Kinetic crank saver question

[CrackedHorn]

I have read that a possible cause of crank snout failure is bottoming out the crank pulley bolt during install. (Aside from aftermarket dampener and/or a bad crank)

Since the crank saver bolt is longer and designed to fill the void that Ford left in the crank, wouldn't this crank saver bolt run the risk of bottoming out in that cavity or putting extra strain on the nose? Especially, since a person may need to deburr that cavity?

I know the homebrew method for improving other ford cranks is drilling out the cavity to the main bearing to anchor the bolt/stud. The crank saver obviously doesn't replicate this.

Also, while the aftermarket bolts are stronger, it seems the failures are in the crank nose itself. So while the bolt may survive, I'm not sure I see how it would make the crank nose less likely to fail.

So is there any real benefit to the crank saver? Or the ARP bolt? When compared to a new ORM crank pulley bolt.

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[SheepDog]

1- the OEM bolt does not bottom out in the crank.
2- By shoring up the void in the crank, the lateral loads on the snout are much more evenly distributed than the OEM bolt, so it is less likely to break ( I assume you are talking about a supercharger install, and the extra strain it places on the crank)
3- Use a Griptec pulley on the supercharger so that you dont have to put unecessary tension on the belt to prevent slipage. This also makes the 10 rib setups unecessary for most applications
4- avoid any supercharger kit that uses an extended harmonic balancer/crank pulley setup. Seems to me that most of the failures on here are using something like this, and the additional leverage on the snout along with all the additional vibration and extra force that it takes to drive the supercharger are what snap them.

Apex torque also makes a crank stud kit, but it doesn't fill the void like the Kinetic offering does. Still better than a bolt though

 

[DougS550]

I have read that a possible cause of crank snout failure is bottoming out the crank pulley bolt during install. (Aside from aftermarket dampener and/or a bad crank)

Since the crank saver bolt is longer and designed to fill the void that Ford left in the crank, wouldn't this crank saver bolt run the risk of bottoming out in that cavity or putting extra strain on the nose? Especially, since a person may need to deburr that cavity?

I know the homebrew method for improving other ford cranks is drilling out the cavity to the main bearing to anchor the bolt/stud. The crank saver obviously doesn't replicate this.

Also, while the aftermarket bolts are stronger, it seems the failures are in the crank nose itself. So while the bolt may survive, I'm not sure I see how it would make the crank nose less likely to fail.

So is there any real benefit to the crank saver? Or the ARP bolt? When compared to a new ORM crank pulley bolt.

The directions state to Finger Tight Only. The bolt does not assert pressure on the crank inside thread of the snout.

 

[tdstuart]

Apex torque also makes a crank stud kit, but it doesn't fill the void like the Kinetic offering does. Still better than a bolt though

Would avoid any apex torque products. Lots of headstud issues that they denied and never did anything about

 

[Angrey]

I think the other aspect that's overlooked is the ability to more accurately measure proper torque with a stud and nut than a bolt with a flanged head.

It's not controversial to say that many of the crank failures are associated with improperly installed crank bolts. I'm also not a fan of torque to yield.

 

[80FoxCoupe]

I have read that a possible cause of crank snout failure is bottoming out the crank pulley bolt during install. (Aside from aftermarket dampener and/or a bad crank)

Since the crank saver bolt is longer and designed to fill the void that Ford left in the crank, wouldn't this crank saver bolt run the risk of bottoming out in that cavity or putting extra strain on the nose? Especially, since a person may need to deburr that cavity?

I know the homebrew method for improving other ford cranks is drilling out the cavity to the main bearing to anchor the bolt/stud. The crank saver obviously doesn't replicate this.

Also, while the aftermarket bolts are stronger, it seems the failures are in the crank nose itself. So while the bolt may survive, I'm not sure I see how it would make the crank nose less likely to fail.

So is there any real benefit to the crank saver? Or the ARP bolt? When compared to a new ORM crank pulley bolt.

As stated the stock bolt does not bottom out. The kinetic unit is a stud. Thicker and is of a harder material. Therefore torque applied will be higher than oem. Failure of snout typically occurs when applied pressure of balancer hub/crank sprocket/crank snout shoulder is lost or reduced. The above stack adds strength to the snout itself, when properly torqued. The kinetic stud applies more pressure to the stack than an oem bolt.

 

[DougS550]

I think the other aspect that's overlooked is the ability to more accurately measure proper torque with a stud and nut than a bolt with a flanged head.

It's not controversial to say that many of the crank failures are associated with improperly installed crank bolts. I'm also not a fan of torque to yield.

I ABSOLUTELY "HATE" torque to yield bolts. BS

 

[ice445]

I ABSOLUTELY "HATE" torque to yield bolts. BS

I get that they're annoying but they provide a more consistent clamp load. Achieving desired stretch is easier than achieving a specific torque value, especially in the factory.

 

[Whitedevil95]

Ive had my Kinetic stud sitting on my work bench for like 6 months. I gotta slap that thing in.

 

[DougS550]

Ive had my Kinetic stud sitting on my work bench for like 6 months. I gotta slap that thing in.

If nothing else, it does give a little more peace of mind I guess.

