My GT500 in failure mode

[denial]

It has been determined that due to a single keyway in the crank, it caused the crank snout to twist off. Innovators West claims a double keyway would keep it from happening again. Either way, IW says they will fix my balancer at no cost accept for the shipping.

My car is the second confirmed case in the country to have done this that has been documented. It has a factory forged steel crank installed. I'm gonna get the motor out and put a new Cobra Jet crank back in it that has the strengthened snout with dual keyway and sell the short block. I'm going with an all aluminum block. The car only has 9,000 miles on it as it sits.

It gets even better! I drove this thing home from my police department in Dayton 30 minutes all the way with a broken crank!

[denial]

here you go!

[cobraman302]

Holy shat! That won't be cheap.

[orangeconv]

thats interesting..... I dont think i have ever seen that

[Anniv.Z]

that really sucks...... you shouldnt been trying to keep up with that stock LS1

[mad max]

Wow , is all i have to say.

[orangeconv]

You sure the balancer didnt go out on it

[denial]

Yup, the balancer is fine. Sending it back to IW to get it re-finished. Thanks lonnie lol.

[MFIELD]

How will a double keyway help with that? That snapped off behind the keyway. What weird is the 4.6 pulleys dont even stick out that far to have a lot of leverage on them.

[denial]

It snapped at the edge of the keyway. I was able to get the snout to almost come off with a puller. They say that with having a second keyway it takes away the shock factor from that the blower adds along with that much boost. All the cobra jet cars run dual keyway with the same balancer with no issues. They also said its strongly recommended for all blower applications.

[cobraman302]

But there are a LOT less Cobra Jets out there than your run of the mill gt500....and there have only been 2 documented cases like this? Personally, I'm not convinced that this isn't from a failed balancer...but I'm def. No expert on the matter. Either way, it sucks and is unfortunate. Can happen to anyone I guess.

[MFIELD]

I understand it from a strength point on shearing and spinning the balancer but dont see how it would make the crank stronger on the end. It sucks for sure but i would be concerned there was something else going on.

[Stangman]

Ouch.... damn. That's no good. Hope you get it fixed soon

[Blkcobra01]

Damn sorry to hear good luck with your build start a build thread on it.

[05yellowgt]

Man I've seen a few failures that they say a double keyway would have prevented, but nothing like that

[03z06vette]

Im just wondering? how many times did you have the ballance off before the failure?

[Stangman]

I would have thought with all the gt500's in the world we would see this more often

[Gearhead]

I thought this was a known issue with the early GT500's (2007) ?? I could be wrong though.....

[denial]

This was an issue with the stock 27# balancer. This unit weighs 12 pounds.

[05yellowgt]

I thought this was a known issue with the early GT500's (2007) ?? I could be wrong though.....
There were issues with the original balancers on the 2007 GT500's the 2008 and newer balancers were revised and it was a required change for 2007's that were putting most aftermarket blowers on, unless you went aftermarket.

[lost cause]

that is crazy.... Ive seen a couple of crank failures, but nothing like this lol

[beefcake]

bischoff double keyed my balancer. i have an ati,

i hear mixed opinions on who has the better balancer

[INSANEBA]

Not cheap none the less, the only time I've ever personally seen this one was on a 355sbc with a Mooneyham 6:71 on top. That thing made wicked power, and went through 3 cranks before he found one to hold the torque of it.