max line bore?

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That would make the main webbing and the main cap bolts kind of close to each other and the main cap a little thin on top.(bottom of cap that is)
 
Here is the forged 3.58 crank with the 318 or 340 mains.

CHRYSLER Mopar Performance P5007253 Mopar Performance Forged Crankshafts | Summit Racing - Free Shipping on Orders Over $99 at Summit Racing
CHRYSLER Mopar Performance P5007253 Mopar Performance Forged Crankshafts | Summit Racing


And here is the cast version.

CHRYSLER Mopar Performance P5007257 Mopar Performance Cast Crankshafts | Summit Racing - Free Shipping on Orders Over $99 at Summit Racing
CHRYSLER Mopar Performance P5007257 Mopar Performance Cast Crankshafts | Summit Racing

Might be cheaper just have the mains turned down on your 360 crank to the 318 340 size.
 
Here is the forged 3.58 crank with the 318 or 340 mains.

CHRYSLER Mopar Performance P5007253 Mopar Performance Forged Crankshafts | Summit Racing - Free Shipping on Orders Over $99 at Summit Racing
CHRYSLER Mopar Performance P5007253 Mopar Performance Forged Crankshafts | Summit Racing


And here is the cast version.

CHRYSLER Mopar Performance P5007257 Mopar Performance Cast Crankshafts | Summit Racing - Free Shipping on Orders Over $99 at Summit Racing
CHRYSLER Mopar Performance P5007257 Mopar Performance Cast Crankshafts | Summit Racing

Might be cheaper just have the mains turned down on your 360 crank to the 318 340 size.
ive looked at them many times, figured it many ways, to many! wish some body made a 3.70ish small journal crank!
 
That would make the main webbing and the main cap bolts kind of close to each other and the main cap a little thin on top.(bottom of cap that is)

It's possible. If the shop really does it the "right" way and just barely skims the block so as not to move the crank up and make a stock timing chain loose, it might take too much off the caps. How thick are they to begin with? At .310, you might as well say you're removing 5/16 (.312) from the cap. That's a lot. Plus then, you'd need to have the bearing lock machined back in. I speck it could be done, but should it?
 
It's a circle so you'd only be cutting half of that .310 out

How much have people been hackin off 440 cranks to go in 400s? A lot. Not as much as .310, but a lot.
 
How much have people been hackin off 440 cranks to go in 400s? A lot. Not as much as .310, but a lot.

People only do that to the 400s when they want to go fast.
If God allows it.
I'm going to have a 360 crank cut down and put in a 318 with a 4-inch bore.
You ask why? Why would you put a 360 crank and pistons in a 318?
Because I want the markings for the 318 on the side of the block. But I want it to run better than a stock 318.
 
People only do that to the 400s when they want to go fast.
If God allows it.
I'm going to have a 360 crank cut down and put in a 318 with a 4-inch bore.
You ask why? Why would you put a 360 crank and pistons in a 318?
Because I want the markings for the 318 on the side of the block. But I want it to run better than a stock 318.

Not a damn thing wrong with that. You couldda just said "cause I want to" that's reason enough.
 
yes it makes more since to turn the crank, cheaper to, not to mention smaller bearing =lower bearing speed! just thinking to much i guess! looking for a different way around the same block, weighing all options!
 
You can't do it "line bore wise" on a 318 cap. there's not enough meat in it no matter what anyone says. It wouldn't last. you have to change the cap if you wanted to even attempt to approach it in such a way...and use studs, not bolts and all that short of threads nonsense.

Turn the mains down or buy a crank.
 
^^^^^^THIS^^^^^ just turn the crank down. How do you think it was done in the 1970’s?
And is still done these days!
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100_3184.JPG
 
I like that. Cheap enough. As far as needs finishing, is that on both rod and main journals to the respected size? 331&379.
Probably.


That forging (could be a casting...I didn’t look at the link) needs every machining process done to it, including the flange and snout.

You have to find a crank grinder with the skill to do it, will do a one off one time deal and then he has to WANT to do it. Those ain’t easy to find. I looked into that and the only one I could find to do it was Marine Crankshaft, and he wasn’t all that enthusiastic about it.

His exact words were “unless you need some oddball stroke to get into a class what you want is certainly cost prohibitive”.

I think he was at 800 bucks on the low side and a grand on the high side.
 
That forging (could be a casting...I didn’t look at the link) needs every machining process done to it, including the flange and snout.

You have to find a crank grinder with the skill to do it, will do a one off one time deal and then he has to WANT to do it. Those ain’t easy to find. I looked into that and the only one I could find to do it was Marine Crankshaft, and he wasn’t all that enthusiastic about it.

His exact words were “unless you need some oddball stroke to get into a class what you want is certainly cost prohibitive”.

I think he was at 800 bucks on the low side and a grand on the high side.
Yea, I ain’t into that. Lol.
 
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