Warning against using ARP L19 rod bolts...

[blykins]

Guys,

A few years ago, I had a rod bolt break on a very high end race engine.  Luckily, it was idling on the dyno so it didn't hurt much, but it was still a punch in the gut.  The rods were Oliver and the bolts were ARP L19 bolts.  All of the rod bolts were torqued by the stretch method and recorded.  Before the oil pan went on, they were checked again, and I put my paint dabs on the bolt heads to indicate that they had been checked.  After the failure, we located both bolt heads, with my paint dabs still on them, with the bolt shanks still in the rod. 

I contacted Oliver about it, but of course they had never heard of such thing, so I wrote it off, repaired, and went on. 

Fast forward to yesterday, I went to dyno, and was discussing engine stuff with the guys there who build some pretty high end race stuff.   One of the guys told me that their shop rule was that whoever bolted the oil pan on also had to go through and check the rod bolts before the pan went on.  He was doing that very thing, cycling through and checking torque, when he rotated the engine over and found a rod cap missing a bolt.  On further inspection, the shank of the bolt was still in the rod, so he started looking around and found the rod bolt head laying on the floor 5-6' away from the engine.  It had broken under load, just sitting on the engine stand, after they had torqued the rod bolts upon assembly a day or two before. 

It was an ARP L19 bolt. 

After they remembered my own incident, they removed all the L19 bolts, threw them away, and installed ARP 2000 bolts. 

I'm telling you this to be cautious...most here won't have rods with those bolts in them, but if you do, please consider changing the bolts out to ARP 2000 or Custom Age 625 bolts if possible.  Obviously, these are isolated incidents, and obviously all L19 bolts won't fail, but you have to realize that these two incidents are not coincidental.   Please be careful.... 

[427LX]

So just sitting there under the stress of being tight they just break?  That's a first for me!  My Scat H rods use 7/16 cap screws and well after 11 years of running I hope those are okay.

[blykins]

So just sitting there under the stress of being tight they just break?  That's a first for me!  My Scat H rods use 7/16 cap screws and well after 11 years of running I hope those are okay.

Yes.  After my failure, I did a lot of internet research and found several sources that stated even your finger oils could affect them.  Not sure if that’s 100% true but I don’t have a good feeling about them.

[67xr7cat]

The ARP L19 rod bolts are susceptible to stress corrosion from hydrogen embrittlement.  You never handle them without wearing gloves and should keep them covered in fresh oil.

[e philpott]

This is similar to Jay’s SOHC snapping off adjusters just sitting on the stand

[67xr7cat]

The ARP L19 rod bolts are susceptible to stress corrosion from hydrogen embrittlement.  You never handle them without wearing gloves and should keep them covered in fresh oil.

Yes it is true. Years ago when I worked for a shop that build race engines we used them many times. Used proper handling and never had a failure.

[MeanGene]

I remember an article many years ago with David Reher where he spoke of bolts, and about an L88 rod with the "boron bolts", and said the head popped off one while sitting on the bench, as he watched. The gist was that the bolts were so hard that they couldn't deflect, and could not conform to a very slight out of square condition of the machined spot that supports the bolt head, and broke from the stress. Old-timers may remember the problem with the "white" NASCAR rod bolts for the LeMans rods- before we had the good aftermarket bolts. I learned about them in an article with Robert Yates, telling about them from his NASCAR engine building days, the white bolts went boom, black bolts were the replacement. Cantrell had given me a set of NASCAR bolts from their large Holman & Moody sale purchase in the late 70's, when I bought one of the NOS sets of C9 SCJ rods. Went and looked, and sure enough they were white- pulled them out and bought a new set of SPS bolts- which are still in the rods, in my Galaxie

[philminotti]

Hmm...I have a set of Oliver rods with L-19 bolts for my new build.  Food for thought.

[blykins]

Hmm...I have a set of Oliver rods with L-19 bolts for my new build.  Food for thought.

I'd consider swapping the bolts out. 

I've used many sets of Oliver rods with L19 bolts over the years, but before a couple of years ago, I had never seen any warnings about how you should handle them.  It wasn't on the spec sheet, but if you do some research, you're supposed to wear gloves, not use certain solvents on them, keep them in oil, etc.  For most scenarios, the ARP 2000 bolt will be just as strong, without all the finicky-ness, or you can switch to the ARP Custom Age bolts. 

