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Fastest Chkn N the South!
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Discussion Starter #1
I'm thinking you have to re-balance the crank when you go to a 107" or 114", is this correct? :thanks:
 

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Why rebalance?
A 114 can come in a few flavors and if it is stock crank big bore if the piston weight is comparable to stock (possible with pin weight juggling) then no need. When a crank kit is purchased and for my money while the cases are split why not have it done. Hoban Crankworks can accomplish this as well as others. Is it absolutly necessary, no. Adviseable yes.
 

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Fastest Chkn N the South!
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Discussion Starter #3
:hmmm: So the crank has to come out to bore the cases anyway, right? So you might as well go ahead and have it balanced while it's out......OR, since you're in that deep on the labor and rebalancing anyway you might as well go ahead and stroke it. And since one crank costs the same as the next....

It seems to me like there are only two logical choices. 98" or 131"!!! :D

My, how we rationalize the madness. :yes:
 

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The crank does not have to come out to bore cases for bigger cylinders. If you have a 02 or earlier 88". you could put a mild 114 together without going into the bottom end, assuming that the pistons weighed the same and the crank was good.

I would not do it to a 03 or later without doing the crank bearing upgrade. If you are building an engine for a bagger that probabley won't see 4500 rpm, there shouldn't be a problem.
 

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Maximum engine size stock bottom end, no case boring for 99-06 TC excp 06 Dyna = 98"
Maximum engine size stock bottom end, no case boring for 06 Dyna and 07 up Big Twin = 107"
 

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<<The crank does not have to come out to bore cases for bigger cylinders. If you have a 02 or earlier 88". you could put a mild 114 together without going into the bottom end, assuming that the pistons weighed the same and the crank was good.>>

How do you get a 4.250 bore cylinder into 02 or earlier stock cases without boring??

:huh:
 

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Fastest Chkn N the South!
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Discussion Starter #7
"How do you get a 4.250 bore cylinder into 02 or earlier stock cases without boring??"

You don't...but that's not what he said.
 

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Fastest Chkn N the South!
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Discussion Starter #8
You already have the Timken bearing setup in the earlier engines...that's all he meant I think.
 

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I see from the statements above that going to 95" with S.E. cast flat top pistons, the weight sould be close enough that reballancing is not needed? Correct?
 

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I'm thinking you have to re-balance the crank when you go to a 107" or 114", is this correct? :thanks:
I think you should go for it, or are you chicken Colonel Sanders.
Ok, couldn't resist that one. I did a 107 all bore and a 104 All bore without balancing. I see no reason to as long as your piston weights are correct.
However, it's apart, you are spending good money on a build why not balance? Smoother ride and it can't hurt longevity. Just be sure to have someone do it who fully understands it. Lots of balance jobs out there that are not balanced at all.
 

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question on balance crank?

i was reading post in the other thread (Question 98"...largest without crank rebalance?) dont really understand the balancing crank,i am doing a 104 build and having the flywheel plug and welded so if i have it all apart i should have the crank balanced too,:confused:thanks
 
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