thanks for all you help steve in seattle and dangalla no solution yet but im not putting many miles on it. ill keep it posted if i find a solution to help others.

 

I had an issue with with my Callies crank threads also. I thought I would tap the threads out to be sure they were clean, but when I put it through, the tap was taking out metal so I stopped. Not that this would be the source of your problem, but I think the tolerance on the Callies crank threads is tighter than your outside threads on most stuff. I would put a die over the bolt to be sure its size makes sense, and put a tap through the crank, if it will go, to be sure about those threads. See how tight or loose the threads are. And does the bolt feel reasonably snug as it goes in, or does it have a lot of play? Also check the threads at the end of the bolt; if they look like the ends have been pulled off some, then the bolt is bottoming out. measure the bolt length, then measure from where the head of the bolt sits when it's all the way in, to the end of the threads in the crank. Hopefully the bolt is shorter.

 

The ARP bolt is just to get the balancer started, that's why it is longer.
You the clean the stock bolt and re use if it is not damaged, and use red locktite.

 

Ummm no. It's only a few threads longer.

I do have a much longer grade 8 bolt i picked up for what you're referring to, but the ARP is definitely for permanent mount.

The problem he's having is either the crank snout's threads are too loose, or too shallow (bolt bottoming out).

 

Ok, I need to stop reading these boards... bad vodo. :-/

I went out for some tuning on my 396 (Callies/CompStar crank, ATI hub, ARP bolt) and sure enough... I saw a rib peeling from the back edge of my serpentine belt.

Looking at the dampener I can see the belt riding up the back edge of the beltway... the hub's coming forward!

So sure enough, once I pulled the ARP bolt out the guys at Speed Secrets almost died laughing. Some jackass (I plead the 5th) took out the $6 Mr.Gasket bolt and replaced it with a fancy $25 ARP bolt... without using the reccomended ARP Assembly Lube.

To be fair, I though it was oily enough already... lesson learnt.

Anyway, the large ARP bolt head dig into the washer surface giving a false torque reading. Even though I pulled the crank sensor to ensure the reluctor wheel was tight (96-97 guys have this advantage... we can see if the hub is fully inserted), the bolt itself didn't get tight enough. The washer was heavily gauled, maybe MAULED is a better description.

If you're shredding belts from a hub backing out, check under the bolt head/washer... they may be gauled and causing false torque readings.

EDIT:
------
The Torque Reading of 75 ft #'s will NOT tell you when the hub is completely on... it takes more than that to drive it on the snout. Do NOT use the 75 ft #'s as a indicator to stop pushing farther. The best method is to use a stud installer with a LARGE nut and thrust bearing to drive it on, then put the bolt in as a retaining bolt (torqued to 75 ft pounds, with anti-seize on threads).

Likewise, IF you plan on using a bolt to drive on the hub (not reccomended), use a LONG bolt that gets several threads (say 3/4") in the snout before pulling... and use anti-sieze on the hub, the keyway, and the bolt threads... then when it bottoms out, switch to a shorter bolt and repeat (or use the same bolt with 1" of thick spacers). Becareful of bottoming out the longer bolts, it will happen and you'll notice quickly (when the engine starts to turn over) and the threads will seem gaulled at the end of the bolt once you pull it out.

I've found that besides the antiseize and leaving the car in gear, placing the serpentine belt on the engine when you think you're close to bottoming out can help eyeball the alignment and additonally helps add resistance to the engine turning over (when the hub is deep it may get tough to drive the last 1/8" or so due to surface resistance).

OBDII cars can pull the crank sensor and use a flat blade screwdriver to try and wiggle the reluctor wheel, but don't use that of a guide when close since it can be cocked and seem tight when it isn't (depends on the key's angle to the CPS opening). The wheel should be tight and not wiggle, and you should be able to see the crank sprocket and timing chain through the hole.

 

no not that i noticed. but to be safe i took the bolt off , put a die on it and cut about a 16th of an inch off put it back on and still the same problem. the only thing i can think of is to send balancer back to ati . if same one comes back then take clutch and flywheel off to have it balanced checked.

 

correct me if i am wrong but the only people who are having problems with the balancer bolt backing out are the ones using an arp bolt. why not try using a gm factory bolt i bought one the other day for 3 bucks. arp usually does a good job with bolts but mabey the hub bolt is not elastic enough for this specific aplication.

 

Agree

 

we just put my motor back together friday. the snout on the compstar cranks vary in depth. my arp bolt was to long that came with it. we actually just cut down the bolt in the machine shop.
i called eric, at VRE, and they comfirmed the depths are different on the compstars. just check it before install.

 

The only catch of course is that the bolt itself shouldn't be what holds the hub on the snout.

Ideally the hub is pressed on, using the snouth threads for a stud, with an interferenace fit and the bolt is left in place an insurance. Many Gen I SBC don't even use a bolt to secure the balancer (crazy as that may seem to us/me).

