Originally Posted By: serversurfer
Originally Posted By: ZeeOSix
There is absolutely ZERO SAE papers that even address the difference in engine wear or engine damage due to draining the sump hot vs cold.
But there are dozens of not hundreds of SAE papers that say using a high efficiency oil filter will reduce engine wear. SAE guys know that the full full oil filter is the device used to keep the oil clean, not draining the sump hot vs cold.
Are you
sure that's what those papers say? Better filters reduce wear? It seems more likely that they would study the effects of contaminants on wear and
separately study the ability of filters to remove said contaminants. So rather than studying again and again whether better filters reduce wear as you claim, they would simply study the ability of new filter
designs to trap contaminants, and then draw their conclusions from there. We know the contaminants cause wear, so we know reducing them reduces wear.
That part doesn't need to be tested again.
Yes, I'm fairly certain that if you look, you'll find plenty of papers on how contaminants cause wear, and how reducing them in turn reduces wear.
But no, they don't study whether a 99% filter results in less wear than a 90% filter, because they already know — from separate studies — that fewer contaminants means less wear. Instead, they study whether
a particular filter design reduces contaminants by more than their old designs did. So I suspect that if you look more closely, those studies you're referring to actually say something like, "Filter X is better/worse at removing wear-causing particles than Filter Y." The
effects of wear-causing particles will be found in other, separate studies.
By extension, because we know that fewer contaminants means less wear, we know that
everything we do to reduce contamination will reduce wear in turn; everything from engineering efforts like improved filter design to service techniques like hot drains.
They certainly have looked at the level of engine wear vs the efficiency level of the oil filter. If you read what's shown in this SAE paper (and many others), they compare filters of different known efficiencies and correlate engine component wear levels (rings, bearings) to the filter used. It's pretty clear that more efficient oil filters reduce engine wear. Look at Table 2 and Figures 3 and 5 in this SAE paper:
http://papers.sae.org/881825/
Lots more:
http://www.sae.org/search/?qt=engine+wear+vs+oil+filter+efficiency
Originally Posted By: serversurfer
Quote:
And BTW serversurfer, just in case you missed it, I'm not advocating everyone should drain there oil cold. What I'm saying is there is no proof it hurts anything ... zero documented proof, it's all conjecture - unlike proof that high efficiency oil filters do reduce engine wear. Using high efficiency oil filters will do way more for your engine than draining the oil hot.
But it
has been proven. It's been proven that hot solvents hold more solute, so the hot oil coming out of your sump is carrying more contaminants with it. It's also been proven that having fewer contaminants results in less wear. Ergo,
it has been proven that hot drains reduce wear.
If it's been proven that cold drains causes more engine wear, then where's the technical paper that outlines by what method, and the results that proves it actually happens? You know that all the oil that lubricates the engine first gets filtered, so any debris in the sump that gets stirred up and re-suspended will get filtered out. In those oil filter tests for engine wear, they were putting wear particles into the oil that would be even worse than a bunch of debris being stirred up and re-suspended into the oil. Yet the filters captured the particles and prevented wear. This is why I do advocate using a high efficiency oil filter, because no matter what's in the sump, the filter is what keeps the oil that really matters clean.
Like I said before, proving that cold drains cause increased engine wear would actually make for a good SAE paper. If you search the 'net and you won't find anything unless you're more lucky than I am in searching.
Originally Posted By: serversurfer
Remember too that different elements have different densities and different solubility. Lead likely precipitates out before iron, I'd guess. If your lead precipitates out before you drain, then you're leaving all of that lead in the sump to accumulate over time, even if you're getting the iron out. And the ever-increasing lead levels won't show up on your UOA, because we've already established you're leaving it in the sump, where it can't be measured. But whatever the specific contaminants we're dealing with,
anything that precipitates out before your drain is just gonna accumulate in your system over time, escaping the detection of your UOAs.
You might find this interesting. Guy took a UOA sample right after hot shutdown, then another when the oil cooled all the way down. No real difference seen in the UOA. Apparently, the elements tested in a UOA must stay suspended for a very long time, or many never fall out of suspension. So if someone drains the oil after it's cooled back to room temperature (say 12 hours after shutdown) is that worse off than draining the oil when it's still 150+ deg F? ... rhetorical question.
http://forums.pelicanparts.com/off-topic...s-provided.html
Originally Posted By: serversurfer
Hey, there's an experiment you can actually do yourself. Take an engine you've been cold-draining for a while, and do a scalding hot drain on it instead, then compare that UOA to your cold UOAs. My guess is that the hot sample will show more contaminants than the cold samples had been, but that if you continue with a hot-drain regimen, you'll see those levels drop and stabilize over time.
Could be ... but again, hard to find any testing results like this to prove the theory.
Originally Posted By: serversurfer
Ironically, you agree that hot drains will help to de-sludge an engine, while somehow failing to recognize that those hot drains will be even more effective in preventing sludge from forming in the first place. After all, the sludge is
literally the un-removed contaminants. So hot drains will clean an engine, but do nothing towards
keeping it clean? You're arguing that a hot drain makes no difference while simultaneously conceding that it does.
Like I showed in the post to 02SE, sludge forming in the first place is not caused by cold sump drains - it's caused by factors that cause the sludge during the use of the engine. An engine that is basically very clean inside could become sludged before the next oil change/drain if it was abused and the conditions were right for sludge formation. Of course, once the sludging starts and continues because the real cause isn't rectified, then the build-up will just become worse and worse.
Draining the oil hot might help keep more out of the pan, but it's not going to prevent sludging or reverse it if the root cause isn't rectified. If an engine is sludged up and the sump is full of crud, then draining it hot will probably help remove more sludge - that's the only difference a hot drain will do in that case. If an engine is kept clean with good maintenance and proper driving cycles (meaning not many super short repeated drives, especially in very cold weather) to prevent sludging from starting and continuing, then there really shouldn't be much crud in the sump.
Originally Posted By: serversurfer
Oh, and you can just call me Surfer.
You got it.