[galaxiex]

From the ARP website....

"L19: This is a premium steel that is processed to deliver superior strength and fatigue properties. L19 is a very high strength material compared to 8740 and ARP2000 and is capable of delivering a clamp load at 260,000 psi. It is primarily used in short track and drag racing applications where inertia loads exceed the clamping capability of ARP2000. Like most high strength, quench and temper steels – L19 requires special care during manufacturing to avoid hydrogen embrittlement. This material is easily contaminated and subject to stress corrosion. It must be kept well-oiled and not exposed to moisture."

[jayb]

This is similar to Jay’s SOHC snapping off adjusters just sitting on the stand

I had exactly the same thought.  It's hard to believe that can happen until you see it first hand.  And those SOHC adjusters were certainly not L-19 material; suspicion at the time was a bad heat treat.

[Rory428]

Not sure if it was the same model of bolts, but several years ago, a local racer I knew had just finished assembling a new SB Chevy for his Nova drag car, and he was just about ready to turn off the lights and call it a night, when he heard a strange "ping" sound, followed by a clink. He looked around the shop didn`t find anything. The next morning when he rotated the engine on the engine stand, to install the motor mounts and oil filter adapter, he heard an odd rattle noise. He removed the oil pan, and found the heads of 2 of his rod capscrews had popped off. If he had put oil in the pan, or left a few minutes earlier, he would not have heard anything, and had no idea there was a problem until the engine blew up on the track. It makes you wonder if a rod bolt is so delicate in handling, if inside a race engine, with oil flying around was a good place for such hardware.

[67xr7cat]

Hmm...I have a set of Oliver rods with L-19 bolts for my new build.  Food for thought.

I'd consider swapping the bolts out. 

I've used many sets of Oliver rods with L19 bolts over the years, but before a couple of years ago, I had never seen any warnings about how you should handle them.  It wasn't on the spec sheet, but if you do some research, you're supposed to wear gloves, not use certain solvents on them, keep them in oil, etc.  For most scenarios, the ARP 2000 bolt will be just as strong, without all the finicky-ness, or you can switch to the ARP Custom Age bolts.

An ARP 2000 bolt is not as strong as a L19.  The Custom age 625+ is stronger than an L-19. Are so many applications that even an ARP 8740 bolt is fine that we forget to consider what is needed for a given application. Without knowing the weight of the rod/piston, stroke, and RPM and calculating the load the bolts will see nobody can say a lesser bolt will be ok.  If the rods are new and have been stored/handled properly I see no reason not to use them.  If you want to go with a different bolt I'd suggest call Oliver and let them recommend what bolt will work for your application.  Whenever possible before changing anything with rod bolts always best to speak to the rod manufacture as the design and material of the rod go hand in hand with the rod bolt.  Most connecting rod manufactures custom spec their rod bolts.

Just remember changing to a different bolt may require resizing the rod big end.  Really should check the big end with the bolts properly stretched regardless.

[FERoadster]

I've got 2 packages of ARE FE rod bolts, both packages are 155-6001 are these the L19's to be wary of?
What info would be on the package?
Richard >>> FERoadster

[galaxiex]

I've got 2 packages of ARE FE rod bolts, both packages are 155-6001 are these the L19's to be wary of?
What info would be on the package?
Richard >>> FERoadster

Those are 8740 Chromoly. not L19.

[blykins]

Hmm...I have a set of Oliver rods with L-19 bolts for my new build.  Food for thought.

I'd consider swapping the bolts out. 

I've used many sets of Oliver rods with L19 bolts over the years, but before a couple of years ago, I had never seen any warnings about how you should handle them.  It wasn't on the spec sheet, but if you do some research, you're supposed to wear gloves, not use certain solvents on them, keep them in oil, etc.  For most scenarios, the ARP 2000 bolt will be just as strong, without all the finicky-ness, or you can switch to the ARP Custom Age bolts.

An ARP 2000 bolt is not as strong as a L19.  The Custom age 625+ is stronger than an L-19. Are so many applications that even an ARP 8740 bolt is fine that we forget to consider what is needed for a given application. Without knowing the weight of the rod/piston, stroke, and RPM and calculating the load the bolts will see nobody can say a lesser bolt will be ok.  If the rods are new and have been stored/handled properly I see no reason not to use them.  If you want to go with a different bolt I'd suggest call Oliver and let them recommend what bolt will work for your application.  Whenever possible before changing anything with rod bolts always best to speak to the rod manufacture as the design and material of the rod go hand in hand with the rod bolt.  Most connecting rod manufactures custom spec their rod bolts.