 

[Angrey]

I get that they're annoying but they provide a more consistent clamp load. Achieving desired stretch is easier than achieving a specific torque value, especially in the factory.

I don't buy that one bit. To achieve the desired stretch, it's based upon a torque value and an additional rotation after that, so in either case (TTY or not) you have to measure a torque value.

Furthermore, like I said, a stud with a nut is going to be more accurate and consistent (especially if it's wet with lubricant) than a flange head bolt. Depending on whether the bearing surface is dry or has contaminants on it will wildly effect how much actual force is imparted into the threads.

TTY is cheaper. THAT is why it's employed (rather than just purchasing higher tensile material). It also creates additional down stream revenue and sales through service and repair (being one time use and throw away you get to sell a zillion more shitty ass TTY bolts).

 

[ice445]

I don't buy that one bit. To achieve the desired stretch, it's based upon a torque value and an additional rotation after that, so in either case (TTY or not) you have to measure a torque value.

Furthermore, like I said, a stud with a nut is going to be more accurate and consistent (especially if it's wet with lubricant) than a flange head bolt. Depending on whether the bearing surface is dry or has contaminants on it will wildly effect how much actual force is imparted into the threads.

TTY is cheaper. THAT is why it's employed (rather than just purchasing higher tensile material). It also creates additional down stream revenue and sales through service and repair (being one time use and throw away you get to sell a zillion more shitty ass TTY bolts).

Most of the measured torque values are very low in comparison to the final value. There's less error margin on the assembly line by doing it this way. Sure, a stud and a nut is the most accurate, but also the most costly, along with requiring more assembly steps. So while I agree cost is a consideration, it's definitely better than the old way of everything having a fixed torque value. Torque measuring devices need to be calibrated fairly often and 10% error margin is a lot more with a 200ft/lb value than a 40ft/lb one.

I will agree having all these throw away fasteners is very wasteful though.

 

[Angrey]

Most of the measured torque values are very low in comparison to the final value. There's less error margin on the assembly line by doing it this way. Sure, a stud and a nut is the most accurate, but also the most costly, along with requiring more assembly steps. So while I agree cost is a consideration, it's definitely better than the old way of everything having a fixed torque value. Torque measuring devices need to be calibrated fairly often and 10% error margin is a lot more with a 200ft/lb value than a 40ft/lb one.

I will agree having all these throw away fasteners is very wasteful though.

You're discounting the biggest issue which is why the choice of a stud and nut is advantageous over a bolt in the first place. With a bolt, the measured torque value is fighting two friction factors, the bearing surface as well as the threads. With the stud, the threads are already set and now the nut just has to be turned to pull on them to the desired tension.

TTY makes sense if you're NEVER going to remove the bolt again.

I'm not an ME, but I work with Structural engineering all the time and for the most critical connections and fasteners, they don't utilize bolts if it can be helped, they try to employ embed anchors with nuts, torqued to spec and pin welded.

I'm with you on it being cost effective, but I'm not with you on it being better or more consistent.

And as far as calibration of torque measurements, again, you have that aspect in either approach as the only way to achieve the desired stretch/yield is to first turn it to a desired torque and then over stretch an additional radius. So there's a measurement present in EITHER approach.

I'd venture that having a stud, removing the thread friction component and wet torquing (the way ARP generally recommends) is the most accurate way to get the desired clamp load. And I'd much rather start off with a higher grade material that's already been cold worked to strength close to it's yield.

We can both agree that in any case, a bunch of crank issues are improperly installed balancer. I personally believe that part of that can be resolved by simply avoiding the press fit and double keying (but that's my personal opinion). Again, if part of the torquing is fighting to seat the balancer on, it's giving a false end state of desired torque/tension.

 

[ice445]

You're discounting the biggest issue which is why the choice of a stud and nut is advantageous over a bolt in the first place. With a bolt, the measured torque value is fighting two friction factors, the bearing surface as well as the threads. With the stud, the threads are already set and now the nut just has to be turned to pull on them to the desired tension.

TTY makes sense if you're NEVER going to remove the bolt again.

I'm not an ME, but I work with Structural engineering all the time and for the most critical connections and fasteners, they don't utilize bolts if it can be helped, they try to employ embed anchors with nuts, torqued to spec and pin welded.

I'm with you on it being cost effective, but I'm not with you on it being better or more consistent.

And as far as calibration of torque measurements, again, you have that aspect in either approach as the only way to achieve the desired stretch/yield is to first turn it to a desired torque and then over stretch an additional radius. So there's a measurement present in EITHER approach.

I'd venture that having a stud, removing the thread friction component and wet torquing (the way ARP generally recommends) is the most accurate way to get the desired clamp load. And I'd much rather start off with a higher grade material that's already been cold worked to strength close to it's yield.

We can both agree that in any case, a bunch of crank issues are improperly installed balancer. I personally believe that part of that can be resolved by simply avoiding the press fit and double keying (but that's my personal opinion). Again, if part of the torquing is fighting to seat the balancer on, it's giving a false end state of desired torque/tension.

That's fair. You probably know more about this stuff than me, that's just how it was explained to me a long time ago when I looked into the subject. I can totally see it being more about cost though, especially when factoring in the robots and what they're good at doing.

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