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LS7 titanium rod failure

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Old 09-13-2018, 01:47 PM
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FNBADAZ06
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Default LS7 titanium rod failure

There's been a few comments under some recent threads that have brought up OEM titanium rod failures due to the anti-friction coatings wearing thru, allowing the rod big ends to eat into one another causing both bearing failures and titanium "dust" debri to circulate throughout the oiling system.

I recently had such an event on my shortblock that was recently refreshed roughly 5K miles ago, for which I will share with everyone so they can keep an eye on their engines.

First, the particulars:

The shortblock had roughly 87K miles on it when it was refreshed with a set of forged pistons, new bearings throughout, ARP hardware, and Katech blue LS7 oil pump. The car sees frequent trips to the dragstrip, 1/2 mile events, and early morning shenanigans to blow the carbon out The rods were my originals that had been upgraded to APR bolts and a stronger wrist pin upgrade with my pistons. They were not rebushed, nor were they recoated.
The failure happened at the 92K mile mark, and while catastrophic with two rods being destroyed, the associated rod bearings being spun, crank journal being scored, etc. , the block cam thru unscathed, intact, and rebuildable.
Oil pressure at the time of failure was a solid 35+ psi idle hot , 55-65 psi at cruise and WOT. Amsoil 10W-30 Z-Rod.

#1 rod, crank journal, and associated rod bearing.....






The titanium, and ultimately the bearing material, destroyed my Katech oil pump (not surprised).










Below is a link to a video...hopefully it works

https://photos.app.goo.gl/dYR7vCWttt2hxLk3A


I believe Katech doesn't recommend any recoating services on OEM rods once the anti-friction coating wears off, and would rather see them replaced. That being said, several builders have shipped the OEM rods to Calico for a recoating of the anti-friction coating....I don't have any data to suggest this might be a long term solution or not.
This initial deterioration of the coatings would show up in an oil analysis as a higher concentration of titanium material, as the bare rod shoulders would begin to make contact with one another and grind titanium off the big ends.

I know there have been several of us who have suffered catastrophic rod failure in the last few months....I'll leave it up to them to share their experiences if they so choose. I don't know how many miles those engines had on them, but I believe all of them were in excess of 50K miles, were highly modified and are raced regularly, and were un-opened bottom ends (original bearings and rotating assemblies).

My engine is currently torn apart for a rebuild, which i will share with you once everything is together and running.
I'd also like to point out that I recently had my WCCH heads inspected after 18-20K miles of use during this tear down, and identified that the exhaust valve guides were out of spec. While there is no real conclusion on the guide wear issue on my heads, I can't rule out the possibility that the contaminated oil with the titanium material circulating throughout the engine could have also contributed to the wear of the guide material.

To those who are concerned with this type of failure who have higher mileage or are highly modified, I'd suggest an oil analysis at least every other oil change to give you a heads up to any impending rods issues.

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Old 09-13-2018, 01:57 PM
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In for rebuild details...
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Old 09-13-2018, 02:27 PM
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This is what really makes me angry!! Iím rebuilding my set up now, 16k miles on the motor. One thing lead to another blah blah, complete bottom end refresh. All new coated bearings, ARP everywhere superfinised crank all honed and balanced with torque plate. New forged Racetec pistons and I chose to keep the titanium rods. Calico no longer offers a coating for these rods, I was going to re-coat just for piece of mind. With only 16k miles on them and the fact they are light and titanium I wanted to keep them, not planning on making more than 800hp. Whatís also very annoying is finding a value of these rods. You can search eBay and find used rods for various prices. Iíve seen them from $799-$1500 some with pistons some without but thatís the range Iíve seen on eBay. I even emailed a few sellers for more details. A few I got zero reply and a few replied but have very vague answers to my questions about why are you selling? miles on them?what happened to the motor they where in? Know how much titanium cost I assumed these things were very expensive, I mean titanium lug nuts are $300+, the Arkapovic Ti exhaust....$$$$. What I found is there isnít a real market value for these damn things. It seems nobody is crazy enough to buy these used from a private seller(makes sense) and the only place I found them for sale new is GMPerformancemotors.com. Now if they even have them I have no clue, they are listed with no photo or details, it appears they are $653.38 each! So thatís $5227.04 for the set. I looked at other connecting rods they offer and the sets are labeled and pictured in sets of 8 while single rods are labeled and pictured accordingly. I email them several times as well and asked for clarification and got no response. So it would appear that used titanium LS7 connecting rods are damn near worthless monetarily.😡😡😡




