How Many Hours Between Oil Changes?

[carusoam]

Astra,

A fair number of us are all ears for deep technical discussions...

Thanks for sharing your details on oil analysis.

Too bad we don't have a sensor to connect to an iPhone for measuring TANs and TBNs... that would make an interesting way to check our oil along with its level...

Best regards,

-a-

Edited May 22, 2017 by carusoam

[aaronk25]

Astra,
A fair number of us are all ears for deep technical discussions...
Thanks for sharing your details on oil analysis.
Too bad we don't have a sensor to connect to an iPhone for measuring TANs and TBNs... that would make an interesting way to check our oil along with its level...
Best regards,
-a-

I'd like this for my boat and RV too on all the engines which combined equals 5. Run amsoil marine 15-40w with a tan of 12 and the main concern on that is exactly as you stated being the TAN measurement particularly in equipment that sits for long periods and then when used gets operated at a high % of load.




Sent from my iPhone using Tapatalk

[astravierso]

Below is a link to a company page for the device you seek (On-line oil quality monitoring). I have used these unit on large mobile mining equipment engines with great results. The cost is reasonable (compared to other units attempting to do the same thing). it has a small-ish form factor, stores data which can be dumped and analyzed. And in full disclosure, the President of the company is a friend of mine (unfortunately using my name won't get you a discount).

Take a look, then lets talk. We can go a far down the rabbit hole as you are willing to go.

http://www.vsi-oil.com/Advantage/Advantage.htm

Cheers

 

[Will.iam]

On 5/22/2017 at 8:51 AM, astravierso said:

Below is a link to a company page for the device you seek (On-line oil quality monitoring). I have used these unit on large mobile mining equipment engines with great results. The cost is reasonable (compared to other units attempting to do the same thing). it has a small-ish form factor, stores data which can be dumped and analyzed. And in full disclosure, the President of the company is a friend of mine (unfortunately using my name won't get you a discount).

Take a look, then lets talk. We can go a far down the rabbit hole as you are willing to go.

http://www.vsi-oil.com/Advantage/Advantage.htm

Cheers

 

Wholly cats has anybody done this? It seems fascinating to me that you could get feedback after every flight and updated on just how well your oil is doing like the oil life readings on some new cars now that take into account how hard and frequently you drive your car. Couldn’t this be applied under that NOSEE reg as it would definitely enhance safety? 

[carusoam]

Adding a decent oil level sensor would be a good idea... a step up.

Would have helped at least two people around here...

 

oil quality in real time?

I don’t think you will find too many people willing to pay to develop the STC for that...

I can’t think of anyone that has ended a flight to find out their oil has gone bad...

maybe I missed something... 

Best regards,

-a-

[Will.iam]

39 minutes ago, carusoam said:

Adding a decent oil level sensor would be a good idea... a step up.

Would have helped at least two people around here...

 

oil quality in real time?

I don’t think you will find too many people willing to pay to develop the STC for that...

I can’t think of anyone that has ended a flight to find out their oil has gone bad...

maybe I missed something... 

Best regards,

-a-

No probably not but if you knew your TAN and TBN was already at half the level after a certain known time you could make a better informed decision to change the oil early or the converse is true if you were coming up on your normal 25 hours and you were showing plenty of TAN and TBN left you could goto 30, 40 or 50 if the TAN and TBN were holding up and realize the savings. I know i could get a trend by testing for these with my oil analysis but that only holds up if i make the same kind of flights. I. E. How much do short pattern flights effect oil compared to long cross country flights. Summer compared to winter. Low alt compared to high altitude phillips 20w-50 compared to AS 15w-50 or w100. With and without camgard. LOP vs ROP 75% vs 60% 2500 vs 2200. You get it alot of variables that i would like to know what effect they have on degrading the oil and how fast it happens. Just look at all the interesting knowledge we got when they put detonation sensors on an engine and tried different settings and mixtures.  

[Tcraft938]

From Lycoming..... "

It has often been said that regular doses of clean, fresh oil provide the least expensive maintenance an owner can give an engine. Lycoming Service Bulletin No. 480 makes these specific recommendations for oil changes under normal operating conditions:

A. 50-hour interval oil change and filter replacement for all engines using a full-flow oil filtration system.

B. 25-hour interval oil change and screen cleaning for all engines employing a pressure-screen system.

C. Even if the aircraft is flown only a few hours, a total of four months maximum between changes for both systems listed under “A” and “B.”

