shop who had never bored a Hemi block. He had to sharpen his tooling three times in eight holes...
 
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