# Oil + LSPI



## gmansyz (Dec 23, 2018)

Let's start a proper discussion on this.
G


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## snowwy66 (Nov 5, 2017)

There's already been multiple discussions.


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## gmansyz (Dec 23, 2018)

But no one has thought of the blowby.


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## Ma v e n (Oct 8, 2018)

gmansyz said:


> But no one has thought of the blowby.


Not sure where you got that from, you must've just missed it.

Blowby is obviously a contributor to it, and it's one reason why NOACK volatility specs are tighter on Dexos1 than API SN. 

Evaporation losses increase the quantity of vapors in the crankcase, lower volatilities reduce the amount of evapoartion​ that occurs in the ring pack/hydrocarbon shelf area.(and off of valve stems/guides, etc)

Dexos1 Gen2, and API SN+ were both created/updated largely to mitigate LSPI.

Additionally calcium and sodium reductions, along with ZDDP group packages being increased to quench LSPI are major changes. Additional work is ongoing as while ZDDP has proven quenching abilities it's not possible to increase phosphorus levels beyond a certain point due to API specifications which are intended to reduce catalyst poisomging


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## Blasirl (Mar 31, 2015)

Whoa! What was that? Must have been the suction of my brain out of my skull as that conversation flew over and under my head!


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## XtremeRevolution (Jan 19, 2012)

Surprised to find someone who actually has some facts. Kudos to Maven. 

Dexos1 NOACK IIRC was only 13%. Not sure if that improved with dexos 1 gen2 but it's simply not enough. I don't consider anything with a NOACK above ~10 to be worthwhile in such an engine (in a 5W-30). AMSOIL SS by comparison comes in at 6.7% for the 5W-30 and 8.5% for the 0W-20. Vaporization loss plays some part but ultimately it's not the biggest cause. 

Dexos1 Gen2 allows 4 LSPI events to pass. API SN+, which uses Ford's LSPI testing, allows 5 LSPI events to pass. I prefer zero LSPI events. Shameless plug: AMSOIL's OE, XL, and Signature Series oil all test with 0 LSPI events across five consecutive runs of GM's dexos1 gen2 LSPI test. 

Sodium is the biggest contributor, followed by Calcium. ZDDP as well as Moly and other antioxidants counteract it. It's important to note however that this isn't a blanket rule. It's not "Calcium bad, Magnesium good." In testing that Joe Gibbs performed, they found that you can use about 1,000 PPM of Calcium and still not have any LSPI. It's when you exceed a certain concentration, which depends on the oil formulation in question, that you start seeing LSPI. 

Now, the technical side. The actual root cause of LSPI is related to how much time, in degrees of engine rotation, it takes for the fuel to ignite from the moment it leaves the injector tip. In a port injected engine, you have far more time as you have to go through the port, be sucked through the valve on the intake stroke, then mix during the compression stroke, then ignite. On a direct injected engine, you have far less time; in some cases you are spraying fuel after the compression stroke has even reached TDC. The end result of this is that you are trying to burn liquid fuel, and liquid fuel does not combust the way you think it does. On a port injected engine, by contrast, the fuel has plenty of time to atomize and vaporize, which is why you see relatively little fuel dilution in those engines. 

On direct injected engines, you are spraying liquid fuel and trying to ignite it, often while the piston is on the compression stroke, resulting in a "washing down" of the cylinder walls and subsequent fuel dilution as the oil droplets around the piston rings meet the fuel droplets. 

Here is the critical point:
The liquid fuel droplets mix with the oil droplets, and the additive chemistry in the engine oil reduces the octane level of the fuel droplets. This results in auto-ignition of the fuel droplets, which depending on volume, location, and heat, can be absolutely disastrous. This is also why piston damage caused by LSPI is always evident around the ring lands, not the piston crown. 

Joe Gibbs went to great lengths to test this in order to develop oils resistant to LSPI. They did this by sourcing individual additive packs and mixing them with the oil to determine what effect each would have on the octane level. They discovered it was the calcium and the sodium that caused a significant drop in fuel octane level. Mixing straight base oil as a 2-stroke mix in their fuel proved to have almost no effect on fuel octane, dropping something like 0.1 octane even at high mix ratios. 

Understanding the root cause of LSPI on a technical level, you can make better decisions on what you can do to prevent it. Adding a catch can won't prevent it. Using a low volatility oil, alone, won't prevent it. You need to use an oil that has a chemistry specifically developed to *prevent *LSPI. Note that my choice of words is prevention, not mitigation. 

I imagine there may be a point where conditions exist that the best oil in the world cannot prevent a catastrophic LSPI event, but my recommendation has been to do the best you can and use the oil best suited for LSPI prevention available for your engine in your region.


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## gmansyz (Dec 23, 2018)

Now this is what I wanted to hear!
So we are talking washdown now. What about dieseling?
Now with wash down, you are having less lubricant on the walls and this can be forced down into the crankcase then to be reintroduced in the intake system.
Detonation and preignition cause the shockwaves the break ring lands and fracture rings. Though you can run it too lean which can overheat and soften the piston, I suspect that with the redesign, the injector pattern and new dome/deflector, the spray is less likely to be on the cylinder walls.
But, maybe still dieseling.
G


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## XtremeRevolution (Jan 19, 2012)

gmansyz said:


> Now this is what I wanted to hear!
> So we are talking washdown now. What about dieseling?
> Now with wash down, you are having less lubricant on the walls and this can be forced down into the crankcase then to be reintroduced in the intake system.
> Detonation and preignition cause the shockwaves the break ring lands and fracture rings. Though you can run it too lean which can overheat and soften the piston, I suspect that with the redesign, the injector pattern and new dome/deflector, the spray is less likely to be on the cylinder walls.
> ...


