Broken ARP head bolt
Thread Starter
Launching!
Joined: Apr 2003
Posts: 272
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From: Cincinnati, Ohio
Broken ARP head bolt Well, I'm more surprised than mad, but I can't say I'm not a LITTLE mad. I've used more sets of ARP fasteners than I can count, and I've never had an issue... until tonight. BAM. The bolt broke on the third pass.
That's the first time I've had to do a head bolt extraction on an LS1, and it wasn't very friendly. DEEEP recess into the block. Anyway, after 20 minutes or so of center punching and drilling, it came out.
Very strange though. I know that there has to be some allowance for manufacturing defects, and I'm glad I found it upon assembly instead of in sometime down the road, but I'm still a little disappointed. Now I've got a car that's down until Wednesday, MINIMUM.
I will take it up with ARP on Tuesday. Hopefully they'll make it right. I'm just concerned about backorder. Has anyone else had anything like this happen with an ARP fastener? I'm just about disgusted enough to go to the dealership and get a set of factory torque to yields.
That's the first time I've had to do a head bolt extraction on an LS1, and it wasn't very friendly. DEEEP recess into the block. Anyway, after 20 minutes or so of center punching and drilling, it came out.
Very strange though. I know that there has to be some allowance for manufacturing defects, and I'm glad I found it upon assembly instead of in sometime down the road, but I'm still a little disappointed. Now I've got a car that's down until Wednesday, MINIMUM.
I will take it up with ARP on Tuesday. Hopefully they'll make it right. I'm just concerned about backorder. Has anyone else had anything like this happen with an ARP fastener? I'm just about disgusted enough to go to the dealership and get a set of factory torque to yields.
Re: Broken ARP head bolt A local guy who bought Colonel's old 422 had an ARP break when they were torquing down the passenger side stud for cylinder 6. They had to pull the engine back out of the car and they managed to get it out.
He ordered a brand new set of ARP studs and they installed fine. They had another setback later unrelated to the ARP's and the engine is still not running.
He ordered a brand new set of ARP studs and they installed fine. They had another setback later unrelated to the ARP's and the engine is still not running.
Re: Broken ARP head bolt Never had a problem with an ARP fastener.
What did you use for lube? What did you torque to? and in what increments?
When is the last time your wrench was calibrated?
I'm not saying they can't have failures. Every product will have some problems at some time but when your dealing with a company that has quality control like ARP it just doesn't happen very often.
What did you use for lube? What did you torque to? and in what increments?
When is the last time your wrench was calibrated?
I'm not saying they can't have failures. Every product will have some problems at some time but when your dealing with a company that has quality control like ARP it just doesn't happen very often.
Thread Starter
Launching!
Joined: Apr 2003
Posts: 272
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From: Cincinnati, Ohio
Re: Broken ARP head bolt The torque wrench was calibrated less than 6 months ago, I used ARP moly lube, and I torqued in 30-50-70 increments. What was so annoying about it was that it was the LAST bolt, on the LAST pass. lol 19 bolts torqued to perfection, and one bastard bolt at the very end.
The bolt that failed on me was one of the short 11mm corner bolts... cylinder 8
The bolt that failed on me was one of the short 11mm corner bolts... cylinder 8
10 Second Club
Joined: Nov 2001
Posts: 1,724
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From: Fenton, MI
Re: Broken ARP head bolt Wow, I am surprised, too. I have only had one problem with them before. I had a set of big block chevy valve cover and the ARP valve cover bolts were too short to work with the thick cast aluminum valve covers that I had. Never seen anything from them break before though.
Jordan
Jordan
Re: Broken ARP head bolt Had the same thing happen to me with the factory bolts last pass number eight broke I was so pissed I did not even try to remove it and ran the truck I had no problems or leaks truck was totaled a few weeks later so no telling what would have happened in a few months. I was thinking of going with ARP bolts on my Z just because of that insident. Guess I might just try the stockers again.
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TECH Junkie
Joined: Nov 2001
Posts: 3,604
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From: Los Angeles
Re: Broken ARP head bolt Maybe those short ones should be torqued a little less. ARP doesn't specify, but I'd imagine a shorter bolt will take a little less torque before it snaps.
If anybody talks to ARP, maybe they can ask.
Another thing it could be is inproperly cleaned out bolt holes. Those back bolt holes seem to get loads of oil in them somehow, and unless you get it out it may hydrolock and try to compress that oil. If you cleaned the back holes out well, then obviously this isn't the case.
If anybody talks to ARP, maybe they can ask.
