Originally Posted by A_Harman
Originally Posted by Dirty_Howie
Originally Posted by A_Harman
The OP is obsessing too much over autocrossing an LS7 Corvette for about 30 minutes during a 3000 mile oil change interval.
Relax.
The dry sump system in a C6 Z06 holds a lot of oil, and 1.5 minutes on an autocross course is not long enough to heat the oil to any worrisome temperature.
He could safely run the oil until the OLM says to change it. He could probably even safely use M1 5w30 instead of the 0w40.
The decrease in lead after the switch from Redline to M1 is interesting, but I haven't seen anything in this thread that changes my opinion about the cause since I posted it in 2015.
I wonder about the low Phosphorous readings that Blackstone has been getting (from 7/2016 to 8/2017), and would ask them about it. M1 0w40 should have 1000 ppm. I have noticed that Blackstone's Phosphorous readings are often less than the PDS specs, but not by that much. The Iron wear numbers were low during that period.
The Iron wear rates are all less than 1 ppm per 1000 miles, and that's pretty darn good.
Although I appreciate your input I have no idea where you are getting this "obsession over autoX" from. I used to road race regularly and don't think AutoX compares at all in terms of engine wear. The ONLY thing I was ever concerned about was LEAD level. And the ONLY reason for that was that it likely meant bearing wear. The LS7 is an extremely expensive engine to replace so I feel OCI at 3-4K and closely watching my wear metals is prudent.
And I agree about phos levels but don't see where ou get the iron wear rate calculation from??
Thanks
DH
My goodness this thread had a lot of life after I posted in it back in 2015!
But to answer your most recent question: The Iron wear rate calculation is directly from the data on the report: ppm Iron divided by the oil change interval miles.
I used to track my Camaro regularly on Redline 5w30 and never had a problem with Lead concentration in a UOA. Here is an old UOA from my Camaro on Redline 5w30:
https://www.bobistheoilguy.com/foru...e-5w30-ls1-camaro-5800-miles#Post2906981
One of the big differences between your LS7 and my LS1 is that my LS1 doesn't have Titanium rods.
By saying "obsessing over autocrossing", I was trying to encourage you to extend the OCI to the point where the oil life monitor tells you to change it.
I stated long ago that the LS7 has aluminum bearings in it, and that the lead was likely coming from the connecting rod small end bushings. The LS7 has Titanium rods and needs leaded bronze small end bushings. But everybody kept saying it was bearing wear. I think it was the high concentration (500+ppm) of Moly in the Redline leaching Lead out of the rod small end bushings. So it was chemistry, not physics, that was likely causing the elevated Lead readings.
I appreciate your input and analysis.
Like I said before I am glad I took the advise of the majority here and made the switch from Reline to Mobil. I have 71K miles now and would not have wanted leaching or wearing of the lead for all this time either from street or AutoX driving. I will leave it to you experts to draw conclusions from the data I am providing.
DH