The biggest and most critical issue is that you have liquid fuel mixing with oil droplets in the ring lands, where the fuel drops in octane level and auto-ignites under stress. That's really the biggest problem. You have a high pressure explosion inside the ring lands of a piston and that pressure has nowhere to go, so it breaks a piece of metal clear off the piston. 

https://www.amsoil.com/lander/lspi-update/

[imt]https://www.amsoil.com/lander/lspi-update/images/piston-damage.jpg[/img]


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## snowwy66 (Nov 5, 2017)

Blowby was brought up also.


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## gmansyz (Dec 23, 2018)

Why would anyone even stretch the change interval to 7500 miles? 5000 is fine. And to be safe as well.


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## Ma v e n (Oct 8, 2018)

Calcium has been found to be the biggest individual additive causing the issue, and higher levels of sodium mixed with the calcium actually make it worse. Sodium all by itself has minimal affect and remains a quality detergent. The fuel is what combusts, but it's the detergents holding on to unburned fuel and "storing" them in the ringlands. The ECM tuning, the fuels initial AKI("octane") rating, the physics of the spark ignition direct injection combustion propagation, and the fragility of the piston and rings package.

The problem is that virtually all SN oils have used significant calcium chemistry based detergent packages. So getting rid of the calcium is difficult. I don't have D1g2 specs I'm front of me but it wasn't uncommon to see calcium levels over 2500 on quality gen1 oils. Now on the gen2 licensed oils your unlikely to find anything over 1500,(save for ACDelco 0w20 coincidentally...Which as tested by PQIA shows over 2000!) And most of big name oils will be in the 1000-1200 range. There are good oils with sub 1000 calcium levels, and their are awesome oils in that upper 1000 range, but they'll typically a larger hit of ZDDP or similar chemistries.


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## XtremeRevolution (Jan 19, 2012)

gmansyz said:


> Why would anyone even stretch the change interval to 7500 miles? 5000 is fine. And to be safe as well.


Because they can, that's why. Oil change interval has literally nothing to do with LSPI. You can get better protection against LSPI with AMSOIL running 15k mile intervals than you can with Mobil 1 at 5k intervals, just as an example. 



Ma v e n said:


> Calcium has been found to be the biggest individual additive causing the issue, and higher levels of sodium mixed with the calcium actually make it worse. Sodium all by itself has minimal affect and remains a quality detergent. The fuel is what combusts, but it's the detergents holding on to unburned fuel and "storing" them in the ringlands. The ECM tuning, the fuels initial AKI("octane") rating, the physics of the spark ignition direct injection combustion propagation, and the fragility of the piston and rings package.
> 
> The problem is that virtually all SN oils have used significant calcium chemistry based detergent packages. So getting rid of the calcium is difficult. I don't have D1g2 specs I'm front of me but it wasn't uncommon to see calcium levels over 2500 on quality gen1 oils. Now on the gen2 licensed oils your unlikely to find anything over 1500,(save for ACDelco 0w20 coincidentally...Which as tested by PQIA shows over 2000!) And most of big name oils will be in the 1000-1200 range. There are good oils with sub 1000 calcium levels, and their are awesome oils in that upper 1000 range, but they'll typically a larger hit of ZDDP or similar chemistries.


Fast forward to 54 minutes, or watch the whole 1 hour 23 minute episode: https://www.youtube.com/watch?v=7n08OX53scE

Sodium on its own was tested to raise knock events. I had mixed it up; it was in fact Calcium that was the worst contributor. 

It isn't the storage of fuel in the ring lands but, as I explained pretty clearly in the last post, the drop in octane of the fuel as it mixes with the oil droplets. Don't take my word for it, the research was done pretty thoroughly on this.


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## snowwy66 (Nov 5, 2017)

Gasoline won't be perfect for today's engines. 

Yesterdays engines still need valve lubrication somehow. Since lead is no more. Something had to replace it.


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## Ma v e n (Oct 8, 2018)

XtremeRevolution said:


> It isn't the storage of fuel in the ring lands but, as I explained pretty clearly in the last post, the drop in octane of the fuel as it mixes with the oil droplets. Don't take my word for it, the research was done pretty thoroughly on this.


I think we are playing semantics here and I wont say you're wrong, but you may be looking at the tests and data at weird angles(you're interpreting in ways they weren't meant to be, perhaps oversimplifying or overextrapalating)

It is in fact the additive package absorbing/storing the fuel in solution with the oil in the ringlands. Without this fuel/oil/additive solution there wouldn't be a combustible source to cause the damage during the SPI event. And it is the combustibles in the ringlands causing the damage on the 1.4/1.5, that's why we by and large aren't seeing piston crown failure or rods failures, it's ringlands failures.

The oil itself isn't causing the drop in octane, it's an as yet unknown chemical reaction that occurs between the fuel and the additive package. The theory that the base oil itself lowers the octane has been disproven, testing fuel and base oil mixtures (like a 2 stroke fuel) for AKI readily showed that even at ratios as high as 25:1 base oil didn't lower the AKI rating by even a whole octane point, proving it's not the oil itself, it's the additive package.

There's either some sort of exothermic reaction occuring amongst the oil additive package and the fuel constituents igniting the mixtures or truly random events like super heated soot/carbon particulate or completely unknown and undiscovered chemical process causing the issue.


