I am Tired of Hearing About Fuel Dilution Thinning

[Gary Allan]

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Gary,

The way that I understand it is that Terry's lab uses FTIR to measure fuel % not a calculation from fp.

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Yes, and I agree ...but since Terry's FP readings and independent fuel readings appear to follow a linear path (they track)........then it's obvious that Terry could abandon the actual fuel reading and just use his FP readings to calculate fuel % ....which is what B-S does ..except that they use a different process than Terry for determining FP.

See what I'm saying?

The only thing that could be wrong is that B-S is using the wrong table for their particular FP test.

Terry's fuel numbers have a much higher resolution than B-S.

 

[dkryan]

Way off topic (sorta)

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Fuel in the oil is not good.
It can be tolerated, within limits. But nothing is benefited or improved with fuel in the engine oil.
Well, OK... The P47 Thunderbolt manual says to dilute the oil with gasoline for extreme cold weather starting and flow.
But that was straight 70 W in 1944.

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While the P-51 was the "Cadillac of the Skies," you can't go wrong with the P-47, either!

 

[Steve S]

cam to lifter ,then rocker arm "cam in block" is the highest pressure /wear area in an engine .

 

[Gary Allan]

Sure, but why would that assure that fuel dilution would result in those places being the highest wearing in the midst of fuel dilution? Our cam wiping contributer here DUMPED enough fuel into his oil to lose lubrication properties.

If we assert that fuel attacks and disrupts the AW layers ...it surely does so in the cylinder/ring area where only boundary layer lubrication exists.

I'm open to other points of view ..but the mere instance of someone having aluminum block and not seeing elevated Al... is as good as one guy managing to dump fuel in his oil and NOT wiping his cam.

 

[BuickGN]

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Sure, but why would that assure that fuel dilution would result in those places being the highest wearing in the midst of fuel dilution? Our cam wiping contributer here DUMPED enough fuel into his oil to lose lubrication properties.

If we assert that fuel attacks and disrupts the AW layers ...it surely does so in the cylinder/ring area where only boundary layer lubrication exists.

I'm open to other points of view ..but the mere instance of someone having aluminum block and not seeing elevated Al... is as good as one guy managing to dump fuel in his oil and NOT wiping his cam.

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Yes, my case was much more fuel dilution than you would ever get from a cold idle or slightly rich condition through the rpm range. My only points were the cam and lifters were the first to go and I thought it would be the rings. The motor still had only 5% leakdown before I pulled it apart. While this was a lot of fuel in the oil, keep in mind it wasn't enough to change the oil level on the dipstick.

 

[RI_RS4]

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If we assert that fuel attacks and disrupts the AW layers ...it surely does so in the cylinder/ring area where only boundary layer lubrication exists.

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Gary, you're making a fundamental mistake here. The AW layers I'm talking about are the high pressure wear and friction reducing additives. These have no major function in the cylinder/ring boundary layer. As a result, you'd not expect to have a major change in wear with fuel dilution. Remember, even with 5% dilution, you still have 95% oil in the mix, and it will still lubricate the rings.

 

[RI_RS4]

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The only thing that could be wrong is that B-S is using the wrong table for their particular FP test.

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Not totally true. I've done comparisons where B-S showed absolutely zero flashpoint change between a VOA and a UOA on the same oil. In a fuel diluting engine like mine, this is impossible. A Dyson sample taken at the same time showed a significant flashpoint reduction. Over and over again, I look at Blackstone UOAs and I see some very specific signs of fuel dilution in the data, but flashpoint shows nothing. I maintain that their open cup test methodology is somehow flawed.

 

[RI_RS4]

bruce,

I guess you'll just need to come up with an alternative explanation for oil shear (beyond viscosity thinning) in the presence of fuels.

 

[Lonnie]

And to continue what RI_RS4 mentioned about wear caused by fuel dilution. The problem with oil that has been diluted with fuel is adhesive wear in the bearings under load. For the same contaminated oil this wear occurs and causes damage long before boundary layer lubrication becomes a problem. In tear downs we have seen engine failures with adhesive wear and cylinder walls untouched. If the flash point of a diluted oil starts to approach the temperature of the oil, adhesive wear can be the match that completes the job of failing the engine.

 

[Gary Allan]

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The only thing that could be wrong is that B-S is using the wrong table for their particular FP test.

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Not totally true. I've done comparisons where B-S showed absolutely zero flashpoint change between a VOA and a UOA on the same oil. In a fuel diluting engine like mine, this is impossible. A Dyson sample taken at the same time showed a significant flashpoint reduction. Over and over again, I look at Blackstone UOAs and I see some very specific signs of fuel dilution in the data, but flashpoint shows nothing. I maintain that their open cup test methodology is somehow flawed.

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Well, then they're using the wrong table for their fuel %#. You yourself PROVED that FP in the closed cup method tracks validated fuel % numbers independently obtained ...proving that there is a direct correlation between FP (closed cup) and fuel dilution %'ages. This you've proven. Now if open cup and closed cup FP have any relation to each other at all ...then there MUST ALSO be a direct correlation between FP and fuel dilution ..albeit less definitive.

Look at it this way:

RI_RS4 proved that Terry's FP tracks Fuel %
RI_RS4 asserts that someone else using FP to track fuel % is flawed and lame and totally whacked because they didn't validate it with independent testing of fuel.

