When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
I'll create a new build thread in the coming months......should be pretty exciting as it will be more in line with what many consider the upper end of a "max" build.
Plus, I've got a set of 3.90's in the rear to give me a bit more go-go with my ZR1 MH3 geared transmission.
This time, I'm hoping to get the new build on an engine dyno too !!!!
I think ultimately, people will need to perform an oil analysis every once in a while to check for the tell tale signs. Note that I do not think a titanium intake valve could be a source for titanium content to be present in your oil, so it can only come from the rods.
And I don't think that small traces of titanium suggest that catastrophic failure is imminent, but it does suggest the anti-friction coating is beginning to wear off and there's no way to prevent it from getting worse.
I think ultimately, people will need to perform an oil analysis every once in a while to check for the tell tale signs. Note that I do not think a titanium intake valve could be a source for titanium content to be present in your oil, so it can only come from the rods.
And I don't think that small traces of titanium suggest that catastrophic failure is imminent, but it does suggest the anti-friction coating is beginning to wear off and there's no way to prevent it from getting worse.
Stands to reason that if you're past that coating and into the Ti, the coating is gone. Time to drop the motor and get the rebuild underway.
I think ultimately, people will need to perform an oil analysis every once in a while to check for the tell tale signs. Note that I do not think a titanium intake valve could be a source for titanium content to be present in your oil, so it can only come from the rods.
And I don't think that small traces of titanium suggest that catastrophic failure is imminent, but it does suggest the anti-friction coating is beginning to wear off and there's no way to prevent it from getting worse.
I got my 09Z in Nov. 2010 with 8500 miles on it. I had 0 Ti up thru the first sample after my HCI build June 2016 at 47K miles. Lead levels were ~ 2PPM
My next samples at 52K and 57K miles had 7 and 8 PPM of Ti and the lead levels went to 6 and then 13 PPM. Around that last sample time I got two low oil pressure light warnings at idle and had oil pressure drop at idle after 40 seconds on my drive down to CPR to have the bottom end done. While the Ti and lead level increases are low, I suspect CPR will find some bearing damage and at least two rods with the coating worn off. Given my oil pressure indications I would not want to go beyond what I did without having the bottom end checked. Oil used was Amsoil Z-rod 10W-30 and M1 0W-40.
In April at about 58K miles I did 4 passes at the Mojave Magnum in the 198-201 MPH range, so the engine was still making good power.
Happy with my Callies Ultra Billet I beams. Not cheap, $1800+ but lasted at 1000+rwhp for 22k+ miles, and came out looking perfect, going right back in the new motor.
Yes they are heavier, but for a car that is raced like ours, getting a high quality part that can be reused on build after build has a lot of value. I think as these cars get miles, we are going to see a lot more failures in rods and lifters from the fairly aggressive combos people are running.
Amazing how many people, even just locals are not on original motor.
🤣 thanks man....I’m using what I’ve got, just ranting about such an expensive part being made worthless by GM. I guess from a share holder stand point it’s brilliant though.
Worthless? Do tell. Didn't the OP's rods last 92k miles? That seems ok for an exotic.
Worthless? Do tell. Didn't the OP's rods last 92k miles? That seems ok for an exotic.
well I didn’t think it would need further in depth explanation, I tend to give vette owners and forum members more “assumed” knowledge and comprehension.....I’ll take that hit.
Obviously or maybe not in this case.....Titanium rods that are in a working LS7 motor have purpose and value, without rods the motor won’t work, kinda figured that was obvious and didn’t need any clarification. My comments of used titanium rods having no value was pertaining to when you have the block out for a rebuild or refresh now they have no value other than being a part of your motor that’s needed to make the motor work. If you want to sell them or replace them with aftermarket rods good luck getting any money for your used titanium rods even if they are in perfect working order. It appears nobody is will to take the risk of buying used titanium rods and if you do manage to get any money it’s fractions of the 5k+ GM is selling them for. Kinda disappointed I had to go into this much detail about such an obvious statement.
Last edited by 73DBG; 09-14-2018 at 01:10 PM.
Reason: Sp
Victor, putting this out there, since you didn't mention it (intentionally, I assume).
From your description of events, one could ask "what part did the new components (swapping rod bolts, etc.) and the machining and setup work done by the shop play in this failure?".
I realise that we've witnessed plenty of failures of this type on un-touched bottom ends, but it's the elephant in the room..
Last edited by Dan_the_C5_Man; 09-16-2018 at 12:01 PM.
Sorry to hear about the damage. Thanks for posting your observations. Good luck with your build and keep us posted.
As for rods, there are other options.
If one was looking for lightweight rods that are streetable, BME has aluminum rods that will work.
This discussion does bring up valid points.
All parts have a service life.
Once beyond that use, we need to change them out.
Some people expect parts to last forever.
That is not the case.
I remember hearing that there was something to the ARP rod bolts in these motors. Something along the lines of they don't always work without rehoning the big ends. Then if you do that there is a chance to compromise the coating with predictable results. Katech supposedly used to have the only bolts that worked but then their supplier went out of business unexpectedly. No first hand experience just third hand stuff.
I remember hearing that there was something to the ARP rod bolts in these motors. Something along the lines of they don't always work without rehoning the big ends. Then if you do that there is a chance to compromise the coating with predictable results. Katech supposedly used to have the only bolts that worked but then their supplier went out of business unexpectedly. No first hand experience just third hand stuff.
I haven't gotten feedback yet on my LS7's bottom end that is being rebuilt, but it was untouched with 46K OEM and then 12K miles on HCI ~600rwhp. I expect at least two OEM Ti rods will have worn thru their coating.
I've been doing an oil analysis after every oil change. Blackstone has mentioned the titanium in my samples may be due to the rods. I'm not sure what Ti levels people are seeing when the rods are wearing. I just figured I was seeing some ti intake valve wear since I'm still running a stock rocker. Heads were redone with bronze valve guides earlier this year. My latest sample analysis showed less Ti than the other two I did. The first two were on Amsoil 5w30. The latest was on Mobile 1 0w40 Euro. The latest sample is the far left column. The two with amsoil are to the right of the grey column.
Any info on Ti levels people are seeing when the rods are wearing would be great.
My Ti levels after HCI work went from 0 to 7 or 8PPM, but my lead levels also doubled. I just had a forged bottom end installed. The Ti rods showed some wear and a couple of the main bearings were marginal. When the Ti levels showed up I also got some low oil pressure excursions.
You show very low lead levels, so your 09Z should be OK.
Surprised/sad to hear of the coatings wearing off even with guys running high quality, high zinc content oils. I have been running Mobile 1 Racing off road only oil thinking the extra zinc would protect this engine.
09-13-2018, 05:14 PM