Another thing it could be is inproperly cleaned out bolt holes. Those back bolt holes seem to get loads of oil in them somehow, and unless you get it out it may hydrolock and try to compress that oil. If you cleaned the back holes out well, then obviously this isn't the case.
Thread Starter
Launching!
Joined: Apr 2003
Posts: 272
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From: Cincinnati, Ohio
Re: Broken ARP head bolt I would have been happy to drink whatever residue someone could have produced from those bolt holes. I cleaned, re-cleaned and cleaned them some more. I chased the threads, I swabbed out the hole. I even taped 2 Q-tips together to swab the bottom of each hole to make sure that I didn't have any oil or coolant to compress.
Once I tapped out the broken bolt, I used a bore scope (a tool for inspecting rifle barrels) to look into the bolt hole. It was very clean, and bone dry all the way to the bottom.
As far as the torque theory goes, I'm not sure. I'll be on the phone with them Tuesday, so I'll see what they have to say then.
Once I tapped out the broken bolt, I used a bore scope (a tool for inspecting rifle barrels) to look into the bolt hole. It was very clean, and bone dry all the way to the bottom.
As far as the torque theory goes, I'm not sure. I'll be on the phone with them Tuesday, so I'll see what they have to say then.
Thread Starter
Launching!
Joined: Apr 2003
Posts: 272
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From: Cincinnati, Ohio
Re: Broken ARP head bolt Oh, the other thing I should add to drive the point home about the bolt holes being clean is, the engine is OUT OF THE CAR. This car was getting a clutch and K-member swap at the same time, so I dropped the drivetrain out the bottom.
I wasn't straining over the fender to try and do a half-@ss cleanup job, I was sitting on a stool in the middle of the floor right next to my work. Likewise with proper torquing... I was right next to the work, putting a nice even pull on the torque wrench. It was a bolt failure, plain and simple.
I've been thinking about what JMX said about less torque on the 4 shorter 11mm bolts, and I can see the logic. I mean, if the bolt is shorter, it has less stretch, so all things being equal, it should fail under less torque/stretch than a longer bolt of the same material. However, if that's the case, 70 ft/lbs of torque must be right on the EDGE of that bolts failure point, seeing as how the other 3 torqued without issue.
I wasn't straining over the fender to try and do a half-@ss cleanup job, I was sitting on a stool in the middle of the floor right next to my work. Likewise with proper torquing... I was right next to the work, putting a nice even pull on the torque wrench. It was a bolt failure, plain and simple.
I've been thinking about what JMX said about less torque on the 4 shorter 11mm bolts, and I can see the logic. I mean, if the bolt is shorter, it has less stretch, so all things being equal, it should fail under less torque/stretch than a longer bolt of the same material. However, if that's the case, 70 ft/lbs of torque must be right on the EDGE of that bolts failure point, seeing as how the other 3 torqued without issue.
TECH Junkie
Joined: Nov 2001
Posts: 3,604
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From: Los Angeles
Re: Broken ARP head bolt When you talk to ARP be sure to ask an engineer about it. Their instructions say nothing about less torque on the shorter bolts.
If they say something different, let us know and I'll change the instructions on my website for future modders.
If they say something different, let us know and I'll change the instructions on my website for future modders.
Thread Starter
Launching!
Joined: Apr 2003
Posts: 272
Likes: 0
From: Cincinnati, Ohio
Re: Broken ARP head bolt Well, I spoke with ARP and I have to say they didn't disappoint. The representative I spoke with was more than willing to help, and was apologetic about the bolt failure.
I explained to him how the whole thing occurred and he was as confused about it as I was. He said he could think of nothing that I did wrong, and it just sounded like a freak occurrance. He got replacement bolts out for next day delivery.
Top notch service... definitely what you'd expect from a company that size. Does it suck that it happened? Yes. Did the way they handled the situation make up for some of the inconvenience? Definitely.
Also, I inquired about torque specs. 70 ft/lbs was what they said to use for all the M11 bolts.
I explained to him how the whole thing occurred and he was as confused about it as I was. He said he could think of nothing that I did wrong, and it just sounded like a freak occurrance. He got replacement bolts out for next day delivery.
Top notch service... definitely what you'd expect from a company that size. Does it suck that it happened? Yes. Did the way they handled the situation make up for some of the inconvenience? Definitely.
Also, I inquired about torque specs. 70 ft/lbs was what they said to use for all the M11 bolts.
Re: Broken ARP head bolt Also, I inquired about torque specs. 70 ft/lbs was what they said to use for all the M11 bolts.