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Old 09-13-2018, 02:36 PM
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I think a few builders just recently had a set of rods recoated with Calico, but I could be wrong.
As most that have had this type of failure lose #1 and #2, I know that you find sets of 6 good rods for sale on a regular basis....that's the give away that the engine had a rod failure.
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Old 09-13-2018, 02:48 PM
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Originally Posted by FNBADAZ06 View Post
I think a few builders just recently had a set of rods recoated with Calico, but I could be wrong.
As most that have had this type of failure lose #1 and #2, I know that you find sets of 6 good rods for sale on a regular basis....that's the give away that the engine had a rod failure.
I spoke with calico last week, they only offer an oil shedding coating.
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Old 09-13-2018, 02:55 PM
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Originally Posted by 73DBG View Post
This is what really makes me angry!! Iím rebuilding my set up now, 16k miles on the motor. One thing lead to another blah blah, complete bottom end refresh. All new coated bearings, ARP everywhere superfinised crank all honed and balanced with torque plate. New forged Racetec pistons and I chose to keep the titanium rods. Calico no longer offers a coating for these rods, I was going to re-coat just for piece of mind. With only 16k miles on them and the fact they are light and titanium I wanted to keep them, not planning on making more than 800hp. Whatís also very annoying is finding a value of these rods. You can search eBay and find used rods for various prices. Iíve seen them from $799-$1500 some with pistons some without but thatís the range Iíve seen on eBay. I even emailed a few sellers for more details. A few I got zero reply and a few replied but have very vague answers to my questions about why are you selling? miles on them?what happened to the motor they where in? Know how much titanium cost I assumed these things were very expensive, I mean titanium lug nuts are $300+, the Arkapovic Ti exhaust....$$$$. What I found is there isnít a real market value for these damn things. It seems nobody is crazy enough to buy these used from a private seller(makes sense) and the only place I found them for sale new is GMPerformancemotors.com. Now if they even have them I have no clue, they are listed with no photo or details, it appears they are $653.38 each! So thatís $5227.04 for the set. I looked at other connecting rods they offer and the sets are labeled and pictured in sets of 8 while single rods are labeled and pictured accordingly. I email them several times as well and asked for clarification and got no response. So it would appear that used titanium LS7 connecting rods are damn near worthless monetarily.😡😡😡
There...I just saved you like $360



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Old 09-13-2018, 03:11 PM
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🤣 thanks man....Iím using what Iíve got, just ranting about such an expensive part being made worthless by GM. I guess from a share holder stand point itís brilliant though.
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Old 09-13-2018, 03:16 PM
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Originally Posted by 73DBG View Post
🤣 thanks man....Iím using what Iíve got, just ranting about such an expensive part being made worthless by GM. I guess from a share holder stand point itís brilliant though.
I feel ya .
I'm looking at a new combo for crank/rod/piston that hopefully won't weigh any more than the OEM setup.
Still in the preliminary stages
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Old 09-13-2018, 03:35 PM
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Thanks for the post, Victor and sorry for the failure. When I get more info on my rebuild, I will post it in my thread. The bottom end is being done because my last two oil samples tested 7-8 PPM Ti for the first time and lead doubled. I am hoping some of the rods may be available for resale (58K miles with 12K miles on the HCI build). https://www.corvetteforum.com/forums...post1597925121
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Old 09-13-2018, 03:44 PM
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I'm really new to all this. Are you guys saying there's no legit alternative aftermarket rods for these things? Or are you just saying the Ti rods are nice due to the weight and not wanting another alternative?
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Old 09-13-2018, 03:46 PM
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Sucks this engine has another weak link to an extent. Wouldnít it be more cost effective and reliable to use differnt rods than titanium. What other option would be the next best rod?
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Old 09-13-2018, 03:56 PM
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Originally Posted by K-Spaz View Post
I'm really new to all this. Are you guys saying there's no legit alternative aftermarket rods for these things? Or are you just saying the Ti rods are nice due to the weight and not wanting another alternative?
There are alternative steel rods, just not nice to have to replace these expensive rods. My build will have new forged crank, rods and pistons. see my build link above for the specifics.

