Corvette UA0 with Redline 5w30: High Lead

Originally Posted By: Ramblejam
Originally Posted By: dave1251
You can continue to use Redline. If you want your lead PPM to decrease just do not change your oil so often.


This is a fundamental misunderstanding of the chelate phenomenon.

Nope try again.
 
What is the "chelate phenomenon" of Redline? I know what chelates are in a general chemical sense, but I don't see how that would affect what is seen in an AA or ICP. Either the metallic element is there or it isn't, regardless if it is bound to a ligand. No organic compound is going to pass trough an AA flame or ICP and not be decomposed.
 
My .02 is that the high Moly content of Redline is leaching lead from the conn rod small end bushings. This is the only thing that makes sense, as I believe the LS7 has aluminum-lined bearings everywhere else.

Try something with lower Moly. For street use and a monthly autocross, thick (higher than Xw30) oils and aftermarket dry-sump oil systems aren't required.
 
Originally Posted By: A_Harman
My .02 is that the high Moly content of Redline is leaching lead from the conn rod small end bushings. This is the only thing that makes sense, as I believe the LS7 has aluminum-lined bearings everywhere else.


Ahha, well my bad, leaching is certainly a better word then (or dissolving). Chelating compounds generally only sequester already existing metal ions, rendering them invisible to other processes. That's the first time I've ever heard the word used in the sense to extract a greater concentration than would otherwise be present.
 
I don't know if it has been asked, but any chance leaded race gas was used for the track events?

Or a gas additive/octane boost that had some lead in it?
 
Originally Posted By: dave1251
Originally Posted By: Dirty_Howie
Can you explain this please ??

DH


Redline has an chelate effect due to the esters it uses as a basestock and the chelating effect is more pronounced with fresh redline. Thus the more often you change redline the higher your metal readings are going to be in UOA's.


I'm surprised nobody mentioned the chelation effect causing high lead on UOA before now. We've seen this in other Redline UOA's in the past. We just don't see as many Redline UOA's as we used to.

The high lead numbers are most likely spurious. I would talk to Redline's tech line about it. If they think it's fine then I'd stick with what you're doing now. The other numbers look good.

You might be a good use case for getting a higher end UOA from a former member of this board, he does $99 UOA's that are a lot more detailed. I'm not sure if mentioning his name is breaking the rules, though.
 
High lead is common GM garbage wearing itself out continually.

Some people feel important throwing out useless data.
Chelation... scare tactic....forget about it.
Moly issue... forget about it.

Go thicker or cooler. Obviously, the oiling system was so good that GM increased the sump size a couple years later. I would get the later sump or an aftermarket one that holds more oil. And, with either GM sump, consider the baffle mentioned in my earlier post.

What oil/water temps are you seeing at the end of the track run? and is the engine warmed up prior to starting the event?
 
Originally Posted By: Brons2
Originally Posted By: dave1251
Redline has an chelate effect due to the esters it uses as a basestock and the chelating effect is more pronounced with fresh redline. Thus the more often you change redline the higher your metal readings are going to be in UOA's.


I'm surprised nobody mentioned the chelation effect causing high lead on UOA before now. We've seen this in other Redline UOA's in the past. We just don't see as many Redline UOA's as we used to.

You might be a good use case for getting a higher end UOA from a former member of this board, he does $99 UOA's that are a lot more detailed. I'm not sure if mentioning his name is breaking the rules, though.


It's been mentioned but not explained. Do you know what a chelating compound is and how it works? I'm still a little fuzzy on how that creates a higher ppm of metal in the oil.
 
More thanks for the very interesting conversation.

There has been no racing fuel or lead additives.

I have never heard that the bearings are aluminum lined.

I have heard enough feedback now to be concerned that the Redline may be the cause. So I will try a different oil on next fill. Unless you guys think its a bad idea I will use Mobile1 0w40 as I know having used it on my last LS7 that the lead was not elevated.

DH
 
It will take a few Mobil-1 0w40 runs to rinse that engine. Try it at least 2-3 times... should be interesting data.
 
I have emailed Redline and they mostly repeat whats in the comments section of the report. At first they were ok with the elevated level since it was consistant. On this last report as you can read it they are more concerned because of the stated spike.

DH
 
Originally Posted By: Greasymechtech
High lead is common GM garbage wearing itself out continually.

