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Mineral Oil Myth

It may be a myth but it does work. If you are the guy that has to warranty the situation, if the engine doesn't break in correctly, you tend to go with advice that you know works. So, if the engine manufacturer or overhauler wants you to use mineral oil, you should do it, because he is the one that has the finical liability of fixing the problem, if the engine doesn't break in correctly. In my opinion, you should do it his way and expect the results he says you will get. If you don't get those results, the onus is on him to rectify the problem. Or, you could do it a different way, then the manufacturer or over hauler recommends, and get results that you don't like, but then you will be on your own to rectify the problem. If it does break in OK, without following his requirements, then you didn't loose anything but if it doesn't, it would be unfair to expect the manufacturer or overhauler to warranty the situation because you didn't follow their requirements.
For certified aircraft, it would actually be a violation to not use mineral oil, as the Manufacturer recommends. Just because it seems like a good idea isn?t justification to do it. We are required by law to follow the Manufacturer's Instructions for Continued Airworthiness and if they say use minreal oil then we have to do it.
Still recommending mineral oil, where applicable, and having no break in issues.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."
 
Webb said:
This should start a lively discussion. I've got another thread going on engine break in but ran into this article.

Let the fun begin.

http://www.avtoday.com/am/categories/maintenance/564.html
Click to expand...

We had this situation come up a couple of months ago. I only skimmed the article but it looked like it was saying that there is no reason why you shouldn't use regular oil for breakin (at least scientifically). My theory is why not use mineral oil. Its not that big of a deal. Plus, if I heard correctly, not using mineral oil could have an affect on your warranty (at least in the certified engine world). I say do what the manufacturer says its not a big deal to change the oil at 25 hours or however long it takes for a breakin on a particular engine.

Are there any upsides to using regular AD oil?
 
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not all AD oil is the same...

... at least that is what two different presentations at Sun N Fun said. Phillips X-C is an AD oil, but it does not have an "anti-wear package" in the formulation. In contrast, every other AD oil commonly available has some type of EP/ anti-wear formula. That is why Phillips X-C was singled out by Lycoming for the requirement to add LW16702 additive.
This fact makes X-C a very good choice for break in.
I DO NOT work for Phillips, by the way.
But, I have used X-C for break in twice now, with good results.
BTW, the article was written 2003? I think Lycoming has changed it's stance since then...
 
OKAV8r said:
... at least that is what two different presentations at Sun N Fun said. Phillips X-C is an AD oil, but it does not have an "anti-wear package" in the formulation. In contrast, every other AD oil commonly available has some type of EP/ anti-wear formula. That is why Phillips X-C was singled out by Lycoming for the requirement to add LW16702 additive.
This fact makes X-C a very good choice for break in.
I DO NOT work for Phillips, by the way.
But, I have used X-C for break in twice now, with good results.
BTW, the article was written 2003? I think Lycoming has changed it's stance since then...
Click to expand...

I too have used Phillips X/C for the initial fill on a newly overhauled engine. It was and still is recommended by ECI for break-in on all their engines and cylinders. Mine sealed up really quick and won't even use a quart between oil changes. I for one don't buy into the "straight mineral oil" myth.
 
Aeroshell 100W doesn't have the antiwear package either (100+ does).

Like many things in aviation, the good theory is lost on people who don't understand what is really going on. The result is an explanation that lacks scientific backing, and therefore is disproved eventually. Mineral oil is no less "Slippery" than AD oil, we all know that is just absurd (or at least we should).

The real basis for using NON-AD oil in engines for break-in has to do with exactly what they are talking about in the article, particle suspension. The AD suspends particles in the oil, which in turn can start to fill in some of the grooves in the cylinder walls (especially with the high metal content in the first few hours) and result in glazing the cylinder wall.

With NON-AD oil, the particles will settle out after the engine run, and won't stay suspended.

All above information is simply my understanding, not trying to agree or disagree with above article.

But why not? What do you have to lose by running cheaper mineral oil for the first 50hours?
 
Doesn't mineral oil need to be changed at 25 hours instead of 50 hours like AD?
Mineral oil does not have an additive package, which extends the useful life of the oil.
I don't see any other engines (car truck ship or rail) that require mineral oil for break in.
On the other hand, the break in oil should not stay in the engine very long, (in a hard working engine with only a few quarts capacity) particularly if you only have an oil screen (no filter). Run that new engine a bit, then dump that oil to get the 'grinding paste' out, and put in some new oil. The break in oil should not be in the engine long enough to need a life extending additive.
I don't think it's important enough to argue about one way or the other.
 
