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Oil ! To Filter or Not to Filter ?

HIIFLY

HIIFLY

Well Known Member
Talking at the Hanger Powwow last night the question was asked . If you have a 180 HP Lycoming and you use an Oil Filter , What is the Factory TBO ? And If you do Not use an Oil Filter What is the TBO ? As far as we could figure out , It is the Same ! Both are 2000 hrs. If you change Oil at the recommended Hrs. For either way .
What do you think about this ? :confused:
 
HIIFLY said:
Talking at the Hanger Powwow last night the question was asked . If you have a 180 HP Lycoming and you use an Oil Filter , What is the Factory TBO ? And If you do Not use an Oil Filter What is the TBO ? As far as we could figure out , It is the Same ! Both are 2000 hrs. If you change Oil at the recommended Hrs. For either way .
What do you think about this ? :confused:
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Sounds like a plan. :)
 
If I recall correctly, no change in TBO published, however oil changes are recommended at 25 hrs with the screen and 50 hrs with the spin on filter.

I think there have been thoughts that the spin on filter filter helps to get you to TBO also.
 
You cut your oil changes in half, which should pay for the filter mount over the TBO period. Further, filtered oil has been proven to reduce wear on many different engine components and I cannot imagine how this would not increase the actual time before your engine NEEDS an overhaul, which is not really related to Manufacturers TBO.
 
While both may make it to TBO, how close to the limits are the parts from the non-filtered engine and can they be reused?
 
Like said previously the extra oil changes will cost as much as the filters. Something I didn't see mentioned is what a mess and pain in the rear it is to remove clean and reinstall the screen. I would give the advantage to the filter.
Ryan
 
131RB said:
Like said previously the extra oil changes will cost as much as the filters. Something I didn't see mentioned is what a mess and pain in the rear it is to remove clean and reinstall the screen. I would give the advantage to the filter.
Ryan
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Not sure where you are buying your oil but the oil costs me more than the cost of the filter.
 
The ability to cut open and inspect the filter is a great help in determining if you actually are going to make it to the completely theoretical TBO...as is oil analysis. I certainly wouldn't go filterless without committing to an analysis program religiously. I thnk in the spirit of hangar discussions you still can't make a convincng case for no filter. The cost of the engine and down time argues in favor of giving yourself every option of keeping things clean internally. I just don't see a downside to filtration. My old Aircoupe even had an option of putting heatsink fins on the filter to help bring down oil temps on the mighty C-90!
 
Oil screen = 60 microns.
Aviation oil filter = 40 microns.

Not that much better.

Oil analysis = waste of time and $.

On my rocket I'm going back to the screen, but am using a bypass oil filter. Working on some mods to the screen to make it easy to clean and check without having to take the housing off.

1850 hours on my C150 with a screen. A few years ago I put a filter adapter on it and haven't seen a thing in it yet.
 
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jjconstant said:
..... I just don't see a downside to filtration. My old Aircoupe even had an option of putting heatsink fins on the filter to help bring down oil temps on the mighty C-90!
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Even without the fins on the filter, oil temps. are somewhat reduced because of the extra quart in the system.
 
rocketbob said:
Oil screen = 60 microns.
Aviation oil filter = 40 microns.
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Bob, Is that a verified figure? I am looking at my oil screen right now and while I have no good way to measure it, the openings in the inner screen seem to be about .005", comparing to a calipar by eyeball under magnification. That would be around 125 Microns.

DISREGARD: I found a reference at 60 microns. Seems odd. The screen appears that it would allow larger particle, but apparently not.
 
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Operated a Cessna 310 Twin for 13 years - A pair of IO470s with no filters causing me to change oil every 25 hours. I tried to push it one time and at 35 hours it was like sludge. Both went to TBO (1500 on the 10-470) but during overhaul I purchased a set of Airwolf remote mount filters. Expensive but worth it in my opinion.

To each it's own, don't use filters and go with screen if you like but logic says filter provide a cleaner oil to the engine for a much longer duration than screen. Sort of like saying, "my Grandpa smoked till he was 93 years old".... smoking won't kill ya..... well we know better.
 
rocketbob said:
Oil screen = 60 microns.
Aviation oil filter = 40 microns.

Not that much better.

Oil analysis = waste of time and $.

On my rocket I'm going back to the screen, but am using a bypass oil filter. Working on some mods to the screen to make it easy to clean and check without having to take the housing off.

1850 hours on my C150 with a screen. A few years ago I put a filter adapter on it and haven't seen a thing in it yet.
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Not saying you are incorrect, Bob, but industry standard for oil filters is about 30 micron. I am a little surprised.

Regardless, oil particle measurements show an increase by the hour, up to the point that the filter actually begins to work. For large diesels, my memory is not good, but I think it was in the 50 hour range. It is just possible that 25 hours would yield no change, unless a large, hard chip passed and imbedded in a bearing. The real question is, do unfiltered cranks show more wear at TBO than filtered. The remainder of the parts might not care so much.

You might just do some oil sampling for particle count and size each 10 hours to see. Just add a spout so you can get a running sample. (Watch that prop!!) That would be a good use of sampling! Let us know the results.
 
Years ago there was a pretty good study comparing a lyc screen, a champion filter, and Airwolf screens. Filtering efficiency was quantitatively measured and the results...almost no difference.
 
rocketbob said:
Tempest filters are 40 micron.

http://www.tempestplus.com/Portals/0/PDFs/TechTips/Oil Filter Magnets 0912.pdf
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Well that puts that to rest. Thanks Bob. Now, I wonder what Champion filters are. Maybe the same as Tempest? I sent an email and will post the response.

Edit, ok more information

Tempest information: "40 micron media may only stop 80% of 30 micron particles, 40% of 20 micron particles, and 10% of 5 micron particles."

Champion email :"The filtration efficiency of Champion Aerospace filters can be considered 25 micron nominal or 40 micron absolute. At Champion Aerospace we use 40 micron absolute. Absolute rating is less 'fuzzy' and we feel it gives a truer picture. Champion oil filters using our composite cellulose/fiberglass filter media are 80% efficient at 25 micron (roughly the size of a white blood cell) and 98% efficient at 40 micron (the lower limit of visibility to the naked eye). Both are the highest efficiency ratings of any piston aircraft oil filter in the market"

My memory was of nominal micron capture, so this is pretty good.
 
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aerhed said:
Years ago there was a pretty good study comparing a lyc screen, a champion filter, and Airwolf screens. Filtering efficiency was quantitatively measured and the results...almost no difference.
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Maybe so, but I just can't bring myself to circulate unfiltered oil in ANY engine, much less the high-dollar powerplant on my airplane.
 
The tolerances being what they are in an aircraft engine really getting the metal out of the oil doesn't buy you much. But I believe a bypass oil filtering system can make the oil last indefinitely.

There have been a number of systems installed in certified aircraft under 337's that I've seen...like the Amsoil bypass filter setup.
 
Oil type matters also, AD vs straight mineral.

Way back in the long ago, before oil filters were common, part of the oil cleaning process was for the particulate matter to fall to the bottom of the oil pan/sump and stay there. This was facilitated by the use of straight mineral or "non detergent" oils.
 
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