Just remember changing to a different bolt may require resizing the rod big end.  Really should check the big end with the bolts properly stretched regardless.

In my situation, the engine had come back for freshening and I replaced all of the rod bolts with brand new ones.  They came right out of the package from Oliver, got lubed up with CMD, then cycled to check stretch.  They were brand spankin new bolts and my guess is that one fractured/failed, which caused the other to fail because it couldn't handle the load by itself. 

In my buddy's situation, they called the rod manufacturer and the rod manufacturer told them to just switch to ARP 2000 bolts.  The rods didn't need resizing, so they went with it. 

I do agree that Phil should call Oliver and ask their opinion on a different bolt (they do have different options), that's why I used general terms such as, "I'd consider swapping them" and "For most scenarios..."   

In a lot of cases, the ARP 2000 bolt may be a solid option.  I'm starting a couple builds that will use Jay's heads and one of them is using a set of Molnar Power Adder rods.  They have ARP 2000 bolts. 

He will just have to call Oliver and see what they suggest, but I would firmly urge him (or anyone) to call and inquire.  This is the second instance of an L19 bolt failing close to home and a quick Google search will show many more.   You just don't see/hear that from the other bolts. 

[blykins]

Phil, I got out the torque sheet for Oliver rods and they offer 3 different bolts with their rods:  L19, ARP 2000, and the 625 bolt.   Since they offer the rods with all of those bolts, it would be an easy phone call to see what would be needed with the other two. 

What stinks is that their instruction sheet says to clean all parts thoroughly before lubing the bolts up and checking stretch.   It certainly doesn't tell you how to handle the L19 bolts and from reading some other sources, the L19 bolt doesn't like some types of solvents. 

[philminotti]

Yeah, I did the research when I bought the rods a while ago... It's something that crossed my mind.  I was aware of the handling precautions... That being said, if a rod bolt needs that much TLC to avoid potentially catastrophic failure, philosophically that's just a bit weird, in my opinion.  Good grief, this isn't a Space X Raptor engine for chrissakes. I wasn't planning on doing my build in a sealed, positive pressure clean room, surrounded by HEPA filters, bathed in UV light while wearing a bunny suit😂

[blykins]

Yeah, I did the research when I bought the rods a while ago... It's something that crossed my mind.  I was aware of the handling precautions... That being said, if a rod bolt needs that much TLC to avoid potentially catastrophic failure, philosophically that's just a bit weird, in my opinion.  Good grief, this isn't a Space X Raptor engine for chrissakes. I wasn't planning on doing my build in a sealed, positive pressure clean room, surrounded by HEPA filters, bathed in UV light while wearing a bunny suit😂

Hey, let’s be serious. There’s nothing at all wrong with wearing a bunny suit while working on engines.

[67xr7cat]

It is totally possible had some bad bolts. Was some ARP 2000 bolts guys were saying broke too. For sure even an ARP 8740 is more than enough for most applications and that may surprise some. Really comes down to application, how much margin of error, and comfort level.

Can add to the list moisture for the L-19. Really to a much lesser extent the ARP 2000 and ARP 8740 can have same issue. Really have go to the Custom Age 625+ to be fully rid of it. Of course that is a better bolt all around just expensive.

I've always run the bolts in and out and torqued then 3-4 times. Measure the length before and after. I know with the new lube say don't have to, but cannot hurt and maybe put a few cycles on them if have a bad bolt the stretch will change.

Then is the lost art of feel. Long time ago we had a Custom age bolt that when tightened felt different. That bolt got replaced.

I just cannot get on the L19 "look at it sideways
it will explode" bandwagon. Yes need to wear gloves and keep them oiled something should do anyway, but I'd think if was really that bad ARP would have stopped selling it, but each should do what they are comfortable with.

[frnkeore]

This is kinda odd to me. Even with the few instances described here, I'm sure there are more. Are people not relating this issue to ARP?

If they are telling ARP, I would think ARP would ask for all the bolts in those engines back, to research what is happening.

