Oil analysis for an LS2 engine

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Hello,
Am new here and was looking for thresholds for LS based engines and to see if it is looking like rebuild time (I suspect it is). This engine is used in an offroad race car.

Brand of oil: Castrol GTX
Miles on oil: 150
Metals (ppm)

Iron (Fe) | 57
Chromium (Cr) | 4
Lead (Pb) | 852 (Note - race fuel is used in this engine so suspect this has skewed the ppm count)
Copper (Cu) | 56
Tin (Sn) | Aluminium (Al) | 45
Nickel (Ni) | Silver (Ag) | Titanium (Ti) | Vanadium (V) | Contaminants (ppm)
Silicon (Si) | 15
Sodium (Na) | 26
Potassium (K) | 1
Additives (ppm)
Magnesium (Mg) | 21
Calcium (Ca) | 2237
Barium (Ba) | Phosphorus (P) | 924
Zinc (Zn) | 991
Molybdenum (Mo) | 80
Boron (B) | 156
Contaminants Water (%) | Coolant No Physical Tests Viscosity (cSt 100C) 11.6 Physical / Chemical Base Number (mgKOH/g) 6.6


Based on what I have read it would appear the pistons, bearings, and just about everything else are starting to wear. The engine runs great but know they run best before they blow up.
laugh.gif
Thanks in advance for any guidance or recommendations.
 
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Specifically, what oil was used?
Why changed at 150 miles?
Has it been modified in any way?
Is this a production LS2, or something along the lines of NASCAR-spec?
 
Castrol GTX 10w40 racing oil
Last oil change was about 150 miles ago. Oil is changed in this engine every 200-1000 miles due to the nature of use.
This is a tuned LS2 that is relatively stock and has no emission items. It is used in an offroad Baja race car. Power output is estimated to be around 500hp.
 
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Thanks for answering the questions. Is it stock internally?

Originally Posted By: SJ073
Castrol GTX 10w40 racing oil

I'm unaware of this product existing. Please double-check.
 
The motor is believed to have stock internals. I purchased it used and am not sure if it came out of a Corvette or GTO.

I will double check the oil weight and post it up in a few days.
 
Ok, good. "LS2" can mean vastly different things depending on who you're talking to.

Do you know specifically what fuel you're using?
 
Copy that. The motor is tuned for pump gas but we usually use a mix of 91 octane and 104 race fuel.
 
It's important to know (using this word again...) specifically which race fuel.

Sunoco 260 GT Plus is 104, but unleaded.
 
A 50/50 mix of 91 octane and 100 octane from Rebel fuels. In the past we have used VP 110 but for the last 150 miles we used this: http://www.rockettbrand.com/ps_100.html

The spec sheet for this fuel does indicate it contains no lead.
 
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It'll take awhile for lead to get back down. Keep sampling, and stick with the unleaded.

I would however recommend picking up Mobil 1 15w-50 from your local Walmart. Purchased in five quart jugs, it's inexpensive, and a good match for the LS in a racing application.

Keep us updated, and good luck.
 
It's tuned for pump gas so try running pump gas for a while and get another analysis. Also try a longer OCI. Otherwise we can scratch our heads at the UOA all day. 150mi OCI is a waste for anything.
 
It had leaded gas run in it, that will throw your lead count way up. The LS2 is a tough engine, keep driving it.
 
Here's my two cents worth:

I have been doing UOA on my personal vehicles for several years prior to joining BITOG. There is just as much MISinformation on BITOG as there is useful information. Contrary to the opinions of many here, you do NOT need 3 or 30 UOA to develop a "trend" when there are issues; for example, I had ONE UOA that revealed 442 ppm Potassium. I had an antifreeze leak; yet my oil was a golden honey color...so much for oil "appearance."

The basic math on your engine is terrifying. The two worst things you can have in your oil are Iron and Silicon. Iron is your engine disintegrating (microscopically) and Si is rock, harder than Iron. Oil Analyzers, the test lab I use, running synthetic oil, does not want an oil sample b4 having 7500 miles on the oil, and with 7500 mi on the oil, MOST test labs consider Iron ppm condemning limits to be in the 100-150 ppm for gasoline engines.

So, the basic math on your engine is you've done 150 miles and you have 57 ppm Iron. If we multiply this out to be equivalent to 7500 miles, we have 150 X 50 = 7500. If we multiply your Iron ppm likewise, we have 57 X 50 = 2,850. This is indicative of impending catastrophic failure. Your engine is in self-destruct mode.

What I would do in your position is doubt me. Please call the test lab that performed your oil analysis and ask them if they agree with my extrapolation and conclusions. They might suggest another short OCI to verify the results. If you get TWO
 
Here's my two cents worth:

I have been doing UOA on my personal vehicles for several years prior to joining BITOG. There is just as much MISinformation on BITOG as there is useful information. Contrary to the opinions of many here, you do NOT need 3 or 30 UOA to develop a "trend" when there are issues; for example, I had ONE UOA that revealed 442 ppm Potassium. I had an antifreeze leak; yet my oil was a golden honey color...so much for oil "appearance."

The basic math on your engine is terrifying. The two worst things you can have in your oil are Iron and Silicon. Iron is your engine disintegrating (microscopically) and Si is rock, harder than Iron. Oil Analyzers, the test lab I use, running synthetic oil, does not want an oil sample b4 having 7500 miles on the oil, and with 7500 mi on the oil, MOST test labs consider Iron ppm condemning limits to be in the 100-150 ppm for gasoline engines.

