Take an impact that's rated around 250lbs torque...put blue loctite on balancer bolt...crank on the bolt for about 5 seconds...put a reference mark on the bolt head and the balancer...crank it again for another 5 seconds...check the marks...if the bolt moved do it again...keep doing until the marks don't move...been doing it that way for many years now and never had that bolt come loose...
Need input on broken crank and balancer!
- Thread starter Daniel Jost
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I am talking factory stuff here not aftermarket,I have never needed anything more than a slight tap with a dead blow to get one on or off.:wink:
Just a Six??
OK! Who Farted??
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Same as mine but I use a puller to get them off. A deadblow would do but I got the tool so I'm using it!! Thats why I paid for it!!
Red Locktite & 250 lbs & away she goes! Funny that the bolt has never been a problerm getting off even with the Red Loctite on it? Impact removes it in a couple seconds or less.
Ya know. I think I'm going to move up to 250. Even though my ATI balancer has always inspected good as far as wear, it can't hurt.
I've always used red loctite on the crank bolt. Never a problem getting it off.
Have you guys really found it necessary to use over 200 ft. lbs. The spec is 200. Are higher power levels the reason? Are they coming loose on you?
I've always used red loctite on the crank bolt. Never a problem getting it off.
Have you guys really found it necessary to use over 200 ft. lbs. The spec is 200. Are higher power levels the reason? Are they coming loose on you?
TURBOTIMMER
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I found my balancer was loose on my untouched 55k mile stock motor. Seems like its an issue even if the factory put it together. I didn't even realize it til I pulled the motor to button up the oil leaks. The crank checked out fine other than some light marks on the snout. I torqed the bolt to 220ftlbs with red locktite, and so far, so good.
You sure Don? I know there are 2 different size bolts used over the years. The early one is smaller and requires less torque. The ones on the later engines are a much larger thread. 200 doesnt seem even close to being enough. Im too lazy to look through the factory manual though:tongue:
I looked up the torque in my factory manual, which is about 10 inches thick, for a 1984 Buick Regal. It includes all models of engines that was available for that production year. For the turbocharged V6 it states 200. Not a range of this to this. Just 200. I don't know if it might be different for a 1987.
Daniel Jost
Squirtin six
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man i have had a lot more help then i imagined would come in on this question! thanks guys it looks like i need to get a balancer TQ it somewhere between 250 and 280 with loctite and ill be ready to go!
I've always torqued mine to 219 ft. lbs. with loctite using a torque wrench and never had one come loose.
This is where i got the torque spec from.
Bolt Torque Explained
John :smile:
This is where i got the torque spec from.
Bolt Torque Explained
John :smile:
turbodave231
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No one has addressed your original question......Why is it breaking?
The factory balancer is made from cast iron and is inherently weak!
It was intended to work (and live) on an engine that made a conservative 235 HP.
Don't use it for anything but a door stop. Upgrade to an SFI rated balancer and sleep better at night. ATI and BHJ make some of the best........and yes they aren't cheap. But, how much have these failures cost you so far?
The factory balancer is made from cast iron and is inherently weak!
It was intended to work (and live) on an engine that made a conservative 235 HP.
Don't use it for anything but a door stop. Upgrade to an SFI rated balancer and sleep better at night. ATI and BHJ make some of the best........and yes they aren't cheap. But, how much have these failures cost you so far?
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A couple things come to mind, as to why this ocurred:
