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Author Topic:   Stock Cranks
chief4car
Dirt Full Roller

Total posts: 56
posted October 09, 2002 08:14 PM
Guys,

I am building a 12.5 to 1 compression 500 to 550 Hp 406 that will run at about 6800 to 7000 rpms.

Will a stock crank hold up or should I bite the bullet and by aftermarket (not scat ot eagle either)

Thanks
Jim

Monster
Dirt Maniac

Total posts: 135
posted October 09, 2002 09:41 PM
I've never been impressed with the appearance of stock Chevy cranks, especially the 400s, but you can't judge a book blah, blah, blah.I'm not going to say 'no way', but I guarantee this: you will have a better feeling in your gut with a good strong crank in that engine. Personnally, I have never had a problem with the foreign-forged stuff, but I do check things out very thoroughly before use. I look at them as a good starting point, with more work needed to make them useable. Also, I have never bought a NEW high dollar Crower, Bryant, or Winberg piece for my own personal engines. Good used ones are very available if you don't mind hunting them down. I guess it depends on budget: Little as possible, stock stuff. $500-750, Budget aftermarket. $1000-1500, used hi-dollar. $2000-3000, you are THE MAN, and you probably can afford to pay someone to make this decision for you! LOL! Keep this in mind: when a crank breaks, it usually ruins the block as well, so that should factor into your decision also.

c21
Dirt Freak

Total posts: 346
posted October 10, 2002 11:18 AM
I'd suggest aftermarket crank, rods and .....
splayed main caps (a girdle over the rear cap would probably be OK)... Those 400 blocks are a little weak and tend to give it up at those power levels.

c21

chief4car
Dirt Full Roller

Total posts: 56
posted October 10, 2002 11:46 AM
Monster,

When you talk about the foreign cranks being a good starting point what do you mean. Do you perform extra machining on them or what.

I have learned a lesson about checking and rechecking things. We lost our last motor to a spun bearing that was probably caused by the big end of the rod not sized properly or out of round, this was a scat rod. This is why I have a bad taste in my mouth for the foreign stuff. But if you have used then succesfully i would like to hear how.

Thanks
Jim

Flatlander
Dirt Freak

Total posts: 310
posted October 10, 2002 01:21 PM
Well I don't know about that much compression on a stock crank I've run a lot of 10.to 1 motors amd turned them up to 6500 or so But I bought a dragonslayer and have had good luck I have had good luck out of scat rods but like monster said check all the pieces yourself and know what you got when you put it together and BALANCE BALANCE the assbly I know as a rule everyone knows this but even if it says it comes balanced get someone you trust to check it out

ray14
Dirt Full Roller

Total posts: 67
posted October 10, 2002 11:21 PM
we use eagle 4130 steel cranks in our limited late model turning around 7500 to 8000 rpms an had no problems,we also use eagle 6" rods. bye the way we runing 675 horse 383.

'

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