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Hugie03flhr
| | Posted on Saturday, June 13, 2009 - 06:01 pm: | 
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I did not experience a failure yet but I would think a few small, well placed hole drilled in the Drag Specialty mount would soften it to stock specs. Also some safety wire or cable may not be a bad idea in case of failure. Just my .02 |
Oldog
| | Posted on Monday, June 15, 2009 - 10:34 am: |
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I did not experience a failure yet but I would think a few small, well placed hole drilled in the Drag Specialty mount would soften it to stock specs.
please elaborate
Also some safety wire or cable may not be a bad idea in case of failure. Just my .02
If you loose the mount bolts only the tie bars hold the motor inplace what are you suggesting that can be safety wired? |
Guell
| | Posted on Monday, June 15, 2009 - 10:44 am: |
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Safety wire isnt going to do much if the bolts are shearing off/heads cracking |
Kalali
| | Posted on Monday, June 15, 2009 - 12:03 pm: |
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My intuition (and engineering training) tells me that drilling holes in the rubber would create stress points causing the rubber to separate right around those holes. |
Hugie03flhr
| | Posted on Wednesday, June 17, 2009 - 06:43 pm: |
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You maybe right but I would think that is better than a busted bolts and mounts. As far as safety wire goes...I should have said safety strap (like a heavy duty wire tie that loops around the frame and through the mount. If my mount goes I'll be a test dummy but it hasn't...God knows I keep trying though |
Fullauto
| | Posted on Wednesday, June 17, 2009 - 07:24 pm: |
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I'm sorta coming to the conclusion that mount/bolt breakages and iso failures are unconnected. The first two times the iso was torn when I did the mount/bolt breakage repair, but this time around, the iso was undamaged. |
Kalali
| | Posted on Wednesday, June 17, 2009 - 09:35 pm: |
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So the head bolts broke while the ISO was totally pristine?
The plot keeps getting thicker... |
Fullauto
| | Posted on Thursday, June 18, 2009 - 08:28 am: |
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Correct. It only had a few thousand kilometers on it and was undamaged. Some people seem to have problems with isos and others with mounting bolts, sometimes together, but not always. |
Hugie03flhr
| | Posted on Thursday, June 18, 2009 - 12:42 pm: |
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I did notice my front mount hits my rocker cover. I had to take a few thousands to reinstall the cover. I was warned about unbolting the mount from the head so I shaved it but I wonder if the bolt breakage comes from an up and down motion or a forward and back motion of the engine? With it hitting the rocker cover forward motion would really stress the bolts. |
Ebutch
| | Posted on Tuesday, June 23, 2009 - 11:22 pm: |
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S2T does not like Drag iso.Shacks to much with hard rubber.I will replace with stock parts.Will newer rear iso,s fit S2 can not tell me at dlr.They Say it would take too long If they called Buell.Then maybe not get an answer. |
Oldog
| | Posted on Wednesday, June 24, 2009 - 09:33 am: |
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I was warned about unbolting the mount from the head so I shaved it but I wonder if the bolt breakage comes from an up and down motion or a forward and back motion of the engine?
Bolt breakage appears to be related to loss of clamping load on the head
excepted practice is that you replace the GRADE 911 Bolts in the head mount if you remove it,
I would consider following that practice.
as the properties of the bolts are vastly different from the "home cheapo" bolts commonly available. |
Hughlysses
| | Posted on Wednesday, June 24, 2009 - 10:03 am: |
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If loss of clamping force is the problem, one fix would be to use Belleville spring washers. These things have been around a long time, and Buell already uses them in some applications (saddlebag brackets for my Uly for instance). These things look like flatwashers but they are slightly "cone" shaped. They can be stacked if required to provide additional spring load.
Just to give you an example of what these can be used for, an engineer in Argentina applied them to the bolted frames of steam locomotives used there in the 1960's. Most steam locomotive frames are bolted together and have two cylinders (also bolted together) which are bolted to the frame. ALL of the bolts on these frames were notorious for working loose with time. This was countered by reaming every bolt hole for a tight fit, tightening the snot out of every bolt with hammer wrenches, and periodically replacing the bolts with oversized bolts which required the holes to be re-reamed to size. After this engineer in Argentina applied Belleville spring washers to all the bolts on his locomotives, the frames proved to be pretty much maintenance-free for the life of the locomotives.
I think Belleville spring washers might just be the answer to this problem on the engine mounts. More info here:
http://www.bellevillesprings.com/ |
Kalali
| | Posted on Wednesday, June 24, 2009 - 07:31 pm: |
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So, would it be a good practice to loosen the bolts and tighten them according to the torque values in the FSM?
If so, what are the correct torque values? |
Buellistic
| | Posted on Wednesday, June 24, 2009 - 09:08 pm: |
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Kalali:
You must use 2002 FSM and hope it is right ???
You can use the TORQUE SPEC's. out of a 2009 BLAST FSM as they are the same ...