OSXUSER hit it pretty much on the head.

I had a long conversation with the guys at the Shell oil booth at OSH about the detergent/non detergent thing.

To make a long story short, non detergent, AKA "Mineral" oil lets the particulate matter fall out to the bottom of the pan. It stays there until you open the engine, and scrape it out:eek:--the oil pump pick up was usually mounted quite above the bottom of the pan, just for this reason.

This was desired in the days before engine makers used oil filters.

With the use of oil filters, the particulate matter needs to be suspended in the oil, so it can be removed, thus the advance of detergent oils.

The goal of either method was to keep the crud out of the lubrication, where it will cause damage.
 
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semantics schemantics

Call me anal, but....

Being a newbie a few years back when I bought my engine, I was confused by the terminology used in discussing this subject - specifically the terms "mineral oil" and "detergents". My research has indicated that these terms are thrown around quite loosely, and apparently often incorrectly. My understanding is that, in correct useage, "mineral oil" means only that it is petroleum based - i.e. produced from an oil well, as opposed to synthetic oils, which generally are not used in our RV engines (the Rotax 912 is an exception - blends of petroleum based and sythetic based oils [semi-synthetics] are recommended for those engines).

So, we are all using mineral oil. I believe what is being discussed here is, more correctly, only whether or not our (mineral) oils should include an ashless dispersant (AD) additive during break-in. As noted above, Lycoming and TCM say no. ECI says yes.

"Detergents" are not used in modern oils. This term is often incorrectly used to refer to oils with AD additives.

It would be helpful to the younguns to be clear and use the correct terminology here; granted, the vocabulary is a bit entrenched at this point.

best regards
erich
 
Mike S said:
With the use of oil filters, the particulate matter needs to be suspended in the oil, so it can be removed, thus the advance of detergent oils.
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Sounds bogus. The particles of combustion are nowhere near big enough to be removed by a paper oil filter.

Everybody agrees that a non-synthetic--aka mineral--oil should be used for break in. Should that mineral oil have the AD package or no? I would sure follow the engine makers recommendation.
 
erich weaver said:
Call me anal, but...........

the vocabulary is a bit entrenched at this point..............

best regards
erich
Click to expand...

Yep, to both:D

http://www.answers.com/topic/detergent-oil?cat=technology

"Detergent" is a generic term used to describe the dispersant component of the oil.

My guess is that older dispersants either turned to ash in the engine, or were formulated from some kind of ash. Either way, the ash aparently isnt good, therefore the new "ashless" dispersant compounds.
 
rfinch said:
Sounds bogus. The particles of combustion are nowhere near big enough to be removed by a paper oil filter.

Everybody agrees that a non-synthetic--aka mineral--oil should be used for break in. Should that mineral oil have the AD package or no? I would sure follow the engine makers recommendation.
Click to expand...

Re read my post.

I said "particulate", not product of combustion.

I agree, soot, and other stuff is too small, by themselves to be trapped in a filter. I suspect that the detergent may act like a flocculation promoting agent here.

In addition, metal particles, varnish, and a host of other things are in the oil, and that is what the filter collects.
 
Mike S said:
My guess is that older dispersants either turned to ash in the engine, or were formulated from some kind of ash. Either way, the ash aparently isnt good, therefore the new "ashless" dispersant compounds.
Click to expand...

Correct - the concern is burning small amounts of the oil and creating (or not) ash in the combustion chamber. Two cycle engines use ashless lube oil for this reason. Four cycle engines don't burn nearly as much of the oil, but they still burn enough to need ashless oils.
 
airguy said:
Correct - the concern is burning small amounts of the oil and creating (or not) ash in the combustion chamber. Two cycle engines use ashless lube oil for this reason. Four cycle engines don't burn nearly as much of the oil, but they still burn enough to need ashless oils.
Click to expand...

Thanks Greg.

Appreciate the validation.
 
How effective are filters?

Of interest, at your next oil change, put that dirty oil into a colorless gallon bottle. Put that bottle away somewhere in storage for about 6 months. What you?ll find then is a bottle of clear oil with a black coating at the bottom of the jug. Goes to demonstrate that paper filters don?t get everything.
 
The $62 Question

So I wonder if you used the clear gallon bottle test: AD oil VS the Mineral oil, which one would settle out faster? Given the lore of AD oil keeping the dirt in suspension so it does not settle out in the engine?
 
