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Can I use Mobil 1 oil?

bret

bret

Well Known Member
Just read an interesting Ave web article from 1995 about the lawsuit that came about from its inability of this synthetic oil to scavenge the lead out of aircraft engines, which eventually caused oil control ring fouling and prop hub sludge buildup and engine lube related wear ect. My question goes out to folks that are burning auto unleaded fuel, are you still using ash less disbursement oil? I plan on experimenting with auto fuel in my full Dual EFII setup. The only drawbacks that I found with the synthetic oil was that it is so slippery with its long chain molecules is that it will not hold onto the lead from blow by and it will cause sludge, but what if there is no lead? On a different note, I have been doing an unofficial test with this Mobile 1 15/50 Oil in the Nitrous Ducati, four riding season and 30 K on the odometer, I have ran 60 LBS of NOS through this engine, many runs at full load and 10,000 RPM upshifts with no engine, clutch or transmission problems, and does not burn any oil between 5K oil changes. Mobil 1 appears to be a good lubricant because Ducati is not know for its reliability ;-) here is the article http://www.avweb.com/news/news/182891-1.html
 
How do you intend to fly cross country without, at some time or another, using leaded fuel. I wouldn't chance it.
There are several synthetic blends that get along fine with lead.
 
Cross County? never thought of that? but Back to the root problem, folks were told they (could go) 200 hrs before an oil change, I'm sure some tried this and may have been part of the original problem, then there is the leaning ability, with (fully atomized) fuel, from EFII injectors, there will be better leaning ability with less unburned fuel available to get past the rings, and with the ASA crankcase evac system, there should be even less contaminates in the oil. Just think back 20 - 30 years, were the average spam can drivers running lean of peek? I was not, (what's an EGT? ya got 4 ? )
 
A lot of aircraft engines were ruined, some with inflight failures caused by running Mobile 1.
You're free to run anything you like.
 
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OIL

lots of discussion about this in search I think you should try and see how it works out











Not just kidding
Bob
 
If we are talking about Lycoming engines think this.

They were designed over 70 years ago as basic agricultural and pumping engines. They were quickly developed into aero engines because they could deliver the horsepower at lower rpm suitable to our prop speeds - big capacity, low revving.

They are dinosaurs. They are mega old technology and sometimes things need to stay a bit relaxed and old fashioned.

Personally, the best thing I do to my Lycosaur is feed it new Shell or Total or Phillips 20/50 multigrade every 25 hours or so.

The oil is cheap, the change takes moments, the motor goes...... Gee thanks :D

If your are flying an RV12 with a Rotax, follow the new path of modern oils etc. If you are on a Lycoming, stay with the old stuff.

My Toyota Hilux (Tacoma) has a 3.0 diesel motor and I do run Mobil 1. Have for 20 years through Mercedes, Volvo, Mercedes and now Toyota.

Hundreds of thousands of miles, no problem. Mobil 1 is a fine oil for modern motors, not for museum pieces :D
 
bret said:
folks were told they (could go) 200 hrs before an oil change
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I would like to meet the person that is willing to go 200 hours without taking the cowl off and looking at the engine. And if you are taking the cowl off, why not just change the oil since the hard part is already done :)
 
Just a thought . . .

This would be a good topic to discuss with the aero Shell oil guys - full synthetic. They have the test results and know what to look for. Surely they are involved with the non-leaded replacement fuels testing. This approach might offer an improvement in friction and wear characteristics with lower risks. If it were automotive, you would have to dig deep to make that expert contact. I suspect at OSH you could get to that person pretty quickly, aero is a much smaller world, and structured differently.

Alternatively, you could use oil analyses to extend the oil life of standard oils when using (mostly) unleaded.

BTW: Will angle valve engines burn auto fuels w/o detonation?
 
ok, please read first post, we all know lead is bad for none dispersant oil, my question is about synthetic oil use with Unleaded fuel. We know the main problem with auto fuel is its low vapor pressure. with EFII a large percent of fuel is being circulated back to tank so the vapor lock problem is greatly reduced. OK, Flame Jacket....ON
 
bret said:
ok, please read first post, we all know lead is bad for none dispersant oil, my question is about synthetic oil use with Unleaded fuel. We know the main problem with auto fuel is its low vapor pressure. with EFII a large percent of fuel is being circulated back to tank so the vapor lock problem is greatly reduced. OK, Flame Jacket....ON
Click to expand...