So, the basic math on your engine is you've done 150 miles and you have 57 ppm Iron. If we multiply this out to be equivalent to 7500 miles, we have 150 X 50 = 7500. If we multiply your Iron ppm likewise, we have 57 X 50 = 2,850. This is indicative of impending catastrophic failure. Your engine is in self-destruct mode.

What I would do in your position is doubt me. Please call technical support at the test lab that performed your oil analysis and ask them if they agree with my extrapolation and conclusions. They might suggest another short OCI to verify the results. If you get TWO UOA with similar results, I would perform an investigative tear down before you're left with a pile of shrapnel. I would also take a stethoscope around the engine while idling. Isn't verification of internal engine condition supposed to be one of the benefits to performing UOA?

I don't like your Cu or Si or Cr counts either. I have better counts on these metals with 16K and 20K on my oil. Do whatever lets you sleep at night. Just my two cents worth.
11.gif
 
Maybe try another oil ? I know Castrol GTX was great in the past, but around here it is considered as a cheap and not so good oil...
Looks like high iron and copper, silicon too. Maybe double check air intake ?
 
Originally Posted By: Ihatetochangeoil
Here's my two cents worth:

I have been doing UOA on my personal vehicles for several years prior to joining BITOG. There is just as much MISinformation on BITOG as there is useful information. Contrary to the opinions of many here, you do NOT need 3 or 30 UOA to develop a "trend" when there are issues; for example, I had ONE UOA that revealed 442 ppm Potassium. I had an antifreeze leak; yet my oil was a golden honey color...so much for oil "appearance."

The basic math on your engine is terrifying. The two worst things you can have in your oil are Iron and Silicon. Iron is your engine disintegrating (microscopically) and Si is rock, harder than Iron. Oil Analyzers, the test lab I use, running synthetic oil, does not want an oil sample b4 having 7500 miles on the oil, and with 7500 mi on the oil, MOST test labs consider Iron ppm condemning limits to be in the 100-150 ppm for gasoline engines.

So, the basic math on your engine is you've done 150 miles and you have 57 ppm Iron. If we multiply this out to be equivalent to 7500 miles, we have 150 X 50 = 7500. If we multiply your Iron ppm likewise, we have 57 X 50 = 2,850. This is indicative of impending catastrophic failure. Your engine is in self-destruct mode.

What I would do in your position is doubt me. Please call the test lab that performed your oil analysis and ask them if they agree with my extrapolation and conclusions. They might suggest another short OCI to verify the results. If you get TWO



I would heavily weigh the difference between 7500 miles in an engine that is on average, maybe 10% under load, and seeing an average RPM of 2-3,000 vs 150 miles of flat out, hammer down, abuse. Then consider he is offroad. The load is something no vehicle with a LS2 could find on the street. Say this LS2 is experiencing and equivalent of 7500 miles worth of street wear every 150 miles. An LS2 should go 200,000 miles easily if maintained reasonably well. That would be about 3700 miles of off-road abuse, going by his numbers. Not bad.

He is just as likely to eat a lifter or stretch a rod bolt than have a wear related failure.
 
Correction am using Castrol GTX 20w50.

Thanks for all the guidance and replies. Here is some history and usage of the motor:

I know it's an LS2 but not sure what it came from originally. It was tuned by an after market company but to my knowledge has stock internals. I am not sure how many miles or races the motor had on it before I got it. I have run it in four races ranging from 180-300 miles each. Usually around 50-75 test and tune miles in between races. We change the oil after every race and the most miles the oil would ever see would be 1,500 (plan to run longer races in the future). Sustained RPMs are 3-6K. I do my best not to leave it above 5K in the interest of saving the motor but 3-4K sustained during races conditions is normal. It has an external oil cooler, filter, and fan.

The motor runs very well right now but am sure it is at or past it's half life so am starting do oil analysis to learn a little more about wear. I agree, the motor is more likely to break or tear something up before expiring due to wear. I will run it a few hundred more miles and take another sample to see what changed.

I know in a 1,200 mile offroad race, these offroad cars pick up the equivalent of 120,000 miles of wear and tear. You can literally watch a car deteriorate around you in that time frame.

Thanks again for sharing your insights, am learning a lot.
 
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Originally Posted By: Ramblejam
Thanks for answering the questions. Is it stock internally?

Originally Posted By: SJ073
Castrol GTX 10w40 racing oil

I'm unaware of this product existing. Please double-check.


sorry - Castrol GTX 20w50
 
Holy Cow! This 20W50 sheared into a 30 grade? This oil is beat to oblivion.
I second the Mobil 1 15W50 if you are sticking to off the shelf, but a racing oil might be better suited to this application. Like Schaeffers #705 20W50 Synblend or #9001 5W50 full syn. Both have an HTHS above 5.
Are you running a dry sump?
 
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Specifically, what is your involvement with this race car?

Originally Posted By: SJ073
sorry - Castrol GTX 20w50


I stand by the recommendation of Mobil 1 15w-50. When purchased in 5 quart jugs at Walmart, it's very inexpensive, and is matched well to this engine.

Originally Posted By: SJ073
I do my best not to leave it above 5K in the interest of saving the motor but 3-4K sustained during races conditions is normal.


Then I have no idea why you're running race fuel, let alone leaded. Get high octane/premium pump gas from a top station (Shell, Chevron, Texaco).
 
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