There's some inherent contradiction in rationale there.

Again, Terry's testing is far more defined/detailed/comprehensive (Hey, pal - I use him) ..but you yourself PROVED that one can get a fuel % by using FP ..you went to great lengths to prove it. You can't just say that it's lame just because someone else does it too.

You must also say that open cup testing is totally invalid ...or that their tables are flawed ...but you can't knock the process. You, yourself, proved it viable and reliable.

Now you can say that B-S may not know how to do a reliable FP test as in repeatably consistent.

See what I mean

 

[AEHaas]

I think there is a false sense of security by using thicker oils if you have fuel dilution. The slightly thinner resulting viscosity is not the cause of higher wear numbers.

The person who chooses to use a thicker oil may then feel safe. It is the presence of the fuel causing issues. I wonder what really happens in this situation.

The only thing that goes against this is that Many sports cars have a Lot of fuel dilution but last as long an any other car. How do you explain this? Are they made better somehow?

aehaas

 

[SargeGTO]

No they have much shorter OCI's.

 

[RI_RS4]

Gary

I don't know what your issue is here. I agree that you can calibrate a translation table from closed cup flashpoint to fuel dilution. Closed up flashpoint testing is extremely accurate, since the environment is totally closed. The point of my graph of fuel dilution vs flashpoint was to show that the numbers Dyson Analysis shows are believable, because they are consistent across two totally independent methods.

As for open cup I don't know about it's accuracy, or repeatibility. What I do know is that what Blackstone provides is not correct for dilution and that they commonly blow the flashpoint number totally. I think their issue is with flashpoint measurement methods and calibration, but I'm just guessing about this. If they were to fix this, I suspect that the would be able to more accurately characterize fuel. Right now, IMO, they are not to be believed.

 

[RI_RS4]

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Well, then they're using the wrong table for their fuel %#.

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That is not what I'm saying, Gary. If the flashpoint measurement itself is flawed, then no translation table can fix that problem. As an example, when my engine was new and still breaking in, I had Flashpoint measured by Blackstone and Dyson as a comparison, to determine which service I was going to use. Here were the results.

VOA Dyson closed cup 420F
UOA 1326 miles on oil Dyson 320F
UOA Fuel 1.35%

VOA Blackstone open cup 410F
UOA 1326 miles on oil Blackstone 410F

The Blackstone measurement for Flashpoint was clearly high. There were additional trace elements in the Blackstone analysis that were indicators for fuel dilution.

Maybe the Cleveland Closed Cup method has problems with low levels of fuel?

 

[Gary Allan]

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I don't know what your issue is here.

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Follow the thread back on this line of thought (sub topic, if you will). Someone (repeatedly) gleaned from your graph and related comments ..that no other FP/fuel numbers were valid. I merely pointed out that you did nothing of the sort and actually BOLSTERED the notion that INDEED a fuel number can SURELY be derived from FP.

It's as simple as that. B-S may be lame in whatever way they do this in the variance or whatever ..but the basic concept of fuel from FP is entirely valid. You proved it.


You've got to be careful what "truths" are implied with your findings. It's not too far off of the "synthetic oil, after a long run on dino, will create a "lapping paste" and destroy your engine". A half myth has been created ...the user of that half myth provides the rest of the mythos.


Other than that ...be happy ...be free ...enhance your calm ..and be well

 

[RI_RS4]

Gary, got you. Actually other tables are valid, if the starting flashpoint of the oil is significantly different than the "normal" 390F to 420F.

 

[bruce381]

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bruce,

I guess you'll just need to come up with an alternative explanation for oil shear (beyond viscosity thinning) in the presence of fuels.

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No not really since it has not been proven to exist.

I have seen NO data to prove that there is chemical shear only terry and your say so.

The varibles in feild engine testing is conditions are not standarized and as such it makes a field test comparing sample of various oils with and without fuel dilutiion hard to determine, perhaps you have done all this but is "proprietary" so be it but do allow me to not buy it till I see it.

There is a way to test it tho run a sample of oil with and with out say 2% fuel in both a standard vis and a high shear test, Savant labs can run it and that should be able to tell other wise all I've heard on this is from terry and most/all he says is mostly non provable since it is all proprietary.

I'm not argueing the "theory" but until I see any test data that has been peer reviewed and/or published somewhere "chemical shear" will only a theory that to me. Could be true but not proven.

bruce

 

[bruce381]

""Maybe the Cleveland Closed Cup method has problems with low levels of fuel?""

You are correct Closed Cup is the perfered method.

Or FTIR BUT it must be fully "calibrated" with the oil being used IMHO to give the most accurate answer.

 

[AEHaas]

I looked over the Excel chart I posted to start this thread. There are quite a few UOA with fuel at or above 4 or 5 percent with depressed viscosities but totally normal wear metals.

aehaas

 

[G-MAN]

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I looked over the Excel chart I posted to start this thread. There are quite a few UOA with fuel at or above 4 or 5 percent with depressed viscosities but totally normal wear metals.

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Which really means nothing. The fuel level in the oil could have been extremely low for the entire duration of the OCI but was elevated at the time of sampling due to any number of reasons, not the least of which is (usually) not allowing the oil to come up to normal operating temp before sampling/changing.

RI_RS4 has shown clearly what the effects are of an engine that, by design, dumps an excessive amount of fuel into the oil. The result is excessive wear.