Much less will settle out of the NON-AD oil, since there isn't much at all in suspension in the first place. But whatever is in the NON-AD (notice my use of terminology is slightly different than most) will settle out quite fast.

After a couple years of doing oil changes on airplanes for a living, I could easily tell the difference between the different oils that were in the engine, AD oils are much blacker when drained, mineral is a yellowy-milky color. Aeroshell 100+ or the stuff with the Lycoming LW16703 additive turns a little more of a whitish or ash-ish color. Don't know what possible relevance that could have to the discussion.

In any event, AD oil's only purpose IS to carry particles to the paper filter, otherwise, there is absolutely NO advantage to suspending them in the first place. Suspended particles could actually increase wear if there are enough of them.
 
I broke in my Superior XP-360 in my RV-8 using Aero Shell W-100 AD oil. No problems were encountered. I've never used mineral oil when a cylinder was changed as many mechanics tend to do. Again, I have never had a problem with rings seating. I think the secret is to run the engine hard for a few hours and don't shock cool the engine. Tom Schad RV-8 N558TX A&P / IA
 
AD

long ago oil had a lot of parafin in it and it made a lot of ash
in some engines as late as the fifties on a v-8 you could take the intake of and it would be full of ash in the valley parafin = wax i saw a intake rise up an inch when bolts were removed i think that has something to do with term ashless my 2 cents
 
I was Chief Pilot for a skydiving club for 10 years before I went commercial. Now I have 13,000hrs plus getting bored across the Atlantic in an A330, but I am building an RV7 and enjoying it.

However............... back in the 80's, we worked closely with our Engineer and stuck to what he said.

All our engines went to TBO - yep, that's what I said - we were using them for skydiving in a Cessna 206, Cherokee 6 and Piper Lance.

The Cherokee engine was finally overhauled at 3500 hours, the Cessna engine suffered the usual Conti crack at about 2300 hours - the Lance engine is still in at nearly 4000 hours.

So............. what is the secret ?

You work them hard, you stabilise temperatures - no rapid cooling.

You top overhaul at 1/2 life.

You religiously change oil at 25 hours.

You break in on mineral oil.

You lean after takeoff and keep them lean all the way up.

You have an empathy with your engine - if you don't understand, keep asking the questions of the Engineers and experienced operators and eventually, you will get it :D
 
erich weaver said:
My understanding is that, in correct useage, "mineral oil" means only that it is petroleum based - i.e. produced from an oil well, as opposed to synthetic oils...

"Detergents" are not used in modern oils. This term is often incorrectly used to refer to oils with AD additives.
Click to expand...

Mike S et al:

A good general reference, and support for my previous statements, is provided within ECI's "Engine Break-in Instructions and Oil Management" document. The link to the .pdf document can be found at

http://www.eci2fly.com/pages/tech.aspx#breakin

There, mineral oil is defined: "Oil separated from crude oil according to boiling points" (as opposed to synthetic oil)

Detergent is defined: "A cleaning additive; a metallic compound to protect from sludge and varnish build-up. Detergents are not allowed under MIL-L-22851 or MIL-L-6082. No current aviation oil contains detergent compounds."

So, anal or not, there is some basis for my previous statements that there is much misuse of the terms "mineral oil" and "detergent", and thus confusion to boot. Bottom line: when you are set to break-in your engine you will need to decide whether or not you want it to contain an ashless dispersant or not. If yes, the oil container should refer to ashless dispersant or "AD" right on it. "Mineral oil" may or may not be AD oil, and I dont think you will find any aviation oil with a label that indicates it contains "detergent" additives.

regards

erich
 
Scotch tape anyone???

erich weaver said:
So, anal or not, there is some basis for my previous statements that there is much misuse of the terms "mineral oil" and "detergent", and thus confusion to boot.

Regards

erich
Click to expand...

Yep, totally agree that there is a lot of abuse of the terms "detergent" and "non-detergent"

In fact, the "abuse" has transformed the term into something that I suspect a vast majority of the people in this country have accepted as normal, and proper verbiage.

Kinda like "Kleenex" means a tissue, no longer the correct usage to identify a specific product from the Kimberly Clark company.

My personal pet peeve--------we all got em:D------in the juxtaposition of words is using a letter "oh" for the number "zero".

Anyway, I'll continue to use detergent when I talk about oil with a cleaning component in it, you keep using oh, kleenex, or whatever, and we will both be happy:D that there is something we can point at and say "You dummy, dont you know any better"?????
 
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