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Old 09-13-2018, 04:00 PM
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Originally Posted by K-Spaz View Post
I'm really new to all this. Are you guys saying there's no legit alternative aftermarket rods for these things? Or are you just saying the Ti rods are nice due to the weight and not wanting another alternative?
There are alternatives, but it sucks that these rods are considered expendable after the anti-friction coatings wear off.
Having light weight rods is a plus
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Old 09-13-2018, 04:03 PM
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Originally Posted by JesC6Z View Post
Sucks this engine has another weak link to an extent. Wouldnít it be more cost effective and reliable to use differnt rods than titanium. What other option would be the next best rod?
I'm not sure if it would be considered a weak link, but it being a consumable item during a rebuild sure could suck.
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Old 09-13-2018, 04:23 PM
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Originally Posted by FNBADAZ06 View Post
I'm not sure if it would be considered a weak link, but it being a consumable item during a rebuild sure could suck.
Sorry for your motor issues!!!
Were you doing oil samples and if so what were your titanium levels. Similar to Daves??


DH
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Old 09-13-2018, 04:28 PM
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Originally Posted by Dirty Howie View Post
Sorry for your motor issues!!!
Were you doing oil samples and if so what were your titanium levels. Similar to Daves??


DH
No oil analysis were done prior to the failure.
In hind sight, it could have given me some warning, like what Dave had, but ultimately the rods would have had to be replaced regardless. The crank may be salvageable but I'm replacing the entire rotating assembly on this new build.
The block suffered no damage, but I'm moving forward with putting in new Darton sleeves while it's apart
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Old 09-13-2018, 04:28 PM
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Originally Posted by AzDave47 View Post
There are alternative steel rods, just not nice to have to replace these expensive rods. My build will have new forged crank, rods and pistons. see my build link above for the specifics.
Looked at that thread briefly and saw this:
Originally Posted by AzDave47 View Post
You have a lot of other stuff for high HP. I'll be tuned on 91 and not go with NOS or E85 so don't want any more compression (already at 11.6 or .7) than required for cleaning the head and deck. I asked about recoating the Ti rods, but CPR prefers this hardware (they go this route on their 1000HP SC builds). I'll be able to sell the good TI rods (hopefully at least 6)
But when I looked up those rods they spec them for 650hp. Hmmm. Just found that interesting.
Originally Posted by FNBADAZ06 View Post
There are alternatives, but it sucks that these rods are considered expendable after the anti-friction coatings wear off.
Having light weight rods is a plus
I'm with ya there, I just wasn't sure if there were no other rod options due to fitment restraints or whatever. Again, I'm new to all this and trying to read because I suspect I'll have one of these threads soon.

Some of these threads are scary. Especially the wiped bearing pics with Ti smeared all through the wear parts.


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Old 09-13-2018, 04:38 PM
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Originally Posted by K-Spaz View Post
Looked at that thread briefly and saw this:

But when I looked up those rods they spec them for 650hp. Hmmm. Just found that interesting.
I'm with ya there, I just wasn't sure if there were no other rod options due to fitment restraints or whatever. Again, I'm new to all this and trying to read because I suspect I'll have one of these threads soon.

Some of these threads are scary. Especially the wiped bearing pics with Ti smeared all through the wear parts.
I don't think you have anything to worry about
As I noted, my engine has in excess of 92K miles on it, with a lot of 1/4, 1/2, 1 mile, and HPDE runs on it. In it's last iteration, it was revved to speeds in excess of 7300 RPM and made over 600 RWHP.
If it wasn't for the coatings wearing off and allowing the big ends to grind on one another, they would still be usable. I didn't "break them" , and I'm sure with the upgraded ARP hardware and pistons, could have lived happily into the 700-800 RWHP area.
I wouldn't worry about it until you start getting some higher miles on it. Use high quality oil and filter, change it regularly, and sleep good at night.
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Old 09-13-2018, 05:03 PM
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Originally Posted by FNBADAZ06 View Post
I don't think you have anything to worry about
As I noted, my engine has in excess of 92K miles on it, with a lot of 1/4, 1/2, 1 mile, and HPDE runs on it. In it's last iteration, it was revved to speeds in excess of 7300 RPM and made over 600 RWHP.
If it wasn't for the coatings wearing off and allowing the big ends to grind on one another, they would still be usable. I didn't "break them" , and I'm sure with the upgraded ARP hardware and pistons, could have lived happily into the 700-800 RWHP area.
I wouldn't worry about it until you start getting some higher miles on it. Use high quality oil and filter, change it regularly, and sleep good at night.
The weather has broken a little here so it's my first day in quite a while without some rain. I might work outside with an automatic level on my porch after which I'm tempted to pull some valve covers to see about these heads. Thanks for the comforting words about the rods in my car. That's all I would need right about now.
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Old 09-13-2018, 05:10 PM
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What year is your Z. I believe that I read on this forum that there was a change to the chamfer on the LS7 rods to reduce this problem.
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