Crankshaft snout snapped

DAVECS1 said:

My opinion is, yes I believe this would of eventually happened regardless of the forced induction. It would be interesting to sample and run some tests on the rest of the crank.

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What kind of place does that kind of testing?

A place that does heat treating should have a testing facility. Also machine shops that specialize in half shafts or CVs should have the ability to test for this.

That crankshaft was fractured from the installation bolt.It looks like the shank part of the bolt fractured the crankshaft right where the threads start.The install bolt is only used to start the balancer maybe half way on,then you can use the stock bolt to pull it all the way home.This snout broke right where the counterbore stops and the threads start.

Using a bolt to pull on a crank pulley is just asking for it.

Just today I installed my Whipple 20% OD ATI balancer and in the kit they supply a longer bolt to pull on the balancer. I used this bolt as well as a stack of washers to pull on the balancer. It worked very well until I was able to get enough threads on the ARP bolt to grab.

The best way to pull on a balancer would be to use a high grade of threaded rod of course but most threaded rods are a lower grade 8.8 material which will not pull it on adequately.

ATI balancer is nothing more than trouble - they make'em too tight!

veeefour said:

ATI balancer is nothing more than trouble - they make'em too tight!

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How did you come to this conclusion?

Roh92cp said:

How did you come to this conclusion?

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I've seen dozen posts about it - they are really hard to install. On other forums as well.

veeefour said:

I've seen dozen posts about it - they are really hard to install. On other forums as well.

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So you are assuming this causes the snout to snap or stresses it, or do you have actual data on this?

Roh92cp said:

So you are assuming this causes the snout to snap or stresses it, or do you have actual data on this?

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Where did I say that?

EDIT:
But if you wish so. I think "it's possible" that ATI balancer caused this - being too tight, too much stress on threads while installing caused the crack.
P.S.
Mechanic and engineer speaking...

Well when you only have one other option for a damper, that isn't exactly great. Innovator west is not a greatest brand from what ive seen. A lot of the vendor shops on here aren't having an issue. Maybe its more of a lack of knowledge and skill.

Did you see the guy with 512 miles on the stock engine and broke crank?

kcc0521 said:

Did you see the guy with 512 miles on the stock engine and broke crank?

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what another crank snout snapped off?

kcc0521 said:

Did you see the guy with 512 miles on the stock engine and broke crank?

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The ATI does go on quite snug but I'd prefer that over too loose anyway. It's really up to the installer to ensure it's on all the way. When I removed my old balancer it had the MMR name and part number from the timing gear pressed into the end of the balancer. I can assure you that old ATI balancer was on all the way.

These cranks are snapping due to improper installation which is allowing the snout to wobble while running.

tsloms said:

The ATI does go on quite snug but I'd prefer that over too loose anyway. It's really up to the installer to ensure it's on all the way. When I removed my old balancer it had the MMR name and part number from the timing gear pressed into the end of the balancer. I can assure you that old ATI balancer was on all the way.

These cranks are snapping due to improper installation which is allowing the snout to wobble while running.

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I do not buy that. I think it would throw the belts if the balancer was not on all the way. What do you think caused the one inthe thread below to break?

http://www.mustang6g.com/forums/showthread.php?p=1975687#post1975687