External Balance Forged Cranks Exist!
Thread Starter
Race Director
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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External Balance Forged Cranks Exist!
Well, despite the fact I've read/heard several people say ALL forged cranks are internal balance, they're not.
Scat sells their 1pc rear main seal 383 forged cranks in:
External rear/Internal front
Just thought I'd post this cause 1/2 hour AFTER I ordered a cast crank, I found this out.
I may not change/cancel my order for the Scat Cast crank and get a forged instead, but I'll probably sleep on it. FWIW, I'm trying to build for longevity (i.e., 100k mile motor)
Opinions?
530TQ/450HP 383 build (SLP/TPI intake) -- should turn out similar to this build:
http://www.superchevy.com/technical/...t_results.html
Scat sells their 1pc rear main seal 383 forged cranks in:
External rear/Internal front
Just thought I'd post this cause 1/2 hour AFTER I ordered a cast crank, I found this out.
I may not change/cancel my order for the Scat Cast crank and get a forged instead, but I'll probably sleep on it. FWIW, I'm trying to build for longevity (i.e., 100k mile motor)
Opinions?
530TQ/450HP 383 build (SLP/TPI intake) -- should turn out similar to this build:
http://www.superchevy.com/technical/...t_results.html
Race Director
Joined: Apr 2003
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From: moraga ca
Sorry Gregg. I'm trying to understand what you are saying. You ordered a cast crank because you want and externally balanced crank and believed that all forged cranks were internally balanced? Now you've discovered that forged cranks are internally or externally balanced and...?
Le Mans Master
Joined: Aug 2000
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From: Australia
Thread Starter
Race Director
Joined: Nov 2003
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Sorry Gregg. I'm trying to understand what you are saying. You ordered a cast crank because you want and externally balanced crank and believed that all forged cranks were internally balanced? Now you've discovered that forged cranks are internally or externally balanced and...?
Race Director
Joined: Apr 2003
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From: moraga ca
Thread Starter
Race Director
Joined: Nov 2003
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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Though the Scat9000 is rated at 600hp (and presumably similar torque), I have to consider whether a forged will hold up better over time. Seems like factory are cast IIRC, so it's probably nothing I should consider,,,but if I did, now is better than later!
Thread Starter
Race Director
Joined: Nov 2003
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
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Thread Starter
Race Director
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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, doesn't carry the 5.7" forged Scat 1pc RMS)Still doable with no cost for restock, etc...
Le Mans Master
Joined: Aug 2007
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From: WV
I think I've got a thread in here on cast vs forged. I'd have to look.
Though the Scat9000 is rated at 600hp (and presumably similar torque), I have to consider whether a forged will hold up better over time. Seems like factory are cast IIRC, so it's probably nothing I should consider,,,but if I did, now is better than later!
Though the Scat9000 is rated at 600hp (and presumably similar torque), I have to consider whether a forged will hold up better over time. Seems like factory are cast IIRC, so it's probably nothing I should consider,,,but if I did, now is better than later!
Race Director
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..WW
Thread Starter
Race Director
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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Direct from scatcrankshaft sales: 600hp and 7200rpms is their rating.
Eagle cast is 500hp. And White Performance confirmed the Scat cast units are harder to drill into (for balancing) than Eagles.
So....I went with a Scat to get the strongest cast model. Now I know another level exists above that (where I can keep my DMF).
Eagle cast is 500hp. And White Performance confirmed the Scat cast units are harder to drill into (for balancing) than Eagles.
So....I went with a Scat to get the strongest cast model. Now I know another level exists above that (where I can keep my DMF).
Le Mans Master
Joined: Mar 2006
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From: E. Amherst NY
Personally, I'd stick with the 9000 series crank. I don't seem to recall you mentioning spraying or boosting outrageous amounts on the bottom end. And with the TPI setup, its a safe bet you're not spinning it to 7500RPM. 
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Race Director
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From: Overland Park Kansas
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Can forged be just as likely to have a flaw (and break)?
What about the strength of a cast iron SBC block. Is a cast steel crank as strong/stronger than the block. Unless you have a better block, would forged be overkill?
What about the strength of a cast iron SBC block. Is a cast steel crank as strong/stronger than the block. Unless you have a better block, would forged be overkill?
Le Mans Master
Joined: Aug 2007
Posts: 8,735
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From: WV
Direct from scatcrankshaft sales: 600hp and 7200rpms is their rating.
Eagle cast is 500hp. And White Performance confirmed the Scat cast units are harder to drill into (for balancing) than Eagles.
So....I went with a Scat to get the strongest cast model. Now I know another level exists above that (where I can keep my DMF).
Eagle cast is 500hp. And White Performance confirmed the Scat cast units are harder to drill into (for balancing) than Eagles.
So....I went with a Scat to get the strongest cast model. Now I know another level exists above that (where I can keep my DMF).
http://www.pmeracing.com/scat/scatcast.htm
SCAT
9000 Series Nodular Crankshafts
All 9000 Series Crankshafts are manufactured from a new revolutionary Space Age 9000™ Series Material. This material was designed for high strength and fatigue resistance. 9000™ Series material is the strongest cast material available! 25% stronger than the standard cast iron, and 2 to 5 pounds per crank lighter than a stock crank. Estimated horsepower use is 500HP for small blocks and 600HP+ for big blocks.
Last edited by WW7; Dec 9, 2009 at 08:29 PM.
Team Owner
Joined: Mar 2001
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From: Boston, Dallas, Detroit, SoCal, back to Boston MA
I was given the option of having my balanced internal or external.
I went internal since I was going away from the DMF anyways and it puts less of a load on the bearings.
The shop I used had to switch to a Lunati crank, he couldn't get it to balance with the SCAT and the short 5.7 rods.
I went internal since I was going away from the DMF anyways and it puts less of a load on the bearings.
The shop I used had to switch to a Lunati crank, he couldn't get it to balance with the SCAT and the short 5.7 rods.
Pro
Joined: Feb 2005
Posts: 658
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From: Centerville OH
Given your stated goals and usage, I think that a forged crank will be a waste of money. The SCAT cast crank should be plenty strong for your application.
BTW -- I got your e-mails but I haven't had a chance to respond yet.
BTW -- I got your e-mails but I haven't had a chance to respond yet.