Dustin@PremierAutosports

iTrader: (2)

Getting ready to build a LS7 shortblock for my car. I'm working with a shortblock from a 07 ZO6 that had a seized rod. The stock crank looks as if it can be cleaned to stock journal size or at the most turned 10. Since i'm removing the crank anyway milling the extra legenth off of the snout will be easy. My question is with the addition of forged pistons and rods, will the machining and balancing of the crank cost almost as much as an aftermarket crank? Also if I have to go aftermarket crank I will go ahead and make a 440 out of it.

z28mccrory

iTrader: (7)

How much is the machining and balancing going to cost?

JUNK

The LS7 crank is a capable player....u would need mallory for the steel rods ($), and u gotta cut the snout. I would use the stock crank over a compstar or chinese equal. But callies, crower, and lunati all have some nice "upper end" cranks and the cost of these may make it better to stick w/ the stocker. It will hold more power than the block

1.8t

Much like stock blocks, I feel the stock crank is much stronger than anyone will ever give it credit for.

Gen414

iTrader: (38)

Well, even if you buy an aftermarket crank, it is gonna require balancing. But, if a rod seized, I do not see how you are gonna be able to get by with no turn down. .010 or .020 is gonna be more like it. Stock crank is capable of holding alot of power, but I would ask what your intentions are. For all we know, you plan on adding twin turbos and making 1200 HP

Grimes

iTrader: (3)

I would just run the stock crank after getting it fixed.

Dustin@PremierAutosports

iTrader: (2)

It will be a N2O motor and I plan on making in the 900-1000whp range on the bottle. 12.1cr, PRC ported LS7 heads, undecided on cam specs, GMPP single plain w/4500 4bl throttlebody. HSW directport and big shot plate.

any idea what balancing on the stock crank with steel rods runs?

Gen414

iTrader: (38)

This is where you are going to get people telling you that 1000 HP is OK on a stock crank. I am not one of them. If I am building/looking for 1000HP, the last thing I am gonna use is a stock cast crank. Not gonna risk it. Yes, good (read forged) parts can and will break as well, but not as likely as teh stock crank at those power numbers. Because if the CRANK breaks, you do know it's more than likely gonna take out the motor as well. Spend the few extra bucks now and get a forged crank and be done with it.

hookemdevils22

iTrader: (12)

+1. 600 hp, maybe. 900-1000, absolutely not

gnx7

iTrader: (28)

I run steel Lunati ProMod billet rods on my LS7 crank (still dry sump) and it required a lot of mallory for balancing. Balancing would normally be $150 or so and it turned out to be $400 instead due to the cost of the mallory.

I'm planning on throwing a 100-200hp shot at it eventually to see what it can do. I'm more worried about the sleeves cracking or the cylinder heads lifting than any issues with the crank at this level (running nitrous). 575rwhp n/a

In your application I would skip the LS7 heads and go with TFS 235's or larger. They kick the LS7 heads in the nuts in the low/mid range. The LS7 units are finally about level at 6000rpm and then slightly pull away around 6500rpm to 7K+. You will give up a bit of torque in the lower RPM's running the gargantuan runner size the LS7's have.