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Cost vs benefits of a counterweighted crankshaft #2388379
10/16/17 09:04 PM
10/16/17 09:04 PM
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Charlotte, North Carolina
sgcuda Offline OP
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So, I want to build up my Indy block. I've been told not to go over 4.500" stroke by so called "People in the know". I've asked about CCW cranks. Everyone agrees that they are better. But I haven't received a straight answer on if it's worth it for my build. I understand it is easier on main bearings, but $150/set of main bearings compared to doubling or tripling the cost of the crank. If that is the only benefit, I might as well stay with a standard crank. Engine will be around 572 or slightly larger, not turning much past 7,000 rpm.

Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388406
10/16/17 09:45 PM
10/16/17 09:45 PM
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Hemi_Joel Offline
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Obviously, the lesser you pay for a CCW crank, the more worth it it becomes. Ohio crank sells a billet 4.5 for $1650. I would assume that has center counterweights. Or you could look for a good used alcohol crank. I scored a used moldex billet stroker with center counter weights, checked straight and crack free, for just over a grand. That was worth it in my opinion.

Re: Cost vs benefits of a counterweighted crankshaft [Re: Hemi_Joel] #2388415
10/16/17 10:01 PM
10/16/17 10:01 PM
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sgcuda Offline OP
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Originally Posted By Hemi_Joel
Obviously, the lesser you pay for a CCW crank, the more worth it it becomes. Ohio crank sells a billet 4.5 for $1650. I would assume that has center counterweights. Or you could look for a good used alcohol crank. I scored a used moldex billet stroker with center counter weights, checked straight and crack free, for just over a grand. That was worth it in my opinion.


Agreed. But not all alcohol cranks are CCW. The question is "Do I need this for a 1,000 hp N/A combo that is only going to turn around 7,000 rpm?"

If I'm not spinning it to the moon, and I'm not boosting or adding nitrous to make 1,500+ hp, how necessary is a CCW crank? To me, changing out bearings at the end of the race season wouldn't be a big deal, if that's all there is. But if the engine runs smoother and develops more power due to less torsional twist, it might be something to consider.

Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388419
10/16/17 10:08 PM
10/16/17 10:08 PM
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Well, most engines don't have it. On your motor, ccw's would probably be an attempt to fix a problem that doesn't exist. But don't we all love to do that when building a big moter? Just in case? wrench realcrazy

Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388436
10/16/17 10:50 PM
10/16/17 10:50 PM

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A few months ago I got a price for ccw billet hemi crank from Bryant for $3024 and I thought that was a good price considering that the same crank from Callies was $4300. I know it does not answer your question but just a little tid bit on the pricing.

Last edited by Superfreak; 10/18/17 06:17 PM.
Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388444
10/16/17 11:02 PM
10/16/17 11:02 PM
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sgcuda Offline OP
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Ohio Crankshaft has billet CCW cranks for $1645. But is it necessary over their $720 4340 crank? Or is it overkill for what I am building?


[image][/image]
Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388455
10/16/17 11:15 PM
10/16/17 11:15 PM

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You are correct, just looked at there web site and $1645 for the hemi ccw billet crank. Would have to have a register cut on the back side. Most people running in that hp range are using a standard forged crank from what I have read.

Last edited by Superfreak; 10/16/17 11:23 PM.
Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388463
10/16/17 11:23 PM
10/16/17 11:23 PM
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Once you buy a ccw crank, you have a unit that should never fail. I cracked a 4.15 stroke crank at 100 runs, and upgraded to a Crower CCW made of 304m steel. Since you are pushing piston speed and crank loading pretty high with a 4.5 stroke and 7,000++ rpm, I would go CCW.


8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388465
10/16/17 11:24 PM
10/16/17 11:24 PM
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Billet CCW shouldn't cost much if any more than non-CCW. The material is already there in a billet so CCW is most likely less machine time since the material doesn't have to be cut away.

I don't know the answer to your question but if I wanted the answer myself I'd call some people who have experience building big power engines and see what they say. It shouldn't take more than a couple of phone calls to get the answer.

Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388487
10/17/17 12:09 AM
10/17/17 12:09 AM

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There is a good read from "Engine Labs" regarding crankshafts.

Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388615
10/17/17 10:32 AM
10/17/17 10:32 AM
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For this build, I think it's overkill to go w/ a CCW crank. No downsides other than cost, but I don't think it needs it.

I'd love to hear more on the reasoning not to go over 4.5" stroke by those "people in the know" you referred to earlier.


CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax
Re: Cost vs benefits of a counterweighted crankshaft [Re: an8sec70cuda] #2388842
10/17/17 04:59 PM
10/17/17 04:59 PM
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The center counterweights do more than protect main bearings. They reduce the flexing load on the main bearing bulkheads by putting more of the counterweights closer to where they are needed.

It's sort of like the switch from external to internal balance.

R.

Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388849
10/17/17 05:14 PM
10/17/17 05:14 PM
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That's what I was thinking. $1600 is cheap at that power level to reduce stress on the lower block area.

Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388881
10/17/17 06:24 PM
10/17/17 06:24 PM

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So many great big CI engines run and make 1000HP without it
If you are going to ask --call Charlie Buck in King NC
He is in your hood and will have an opinion and answer based on probably more experience in big Mopars than anywhere else
Can't go in that place that Marsh does not have a big Hemi or wedge Monster on the pump--They know!

Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388921
10/17/17 07:48 PM
10/17/17 07:48 PM
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My motor has Mopar Mega block. Don't know whose crank but it was purchased from Indy as a short block well over 10 years ago. It's been in my motor 5 years. The 4.5" crank has a Pentastar stamped in it. Not a pretty "finished bull nosed counterweight" piece. Looks almost like a factory 440 crank. It was used when I got it. I've put around 550 passes at 7000-7200 rpm. Never had an issue. Motor makes somewhere around 900 hp. After my last tear down (300 passes)the rod bearings looked new. Mains were ready for replacement, but not horrible.
Doug

Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2388998
10/17/17 09:44 PM
10/17/17 09:44 PM

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Got a reply from Ohio Crank today and they said the billet can only be made with Chrysler journals.

Re: Cost vs benefits of a counterweighted crankshaft [Re: ] #2389032
10/17/17 11:08 PM
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sgcuda Offline OP
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Originally Posted By Superfreak
Got a reply from Ohio Crank today and they said the billet can only be made with Chrysler journals.


Well, since I don't want to run with anything larger than BBC journals, the billet piece is out.
From the info I have gathered, I have learned that 1) aluminum rods will not clear the cam with crank strokes longer than 4.500" and 2) crank strokes longer than 4.500" will cause excessive piston skirt wear.
Interesting enough, I have read somewhere about a new piston being made with an asymmetric skirt, favoring the major thrust side. Maybe just for this kind of build.

Re: Cost vs benefits of a counterweighted crankshaft [Re: an8sec70cuda] #2389037
10/17/17 11:11 PM
10/17/17 11:11 PM
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sgcuda Offline OP
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Happy Birthday, Chip!

Re: Cost vs benefits of a counterweighted crankshaft [Re: ] #2389069
10/18/17 12:06 AM
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Originally Posted By Superfreak
Got a reply from Ohio Crank today and they said the billet can only be made with Chrysler journals.


That doesn't seem to make sense. I can understand a forged crank only available in a certain journal size but billet is billet. It is all being machined anyway so all they have to do is punch a few buttons and then instant presto you have 2.200 rod journals.

If I got an answer like that from a place claiming to make billet cranks I'd move on down the line. I'm pretty sure if you call Winberg or Bryant or some other place that makes billet cranks and ask them if they can make the cranks with different rod journals they'll tell you sure. They can probably make each journal a different size if you want to pay for it. Someone at Ohio Crank either doesn't know what they are talking about or else they aren't really billet cranks. Or perhaps the cranks are made by someone else and Ohio Crank just sells them......

Re: Cost vs benefits of a counterweighted crankshaft [Re: sgcuda] #2389095
10/18/17 01:03 AM
10/18/17 01:03 AM
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My pops engine has a Ohio center weighted crank and has 2.2" rod journals? Possibly reground but was a new piece when he acquired it in a short block. Would be hard to tell if it was reground thou. Looks like a nice piece.

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