If the hub is wiggling it's way out, I'm not certain its just the bolt that's the issue. Too much honing on the hub before installation perhaps? ATI's literature says that GM snout tollerances are typically +/- 0.0001", while other OEM's are about twice that, and aftermarket snouts are usually +/- 0.0005".

I'm ordering a new from ATI just in case, but I have a feeling that lock-tit won't be enough to keep my hub on in it's current form. I ordered it through VRE and either they or ATI honed it in advance... it's walked out three times total... all with different length bolts (none, including the ARP, bottomed out in the Compstar holes... I know, I measured and installed them myself).

It may not be the bolt's issue. YMMV

 

so steve i did not realize you were having the same problem. im going to try the gm bolt because it cant hurt after that im sending the balancer back to ati for inspection. the only thing i know to do. the hub i got was the lt1-lt4 from thunder racing who provided no tech help whatsoever. i believe it is a 6 3/4 hub i wonder if a larger balancer would help. i read an article somewhere that on larger cubic inch motors to small of a balancer can hurt power and not do the correct job of absording vibration. and i think this is a smaller balancer then stock because there are several differant balancers for this application and i had to get a smaller then stock belt for this balancer. if this is the case i would like ati to switch it out with a 7 1/4 size . i dont know where to go after that. keep me poster with your results as i will with mine. thanks again.

 

I run a 7 1/4" balancer. I'm pretty sure the hub was just honed too large... just not enough interferance. Below 5000 there's no problem, and even on little to no load (neutral, 1st, 2nd) it will rev to 7000 without a hickup... the issue pops up in 3rd/4th around 5200+

EDIT:
Seems the shorter ATI hub "bolt mount surface" combinded with a stock LT1 bolt on a shallow crank threading in callies cranks was also an issue. The honing may also be a problem though if you have a callies/compstar crank... my new ATI hub went on fine with NO honing at all.

Note: the ATI hub is the same length as stock... the serpintein blet is in the right place when it's fully seated, the "shorter" part of the hub is a slightly deeper bolt mounting surface. Why? I have no idea, probably a holdover from a SBC design or something (ie. they may have made the LTx versions longer by addign distance above the bolt mounting surface, instead of below it, but thats jsut speculation on my part).

When buying an ATI hub you DO need the LTx specific hub, but will need to measure the bolt length just to be sure (I used ATI's SBC bolt... it's a high quality bolt that's short enough to avoid bottoming out the threads. I wouldn't use a stock LTx bolt length and assume the crank has enough extra threading to avoid bottoming out... especially with an aftermarket crank.

 

i havent been able to diagnois to problem to that degree i just thought it was the amount of time the engine was running. i ran the car for about 100 miles normal as in hard and babying it and checked it and the bolt was loose. the hub has to be pressed on . i guess when i get time before i send it to ati ill measure the crank and inside the hub. i cant believe only a few people are running in to this problem.

 

I have a new ATI hub I'm hoping will be snugg enough for interference if I don't hone it (we'll see this weekend).

I also received a new ATI Crank Bolt (p/n 951501). It's a high-quality bolt, very ARP-like, but it has an "integral washer" which I assumed was a loose fitting washer that was put on before rolling the threads, however now that I have it.. it's actually a flanged-head bolt... no washer at at, its just a really wide head base (1-piece). Not a great idea if you plan on using the bolt/washer to push the hub on (a hub tool with a thrust washer would be a great idea if you want to use this bolt). The ATI bolt has a 1 7/8" UHL (Under head length), with a 1" hex head, and a 1 5/8" seat diameter (the "integrated washer").

The ARP bolt seems like a better idea if it doesn't bottom out. Loose washer (lube both sides to prevent galling), 3/8" square drive in center, with a DEEPER and slightly wider socket drive (1 1/8" I belive) and the thread depth is a bit longer (the ATI bolt is a stock SBC length).

I'd advise anyone with an aftermarket crank to measure the snout and be VERY careful BEFORE honing the hub they plan on using. ATI says their hubs should have a 0.0010" interferance fit with the snout.

 

I have a 383ci LT1 (1997 Camaro) with a Procharger D1. Also run a Calies dragonslaer 3.75 stroke crank. I use the arp damper hub bolt (5/8), but, had to grind it down so it would not bottom out on the thread. Also use the stock spacer. The hub and crank have about a 0.002/ 0.003" interfearance fit. I recently went with a Pioneer hub (available from Thunder Racing). Used a woodruff key std for SBC. The hub installed great (not like a stock hub). It is under cut so you can line up the key easy. I do run the crank sensor (on 1996 and 97) so, I usually pull the sensor and monitor backlash on the sensor wheel. I have had to continue to press the hub untill it is seated. That is the only way to know if the hub is fully installed. Hope this helps. B.