So there's potential risks as others have discussed but I haven't read any clear advantages to using Mobile 1. No flames, it's your engine.
 
I guess the real question here is being lost: what is the mechanism that makes AD oils a requirement in aviation engines? If it is the huge lead content in the fuel, then what if that goes away because you are running unleaded?

I think Bret has a valid question. We all know that things went bad back in the day, but like Bret, I'm also going with EFI (Ross' SDS) and am hoping the Rocket will be happy with auto fuel. It would be nice to know the particulars about the oil behavior because we might have a game changer now. Not that I'm looking to change oil, just curious.

Not trying to be argumentative, but does anyone have any actual data that relates to a Lycoming engine ingesting ONLY unleaded?
 
There is a lot involved in oil chemistry and it's much more than just AD packages. First, auto oils have been under increasing pressure from the tree huggers for quite some time and modern oils are a compromise with modern engines.

I'll give you an example. Years ago oils had a lot of ZDDP to support high pressure, shear, loads. This was most critical in the cam/lifter interface. By the late 90's, all engines had roller tappets and the oil makers, acting under EPA pressure, cut the ZDDP quantities WAY back to help minimize emissions. The hot rod and classic car guys started eating cams at alarming rates (mostly during break-in, but many failures were in-service). It took several years for people to figure out what was happening. In fairness, a decent percentage of this community was using strong valve springs, but the failures were still very prominent in stock configurations. GM still uses a special additive package in the initial oil fill to accomodate break-in, as the modern oils don't have enough of them to support break-in.

I would not want modern auto oil because it is matched to modern engines and has many compromises in it to specifically fit the current application AND regulatory pressure, at the expense of broad application support. Our aviation oils aren't requlated (API classes) and are engineered for the challenges specifically associated with our engines and that goes beyond just leaded fuel.

EDIT: I would also be worried about anti-scuff additives. Modern engines run tighter Piston/wall clearances and therefore don't need as much scuff protection.

Larry
 
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Mike Newall has the best answer , in that, in an antique (lycoming) use appropriate oil. Any one fortunate enough to have a modern engine I believe Mobil 1 is great..I have used in various engine for 15 yrs..I DON'T BELIEVE IN LEAVING OIL IN ANY ENGINE FOREVER! Use common sense with sythetics as far as changes go..Tom
 
Great question, Bret. It would seem that there was a reason for going to synthetic back then but was not tested sufficiently.

Lead will be going away in the next couple of years anyway so this topic is sure to return.
 
If and when 100LL goes away and eliminates the lead issue, my guess will be that an aviation synthetic will be made available (although I bet it won't be Mobil who I would hazard to guess would be a bit gun shy about re-introducing AV-1).

I admit up front I'm no oil expert, but my limited understanding is even if you were using unleaded fuel you wouldn't want to use Mobil 1 in your Lycoming because it's formulated for water cooled engines that have tight tolerances and operating parameters far different from our air cooled engines. Doesn't mean it wouldn't work, but for me and my limited knowledge the risk of an oil related engine issue doesn't justify the usage of an oil formulated for cars. YMMV....
 
Valid point about the ZDDP issue and its effect on flat tappet camshaft systems. Many of us in the classic car/hot rod world are acutely aware of the problem and have found work arounds. High ZDDP content oils for ?diesel? engines is still available and I know that is an option employed by some. The other is the increasing retrofit of roller camshaft systems to the early engines which eases the pain of reduced ZDDP content. And it is this point which brings this thread back to relevance. Unlike the era of synthetic oil failure in the early 90?s, Lycoming engines have switched to roller cams. So although the basic architecture of the Lycoming is rooted in the ancient times, the materials and internal systems are certainly not.

Automotive oils may still be a bad idea for a current Lycoming, but many of the stated reasons for the early failures are long gone (leaded gas and flat tappets, in particular). It would be nice to discuss the remaining hurdles in an intelligent, technical manner.
 
Mobile 1

Great discussion points presented here. I'll add a data point. Mobile 1 indeed has lowered the level of ZDDP over the last few years, EXCEPT in the 15 w-50 weight. I use this oil in 2aircooled Porsche race cars. I don't see any reason it would not work well in a Lycoming with unleaded fuel.

