Straight Weight Mineral Oil in Lycoming?

[astjp2]

Re: Straight Weight Mineral Oil in Lycoming?

far 43.13 not ac43.13, and the regs changed, it used to be 21.305, i guess i will have to find the current regulation

[Garry Crookham]

Re: Straight Weight Mineral Oil in Lycoming?

43.13 is also an Advisory Circular and 21.305 has nothing to do with the subject:

21.305 Organization.

(a) Each applicant for or holder of a PMA must provide the FAA with a document—

(1) Describing how its organization will ensure compliance with the provisions of this subpart;

(2) Describing assigned responsibilities, delegated authorities, and the functional relationship of those responsible for quality to management and other organizational components; and

(3) Identifying an accountable manager.

(b) The accountable manager specified in paragraph (a) of this section must be responsible within the applicant's or production approval holder's organization for, and have authority over, all production operations conducted under this part. The accountable manager must confirm that the procedures described in the quality manual required by §21.308 are in place and that the production approval holder satisfies the requirements of the applicable regulations of subchapter C, Aircraft. The accountable manager must serve as the primary contact with the FAA.

[Doc. No. FAA-2013-0933, Amdt. 21-98, 80 FR 59031, Oct. 1, 2015]

[astjp2]

Re: Straight Weight Mineral Oil in Lycoming?

wikipedia does a better job explaining, but it is covered under 21.305. https://en.m.wikipedia.org/wiki/Unap..._aircraft_part its also discussed in an article and is covered under far 43.13 https://www.google.com/url?sa=t&sour...MFmsxVdm7Gmvyg

[3Dreaming]

Re: Straight Weight Mineral Oil in Lycoming?

Again I'm not trying to argue, but unless the Advisory Circular is tied to a regulation it is just what it's name states, "Advisory ".

[astjp2]

Re: Straight Weight Mineral Oil in Lycoming?

https://www.faa.gov/documentLibrary/.../AC_21-29D.pdf its an unapproved part IAW 5.3.4, it was in an IA seminar I did about 10 years ago. Had a few crashes because the additives in engine oil had broken down and it was determined to have caused the engine failures.

[3Dreaming]

Re: Straight Weight Mineral Oil in Lycoming?

it is a violation to use expired products in an aircraft....by both pilots and mechanics..

Tim, I am certainly not arguing the point, but do you have a regulatory reference for that?

[astjp2]

Re: Straight Weight Mineral Oil in Lycoming?

Ben used to give a speal during the IA seminars, that is where I learned about expiration dates on oil. How many people know that oil is only good for 4 years in the container? not many and some will argue but it is a violation to use expired products in an aircraft....by both pilots and mechanics..

Then there's used oil analysis. Apparently it can help detect changes in the oil and components including wear metals. Some folks are religious about its application.

Here's an anecdote. In the early '80's on one Lyc O-320 A2B with about 700 hrs TT while using early formulated Shell 15W-50 for a year I began to see a slight silver sheen in my drain oil after a normal 25 hr change. The pressure screen was clean and no finer filter was available at first to examine. My mechanic sent off two oil samples about 25 hrs apart. Nothing remarkable was noted. This was after about 500 hrs on straight 40W Shell followed by about 200 on the multi-vis.

Then we filtered the drain oil through a fine paper filter and noted some "magnetics". Soon particles large enough to be captured by the pressure screen appeared. Pulling a couple of cylinders let us see cam and lifter spalling especially on the lobes shared by two cylinders. We pulled all 4 cylinders and noted exhaust valve to guide clearances that were tighter than spec due to carbon. Fuel used was primarily 80/87 with occasional but limited auto fuel. The initial silver sheen in the drain oil (best seen with a flashlight) was the first indication of wear. Looks just like that silver dope sprayed on fabric diluted with solvent.

We suspected tight exhaust valves, and possibly some cam/lifter corrosion, contributed to the wear. It may have been due to improper metallurgy in the cam or lifter bodies as well. Drainage off metal parts while sitting at ambient air temps was also suggested.

Cost me $$$$ and I've not used multi-vis oil since for some reason, although Shell soon thereafter added some elixirs to help with corrosion and wear.

There were a few of us locally that experienced a similar problem at that time with that particular oil in similar engines (O-320/360's). We later asked Shell's field rep Ben Visser about this phenomena at a local meeting but nothing was forthcoming.

Edit: The reason I had switched to multi-vis was cold weather ops. I pre-heated the engine prior to flight but it was suggested that multi-vis flowed better to far away parts. Now I ignore that benefit and pre-heat as required.

Gary

[PA1195]

Re: Straight Weight Mineral Oil in Lycoming?

Then there's used oil analysis. Apparently it can help detect changes in the oil and components including wear metals. Some folks are religious about its application.

Here's an anecdote. In the early '80's on one Lyc O-320 A2B with about 700 hrs TT while using early formulated Shell 15W-50 for a year I began to see a slight silver sheen in my drain oil after a normal 25 hr change. The pressure screen was clean and no finer filter was available at first to examine. My mechanic sent off two oil samples about 25 hrs apart. Nothing remarkable was noted. This was after about 500 hrs on straight 40W Shell followed by about 200 on the multi-vis.