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## XtremeRevolution (Jan 19, 2012)

Ma v e n said:


> The *base *oil itself isn't causing the drop in octane, it's an as yet unknown chemical reaction that occurs between the fuel and the additive package. The theory that the base oil itself lowers the octane has been disproven, testing fuel and base oil mixtures (like a 2 stroke fuel) for AKI readily showed that even at ratios as high as 25:1 base oil didn't lower the AKI rating by even a whole octane point, proving it's not the oil itself, it's the additive package.
> 
> There's either some sort of exothermic reaction occuring amongst the oil additive package and the fuel constituents igniting the mixtures or truly random events like super heated soot/carbon particulate or completely unknown and undiscovered chemical process causing the issue.


I added a correction to the above quote in blue that I believe you intended to make, based on your explanation. 

Joe Gibbs ended up taking individual additives and adding them to the fuel itself, which is how they discovered that the octane level of the fuel would change. That's why I keep going back to this point. These aren't random events, although to be clear, I'm not saying those aren't possible. The overwhelming majority of them, however, are all oil related, and it is worth repeating that AMSOIL (and presumably Joe Gibbs as well) have been able to successfully reformulate their oil and see an elimination of LSPI events, at least ones related to the oil on otherwise clean and healthy engines. 

I imagine that carbon build up from using an oil with poor oxidation stability that is otherwise otherwise LSPI-compatible may cause issues as well.


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## Blasirl (Mar 31, 2015)

Ma v e n said:


> ... NOACK ... API SN ... API SN+ ... LSPI ... ZDDP ....





XtremeRevolution said:


> ... AMSOIL SS ... AMSOIL's OE, XL, and Signature Series oil ....





Ma v e n said:


> ... AKI("octane") rating, ... SN oils ... D1g2 specs ...


Gentleman,

Can I get you to define these so I can add them to the CruzeTalk Glossary?

Robert


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## XtremeRevolution (Jan 19, 2012)

Blasirl said:


> Gentleman,
> 
> Can I get you to define these so I can add them to the CruzeTalk Glossary?
> 
> Robert


NOACK volatility tests the vaporization loss of engine oil under heat. https://en.wikipedia.org/wiki/Noack_volatility_test

API SN and API SN+ are engine oil specifications. https://www.amsoil.com/newsstand/motor-oil/articles/api-sn-plus-is-here/

LSPI is Low Speed Pre-Ignition. https://www.amsoil.com/lander/lspi-update/

ZDDP is Zinc dithiophosphate. It is an antiwear additive in engine oil mandated by API at no more than 800ppm for zinc and phosphorous. 

AMSOIL SS (Signature Series), AMSOIL XL, and AMSOIL OE are oils made by AMSOIL for street vehicles, which come in a variety of viscosities. OE is rated for OEM drain intervals, XL is rated for 1 year or 12k miles, whichever comes first, and Signature Series is rated for 15,000 miles in severe service, 25,000 miles in normal service, or 1 year, whichever comes first. 

AKI is anti-knock index, and is what we refer to as the octane level of the fuel. 

D1g2 refers to Dexos1 Gen2, which is an oil specification created by GM, similar to but more stringent (in some ways) than API SN Plus.


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## Ma v e n (Oct 8, 2018)

XtremeRevolution said:


> Joe Gibbs ended up taking individual additives and adding them to the fuel itself, which is how they discovered that the octane level of the fuel would change.


I don't recall ever coming across any research where additive packages or constituent chemicals were added to fuel and tested for AKI variances. It's been my understanding and interpretation of testing that after determining that LSPI events were still prevalent regardless of fuel used(or viscocity of oil) that the researchers started making oils with varied additive packages. And it was this experimentation with oil chemistry that the link to calcium, and sodium as the major instigators of LSPI was determined.




> That's why I keep going back to this point. These aren't random events, although to be clear, I'm not saying those aren't possible. The overwhelming majority of them, however, are all oil related, and it is worth repeating that AMSOIL (and presumably Joe Gibbs as well) have been able to successfully reformulate their oil and see an elimination of LSPI events, at least ones related to the oil on otherwise clean and healthy engines.


Again perhaps reading into things or making excessive extrapolation, just because the major source of what can lead to LSPI has been determined doesn't mean they aren't random. GM, who was also involved in the ORLN studies with JGR still doesn't call it LSPI, they have always called it stochastic pre-ignition, which by definition is a random event. They can study, and analyze it, determine contributing factors, but it still can't be predicted completely eliminated. The oil reformulations are just our current best way to mitigate the issue without hardware and software redesigns.



> I imagine that carbon build up from using an oil with poor oxidation stability that is otherwise otherwise LSPI-compatible may cause issues as well.


Yes it certainly could, and it is also believed that soot from the combustion process is one of the variables that leads to the randomness of LSPI/SPI (of course so is quantum mechanics, and it's may be impossible to eliminate SPI with current engine designs, additive packages, fuels and engine control strategies.

Important to note is that while Amsoil is great oil, and I've recommended it, currently nothing "eliminates" or "allows zero" LPSI events. It only doesn't experience it during the relatively short test period. Other things to think about are that the new GF6 spec test will use a Ford 2.0 Ecoboost and thatthings like Fuel temperature, Speed, Air Charge Temp, Coolant Out Temp, Oil Gallery Temp, Exhaust Backpressure and atmospheric conditions are notable variables that even ILSAC is having issues stabilizing in testing in labs. (The GF6 spec is expected to be stricter than SN+ Sequence IX tests, besides just the drop from 5 events to 4)Obviously a tested oil is potentially a better choice than a non tested one, but there's no reason to assume an oil that had 1, 2 or 4 events during testing is leaps and bounds better than one that had zero. Also while Amsoil does indeed state that it's SS, XL, and OE oils exhibited zero LSPI events in testings it's important to note it's only the 5w30 viscocities that were tested and they specify what test standard it was to. Doesn't diminish the oils quality or value, but continues Amsoil ambiguity , to borderline misleading statements that almost always have a caveat or asterisk, which still may not even full explain their position or statement. Again, I like Amsoil, just making objective observations.


