HBsurfer

I just checked my notes from three years ago (what a geek eh?). I used a GM bolt and the proper torque was 37 #/ft and then rotate the bolt an additional 140 degrees.

Vet Interested

Tough crowd!

That being said, I have 45,000 on mine. It barely wobbles but I will not go across country until I get it replaced. I'll be bothering you guys later for part numbers and a source to buy the parts for my 2010 base.

Not So Fast

OK I admit I don't know what you mean about the OEM bolt needing torque plus being degreed 140', never heard of this

I asked and was told the cam install was a lot more complex and costly than the HB R&R so I think I'll pass, for now at least.
My car runs so well now and reliability that I don't want to lose. I drive very conservative anyways.
I'll leave the fast mods to you guys

irok

the GM bolt calls for 37 lbs plus 140 degrees on the second pass and a new dew washer wouldn't hurt.if your installer doesn't have an angle meter such as Kent Moore J 4509 or torque wrench that measures degrees no telling where your torque will end up.the ARP bolt makes this a simple procedure.250lb/ft and forget it.I've changed 12 of them.now that I thought about it I have never seen a Powerbond that was finish machined for the GM dew washer.Wouldn't hurt to pin your crank.simple 10 minute procedure

Corvette_Ed

It's ft lbs, or foot-pound, or feet per pound, not pound per foot.

http://www.engineeringtoolbox.com/AN...ms-d_1622.html

irok

I have sometimers.sometimes I remember and sometimes I forget but at least I remember how to get these cars to run a low 10 and where my VSS is.

Bruze

I'd like to find the guy who decided to reverse that and string him up. What was the friggin' point? The new way sounds dumb, and it's been around for at least 20 years.

Every time I see it like that, I know the author is young.

Corvette_Ed

This so-called "new" way is completely incorrect. Someone just had a brain fart one day, and others who didn't know any better copied it.

Corvette_Ed

I know how to get these cars to run 10's too. It's not rocket science; it just takes throwing money at the car with that goal in mind.

windyC6

Yea....I wouldn't worry about this new newfangled degree the bolt BS. This is obviously someones attempt at trying to look like super techno man. Theres always gonna be someone trying to look smart by re-inventing the wheel. Think you were right on with your researched est. of right around 240 #'s. Most things i've read had it right around the 240-250 range. Now how ya gonna hold that crank while applying that torque ? Theres several methods I've heard of. ....again, good luck.....

Not So Fast

I went down and talked with Darrel (owner) about using the OEM new bolt or did he want an ARP bolt, he said the OEM bolt is fine. So then I asked about this torque stuff, he said yes we have a schedule on how to do it that we follow, different to for each brand of bolt but we'll use the one I bought. (GM)
So I looked back at a torque schedule BlindSpot provided me awhile back and here it is
For the GM bolt
1. Crankshaft Balancer Bolt Step 1 111 ft. lbs.
2." " " Step 2 loosen 360'
3. " " Step 3 59 ft. lbs.
4. Without Z52 Step 4 125 degrees
with Z52 dry sump option 200 degrees
ARP Bolt
it was the high value of 240 ft. lbs. and then more about degrees but I didn't write it down. So it appears that with the OEM bolt you don't have such high torque values to me plus it comes with a shouldered bolt coated with orange Loctite. What all this means is by me
All in all the shop owner gave me confidence he know whats happening so I'll rest easy
Summit has shipped the HB already
NSF

windyC6

Sounds interesting to be sure. What I have a hard time understanding is as important as the proper torque on any bolt is....(at least so say the experts)....how can one know how much torque is actually getting applied if they use a degree method. Unless i'm missing something theres know way to know the actual torque being applied unless some type of measuring instrument is used.....

HBsurfer

Not trying to look smart at all Windy. Just trying to help by giving him the actual torque requirements for the GM bolt he bought. If somebody goes through all the trouble and cost to replace his balancer, why not torque that one bolt properly. I didn't make this **** up. It is the GM spec.
Good luck NSF

Not So Fast

Hey I appreciate all input bro, don't get mad. I thank you Like I have said many times I learn from this forum everyday
Hopefully this repair work goes well, as I said I lay awake at nite thinkin about what could go wrong LOL
NSF

ErikR

Good luck! When I had mine done it, came to right about $900 total. My guy had done many before mine and was quite quick and efficient!

BlindSpot

This is the problem when the "Internet Alley Mechanics" hit these threads and espouse 1960s mechanical techniques they've learned watching daddy repair the 1956 Buick with duct tape and convey repair philosophy as if it applies to modern day engineering design.

Unfortunately, these threads now become timeless and some newbee will come along, and the SAME internet alley mechanics will admonish him/her to "search" for their repair answers only to come across a thread like this.

Perpetuating the low gene pool....

Bruze

That's okay, as long as you don't go climbing a tree and worrying up there.

John Harry

You're right - you don't know how much torque is applied. But actually you don't care. What you really want is a certain amount of clamping force, which can be approximated by torque but is even more accurately determined by bolt stretch. Knowing the thread pitch and the properties of the bolt material, you can calculate how many degrees of turning will generate a certain clamping force. That's why bolt stretch is measured in cases where very accurate clamping force is required.

BlindSpot

Good start, and it only begins there. Not only the materials used, but the tensile strength and the brinell or rockwell hardness of the mating components must be part of the design. Past thread stretch is thread distortion. In this application, as any, more distortion occurs on the female component, crankshaft, (given it's material and hardness) so the material/hardness of the male component is a critical part of the bolt spec. and torque.

GM cut material and machining costs buy designing out a keyway (used by most other mfgrs.) on a component that has a large mass and subjected to significant torque and RPMs. As a manufacturing makeup for the missing keyway, applying a torque yield fastener more ensures clamping integrity to an assembly that is under-designed with the missing keyway.

Torque yield is similar to torquing a bolt so tightly that the clamping forces are at their yield point. Or, in other words, on the brink of failure. The mechanical design assumption GM makes on a MASS produced engine is that it will be assembled at the factory once and last for the working life of the product. That theory is a gamble and usually a good one if the MTBF of the components are such they will last a nominal lifetime....but, in reality, the truth is known about the HB.

The ARP bolt (being case hardened, compared to the NEW GM bolt which is soft), needs a different torque spec (which it has); otherwise, you can destroy the threads in the crank.

I advised Bobby to use the GM bolt given the need he has. If he told me he was building a dedicated race engine that would be subjected to numerous teardown and rebuilds I would have leaned towards the ARP, but since he is affecting a repair on a daily drive car that might not ever come apart again, there is no reason to spend $42 on a $7 bolt that would be misfit to his application. Same with the HB. Spending North of $450 on an ATI HB for a GM replacement on a street car is simply throwing money away, but other than that, both the ATI and ARP work, just wasted money.

windyC6

Well yes....this makes sense. But it also opens up another can of worms (variables) that could effect the accuracy of clamping force. But I won't go there. Seems like i've already been accused of coming from a low gene pool once, so I better lay low on the subject......LOLOLOL......