Then we filtered the drain oil through a fine paper filter and noted some "magnetics". Soon particles large enough to be captured by the pressure screen appeared. Pulling a couple of cylinders let us see cam and lifter spalling especially on the lobes shared by two cylinders. We pulled all 4 cylinders and noted exhaust valve to guide clearances that were tighter than spec due to carbon. Fuel used was primarily 80/87 with occasional but limited auto fuel. The initial silver sheen in the drain oil (best seen with a flashlight) was the first indication of wear. Looks just like that silver dope sprayed on fabric diluted with solvent.

We suspected tight exhaust valves, and possibly some cam/lifter corrosion, contributed to the wear. It may have been due to improper metallurgy in the cam or lifter bodies as well. Drainage off metal parts while sitting at ambient air temps was also suggested.

Cost me $$$$ and I've not used multi-vis oil since for some reason, although Shell soon thereafter added some elixirs to help with corrosion and wear.

There were a few of us locally that experienced a similar problem at that time with that particular oil in similar engines (O-320/360's). We later asked Shell's field rep Ben Visser about this phenomena at a local meeting but nothing was forthcoming.

Edit: The reason I had switched to multi-vis was cold weather ops. I pre-heated the engine prior to flight but it was suggested that multi-vis flowed better to far away parts. Now I ignore that benefit and pre-heat as required.

Gary

Re: Straight Weight Mineral Oil in Lycoming?

There was a time when ordinary non-commercial folks flew enough (because they could and fuel was cheaper) that overhaul shops did enough to compare oils used. Aviation Consumer and other mags would report the findings. Now I'm not sure what their consensus is regarding single vs multi vis oils and engine longevity. Probably varies by engine and type of use but it would still be interesting to compare.

Gary

Other than the charts I saw in the Lubrication Engineers handbook I really never see any data regarding engines and oil.

I have some other lubrication engineering books will look there later.

Mostly comments, opinions, anecdotal evidence show up at websites and forums no repeatable or verifiable data show up.

I had discussions with an engineer from one of the aviation engine manufacturers we didn't see eye to eye. Even in that discussion there was little evidence presented from his side.

Having worked as an engineer for 35 years with engineers and having some subordinate to me from time to time as well I have no problem holding an opinion that apposes some engineer's assertions. They make mistakes and hold on to outdated schemes when revising a scheme could introduce work or personal career risk.

So I find the oil debate to be inconclusive and unconvincing but I suspect that it is also one that is inconsequential since oils are all quite good so whatever you pick your long term costs are about the same. My engine maintenance issues have been related to wear that I could attribute to oil but other things like rust, poor assemble practice, skipping things at overhaul.

That's my opinion.

Dave R.

[Ragwing nut]

Re: Straight Weight Mineral Oil in Lycoming?

well i was delivering phillips 25W60XC to Era Classic Aviation for their DC3's back in the mid 90's and the mechanixs told me that their oil consuption went down by 50% between oil changes compared to Shell W100, and that was a barrel every 25 to 50 hours per engine depending on the engine's oil change requirements . DC6'S was the same, 50% was also common for them. Most warranties dont mean squat in aviation anymore....

yes it does reduce consumption, but it was coming at a price in higher maintenance with cylinder issues and leaks. Its not as big of an issue with flat motors.

[PA1195]

Re: Straight Weight Mineral Oil in Lycoming?

There was a time when ordinary non-commercial folks flew enough (because they could and fuel was cheaper) that overhaul shops did enough to compare oils used. Aviation Consumer and other mags would report the findings. Now I'm not sure what their consensus is regarding single vs multi vis oils and engine longevity. Probably varies by engine and type of use but it would still be interesting to compare.

Gary

[astjp2]

Re: Straight Weight Mineral Oil in Lycoming?

well i was delivering phillips 25W60XC to Era Classic Aviation for their DC3's back in the mid 90's and the mechanixs told me that their oil consuption went down by 50% between oil changes compared to Shell W100, and that was a barrel every 25 to 50 hours per engine depending on the engine's oil change requirements . DC6'S was the same, 50% was also common for them. Most warranties dont mean squat in aviation anymore....

[Ragwing nut]

Re: Straight Weight Mineral Oil in Lycoming?

the type certificate holder is using data from 1930 what? modern oils were developed 1990's when? I would stick with the Philips, reduces consumption and you end up with cleaner oil between changes. Tim

Some multi-vis oils do not give enough protection against wear and tend to weep through cases with porosity issues. I know of several radial engine rebuilders that will void your warranty if you run multi-vis oil. The deal with mineral oil especially on an engine that runs cool, it will help prevent glazing of the cylinders. It also breaks down quicker so it must be changed more frequently.

[astjp2]

Re: Straight Weight Mineral Oil in Lycoming?

the type certificate holder is using data from 1930 what? modern oils were developed 1990's when? I would stick with the Philips, reduces consumption and you end up with cleaner oil between changes. Tim

Re: Straight Weight Mineral Oil in Lycoming?

There were some studies done on diesel boat engines back in the 1930's.

They compared cylinder wear with straight mineral oil and with detergent/additive oils.

The wear rate with straight mineral oil was twice that with detergent oils.

The oil industry didn't develop all those additive packages without a reason. Not sure why we have people that think they have no merit.

If the engine has run a long time with straight oil then switching to detergent may stir up all that settled in sludge and crud and make a problem.