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## XtremeRevolution (Jan 19, 2012)

Ma v e n said:


> I don't recall ever coming across any research where additive packages or constituent chemicals were added to fuel and tested for AKI variances. It's been my understanding and interpretation of testing that after determining that LSPI events were still prevalent regardless of fuel used(or viscocity of oil) that the researchers started making oils with varied additive packages. And it was this experimentation with oil chemistry that the link to calcium, and sodium as the major instigators of LSPI was determined.
> 
> 
> 
> ...


I sent you a link to the video where a guy from Joe Gibbs explained it all. I even told you where to find the information in question, yet you are responding as if it doesn't exist. Just because the research isn't published in the open, doesn't mean it hasn't been done. Go watch the video already and then talk about it; I posted the link a couple of replies ago. 

GM would sure like to tell you they're random, as that would absolve them of as much responsibility to address the problem. If they were to admit that their oil formulation, or their tuning caused the problem, there would be massive legal ramifications. All that ultimately do is muddy the waters of identifying a root cause to a catastrophic failure while they quietly make changes behind the scenes to limit exposure. They've called it SPI; the rest of the industry calls it LSPI. Not sure why GM thinks they're special, considering how late they were to the forced injection DI game. Heck even Mobil 1, GM's largest supplier of synthetic lubricants, calls it LSPI. As far as I'm concerned, SPI is GM-specific terminology, and the fact that they're still dropping pistons while other manufacturers are figuring out how to prevent it doesn't give them any credibility on the subject. 

There is a difference between claiming that all LSPI is eliminated, and claiming that zero LSPI events are found using a specific test. LSPI advertises the latter, and does so in a way nobody else does. Furthermore, because of that relatively short test period, AMSOIL had it run 5 times in a row on their test, which resulted still in 0 events. Now keep in mind, GM allows 4 events in order to pass. There's a lot you can extrapolate from that fact. I don't assume the ambiguity to be intentional; in fact, they were quite specific about which oils were tested. Remember, they don't test the oils themselves; they send it out to a lab like SWRI and have them test it for them, so to run the GM test 5 times on one oil is not going to be cheap. To do it again for every viscosity, when the additive formulation is the same between them all (with the exception of viscosity-related additives) is just a waste of time, especially if they've reached the conclusion (and proven it to work, at least in GM's test) that LSPI is related to the oil additives.


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## Ma v e n (Oct 8, 2018)

API oil classifications info from the API, as opposed to a vendors website  LOL


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## XtremeRevolution (Jan 19, 2012)

Ma v e n said:


> API oil classifications info from the API, as opposed to a vendors website  LOL


I mean if you want to be technical...

https://www.api.org/~/media/files/c...blications/150917thaddendum1-032515.pdf?la=en


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## Ma v e n (Oct 8, 2018)

XtremeRevolution said:


> I mean if you want to be technical...


I didn't want to be technical and neither did the member who asked us for information regarding things we are discussing.


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## Ma v e n (Oct 8, 2018)

I saw the interview with Lake Speed Jr a few months ago. 

DRIVEN racing oils is the company that supplied the base oils and additives for the testing he is talking about in that video.

Additionally GM was also heavily involved in that testing, which was done at ORNL(Oak Ridge Natl Lab). So you're disbelief or distrust in their research is misplaced. GM has been working on resolving the problem as long or longer than any OEM, as evinced by the release of Dexos1 Gen2 , which includes the LSPI test(which Amsoil uses), and was available 8 months before the API SN+ testing and spex.Just because you dont like something doesn't make it untrue.

The statements you keep making, and pointing that mine are incorrect and using that video to back up, are incorrect. The video itself contradicts your statements and coincides with mine. Including the fact that they don't know what causes it, that it's not specifically the oil droplets, that it is indeed stochastic preignition, that they didn't test fuels with oil additives blended in, you get the picture.

As I've been saying, you're not fully grasping even your own source (which references some of my sources) and your making flawed statements regarding g the mechanism of these events.


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## Ma v e n (Oct 8, 2018)

Just a little observation regarding your non sequitor about GM being late to the turbo DI game....The 2.0 LNF was released in early 2006 calendar year as a 2007...How many big players beat them with any notable engines used across multiple platforms/brands?


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## XtremeRevolution (Jan 19, 2012)

Ma v e n said:


> I saw the interview with Lake Speed Jr a few months ago.
> 
> DRIVEN racing oils is the company that supplied the base oils and additives for the testing he is talking about in that video.
> 
> ...





Ma v e n said:


> Just a little observation regarding your non sequitor about GM being late to the turbo DI game....The 2.0 LNF was released in early 2006 calendar year as a 2007...How many big players beat them with any notable engines used across multiple platforms/brands?


It's been a few months since I read through it, but I vividly remember them talking about changing specific additives, and that the change in octane was a specific contributor. 

My distrust in GM isn't misplaced. One too many 1.4 and 1.5 turbo pistons, and LTG pistons dropped in the last few years, many of which were in cars my friends owned. So, telling me that GM somehow has it figured out after presumably 10 years...nope. If I did have to buy a direct injected vehicle, it wouldn't be from GM, I can assure you that much. 

DRIVEN is a brand of oil products made by Joe Gibbs. Whether we refer to it as Joe Gibbs or Driven is ultimately inconsequential as we're referring to the same thing. 

