i do some work from time to time on one of my freinds ls1 race cars. it has a monster 408 with etp heads andruns a 300 shot. near 1000hp. well i was aligning the car friday night and looked up at the balancer and noticed the crank bolt was missing, so i put a new one in. just hammerd it on with my 1/2" impact.
the next evening we go out to the track, made three passes and somthing made me want to check to see if the bolt was still there. it was infact missing! so we put the car back on the trailer and went home.
anyone ever had this happen to them before? i think it was probably because i did not torqe it to spec but i figured my impact would do well enough.

 

So you admit to not installing the crank bolt correctly and are surprised it doesn't stay in? Especially on a 1000 HP motor? Now if the balancer spun much on the crank, even installing the bolt correctly may not work.

 

yes i do admit that i did incorectly install it, and i guess my real surprise was that the engine builder must have done the same thing. i think the balancer has a keyway macined into it to stop the balancer from spinning im not for shure though as its not my car.

 

Unless it was added, stock balancers/cranks do not have keyways, but you don't say what kind it is. Do you know the correct way to tighten a gen3 crank bolt?

 

i think it has a keyway, it is anaftermarket lunati crant and i cant remember the brand of the balancer off hand but i know its high dollar. i dont remember the torque sequence off hand but im shure i have i written down somewhere. the next one will be done right and the crank/ balancer checked.

 

This is if you are using a stock GM TTY bolt.
Using old bolt, tq to 250 ft/lbs to seat the pulley on the crank.
Remove old bolt.
Install new bolt.
Tq to 37 ft/lbs.
Rotate bolt an additional 140 degrees.

 

And you'd better have big wrenches to do it.

 

thanks for the spec. i have a 24 inch breaker bar and a chain wrench that shuold do the job just fine.