I have oil filter and 90hrs SMOH, I still do oil filter and analysis every 25-30hrs.  Partially because the doghouse an minimal sight access under the cowl I like opening up a bit and see/check things.  Always nice to NOT see oil leaks.  Occasionally I will find a few screws out of the doghouse or something like that.  #3 CHT up a bit is usually an indicator that something has loosened on the doghouse.  

[A64Pilot]

Except maybe for some kind of exotic there are no actual oil sensors in automobiles.

GM developed the concept that has been copied by many decades ago, it’s called GMOLS or GM Oil Life System. It’s pretty  simple actually, you start with a number say 1000, each cold start decrements it x numbers. each hour operation at full temp x numbers, each below temp x numbers etc. etc until the number reaches something close to zero, then the change oil light comes on.

Oil analysis is outstanding for determining exactly what’s going on with the oil, not so much of an engine analysis though and that’s what it’s marketed as, but if you want to know about the oil, you can’t beat analysis.

‘Anyway oil analysis is the best way to determine TAN (total acid number) and TBN or (total base number) 50 hours is nothing, we change our oil because it’s full of contaminants, not because it’s worn out, or it times out, over time the contaminants will degrade the oil

I would be astonished if either is even close to being bad in 50 hours of operation, but analysis will tell you.

‘If you are even remotely concerned, shorten your oil change interval, you cannot change your oil too frequently, save the money spent on gadgets, laboratories  etc and spend it on oil instead.

Edited April 26, 2021 by A64Pilot

[LANCECASPER]

On 4/26/2021 at 6:59 AM, Tcraft938 said:

From Lycoming..... "

It has often been said that regular doses of clean, fresh oil provide the least expensive maintenance an owner can give an engine. Lycoming Service Bulletin No. 480 makes these specific recommendations for oil changes under normal operating conditions:

A. 50-hour interval oil change and filter replacement for all engines using a full-flow oil filtration system.

B. 25-hour interval oil change and screen cleaning for all engines employing a pressure-screen system.

C. Even if the aircraft is flown only a few hours, a total of four months maximum between changes for both systems listed under “A” and “B.”

I have oil filter and 90hrs SMOH, I still do oil filter and analysis every 25-30hrs.  Partially because the doghouse an minimal sight access under the cowl I like opening up a bit and see/check things.  Always nice to NOT see oil leaks.  Occasionally I will find a few screws out of the doghouse or something like that.  #3 CHT up a bit is usually an indicator that something has loosened on the doghouse.  

On the Lycoming TIO-540-AF1B engine used in the Bravo, even though it has an oil filter, they recommend 25 hour oil changes.

[M20F]

On 4/26/2021 at 5:36 PM, A64Pilot said:

If you are even remotely concerned, shorten your oil change interval, you cannot change your oil too frequently, save the money spent on gadgets, laboratories  etc and spend it on oil instead.

^this

[Tx_Aggie]

Thread resurrection. 
 

I’ve started changing my own oil after local shops are now charging about $500. Like many other things, once you DIY, you pay more attention. 
 

I find that when I fill my J up with 7 qts (any more gets blown out first flight), it will stay golden until about 15-20 hours. Once it starts to turn black with contaminants, it starts loosing volume. I suspected it’s at this point that the 15-20 hour old oil is breaking down. I’ll add one quart about every 5-8 hours there after until I get to 25-35 hours then change (and replace filter). 500 hours since overhaul at purchase and no issues. 

[Ibra]

In M20J + IO360, I go with 50h or 4 month for my oil changes  (if oil analysis shows something, then I would go with change/cut filter). I fly LOP and aircraft does 150h per year, I think it's ok for 50h change 

If I was flying ROP, less regularly or long breaks, I think changing every 20h or 30h would make more sense 

Edited Sunday at 04:59 PM by Ibra

[Ibra]

On 5/20/2017 at 4:24 AM, RLCarter said:

Another thing to consider is the conditions the oil was used in...Dusty, Hot & Dry, change it more often.

I agree it's worth some consideration, Mooneys are likely to be operated on pavements while sitting on some hangar, if the aircraft is parked outaide and operated on grass/gravel with dust may need more oil changes 

We went to Spain and encounted a dust storm while there. After my return, I opted for an oil change with new oil/air filters, they did not look that bad or dirty as I have expected but I wanted that peace of mind. I think the same would apply to encounters with smoke, ash, haze, dust...