As for what statements contradict what's in the video and in yours, I decided to run back through the video. A few notes from words stated in the video: 

- There is no indication from the video so far that this testing was performed with GM heavily involved, especially with the way GM is referred to during the video. 
- Minute 45 describes what I explained regarding liquid fuel. 
- Minute 47: the mixture with oil and fuel, and the fuel being a liquid is what causes the problem.
- Correction to my previous point, there is a 3rd chemical, that is not oil nor fuel, that has a lower octane than the fuel. That chemical is the oil and fuel mixed together. 
- To prove that it wasn't the base oil, they took different base oils, mixed those base oils into the fuel and ran them in the octane test machine at SWRI. Minute 49. 
- They tested different detergents and other additives to see what would make the difference. I guess I had assumed that they mixed it with the oil, but they may have just played around with the oil additive. Minute 50
- The one that's worse than calcium is sodium. Minute 51
- Minute 1:08, screenshots hows, "research indicates that droplets of oil in the cylinder may be combining with droplets of fuel prompting ignition before spark timing is intended to occur." Basically exactly what I described earlier. 

Now, if we're going to have a technical discussion, please address the specific points you believe to be wrong, with the source for why I'm mistaken, and I'll stand corrected, but the rhetorical "you keep contradicting your sources and you're wrong" rhetoric is unproductive. 

Feel free to address specific points.


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## XtremeRevolution (Jan 19, 2012)

Ma v e n said:


> I didn't want to be technical and neither did the member who asked us for information regarding things we are discussing.


We're in the powertrain section of the forum. It's going to get technical. If you don't want to be technical, why are you engaging in a technical discussion?


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## Ma v e n (Oct 8, 2018)

XtremeRevolution said:


> It's been a few months since I read through it, but I vividly remember them talking about changing specific additives, and that the change in octane was a specific contributor.
> They did change out additives...In the oil.
> 
> My distrust in GM isn't misplaced. One too many 1.4 and 1.5 turbo pistons, and LTG pistons dropped in the last few years, many of which were in cars my friends owned. So, telling me that GM somehow has it figured out after presumably 10 years...nope. If I did have to buy a direct injected vehicle, it wouldn't be from GM, I can assure you that much.


I never said GM figured it out.
Hyundai/Kia has had lots of issues with this on their 1.6 and 2.0GDIT enignes, Subura 2.0GDIT were having issues from the time they were released(recalls issued I believe)Volvo 2.0, Mazda speed3 2.0s, etc, etc....The GM 1.4/1.5 is just the newest one, not the worst.



> DRIVEN is a brand of oil products...


Agreed, I wasn't correcting you, just using the nomenclature I was familiar with and what Lake Speed himself says.




> - There is no indication from the video so far that this testing was performed with GM heavily involved, especially with the way GM is referred to during the video.


you're making inferences as to parties lack of involvement in the research for the solution based on your assumption of their involvement in the cause.
GM was large partner in the ORNL project,slide at 43:30 at least shows them as partner and lists them first. GM engines (the LT series particularly ) are referenced because that's a large area of the consumer area that DRIVEN markets to. DRIVEN discusses the LT engine multiple times because they purchased one to do their own testing, for their own products, which are largely not API cert'd 

Slide and discussion beginning at 52:40. They specifically mention changing oil additives

53:40 is the slide showing calcium/sodium LSPI event. Removing all the sodium from an add pack with 2500ppm calcium didn't change LSPI frequency. Sodium increases LSPI, but not to levels exceeding those acheived by calcium.


{{{{- Minute 45 describes what I explained regarding liquid fuel. }}}}
Yes that touches on fuel wash down and lack of vaporization, but it's not the sole mechanism or the cause of LSPI it's just one contributor

{{{{- Minute 47: the mixture with oil and fuel, and the fuel being a liquid is what causes the problem.}}}}
47:30 forward literally says it's not the fuel or the oil, or the fuel/oil mixture, but an as yet unknown 3rd compound catalyzed from the mixture, and they don't know what causes it or what it is.


{{{{ To prove that it wasn't the base oil, they took different base oils, mixed those base oils into the fuel and ran them in the octane test machine at SWRI. Minute 49}}}}

Which I previously printed out when you stated they were testing oil additives in the fuel.


{{{{- The one that's worse than calcium is sodium. Minute 51}}}}
Lake says those exact words, but it's not borne out by the research or his own presentation.


{{{{- Minute 51:08, screenshots hows, "research indicates that droplets of oil in the cylinder may be combining with droplets of fuel prompting ignition before spark timing is intended to occur." Basically exactly what I described earlier.}}}}

Not sure which thing you described that this "basically exactly" relates to, but note that slide says those MAY cause it, specifically says autoignition is due to a stochastic source, and section where they note : "ignition source- heat?Radicals?Both?". It's not known and can't be predicted, all statements that more closely match my posts than yours.


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## Ma v e n (Oct 8, 2018)

If you've got anything else specific where you find my posts have not been factual let me know. If I've addressed where I thought yours have differed from the source material. This exchange seems to be coming reductive.


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## XtremeRevolution (Jan 19, 2012)

53:40 is the slide showing calcium/sodium LSPI event. Removing all the sodium from an add pack with 2500ppm calcium didn't change LSPI frequency. Sodium increases LSPI, but not to levels exceeding those acheived by calcium.
*- Yet he specifically says Sodium is the worst. Specifically. By name. You ignored that again. That was my only point. It wasn't even that important since none of the oils we're even considering have it. *

{{{{- Minute 45 describes what I explained regarding liquid fuel. }}}}
Yes that touches on fuel wash down and lack of vaporization, but it's not the sole mechanism or the cause of LSPI it's just one contributor
*- Actually, it was explained in great detail how the delivery of fuel in a DI engine is actually how all of these problems start; the liquid fuel. If there was no liquid fuel mixing with oil droplets, we wouldn't have LSPI. Re: LUV/LUJ in the Gen1 1.4 Turbo. Even exceeding the power levels that the Gen2 1.4L Turbo has when the Gen1 is tuned, we don't see LSPI. *