Some people feel important throwing out useless data.
Chelation... scare tactic....forget about it.
Moly issue... forget about it.

Go thicker or cooler. Obviously, the oiling system was so good that GM increased the sump size a couple years later. I would get the later sump or an aftermarket one that holds more oil. And, with either GM sump, consider the baffle mentioned in my earlier post.

What oil/water temps are you seeing at the end of the track run? and is the engine warmed up prior to starting the event?


I do not think I need the larger tank. It purpose is to provide more oil during prolonged high G left hand turns which can only be seen in a racing condition. Thats why I did upgrade on my last motor when I was racing. My oil temp is lower and pressure is higher than it used to be with larger tank running Mobil1 0w40. My driving conditions are exactly the same except for replacing 1 AutoX day with 1 Road Course day.

DH
 
I have a feeling that many posters don't realize how powerful, exotic and badazz that LS7 really is. It would laugh at 2nd gear AutoX runs. Try the 0W-40 M1, maybe it's something in the Redline, but I kind of doubt it. Hopefully it's not a piece of dirt embedded in a bearing somewhere. Make sure the air filter is snug.

http://www.corvettemuseum.org/specs/2006/LS7.shtml
 
Originally Posted By: bigt61
I have a feeling that many posters don't realize how powerful, exotic and badazz that LS7 really is. It would laugh at 2nd gear AutoX runs. Try the 0W-40 M1, maybe it's something in the Redline, but I kind of doubt it. Hopefully it's not a piece of dirt embedded in a bearing somewhere. Make sure the air filter is snug.

http://www.corvettemuseum.org/specs/2006/LS7.shtml


Yes. As I tried alluding to above. You don't need a larger sump than the stock 8qt capacitity of street and AutoX runs. 40 seconds of 2nd gear without redline at 7K is not a work out. Barely gets the oil warm.

I believe the air filter is fine. Its got 36K on it. I will be replacing it soon though. But I think my UAO would show contaminants if it were leaking.

So you would try the Mobil1 0w40 if it were your car/UAO ?

DH
 
Either the 0W-40 or 15W-50 M1. I've used the latter in my big block Suburban when I used to tow race cars and I never had a problem with cold starts. The Suburban doesn't get driven much anymore so I'm changing over to the 0W-40 just for it's long life. I don't enjoy changing oil and the 5W-30 that's in it now has already been in since 2011. Your 39ppm lead isn't super high, but maybe higher than it should be for whatever reason. It's an expensive motor, I'd keep an eye on it with UOAs until things calm down.
 
Originally Posted By: bigt61
Either the 0W-40 or 15W-50 M1. I've used the latter in my big block Suburban when I used to tow race cars and I never had a problem with cold starts. The Suburban doesn't get driven much anymore so I'm changing over to the 0W-40 just for it's long life. I don't enjoy changing oil and the 5W-30 that's in it now has already been in since 2011. Your 39ppm lead isn't super high, but maybe higher than it should be for whatever reason. It's an expensive motor, I'd keep an eye on it with UOAs until things calm down.


I would feel uncomfortable running 15w50 unless I was tracking it on a hot day.

My oil pressure is already pretty high. Startup is 60psi. I run it easy until oil temps get up to 150* otherwise I will exceed 80psi. Cruising on freeway at 1500rpm is 50psi. Idle psi is always above 30 unless its 200* and then it will settle at 30psi.

DH
 
Originally Posted By: Garak
The Vette only has two real purposes. The first is for racing. The second is to satisfy old farts with too much money.
wink.gif

I am an old [censored]. why is the oil pressure too high?
 
The only thing I could think of as to why there is high oil pressure observed in this Vette is that Red Line 5w-30 is a higher HTHS 5w-30 than one would normally use in the application, contrary to the talk about it being a thin grade. It has a HTHSV of 3.7 cP versus around 3.2 for M1 5w-30 and 3.0 to 3.1 for most ILSAC rated 5w-30 options.
 
Originally Posted By: Merkava_4
The car might need a different viscosity or a different oil altogether.


Or in your case a different FONT TYPE
 
Originally Posted By: addyguy
I don't know if it has been asked, but any chance leaded race gas was used for the track events?

Or a gas additive/octane boost that had some lead in it?



I was going to ask something similar. I also would suggest getting the heads redone to prevent a valve drop.
 
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