You could also research it yourself by sending them to a metallurgist and have them tested or if you have access to Xray and a hardness tester, you could do some of it. Inclusions in the metal and out of spec steel or HT (to hard) could cause this but, we won't know until they can be tested, after the fact.

Seems to important to me, that ARP would turn a blind eye to this!

[67xr7cat]

Yes good point Frank would think first thing be call ARP or the rod mfg. when you have a bolt failure. Guess is engine builders get so used to hi performance aftermarket parts not fitting, always needing some kind of work or massaging.

[Yellow Truck]

Yeah, I did the research when I bought the rods a while ago... It's something that crossed my mind.  I was aware of the handling precautions... That being said, if a rod bolt needs that much TLC to avoid potentially catastrophic failure, philosophically that's just a bit weird, in my opinion.  Good grief, this isn't a Space X Raptor engine for chrissakes. I wasn't planning on doing my build in a sealed, positive pressure clean room, surrounded by HEPA filters, bathed in UV light while wearing a bunny suit😂

Hey, let’s be serious. There’s nothing at all wrong with wearing a bunny suit while working on engines.

Seriously, we need pictures.

[1968galaxie]

One must also remember that there are many ARP bolt forgeries (fake parts) available.
Just like aircraft AN parts.
There are many cases where fake (Chinese copies) hardware is sold into the US market.

[blykins]

I reported it to Oliver when it happened and my buddy also reported his failure to the rod manufacturer that he was using.   I'm not sure if they contacted ARP or not, but in my case, the rod bolts had Oliver imprinted on the bolt heads, so I thought I should contact Oliver. 

[67xr7cat]

I reported it to Oliver when it happened and my buddy also reported his failure to the rod manufacturer that he was using.   I'm not sure if they contacted ARP or not, but in my case, the rod bolts had Oliver imprinted on the bolt heads, so I thought I should contact Oliver.

Good so what did they say? Were the bolts sent back for analysis? Am sure they are the real deal. Considering how many rod bolts they make is bound to be a few bad ones.  Sure nobody want to hear that, but that is why have to pay attention to the details. As Jay mentioned about bad heat treat can ruin your day. Bunny suit or not  I'd just sure rather find out while still on the bench then at 7,000 RPM!

[blykins]

I reported it to Oliver when it happened and my buddy also reported his failure to the rod manufacturer that he was using.   I'm not sure if they contacted ARP or not, but in my case, the rod bolts had Oliver imprinted on the bolt heads, so I thought I should contact Oliver.

Good so what did they say? Were the bolts sent back for analysis? Am sure they are the real deal. Considering how many rod bolts they make is bound to be a few bad ones.  Sure nobody want to hear that, but that is why have to pay attention to the details. As Jay mentioned about bad heat treat can ruin your day. Bunny suit or not  I'd just sure rather find out while still on the bench then at 7,000 RPM!

As I mentioned in the very first post, they “had never heard of that” and were unwilling to help. 

Regardless, with the countless numbers of rods that have went through here with ARP 8740 and 2000 bolts with never an issue, here’s two instances of L19 bolts failing in the past 2 years.  Take it for what it’s worth, it was just meant to be a warning. 

[chilly460]

I’m sure it’s not a black/white issue for when L19s would be “needed” or suggested, but what general type of RPM or application would they be needed?  6500rpm heavy piston, 7000 truck puller, 7500rpm bracket racer…or something more radical?  Trying to understand if any hand wringing trying to decide to take the risk of running them is more an academic exercise than practical application in an FE?

[67xr7cat]

I reported it to Oliver when it happened and my buddy also reported his failure to the rod manufacturer that he was using.   I'm not sure if they contacted ARP or not, but in my case, the rod bolts had Oliver imprinted on the bolt heads, so I thought I should contact Oliver.

Good so what did they say? Were the bolts sent back for analysis? Am sure they are the real deal. Considering how many rod bolts they make is bound to be a few bad ones.  Sure nobody want to hear that, but that is why have to pay attention to the details. As Jay mentioned about bad heat treat can ruin your day. Bunny suit or not  I'd just sure rather find out while still on the bench then at 7,000 RPM!

As I mentioned in the very first post, they “had never heard of that” and were unwilling to help. 

Regardless, with the countless numbers of rods that have went through here with ARP 8740 and 2000 bolts with never an issue, here’s two instances of L19 bolts failing in the past 2 years.  Take it for what it’s worth, it was just meant to be a warning.