 

Edited Sunday at 05:33 PM by Ibra

[Pinecone]

On 4/26/2021 at 5:36 PM, A64Pilot said:

Except maybe for some kind of exotic there are no actual oil sensors in automobiles.

GM developed the concept that has been copied by many decades ago, it’s called GMOLS or GM Oil Life System. It’s pretty  simple actually, you start with a number say 1000, each cold start decrements it x numbers. each hour operation at full temp x numbers, each below temp x numbers etc. etc until the number reaches something close to zero, then the change oil light comes on.

Oil analysis is outstanding for determining exactly what’s going on with the oil, not so much of an engine analysis though and that’s what it’s marketed as, but if you want to know about the oil, you can’t beat analysis.

‘Anyway oil analysis is the best way to determine TAN (total acid number) and TBN or (total base number) 50 hours is nothing, we change our oil because it’s full of contaminants, not because it’s worn out, or it times out, over time the contaminants will degrade the oil

I would be astonished if either is even close to being bad in 50 hours of operation, but analysis will tell you.

‘If you are even remotely concerned, shorten your oil change interval, you cannot change your oil too frequently, save the money spent on gadgets, laboratories  etc and spend it on oil instead.

BMW had a system like this.  But they figured out, that fuel used gives about the same interval.

For my 2002 M3, IIRC, the oil change interval is 600 gallons burned.  Run hard on the track, you change oil sooner.  Drive normally, and you get longer intervals.

[slowflyin]

I prefer 25 on my Bravo.  That being said, I've had aircraft in the shop with 60-70 hours and a year since the previous oil change.  I run labs on all of my oil changes and have never had one come back with oil out of spec.  Specifically, TAN has never been high.  Not advocating higher time oil changes, just offering another data point.  

[LANCECASPER]

38 minutes ago, slowflyin said:

I prefer 25 on my Bravo.  That being said, I've had aircraft in the shop with 60-70 hours and a year since the previous oil change.  I run labs on all of my oil changes and have never had one come back with oil out of spec.  Specifically, TAN has never been high.  Not advocating higher time oil changes, just offering another data point.  

On this Lycoming Service Bulletin from 2017, on page two, it calls out specifically 25 hour oil changes for the TIO-540-AF1A and AF1B engine (the one used in the Bravo). All others with oil filter are 50 hour oil changes.

https://www.lycoming.com/sites/default/files/attachments/SB480F%20Oil%20ServicingMetallic%20Solids%20Identification%20After%20Oil%20Servicing%20and%20Associated%20Corrective%20Action.pdf

[Echo]

Nice to see one of my "former life" threads alive and providing value.   

[Bolter]

On 11/24/2024 at 5:44 AM, Tx_Aggie said:

Thread resurrection. 
 

I’ve started changing my own oil after local shops are now charging about $500. Like many other things, once you DIY, you pay more attention. 
 

I find that when I fill my J up with 7 qts (any more gets blown out first flight), it will stay golden until about 15-20 hours. Once it starts to turn black with contaminants, it starts loosing volume. I suspected it’s at this point that the 15-20 hour old oil is breaking down. I’ll add one quart about every 5-8 hours there after until I get to 25-35 hours then change (and replace filter). 500 hours since overhaul at purchase and no issues. 

Your experience is the same as I had on my J.  Increase in consumption as the oil got darker.  It prompted me to aim for 25 hour changes.  

[slowflyin]

2 hours ago, LANCECASPER said:

On this Lycoming Service Bulletin from 2017, on page two, it calls out specifically 25 hour oil changes for the TIO-540-AF1A and AF1B engine (the one used in the Bravo). All others with oil filter are 50 hour oil changes.

https://www.lycoming.com/sites/default/files/attachments/SB480F%20Oil%20ServicingMetallic%20Solids%20Identification%20After%20Oil%20Servicing%20and%20Associated%20Corrective%20Action.pdf

Thanks, I'm familiar.  I practice 25 hour changes on our Turbo 182 as well.    My point was even engines that haven't had an oil change in over a year with 60-70 hours on the oil returned normal labs.  This includes Acidity and Solids.  Crazy considering how black the oil was coming out of these high time changes.  