Of course any time you run something with a small sample size you are taking unknown risks. I have a Subaru engine in my airplane so I know a little about the risk of small population configuration.

-Andy
 
Interesting that one of the downsides is lack of shear strength (assuming that it actually applies to synthetics) on flat tappet cams. The rotary a/c engine guys using RWS gear drives use synthetic engine oil specifically because it seems to provide smoother, quieter operation of the gearbox (engine oil lubes the plain bearing, and the planetary gearset, in the gearbox).

Charlie
 
TD sheets on ashless disperants

ok for the tech. talk. The car oil have ash used mainly for detergent purposes. This under high temps can form carbon. This could happen in turbo charged engines and really only in our non-turbo when descending and forgetting to richen the mixture. Thus ashless dispersents, keep dirt in solution and drain off. As far as the high ZINC there are today many oil made with what they call high Zinc use for flat tappet engines, but it really is the old level of zinc used before the roller tappet. They say right on the bottle. Eaa has a nice video from Mike Bush well done on oil to explain everything about aviation oil.http://eaavideo.org/video.aspx?v=1149666747001. Long but great. You need to get to the TD sheet for the exact oil and look at the ash by wt.% and you'll find 1.2 to 1.6 for most of these oil. Mobil 15/50 http://pds.mobil.com/USA-English/Lubes/PDS/NAUSENPVLMOMobil1_15W-50.aspx check out application ( Not for 2 cycle or aviation engines) also the ash content. You are right lead will be gone and even Mike Bush says when lead is gone it is time to look at synthetics. So this question in a valid question when lead is gone. Soon or Sooner.
 
rv7charlie said:
Interesting that one of the downsides is lack of shear strength (assuming that it actually applies to synthetics) on flat tappet cams. The rotary a/c engine guys using RWS gear drives use synthetic engine oil specifically because it seems to provide smoother, quieter operation of the gearbox (engine oil lubes the plain bearing, and the planetary gearset, in the gearbox).

Charlie
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Unfortunately to the OP, I don't have any DATA.

But to the quoted post: It is what is called boundary lubrication - like gear contact in crawler tractors (and such) with low shear rates but high contact pressures. The ZDP is like magic little ball bearings. Once in my research job I had some super gear/lube experts working for me to develop oils for that purpose (gear box not engine) and they would try dozens of formulations with various test machines for spot wear. It is not an analytical thing. Materials, hardness, surface finishes and the additive packages are all factors. All lubricants are a compromise according the the functions and applications for them.

Don't you think Shell, and others, are already testing additive packages/oils for the non-leaded fuels to understand what they can do? Cams, ring grooves, valve stems/guides all have special needs.

Wouldn't it be great to use an oil that didn't varnish and didn't contribute to exhaust valve sticking, and lasted longer hours? Yes, of course.

Good search Bret!!
 
rv7charlie said:
Interesting that one of the downsides is lack of shear strength (assuming that it actually applies to synthetics) on flat tappet cams. The rotary a/c engine guys using RWS gear drives use synthetic engine oil specifically because it seems to provide smoother, quieter operation of the gearbox (engine oil lubes the plain bearing, and the planetary gearset, in the gearbox).

Charlie
Click to expand...

Gear tooth interface presents different wear factors than the cam/lifter interfaces. There is an insignificant amount of sliding or shear between the teeth. It's all pressure, not shear. With cam/lifter, it's both.
 
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I had a customer ask me this question years ago. He switched to 15/50 Mobil 1 in his Lycoming and had over 800 hours on it last time I heard about 4 years ago. No issues. He was using Mogas locally and 100LL for cross country work. Changed oil every 30-50 hours depending on the amount of 100LL put through the engine.

Not sure if he had flat or roller lifters.

The trend in auto engines over the last 10 years has been to use thinner oils to reduce internal drag and flow between the reduced clearances. 0/20 is common now.

Not sure if I buy the low zinc thing. I've used Mobil 1 since the early '80s (many different formulations in that time) in many race engines with flat tappets and very high spring pressures along with most of my street engines. Never had one lubrication related issue in all that time and we're talking many dozens of engines, many thousands of hours and mostly turbocharged which is very trying on oils thermally and load wise.

