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Author Topic:   4130 crankshafts
jhswords
Dirt Roller

Total posts: 6
posted October 10, 2005 05:36 PM  
what are the good points and the bad points of a 4130 forged steel crankshaft

rocket36
Dirt Freak

Total posts: 209
posted October 10, 2005 11:13 PM  
much better alternative to the near 50 year old factory items but not as durable as 4340.

jhswords
Dirt Roller

Total posts: 6
posted October 11, 2005 02:15 PM  
will they stand up to 500 hp and 7500 rpms?

psycho47
Dirt Full Roller

Total posts: 48
posted October 11, 2005 02:28 PM  
A cast crank prepared well can handle those numbers. I would think a 4130 could handle it but alot of it depends on how well it is balanced and machined.

racefan12
Dirt Roller

Total posts: 7
posted October 11, 2005 07:53 PM  
the 4130 can handle what your wanting but so can a quality cast crank...if you want something nicer than a cast crank go ahead and spend the little bit of difference to get the better 4340

Chuck
www.warriorperformance.com

zeroracing
Dirt Forum Champ
Total posts: 1876
posted October 14, 2005 10:55 AM  
When it comes to crankshafts my recomendation is buy a good quality american made part. Or the new callies I think it is, has a new compstar that is supposed to be a jap forgding and American finish machine. Many of the others Eagle, scat use chinnesse junk and try to machine it out some. Go to 4m.net and look over any of the talk about cranks all the engine builders agree china=junk.
I run a stock crank with prep work, and hold my breath one of my motors.
On the other motor I run a sonny bryant crank, like the engine guy said "this is beyond perfect".

racefan12
Dirt Roller

Total posts: 7
posted October 15, 2005 07:51 PM  
I agree that the American cranks are great, but it is unrealistic to expect a guy to spend $1500-$3000 on just a crankshaft going in to car that is running for $350 to win about 10 weeks a year. A 4340 forged steel "Jap" crankshaft is still considerably stronger than any factory piece and can expect to receive multiple seasons of use. Many of Eagle's, Scat's, and Cat's early cranks were not good on size and had some questionable quality control issues, which has given the entire import crankshaft market a bad name. I personally inspect every crankshaft that goes out our door for size, stroke, and run-out to help combat these problems. I have a number of well-respected engine builders in our region that rely on our products. These guys would not put their reputation on the line if we did not produce quality piece.

Thanks,
Chuck
www.warriorperformance.com

[This message has been edited by racefan12 (edited October 15, 2005).]

oldfordmod
Dirt Full Roller

Total posts: 46
posted October 16, 2005 11:26 PM  
4130 steel is not a good material for crankshafts. It does not case harden very well. 4340 is the best known case hardening steel and makes the best crankshaft. I don't know why someone would forge a crank from 4130 unless it really cost less (china). A cast crank which was nitrided would be as good if not better than a 4130 crank. I have ran them (nitrided) in a class that required stock cranks (351 ford) and never broke one.

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