{{{{- Minute 47: the mixture with oil and fuel, and the fuel being a liquid is what causes the problem.}}}}
47:30 forward literally says it's not the fuel or the oil, or the fuel/oil mixture, but an as yet unknown 3rd compound catalyzed from the mixture, and they don't know what causes it or what it is.
*- Nope, I don't recall them saying it's not the fuel/oil mixture. In either case, that's ultimately irrelevant because it's the mixing of the oil and fuel that creates this chemical that IS OF A LOWER OCTANE, that causes the LSPI events. Meanwhile, you're still suggesting they're random. *

{{{{- The one that's worse than calcium is sodium. Minute 51}}}}
Lake says those exact words, but it's not borne out by the research or his own presentation.
*- Doesn't mean it isn't factual or that they haven't performed other testing outside of the results he presented. Remember, they had SWRI perform some of the tests for them. This radio show was not just a presentation for one testing effort. It was a presentation of their findings overall. *

{{{{- Minute 51:08, screenshots hows, "research indicates that droplets of oil in the cylinder may be combining with droplets of fuel prompting ignition before spark timing is intended to occur." Basically exactly what I described earlier.}}}}

Not sure which thing you described that this "basically exactly" relates to, but note that slide says those MAY cause it, specifically says autoignition is due to a stochastic source, and section where they note : "ignition source- heat?Radicals?Both?". It's not known and can't be predicted, all statements that more closely match my posts than yours
- Yes except they then go into great detail explaining how the mixture of the oil and fuel creates a chemical with a lower octane that causes combustion in the ring lands and blows off chunks of pistons, which is exactly what we've been seeing from day one, and that they are _effectively_ solving the LSPI problem with oil reformulations. 

If you want to talk about other sources of knock, sure, we can have that discussion. As you well know, a small number of pistons had failures (in exactly the same spot) on the Gen1 1.4L Turbo, bone stock, and those may in fact be attributed to carbon deposits, but the failures specific to direct injected turbo engines, as it they relate to the fuel delivery, were explained quite well.


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## XtremeRevolution (Jan 19, 2012)

Ma v e n said:


> If you've got anything else specific where you find my posts have not been factual let me know. If I've addressed where I thought yours have differed from the source material. This exchange seems to be coming reductive.


Re:



Ma v e n said:


> I didn't want to be technical and neither did the member who asked us for information regarding things we are discussing.


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## brian v (Dec 25, 2011)

I 've always gotten excited when X gets involved with these lengthy thought out and researched threads about earl . He always makes us think and do our own research ..

This phenomena of these turboed - gas-direct- injected engines is a very puzzling yet well known occurence .. for any 1 that fears popping an engine . Do not open the throttle fully from a slow speed low RPM and you should be ok .. down shift ...........

X brought up heat to the equation . Here ya go MAP and charge air temp .
Bigger intercooler and keep your boost down .

What about fuel starvation at WOT ?
Some events have been attributed to the occurrences of no fuel at high RPM's . There is speculation that engine design is a factor here . Weak engine housings . 1 side of the block is not thick enough to withstand presssures .

Every body know what kind of oil to purchase ? Amsoil according to X and testing . I run new modern engine API SN + or better . According to testing ..


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## Taxman (Aug 10, 2017)

I'm going back to the beginning here, starting with what I know or think I know about GDI and LSPI.

With GDI, you can inject the fuel into the cylinder after the exhaust valve closes, so that you can have complete scavenging without any fuel going out the exhaust. 

But GDI puts liquid fuel straight into the cylinder, so some liquid fuel gets on the cylinder wall, diluting lubrication and eventually finding its way behind the piston rings or into the oil sump. Fuel behind the rings, combined with oil detergents, can go boom and blow the piston apart at the ring grooves. Hello, LSPI. 

So, obviously we want to use oil formulated to reduce LSPI, even if it means giving up some of the detergents that keep oil residues (varnish) from building up inside the engine. And we might want to change oil more often than with a MPFI engine that doesn't put noticeable quantities of fuel into the oil sump. 

OK, having mentioned detergents, what about the detergents in the fuel that keep the fuel injectors and intake valves clean?
Fuel additives in GDI engines do nothing for the intake valves, and federal minimum detergent standards should be adequate to keep the injectors clean. 
1. So, is less detergent in the fuel better for preventing LSPI?
Am I better off buying gas at Speedway with 150ppm of the Marathon/Speedway detergent package than with getting Top Tier fuel at a Marathon station with 400ppm of the same detergents?

2. What about intake air temps?
If the problem is with liquid fuel running down the pistons, would warmer intake air help it to evaporate before it gets there?
In 30 degree temps, my Cruze runs 35-40 degree manifold air temps. 
Would I be better or worse off if I blocked the intercooler fins in the winter to preserve the heat generated in the turbo?

3. What about alcohol?
Ethanol takes more heat to evaporate, so I would assume that more ethanol in the fuel means more liquid fuel on the cylinder walls. 
Not to mention ethanol is a crap lubricant and you don't want it in your oil. 
So is E85 good for avoiding LSPI because of the high octane rating, or is ethanol free fuel better for GDI engine life to avoid the drawbacks I mentioned?

4. What about engine temps?
The 1.4LE2 uses an 80-82° thermostat, I think the LUV uses closer to 100°.
Do we want higher temps for better evaporation of fuel, or lower temps to make it harder to start combustion without a spark?
Does the cylinder wall temp even have an appreciable effect of the temp of the ring grooves where the LSPI generating liquid fuel is hiding?