I ran Mobil 1 in my Subaru turbo RV6 for 250 hours running 100LL exclusively. When I pulled the pan, there were no lead deposits anywhere, super clean inside. Changes were at 30-40 hours. There were massive lead buildups on everything inside the chambers and turbine though due to the lower temperatures the liquid cooled engine operates at here.

Changed frequently, like every 25 hours, I don't think lead is a big issue with Mobil 1 if your ring seal is decent but given the price of it, draining it so often seems like a waste at the same time. Lycomings generally seem to last well using Aeroshell, so not sure there is a big advantage there until the fuels go unleaded and you can leave it in a lot longer.

Rotax halves the oil change intervals when operated on 100LL exclusively compared to Mogas. One overhauler told me engines with a steady 100LL diet
were usually pretty gunked up in the oil tank and gearbox with lead if people did not follow this advice.

I believe you will see new synthetic aero oils on the market when unleaded avgas is available. Full synthetics are really magic in gearboxes and race engines. Things last which won't last using conventional oils. Whether that translates into big advantages on Lycomings though is hard to say.
 
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rv6ejguy said:
I had a customer ask me this question years ago. He switched to 15/50 Mobil 1 in his Lycoming and had over 800 hours on it last time I heard about 4 years ago. No issues. He was using Mogas locally and 100LL for cross country work. Changed oil every 30-50 hours depending on the amount of 100LL put through the engine.

Not sure if he had flat or roller lifters.

The trend in auto engines over the last 10 years has been to use thinner oils to reduce internal drag and flow between the reduced clearances. 0/20 is common now.

Not sure if I buy the low zinc thing. I've used Mobil 1 since the early '80s (many different formulations in that time) in many race engines with flat tappets and very high spring pressures along with most of my street engines. Never had one lubrication related issue in all that time and we're talking many dozens of engines, many thousands of hours and mostly turbocharged which is very trying on oils thermally and load wise.

I ran Mobil 1 in my Subaru turbo RV6 for 250 hours running 100LL exclusively. When I pulled the pan, there were no lead deposits anywhere, super clean inside. Changes were at 30-40 hours. There were massive lead buildups on everything inside the chambers and turbine though due to the lower temperatures the liquid cooled engine operates at here.

Changed frequently, like every 25 hours, I don't think lead is a big issue with Mobil 1 if your ring seal is decent but given the price of it, draining it so often seems like a waste at the same time. Lycomings generally seem to last well using Aeroshell, so not sure there is a big advantage there until the fuels go unleaded and you can leave it in a lot longer.

Rotax halves the oil change intervals when operated on 100LL exclusively compared to Mogas. One overhauler told me engines with a steady 100LL diet
were usually pretty gunked up in the oil tank and gearbox with lead if people did not follow this advice.

I believe you will see new synthetic aero oils on the market when unleaded avgas is available. Full synthetics are really magic in gearboxes and race engines. Things last which won't last using conventional oils. Whether that translates into big advantages on Lycomings though is hard to say.
Click to expand...

That is some good believable data, thanks for the input. A point made in the vid post 1 there was mention of the turbo guys like the synthetic also. does anyone have any data comparison as far as max temperature before the oil burns or chars into ash?
 
bret said:
That is some good believable data, thanks for the input. A point made in the vid post 1 there was mention of the turbo guys like the synthetic also. does anyone have any data comparison as far as max temperature before the oil burns or chars into ash?
Click to expand...

I looked at the manufacturer's data about 6-7 years ago and the Aeroshell was only about 30-40 degrees below Mobil 1 if I recall. I was surprised how good the Aeroshell was in that respect. As a sidenote, I ran Aeroshell in the Sube for about 25 hours- and it didn't blow up.

Both oils have to withstand going through turbochargers where the bearing housing will be over 400F at the rear, towards the turbine end during operation and much higher than that on shutdown. I've never seen Mobil 1 coke on turbo bearings. It's awesome stuff at high temps.
 
lr172 said:
Gear tooth interface presents different wear factors than the cam/lifter interfaces. There is an insignificant amount of sliding or shear between the teeth. It's all pressure, not shear. With cam/lifter, it's both.
Click to expand...

Could you explain that in a little more detail please.
 
BillL said:
Could you explain that in a little more detail please.
Click to expand...