1. First failure caused crank and/or internal thread damage, that was not found when the second balancer was installed.
2. Second balancer was already cracked, and/or the bore was out of spec.
3. The threads on the bolt were damaged, from running loose during the first failure.
1. First failure caused crank and/or internal thread damage, that was not found when the second balancer was installed.
2. Second balancer was already cracked, and/or the bore was out of spec.
3. The threads on the bolt were damaged, from running loose during the first failure.
I have to completely agree. A slip fit crank hub may be just fine for a 240hp production engine, but it has no business being on anything else. A proper interference fit with a good harmonic balancer is the only way to go if you want to do all you can to control problems associated with harmonic vibration. Overtightening the crank bolt on a stock crank hub is a bandaid fix. The problem is the added level of harmonics that is going on with a high performance engine. Other model 'strictly' drag engines may get away with running a lighter crank hub, but remember, they are being inspected and torn down regularly. And, I'm sure they are, at the very least, press fitted. Most of you are trying to pump out 500hp for 100,000 miles with just a slip fit crank hub? And you wonder why the cranks are breaking? If that slip fitted hub happens to hammer back and forth on the crank keyway, you are begging to have problems. And expecting an overtightened bolt to keep that from happening, to me is just wishful thinking.
I think many of you may need to study up on what the purpose of a harmonic dampener is, first off.
As far as the torque value of the retaining bolt goes. Around 200 ft/lbs is the stock value with a stock crank hub. As power levels go up, I'm sure it becomes necessary to adjust that torque value. As I've already pointed out, 200 with red threadlocker has been working fine for me with my billet crank and ATI dampener. Other combinations, I'm sure, may require a different value. Could it be that because the dampener is doing its' job, I don't need to use a higher torque value? Something to think about.
As was already pointed out, the rotating assembly in question was not balanced properly. That is going to play a large role in all this.
OneQuikSix
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A couple points.
1. Every 109 block/rotating assembly I've ever had rebuilt has been balanced (one of the most expensive processes from my machinist) using the intended balancer and flywheel. Being that both items were necessary to properly balance the rotating assembly, I'm assuming that not having a rebuilt rotating assembly balanced is a bad idea. Furthermore, I'd be surprised if an unbalanced rotating assembly helped that huge crank bolt stay secured regardless of whatever torque specification was used. Short version...rebuilt/new engines should be balanced including whatever parts will be attached to the rotating assembly. If you balance everything, then change something like a flywheel or upgrade to a different balancer, I'm not so sure everything is ready to go without being re-balanced. Maybe someone else can chime in here.
2. I'm having a difficult time understanding how the stock balancer is inadequate for a properly balanced engine making 1000hp/1000lbs torque yet is perfectly adequate for a stock engine turning roughly the same RPM. Again, if someone with much more experience than me could chime in, I'd be eternally grateful. Thanks.
1. Every 109 block/rotating assembly I've ever had rebuilt has been balanced (one of the most expensive processes from my machinist) using the intended balancer and flywheel. Being that both items were necessary to properly balance the rotating assembly, I'm assuming that not having a rebuilt rotating assembly balanced is a bad idea. Furthermore, I'd be surprised if an unbalanced rotating assembly helped that huge crank bolt stay secured regardless of whatever torque specification was used. Short version...rebuilt/new engines should be balanced including whatever parts will be attached to the rotating assembly. If you balance everything, then change something like a flywheel or upgrade to a different balancer, I'm not so sure everything is ready to go without being re-balanced. Maybe someone else can chime in here.
2. I'm having a difficult time understanding how the stock balancer is inadequate for a properly balanced engine making 1000hp/1000lbs torque yet is perfectly adequate for a stock engine turning roughly the same RPM. Again, if someone with much more experience than me could chime in, I'd be eternally grateful. Thanks.
The stock crank hub has no provision to control torsional harmonics which are worse at higher hp levels. Torsional harmonics left unchecked can and will cause premature failure of the crankshaft and/or bearings.
The stock crank hub is just that. It is not a crank dampener. A crank dampener actually works to reduce the harmful affects of undampened crankshaft torsional harmonics.
OneQuikSix
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Interesting. I'd always referred to the hub as a balancer. I had no idea it did not have any actual harmonic balancing qualities. What horsepower level should one seek an actual harmonic balancer?
BTW...I like you sig (we're extremists too
)Interesting. I'd always referred to the hub as a balancer. I had no idea it did not have any actual harmonic balancing qualities. What horsepower level should one seek an actual harmonic balancer?
BTW...I like you sig (we're extremists too
Good question. I don't have the answer to that. I prefer to install a dampener on any engine, other than a stock buildup, that I put together for someone.
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