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## Ma v e n (Oct 8, 2018)

I didn't ignore that he said sodium was the worst. I mentioned that he said it and then I proceeded to say that his own presentation and referenced research doesn't bear out that point. 

Incomplete fuel vaporization is one instigator in the complex chain of events and components that is required to be present for LSPI to occur.
You dont blame a forest fire on the trees. Just like you don't blame LSPI on just DI.

Again, at 47:30 forward they discuss how the research leads to believe it is this as of yet unknown composition created by the fuel/oil mix that is a cause of the LSPI. No need for all caps, I acknowledge and have noted the unknown chemical has a lower octane. I keep suggesting they are random, because they are. Random doesn't mean we don't know anything about it....It means it occurs randomly without definitive pattern or probability. They can't predict accurately when it will occur, they don't know what instigates the autoignition, this is random.

You're correct, just because the presented research does not match Lake's statement doesn't mean it untrue. But it just as strongly doesn't mean it is. 
Stating here that sodium is the worst contributor to LSPI is misleading and not defendable with any data presented. 


Yes there is an unknown chemical composition that is believed to be created that is one cause of LSPI. They don't know how much of this chemical needs to be present to autoignite and cause damage, what this chemicals attributes are, what temperature it ignites at, what temperatures it will form at, why it seems to be a non issue at higher engine speeds (where there is even less time for fuel atomization)

I've never said that oil reformulations weren't mitigating the concern. I've advocated use of Amsoil oils multiple times on this forum.


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## Ma v e n (Oct 8, 2018)

I don't think you'll notice any difference in detergent action of SN+ oils, Mobil1 has met SN+ levels of calcium for nearly a decade. Modern oils SN+ included keep engines clean.

I would stick with top tier. Detergents aren't all the same. GM still recommends top tier fuel. So do many other OEMs. And there is research that shows fuel quality contributes to LSPI as well. Lower quality fuels are believed to increase LSPI events enough to make current attempts at LSPI prediction significantly inaccurate.

Research into fuel quality and volatility affects on LSPI is ongoing, it has been found boiling point of the fuel does affect LSPI. 

I don't think we are going to see changes in charge air cooling or coolant temp regulation as a component of LSPI mitigation. Coolant temperature have far reaching affects in the engine in relation to wear and economy. Some of the most current research indicates that ignition timing, charge air cooling and engine heat transfer are insignificant factors in controlling LSPI. At this time I think any engine modifications are unwarranted if you're not involved in LSPI researxh.


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## XtremeRevolution (Jan 19, 2012)

Ma v e n said:


> I didn't ignore that he said sodium was the worst. I mentioned that he said it and then I proceeded to say that his own presentation and referenced research doesn't bear out that point.
> 
> Incomplete fuel vaporization is one instigator in the complex chain of events and components that is required to be present for LSPI to occur.
> You dont blame a forest fire on the trees. Just like you don't blame LSPI on just DI.
> ...


Fair points. I see what you meant by random. I got the impression when someone suggested something was random that it couldn't be predicted. If you use an oil that isn't formulated for it, it's easy to predict that a failure will occur; it's the "when" that makes the difference. 

The caps is used for emphasis, not anger. I've had more than enough debates in the last decade online to not resort to caps as a form of "online yelling." Just wanted to clarify that. 

As for AMSOIL, I also want to clarify that my intentions in this thread are entirely technical except where otherwise stated (if I'm openly promoting a product). I'm not having the discussion just so I could promote the product; I'm having the discussion for the sake of technical accuracy, and if I learn something in the process, so be it. 

Thanks for engaging, and I apologize for the delay. Tuesday night I got paged for work at 9 PM and I worked clear through the night into 4PM the following day, so I've been taking a break all week from the forums.


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## 17Cruzer (Apr 18, 2017)

Gents.....Great thread and lots of good info. Lets cut to the chase b/c there really is little we can do now to offset LSPI except to use a higher octane fuel. GM errored by saying 87 octane is the standard grade octane. It obviously is not. 93 octane or higher is needed. IMO, 96 octane would be perfect.


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## Ma v e n (Oct 8, 2018)

17Cruzer said:


> Gents.....Great thread and lots of good info. Lets cut to the chase b/c there really is little we can do now to offset LSPI except to use a higher octane fuel. GM errored by saying 87 octane is the standard grade octane. It obviously is not. 93 octane or higher is needed. IMO, 96 octane would be perfect.


No, reformulated Dexos1Gen2 and API SN+ oils, at minimum are required. Even in Europe where 95RON fuel is recommended by GM they still switched to D1G2 oil specs for this engine. The previous 1.4 GM in Europe used Dexos 2, so they switch is integral part of the solution.

I haven't yet seen Dexos2 specs for 0W40, but it could be viable safe alternative as well with very high quality oils coming available as it is now the fill for the Corvette.


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## 17Cruzer (Apr 18, 2017)

Ma v e n said:


> No, reformulated Dexos1Gen2 and API SN+ oils, at minimum are required. Even in Europe where 95RON fuel is recommended by GM they still switched to D1G2 oil specs for this engine. The previous 1.4 GM in Europe used Dexos 2, so they switch is integral part of the solution.
> 
> I haven't yet seen Dexos2 specs for 0W40, but it could be viable safe alternative as well with very high quality oils coming available as it is now the fill for the Corvette.


I'm not in disagreement concerning oil. GM stated 87 octane is ok to use (says so in my 2017 manual)....it is not. The LE2 needs 93 octane or higher.


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## snowwy66 (Nov 5, 2017)

93 or higher is impossible. 