Well in the  "take it for what it is worth category" several years ago some guys (engine builders) were complaining about ARP 2000 bolts breaking. Kinda went the same way. You are certainly not the first to raise the issue of the special precautions for the L-19 bolts. I've never had a bad one or first hand known of a bad one. I know of one instance of a custom age 625+ bolt was bad.  Now I never warned anyone not to use them because of it, but guess maybe I should have. Personally if the application warranted an L-19 rod bolt I'd not be afraid to use it.  To me measure them, cycle them several times, measure them again, and use proper technique and handling regardless of rod bolt.

Will say you would think Oliver would at least want to see the bolts or send you another set. 

[67xr7cat]

I’m sure it’s not a black/white issue for when L19s would be “needed” or suggested, but what general type of RPM or application would they be needed?  6500rpm heavy piston, 7000 truck puller, 7500rpm bracket racer…or something more radical?  Trying to understand if any hand wringing trying to decide to take the risk of running them is more an academic exercise than practical application in an FE?

Is an excellent question. An 8740 and 2000 bolt are about the same strength, just the 2000 has about double the fatigue rating. For a lot of uses a 8740 is fine.  A 2000 is a good insurance policy.  When you start getting into higher RPM and heavy rod/piston weight need to calculate the load that the rod bolt will see and it has to be less than its clamp load. Other thing that enters into it is fatigue life.  A better bolt tends to live longer even if a lesser bolt can take the loading trying to pull it apart.

When you get into endurance racing you start to see better rods and bolts being used.  Shop I worked for in a different life built good number of dirt modified and outlaw engines.  Fairly normal for them back then were Custom age 625+ or WSB rod bolts.  Remember a Prostock BBF had s Bryant billet crank and Oliver rods totally melted the rod bearing. Had the rods and bolts not been of that high quality am sure it would have broke the rod which it did not. The crank polished up. Can say the heat treat was real good on that one! 

Sorry not a straight forward answer, but when racing gets serious so do the parts, especially if the goal is to win.  For most street/strip and bracket racers a scat rod and ARP 2000 bolts more than enough.

[Posi67]

I've managed to mangle the bottom end of my 390 pretty badly with a broken rod and the Std. ARP rod bolt looked fine afterward. I'm never going to be in the world that needs a L19 or better bolt however this is very valuable info so thanks to Brent for starting the discussion. 

[philminotti]

Just some follow-up on this topic... The Oliver 6.7" BBC rod (typical for an FE build that uses a crank with 2.2" rod journals) is C6700BBMX. These ship with L19 bolts.

Per Oliver technical support, the ARP 2000 replacement bolt is P/N BLT005 and the CA625 replacement is BLT003.

They are available factory direct or from Summit.

Phil

[Joey120373]

Hmm, now I want to check what my K1 rods have….

ARP 2000.

[blykins]

Hmm, now I want to check what my K1 rods have….

ARP 2000.

You're good with Molnar or K1.  They use ARP 2000 bolts. 

Ratings are ratings, right, lots of variables such as rpm, tune, etc., but K1 rates their rods for 1400 hp with those bolts.  I read all the time of guys using them on boosted engines up over 1000 hp.

[67xr7cat]

Hmm, now I want to check what my K1 rods have….

ARP 2000.

You're good with Molnar or K1.  They use ARP 2000 bolts. 

Ratings are ratings, right, lots of variables such as rpm, tune, etc., but K1 rates their rods for 1400 hp with those bolts.  I read all the time of guys using them on boosted engines up over 1000 hp.

Think RPM and how much weight hanging off the small end of the rod matter more. Also if you close the throttle and unload the piston at high RPM.  Never understood how you could put a HP rating on a rod.

[blykins]

Hmm, now I want to check what my K1 rods have….

ARP 2000.

You're good with Molnar or K1.  They use ARP 2000 bolts. 

Ratings are ratings, right, lots of variables such as rpm, tune, etc., but K1 rates their rods for 1400 hp with those bolts.  I read all the time of guys using them on boosted engines up over 1000 hp.

Think RPM and how much weight hanging off the small end of the rod matter more. Also if you close the throttle and unload the piston at high RPM.  Never understood how you could put a HP rating on a rod.

Yep, I agree, that's why I wrote what I wrote. 

I was just making the point that those ARP 2000 bolts will hold a lot more than you think.