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Crankshaft question ? #2757330
03/29/20 06:16 PM
03/29/20 06:16 PM
Joined: Nov 2009
Posts: 3,082
St. Paul , Mn.
tubtar Offline OP
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tubtar  Offline OP
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St. Paul , Mn.
Mancini has some small block unmachined forgings for cheap.
220.00
Since I am in the middle of exploring options for a stroker kit , I am wondering if this makes any sense.
I know where there is a set of Carillo 6.125 rods for cheap , and they are small journal Chevrolet size on the big end.
So would it be financially prudent to snag one of these crank shafts , have it offset ground and sized for a 4 " stroke or so , and cyro or heat treated ?
I am guessing that there is very close to enough material to pull this off , even though they say 3.79 stroke , since that is with MoPar sized journals.
Obviously , I'm trying to stick with shelf pistons.
I would be into pistons and rods for around a grand , and have a high end forged stroker rotating assembly.
But I can pick up a decent forged kit for just north of two G's.
Since there is some time before anything can be done due to the ongoing craziness , I have the luxury of entertaining silly ideas.
https://www.manciniracing.com/dealpart143.html

Last edited by tubtar; 03/29/20 06:16 PM.
Re: Crankshaft question ? [Re: tubtar] #2757469
03/30/20 02:13 AM
03/30/20 02:13 AM
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Minnesota
Hemi_Joel Offline
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I would call a crank grinder and see how much they would charge to finish the crank. Then you'll know if you can save any $$

I use crankshaft supply in Minneapolis.


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Re: Crankshaft question ? [Re: Hemi_Joel] #2757534
03/30/20 10:57 AM
03/30/20 10:57 AM
Joined: Nov 2009
Posts: 3,082
St. Paul , Mn.
tubtar Offline OP
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I got some ideas from a couple or guys who would know.
Somewhere between 1000 to 1500 bucks to have it finished.
Besides journals , it would need oil holes , thrust surfaces , key ways ...........then tempering.
Add that it is 1053 steel and it makes no sense to even consider.
Crankshaft Supply did the 3.79 arm in my 405 incher........corrected and took it .010 / .010.
They are about the best up here , but for this work , I would be looking at another 150.00 in shipping it to and from Callies , Crower or ???

Re: Crankshaft question ? [Re: tubtar] #2757574
03/30/20 12:40 PM
03/30/20 12:40 PM
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Alexandria, LA
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Blucuda413 Offline
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Years ago before the 4" cranks were common I had a 3.79 crank offset ground to 2" journals increasing the stroke to 3.91. If I remember correctly it cost me $400-$450 to have that done and it was better than 20 yrs ago. I would imagine that having that crank completely dressed would be much more than a good forged 4" unit.

Re: Crankshaft question ? [Re: Blucuda413] #2757585
03/30/20 01:04 PM
03/30/20 01:04 PM

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Superfreak
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I would checking pricing from Molnar as you would likely get a ready to drop in crank for about $600 - &700

Re: Crankshaft question ? [Re: ] #2757667
03/30/20 05:21 PM
03/30/20 05:21 PM
Joined: Nov 2009
Posts: 3,082
St. Paul , Mn.
tubtar Offline OP
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BPE has one with a 2" journal.........I'm not sure that Molnar does , but I will look.

Re: Crankshaft question ? [Re: tubtar] #2758093
03/31/20 05:49 PM
03/31/20 05:49 PM
Joined: Nov 2009
Posts: 3,082
St. Paul , Mn.
tubtar Offline OP
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I messaged with Rod at BPE and he was having troubles with delivery and tariff issues , so he had nothing in stock that would work for me.
Spoke with Tom Molnar and just bought the crank and rods from him.
Even with the chance at a set of used Carillo rods in 2" for four bones , and then a set of Oliver's in 2.1 " for five , finding a quality four inch crank was looking like a long wait or big $$$ for either.
Using MoPar journals isn't a deal breaker...........not for this build for sure.
But it has been an education.
Especially when looking at throwing together a rotating assembly with used " good " parts.
Grinding a crank .010 / .010 is cheap.
Having one indexed is nothing.
For what it would cost to have unmachined cranks finished ?
Not for the faint of heart. Or wallet.
And by the time I would have chased down everything , the savings would not be all that great.

Re: Crankshaft question ? [Re: tubtar] #2758160
03/31/20 09:15 PM
03/31/20 09:15 PM
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Posts: 20,356
Eagle, Idaho
Neil Offline
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Eagle, Idaho
Normal crank procedures are not too expensive, but when you get into offset grinding and custom stuff it can cost a lot because that is time spent.

My brother is having a steel Oldsmobile crank offset ground to get more cubes, and it's a slow process as the grinding wheel can only take off so much material at a time. Nobody makes a crank with this particular stroke so it is what it is.

Re: Crankshaft question ? [Re: tubtar] #2758249
04/01/20 12:28 AM
04/01/20 12:28 AM
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Oregon
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AndyF Offline
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Oregon
It would only make sense if you have a buddy who owns a crankshaft grinder and is willing to do it for cheap. If you walk in off the street and pay full shop rate then you'll have a ton of money invested in that crank. If the crank shop you take it to isn't on the top of their game then you'll have an expensive doorstop. There used to be a shop in my local area that had a big CNC grinder and they could offset grind Mopar cranks for $150 or $200. The cranks came off the grinder right at spec and ready to drop into an engine. They went out of business back in the big recession and that was the end of that. Now it is impossible to find some in my local area who can do custom work like that. The local shops can barely hit spec doing a basic 10/10 job on a Chevy 350 crank much less something more complex.







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