MAY THE LONG LASTING BUELL BE WITH YOU !!!} |
Kalali
| | Posted on Thursday, June 25, 2009 - 07:56 am: |
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Thanks, but is it worth to go through the lossen/torque process? |
Oldog
| | Posted on Thursday, June 25, 2009 - 02:36 pm: |
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I would think replacement from time to time to eliminate fatuge as a possible failure cause would be worth while,
I would not remove and retorque those bolts, unless you are replacing them the threads in the head were "tight" fits and should be cleaned out totaly and then replaced with new bolts with red loctite on the threads oiling the hardened washers.
tapping to clean them will remove small amounts of metal making the holes looser.
I have a theory I was on the phone with James Ramsey talking about this last night.
over time heat and cooling cycles, shocks drops, wheelies etc the aluminum may fret or bed in resulting in a MINUTE loosening of the clamp loads, placing the bolt in shear, we are talking .002~.003 inch
the loads may be some what a-symetrical
( why the left bolt breaks first )
The result is the same..
Hugh, I wonder if they are made fairly heavy I have seen them in various applications as springs
BTW you still got the s3?
(Message edited by Oldog on June 25, 2009) |
Hughlysses
| | Posted on Thursday, June 25, 2009 - 03:03 pm: |
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Hugh, I wonder if they are made fairly heavy I have seen them in various applications as springs
BTW you still got the s3?
I'm not sure how much variety they offer, but you can stack them oriented in the same direction to increase the clamping force, or in alternating directions to keep the same force but give a longer compression (and hence allow more bolt stretch before the clamping force is released).
No, I sold the S3 last year to Buelltours. IIRC he posted recently about broken motor mount bolts; I hope it wasn't on my old S3 (he has several). |
Skntpig
| | Posted on Thursday, June 25, 2009 - 03:27 pm: |
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At least your bolts broke. Mine ripped the whole bolt out of the head.
ISO was fine looking. |
Fullauto
| | Posted on Thursday, June 25, 2009 - 07:36 pm: |
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I think Oldog just about has a handle on the cause of this. I just sourced a couple of Cat bolts and I'm going to fit these. Rolled threads and Grade 10.
I THINK that these bolts, with my sleeves, will cure the problem. The sleeves will take the shear forces away from the bolts. Time will tell.
We live in hope. |
Hugie03flhr
| | Posted on Friday, June 26, 2009 - 10:40 am: |
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Maybe an ARP stud and bolt would work better? 190,000 tensile strength, no twisting on bolt when scretched and head threads won't be galled. What do you guys think??? |
Oldog
| | Posted on Friday, June 26, 2009 - 02:26 pm: |
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Hugie;
the 911 bolts are made from a high nickel, chrome alloy with 190,000 tensile strength
what is an ARP stud ( an old geezer with a stiffy ? )
the rolled threads may be better than cut threads, what are the properties of "grade 10" bolts?
I posted a link to Foster bolt co who's logo is on the buell bagged bolts that I put in my bike ( and the one I took out )
FA James and I discussed your fix, While I dont on principal agree, I do hope that it works for you,
I have only repaired the machine and have not solved the problem,
Please keep us updated I dont totaly disagree that the sleeve may help, just that it can do much to protect the bolt, most folks have the failure never find the head unless its trapped in the mount by some thing. The weld up and re-machine should help a lot.
I agree that our bikes dont like to be heavily loaded and ridden hard |
Hughlysses
| | Posted on Friday, June 26, 2009 - 02:55 pm: |
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ARP: http://www.arp-bolts.com/
Rolled threads are definitely better- the threads are forged into the metal which causes the grain of the metal to conform to the threads instead of the grain being cut by the threads. OTOH I thought Grade 8 bolts had rolled threads anyway.
Using studs instead of bolts is an interesting idea. I know in the case of cylinder heads, studs are considered superior for clamping force. |
Oldog
| | Posted on Friday, June 26, 2009 - 03:05 pm: |
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Fatigue failure is frequently caused by localized stress risers, such as sharp corners. In bolts, this would correspond to the notch effect associated with the thread form. It is well known that the maximum stress in an engaged bolt occurs in the last engaged thread
From the ARP site, oddly most left had bolts break at the end or on the end of the threads.}
Hugh the stock bolts are quite a bit stronger than grade 8 IIRC the tensile grade 8 is about 160,000 psi, vs 190,000 for the "grade 9"
(Message edited by Oldog on June 26, 2009) |
12mpghwy
| | Posted on Friday, June 26, 2009 - 03:26 pm: |
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My next door neighbor had a lotus that would break some bolts in the rear suspension every 6 months or so like clockwork.
One day he decided he would solve this problem once and for all and ordered some unobtonium grade 14.9 bolts from a specialty fastener shop at fairly high cost.. The normal bolts were grade 10.9.
The grade 14.9 bolts were broken in less than a week.
Now I am not saying that the solution is softer bolts.
(Message edited by 12mpghwy on June 26, 2009) |
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