91 is our max


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## 17Cruzer (Apr 18, 2017)

snowwy66 said:


> 93 or higher is impossible.
> 
> 91 is our max


VP StreetBlaze…..https://vpracingfuels.com/vp-street-legal-fuel/


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## brian v (Dec 25, 2011)

17Cruzer said:


> VP StreetBlaze…..https://vpracingfuels.com/vp-street-legal-fuel/


This fuel is for high performance engines . Econobox engines are not designed for such pressures that would derive from utilizing such of a high octane fuel . End quote ....................


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## 17Cruzer (Apr 18, 2017)

brian v said:


> This fuel is for high performance engines . Econobox engines are not designed for such pressures that would derive from utilizing such of a high octane fuel . End quote ....................


Just because the LE2 is small in CC's doesn't mean its not a performance engine. Back in the day when I owned a 1973 Vega GT Kammback, I longed for the Cosworth version. The LE2 makes more HP than both of those stock, and its at least 500 CC's smaller.


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## brian v (Dec 25, 2011)

17Cruzer said:


> Just because the LE2 is small in CC's doesn't mean its not a performance engine. Back in the day when I owned a 1973 Vega GT Kammback, I longed for the Cosworth version. The LE2 makes more HP than both of those stock, and its at least 500 CC's smaller.


Are u running that fuel in yer cruzen ? Try 104 octane !


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## 17Cruzer (Apr 18, 2017)

brian v said:


> Are u running that fuel in yer cruzen ? Try 104 octane !


No, I'm not. Not yet. Some of the major car manufactures desire a higher octane fuel be made available.....for performance/fuel economy purposes, for small(er) turbocharged engines. 96 octane is the target. 

I recommended VP StreetBlaze 100 (to be mixed with pump 93) as it won't harm emission equipment, and it is street legal in most states. 104 isn't.


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## Farmerboy (Sep 2, 2012)

[QUOTE
I'm not in disagreement concerning oil. GM stated 87 octane is ok to use (says so in my 2017 manual)....it is not. The LE2 needs 93 octane or higher.[/QUOTE]

I’m not sure the reason why but in my previous 12 Eco Mt and current 17 Hatch Auto I have never observed much difference between 91/93 octane or 87. Very little in mpg or performance. And in 69,500 mi. I have never to my knowledge experienced LSPI with 98% 87 octane.


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## Ma v e n (Oct 8, 2018)

snowwy66 said:


> 93 or higher is impossible.
> 
> 91 is our max


It's not impossible, it's just not possible in all 50 states. 93 is widely available or mandated by state law here throughout the NY,NJ,PA,DE,MD,VA super corridor as well as virtually the entirety of the USA east of Mississippi.


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## jblackburn (Apr 14, 2012)

91 is just fine and my car ran great on it through CO mountain passes. Octane drops in the west at higher elevations and is sold as 85/87/91 rather than the 87/89/93 you'll see elsewhere

Sent from my SM-G950U using Tapatalk


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## 17Cruzer (Apr 18, 2017)

Farmerboy said:


> [QUOTE/]I’m not sure the reason why but in my previous 12 Eco Mt and current 17 Hatch Auto I have never observed much difference between 91/93 octane or 87. Very little in mpg or performance. And in 69,500 mi. I have never to my knowledge experienced LSPI with 98% 87 octane.​


​



98% 87 octane? What is that? You said, "I have never *to my knowledge* experienced LSPI with 98% 87 octane".....neither have I, to the best of my knowledge, using 93, but that doesn't necessarily mean its not occurring. It simply means it hasn't been sevre enough to do damage. How did you manage to accumlate nearly 70K miles on a 2017 vehicle? I have about 22K on my Cruze.


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## snowwy66 (Nov 5, 2017)

17Cruzer said:


> Farmerboy said:
> 
> 
> > [QUOTE/]I’m not sure the reason why but in my previous 12 Eco Mt and current 17 Hatch Auto I have never observed much difference between 91/93 octane or 87. Very little in mpg or performance. And in 69,500 mi. I have never to my knowledge experienced LSPI with 98% 87 octane.​
> ...


Another member just hit 105k. He's probably up to 110 by now. On his 17.

I just hit 11k on my 17


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## Farmerboy (Sep 2, 2012)

98% 87 octane? What is that? You said, "I have never *to my knowledge* experienced LSPI with 98% 87 octane".....neither have I, to the best of my knowledge, using 93, but that doesn't necessarily mean its not occurring. It simply means it hasn't been sevre enough to do damage. How did you manage to accumlate nearly 70K miles on a 2017 vehicle? I have about 22K on my Cruze. [/QUOTE]

Ok, first question first. By 98% 87 octane I meant that 98% of those 69,000 mi. was using 87 octane. Did try higher a few times. The “to my knowledge “ meant just that. I agree that you may not always know it but going off of previous discussions on the matter and what some described it to feel like, I have never felt those symptoms. We put on about 33,000 mi./yr the first two years. ☹ Too many. Driving an older second car part time to take some off the Cruze.


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## Ma v e n (Oct 8, 2018)

98% 87 octane...And 2% other octane...Meaning 49 out of 50 times they use 87 octane, and for some reason have tried higher octane infrequently.


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## Ma v e n (Oct 8, 2018)

70k on a 17is easy. If I had purchased a new 17 in September of 2016 I would have over 70k on it by now, my daily commute is 55 miles one way. So 550 per week, plus anywhere up to 300 miles per weekend as a family vehicle. Lots of people drive more than 110 miles per day.


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## 17Cruzer (Apr 18, 2017)

Ma v e n said:


> 70k on a 17is easy. If I had purchased a new 17 in September of 2016 I would have over 70k on it by now, my daily commute is 55 miles one way. So 550 per week, plus anywhere up to 300 miles per weekend as a family vehicle. Lots of people drive more than 110 miles per day.


Agreed. Long ago, my commute was 72 miles each way....it adds up quick!


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