[LANCECASPER]

1 minute ago, slowflyin said:

Thanks, I'm familiar.  I practice 25 hour changes on our Turbo 182 as well.    My point was even engines that haven't had an oil change in over a year with 60-70 hours on the oil returned normal labs.  This includes Acidity and Solids.  Crazy considering how black the oil was coming out of these high time changes.  

Years ago at a MAPA convention in an M20M seminar, the Lycoming rep told about the tests they had done and on the Bravo engine with the heat that it's subjected to, they saw the viscosity drop significantly after 25 hours. Years later they came out with the Service Bulletin.

[1980Mooney]

46 minutes ago, LANCECASPER said:

Years ago at a MAPA convention in an M20M seminar, the Lycoming rep told about the tests they had done and on the Bravo engine with the heat that it's subjected to, they saw the viscosity drop significantly after 25 hours. Years later they came out with the Service Bulletin.

As suspected, this is because of the crap, literally "dinosaur", oil that we use in our airplanes.  Having to change oil at 25 hours because of breakdown is just ridiculous.

A current BMW R1200 classic engine style motorcycle oil change interval is 6,000 miles or one year - that's about 135-200 hours.  Even new Harley is 5,000 miles or about 100-150 hours.  Most current turbocharged automobiles oil change intervals are 10,000 miles or one year - about 200-300 hours.  The big rig semis change oil at 250-500 hours.

I can't wait to see us come out of the Stone Age with fleetwide unleaded fuel and modern lubricants. 

[Ragsf15e]

33 minutes ago, 1980Mooney said:

As suspected, this is because of the crap, literally "dinosaur", oil that we use in our airplanes.  Having to change oil at 25 hours because of breakdown is just ridiculous.

A current BMW R1200 classic engine style motorcycle oil change interval is 6,000 miles or one year - that's about 135-200 hours.  Even new Harley is 5,000 miles or about 100-150 hours.  Most current turbocharged automobiles oil change intervals are 10,000 miles or one year - about 200-300 hours.  The big rig semis change oil at 250-500 hours.

I can't wait to see us come out of the Stone Age with fleetwide unleaded fuel and modern lubricants. 

True, and turbines basically never change it, but air cooled engines with old designs end up with a lot more crap in the oil than other  , newer designs.  Synthetic would probably help, but I think we’ll still have a lot of crap accumulating in the oil and thus circulating through the engine.  Depending on what it is, it might or might not adversely affect the oil performance.  I guess I’ll just keep changing the oil until i can buy that turboprop!

[slowflyin]

1 hour ago, LANCECASPER said:

Years ago at a MAPA convention in an M20M seminar, the Lycoming rep told about the tests they had done and on the Bravo engine with the heat that it's subjected to, they saw the viscosity drop significantly after 25 hours. Years later they came out with the Service Bulletin.

I hadn't heard the justification.  That's interesting.  Do you know if the test were done during the timeframe folks were running the Bravo per the POH?  1750° TIT and associated high CHTs?  That would seem logical.    Running the more conservative values as recommended, I don't see my engine running particularly hot.  Oil temps are never above 195° and CHTs average 365 with #6 the hottest at 385°.   I assumed the 25 hour recommendation was Turbo related.  Seems like running oil through a screaming hot turbo would degrade it faster.  But then again, oil temps in general are reasonable.  Thanks again for the info! 

[LANCECASPER]

16 hours ago, slowflyin said:

I hadn't heard the justification.  That's interesting.  Do you know if the test were done during the timeframe folks were running the Bravo per the POH?  1750° TIT and associated high CHTs?  That would seem logical.    Running the more conservative values as recommended, I don't see my engine running particularly hot.  Oil temps are never above 195° and CHTs average 365 with #6 the hottest at 385°.   I assumed the 25 hour recommendation was Turbo related.  Seems like running oil through a screaming hot turbo would degrade it faster.  But then again, oil temps in general are reasonable.  Thanks again for the info! 

No, Lycoming had distributed the booklet several years previous to this showing that these engines should be operated at 1650 or below. (The 1750 was discouraged very early in the TLS history, but to this day it's still in the POH)

They explained that the  oil going through both "hot sections", the exhaust valve guide area and the turbo area, degraded the viscocity much more quickly than on other Lycoming engines. The oil temp probe measures it at a much cooler point than what the oil actually sees while cooling the valve guides and the turbo. 

[EricJ]

Heat breaks down any oil, including synthetic, so a turbo system with hot bearings that relies on the oil for cooling may be expected to break it down faster than a system that doesn't expose the oil to that much heat.