Blue Angel

So I've done some searching around regarding the crank bolt and pulley install/removal. Lots of people are using the OEM TTY bolt and lots of people are using the re-useable ARP bolt. I haven't found any comments supporting the use of one over the other...

Are there any advantages/disadvantages to either? The ARP bolt can be re-used but costs several times more than the OEM bolt. Thoughts?

Another question: Who sells crank pulley pinning kits? No blower in the near future, but I figure if I'm this deep in there anyway why not?

rodsvet

ARP for the bolt!! Bluvette1 on this forum for the pinning kit. The fixture has a hardened insert and drills true and can be reused many times. When you are done you can sell it and regain some of the cost. Or keep it and use it on your next build. Good luck, Rod

lucky131969

You answered your own question.....

ipuig

The OEM fastener is cheap and well suited for this application. Pinning the crank shaft for a non FI application is a waste of time and can result in damage to the crank snout if not done correctly.
Whichever fastener you decide to use do not forget to measure the snout clearance to verify that the balancer is fully seated on the crank shaft before installing and tightening the crank bolt. You should also have a flywheel locking tool for this job. I do not believe it is possible to seat the balancer and get the desired tension on the joint without it.

vsocks1

In my opinion some good and bad advice at the same time....

Many will agree that crank pinning is worthwhile. As for seating the balancer and getting desired tension without flywheel locking tool - it is possible....but I also used the ARP bolt & torque spec. of 200 ft. lbs
I also agree that a locking tool makes the task easier

ipuig

I suspect that the reason the ARP bolt is "resusable" is becase their torque specification does not take the fastener beyond it's strain point, not because it's made of a better material. 200 ft/lb is not even enough to properly seat the balancer on the crank shaft. The installation procedure calls for torquing to 240 ft/lb with the old balancer bolt, removing it and measuring the crank snout clearance to verify proper seating.
You could probably re-use the OEM bolt indefinetly if you were to torque it to the same value specified by ARP. Of course this would defeat the purpose of the original design specification whichs calls for a TTY fastener on this joint to achieve the desired clamping force and residual tension. This is why I will never use a non TTY fastener on a joint that calls for a TTY fastener.
As far as the locking device is concerned, I challenge anyone on this forum to install the crank bolt to the required value of 37 ft/lbs plus 140 degress of rotation (after the pulley has beeen seated) not locking down the crankshaft somehow to keep it from rotating, not possible.

lucky131969

Per ARP, the bolt torque depends on the lube used:

Moly lube - 196 ft lbs
Loctite - 235 ft lbs
30 wt oil - 247 ft lbs

ipuig

I did not use the ARP fastener so I do not have first hand knowledge of their torque specification, that number was provided by VSOCKS1.
I still do not think there value takes the bolt past the strain point, therefore the feature that it can be reused is pointless. Any fastener which is not streched past it's maximum stress value regardless of material composition and heat treatment can be re-used indefinitely.

lucky131969

Ok, well you confused me(which is not easily done). Why is the bolt being reusable pointless?

ipuig

The ARP bolt is not taken past it's strain point with their specified torque values therefore re-using it should be assumed, not a special feature in my opinion. If the OEM bolt was torqued to a value below it's strain point it would also be re-usable. I suppose ARP would want us to believe that their bolt, when torqued to the values they specify will provide the same amount of clamping force and residual tension that the OEM bolt provides when taken past it's strain point, unlikely.
I don't know what torque value for the OEM bolt is expressed in ft/lb with the OEM specified 37 ft/lb + 140 deg but I'm certain it's more than 240 ft/lbs and probably closer to 500 ft/lbs. I suspect that ARP's bolt would also not be reusable if stressed to this level.
Hope this clears up my previous post.

lucky131969

Your comment would suggest you know something that ARP doesn't. ARP is not what you would call a "newcomer" to the high performance hardware industry. What would they possibly have to gain, by exaggerating their specs?

waddisme

Don't install the balancer right with stock bolt and it will walk right off. Irrelevant with ARP bolt. Cheap insurance even if you never remove it again.

ipuig

I don't have access to ARP's material spec and I don't claim to know something they do not. My only point is I don't believe you can achieve the same clamping force and residual tension with the torque values they recommend.
I'm sure they make a fine product, however the OEM bolt is no slouch either. It's a property class 10.9 medium carbon steel metric fastener with an ultimate tensile strengh of 150,000 psi (SAE GRADE 8 or better).
Perhaps you should ask Eric or ET if the ARP bolt provides the desired clamping force with the torque value they recommend.

lucky131969

While I respect ET and Eric's knowledge, and contribution to the forum, I can put my mechanical engineering degree to work, if I want to know the exact numbers. I'm more interested in what you are basing your conclusions from, based on your statement:
"My only point is I don't believe you can achieve the same clamping force and residual tension with the torque values they recommend. "

ipuig

The delta in the tensioning values between the OEM and ARP specs are too great to compensate for any increased yield strengh the ARP bolt may have in my opinion.

lucky131969

I see. Then the ARP bolts should loosen, if torqued to the specified value by ARP......if it is truly inadequate, based on the torque for value OEM bolt.

ipuig

Perhaps, if the joint is exposed to forces that through either vibration, thermal cycles or cyclic fatigue exceed the clamping force the ARP bolt provides. Run the calculations and we'll both know.
As for me, I'll choose not to second guess this one, I'll use the OEM bolt torqued to the design spec.

MJD

Go ARP and get the 6 point instead of 12 that way if you want to use an impact gun you can. I like the ATI pin kit and have used it. Very easy and works great for a keyed balancer plus if you ever have to replace the balancer you won't have to do it again.

Cobra R

Using a Snap-on Tech torque wrench, which has the angle meter built into it, also gives the value of torque used to reach the desired angle. In every instance of using a stock bolt and doing the final pass of 140 deg, the torque value was 230-250 lbft of torque.

I personally wouldnt use an impact on the bolt. Impact is hard on the threads and not worth possibly killing a crank over.

Chris Stewart

ARP bolt works great for me. The reduced hassle of the stock bolt is worth the extra $$. I like the 12 point style. It allows me to put a box wrench on the snout and turn the crank, that helps when I line up my torque tube input clamp (following drivetrain service).