In very simple terms, gear teeth roll against one another with the pressure point (essentially a tangent with a very small, effective contact patch) constantly moving on both teeth. The teeth don't slide against one another even though the pressure point (i.e. intersection of two distinct points on both teeth) is moving. The constantly moving pressure point creates a large wear patch, but it is not from sliding or shear forces. Clearly high pressure is involved (all force applied across a very small contact patch) and the oil must prevent wear. Different additives/properties are used for limiting the affects of shear and the affects of high pressure.

I am not a mechanical engineer.

Larry
 
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jim etcheverry said:
Eaa has a nice video from Mike Bush well done on oil to explain everything about aviation oil.http://eaavideo.org/video.aspx?v=1149666747001. Long but great. You need to get to the TD sheet for the exact oil and look at the ash by wt.% and you'll find 1.2 to 1.6 for most of these oil. Mobil 15/50 http://pds.mobil.com/USA-English/Lubes/PDS/NAUSENPVLMOMobil1_15W-50.aspx check out application ( Not for 2 cycle or aviation engines) also the ash content. You are right lead will be gone and even Mike Bush says when lead is gone it is time to look at synthetics. So this question in a valid question when lead is gone. Soon or Sooner.
Click to expand...

Mike Busch's webinar is worth watching. You ought to watch it just to become familiar with who he is. A synopsis of recommendations from him backed up with truth and logic is based upon the fact that we rust out engines rather than wear out engines. 1) Use NO Synthetic oil. Revisit this when lead is removed form fuel. 2) Use Single Grade AD oil (50wt) 3) Use Phillips XC when sub freezing engine starts are expected. 4) Use ASL Cam Guard, but no other additives.

Lastly, Mike Busch's C-310 has run his two engines over 200% past TBO. 8 of 12 cylinders are original.
 
Slight drift, just watched this vid, WOW! calling Allen from ASA, did you see this, this guy dose not like oil air separators.......I'm on the side of having one only because of the very poor, or lack of any baffling for the crank case ventilation path.
 
Bcone1381 said:
Mike Busch's webinar is worth watching. You ought to watch it just to become familiar with who he is. A synopsis of recommendations from him backed up with truth and logic is based upon the fact that we rust out engines rather than wear out engines. 1) Use NO Synthetic oil. Revisit this when lead is removed form fuel. 2) Use Single Grade AD oil (50wt) 3) Use Phillips XC when sub freezing engine starts are expected. 4) Use ASL Cam Guard, but no other additives.

Lastly, Mike Busch's C-310 has run his two engines over 200% past TBO. 8 of 12 cylinders are original.
Click to expand...

We know lead and synthetic do not make a good match for long drain intervals. My email to Mobil engineers said as much but that's not really the question here since the OP was discussing unleaded Mogas use.

I respect Mike Busch very much but I'm guessing he has little experience with synthetic oils as far as long term sitting corrosion goes. I've used the stuff for something like 33 years, never seen corrosion anywhere inside an engine, even some which were stored for 4 years and a number of these were run on 100LL.

Camshafts and lifters on most engines are are made from very similar material no matter what their mission is. This suggests that the additive package in Mobil 1 might be better than aero oils with regards to corrosion protection. I haven't had a cam go bad since 1983 (not using Mobil 1 in that engine).

The fellow who contacted me many years ago didn't believe all the opinions he read about the matter so decided to just try it himself. He was well aware it could be an expensive lesson so he asked me not to use his name or talk about it back then in case the experiment failed. He didn't want to face the flaming he'd receive.

Like so many things in Experimental aviation, we have many who rarely step outside the tried and true boundaries and issue dire warnings based on little or no fact or experience. This often limits our growth of knowledge and keeps aviation engines way behind other markets.

It's prudent to listen for sure but nothing beats actually doing something to prove it true or false.

"The world is changed by your example, not by your opinion" Paul Coelho

Chinese Proverb: "Those who say it cannot be done should not interrupt the people who are doing it."

The only test case I know of shows it worked fine for at least 800 hours. Just one sample to be sure but it's a start at least.
 
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Oil

About 15 yrs ago a couple buddies and my self restored a Stearman with Cont. 220 radial I flew it for a few year before I sold out my part the funny thing was when we ran Aero Shell 15-50 the radial loved it and used hardly any oil.Then when we used W-100 in the engine it would throw a lot down the side of the fuse on start up and used a lot more pre hour.After that I always questioned if straight weight stuck to parts as well as multi weight.
Bob
 
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