How important is an oil filter ?

I have been struggling with a B&C filter adaptor on my O320 RV-3 w/ conical mount. A custom adaptor spacer and smaller filter might work, but solutions keep getting heavier with more potential points of failure. I can remote the filter from the adaptor with pieces from summit racing, but thats even more weight and hardware. The engine is 100% new parts and the builder says no filter= No Warranty. I really don't care about the warranty, but would like to be informed if I decide to put the Vernatherm/OT sensor back on and forget filters.

So, is anyone aware of testing/data that says an oil filter is more EFFECTIVE regarding ENGINE LIFE than changing oil every 25 hours as was done for decades ?

It's been shown that there is very little gain in a paper filter versus the lycoming screen. There was a side by side test of the Airwolf, stock screen, and a champion filter once. Bottom line...not much difference. Filter cost today equals about four quarts of oil. Also, most people don't realize that only the tall filters are supposed to be good for fifty hours. The short filters are still 25 hour filter changes.

Thanks much Airhead

Decision made, I will move on with $500 in the rear view mirror. If anyone wants a New B&C adaptor out of the box, never installed at a dicount, PM or email and its yours !!!!!!!!

aerhed said:

It's been shown that there is very little gain in a paper filter versus the lycoming screen. There was a side by side test of the Airwolf, stock screen, and a champion filter once. Bottom line...not much difference. Filter cost today equals about four quarts of oil. Also, most people don't realize that only the tall filters are supposed to be good for fifty hours. The short filters are still 25 hour filter changes.

Click to expand...

Huh. Haven't heard either of these claims before. Got references you can share? Good info if true.

Thanks
Erich

another never-ending debate????

ok, so take this for what it's worth, just an idea.



taken that the filter area is probably half that of a full size aviation filter, this is the only thing that will really fit on my engine....a shorty auto filter. same exact burst pressure, bypass pressures etc as the Champion. They are used on similar displacement auto engines, etc. etc.
why would you not 'clean' a lot of the fines out of the oil, if you can?
Slap a magnet on there, and grab a lot of the iron, rather than let it go round and round thru the engine.
If screens were really 'no different' from using a filter, why do they use filters on engines worth many tens of thousands of dollars?

I am open to educated input on the pros and cons of using this?
( haven't done it yet!)

I have a conical mount O-360. It's old enough to have the 'velocity valve' control for oil cooling instead of the vernatherm. I use the original screen as well. Seems fine so far.
I like the idea of an oil filter tho- I think it should have an internal bypass valve and should be oriented so the swarf collected in the filter gravitates away from the bypass valve.
I like the idea of a magnet on the outside of the filter too.
Also, you could use the small automotive filter and pull it at 25 hours, but leave the oil in for 50 hours. (2 oil filters used per batch of oil)
Or you could follow the convention, and cut the oil filter open and inspect it. I find that even a small oil filter would be OK, as there is usually next to nothing in the filter of a good engine.

Erich, I'd have to dig for that info. It was 25 years ago at least. I'm sure I got it from a glossy magazine.

You can find the short/tall filter in lycoming pubs.

Here's how Tony mounted the Airwolf (I think) remote oil filter on the -3 with conical mount. He made a heavy bracket and fastened it to the tubes of the engine mount with Adel clamps. I took this picture just before I removed it so I'd remember how to put it back on. I don't see how a non-remoted oil filter would work behind an O-320 on a 3. Not much room back there! It's super easy to access the filter right here.

The standard Lycoming screen has always seemed archaic to me. The fact that so many airplane engines fly around with just a screen really surprised me when I started learning about Lycomings. Maybe it's because I've worked on antique Farmall tractors built in the 1920s and 30s with factory-equipped Purolator oil filters and I just assumed an airplane engine would have a filter too. I know I'm not flying around in the dirt like the tractors did, but it's not something I would fly without, at least if I owned the engine! (A new engine, at that.)

Good picture Katie - that is about how we mounted the slobber pot for our Half-Raven inverted system - really worked out well.

We're using the angled adapter for the oil filter on our -3, and it's fine (with the correct spacer). Tight, but it works - for the dynafocal mount, of course. Don't know how the conical would look.

Paul

Ironflight said:

We're using the angled adapter for the oil filter on our -3, and it's fine (with the correct spacer). Tight, but it works - for the dynafocal mount, of course. Don't know how the conical would look.

Paul

Click to expand...

Sure it fits, but can you reach up behind there and remove the filter without getting your hands dirty?

I've got a thousand hours flying an 0-320-E2D with just the oil screens (btw, there are two: the coarse suction screen in the sump and the fine screen at the back of the accessory case). There just wasn't enough room in my installation for a spin-on oil filter rig. Do I wish I had one? Sure. Is it necessary? Nope. Lycoming still calls out the screen in the rebuild docs, and you should see the little dinky specs of silver metal and grit the fine-screen catches. Change the oil every couple months like the manual says, check the screens and do oil analysis - if the engine starts making metal you'll see it same as a spin-on filter.

A question was also raised about the vernatherm oil cooler bypass valve. I had one fail in the air last summer, oil temp went near to redline. What happened? The thing stuck open. The vernatherm is a complicated little gadget that is supposed to expand with increasing oil temperature, then seat on an oil passage to shunt oil out to the cooler. During the boiling-water test after the airborne incident, the thing wouldn't budge, wouldn't expand. Imagine: the failure mode of the silly thing was to stop routing oil to the cooler! Nuts to that. So I replaced it with the old viscosity valve, which is a simple spring and plunger. Lycoming still sells them, calls them out in their docs (along with the vernatherm valve). Takes a little longer to warm up the oil in the morning, but now if the valve fails and gets stuck, then ALL the oil will get routed to the cooler ALL the time. I like ho-hum failures better than hot failures, and I'll take simple vs. complicated any day, but that's just me (get me going on CS vs. fixed-pitch props sometime!)

- Steven
(1000+ RV3 hours ... another one yesterday!)

Larry, I will through in some comments to weigh. Basics-an oil filter, nearly all, are a 30 micron filter designed to take out some average of particles. Many smaller ones will get caught and no big ones will pass (if they make it through the screen). Particles come from all sorts of parts, more when freshly rebuild/built, but when in operation, more comes from particles in the air scraped off the cylinder walls from the air stream for combustion. So is that bad? Well, it is a relative thing. Like Katie noted for a tractor, it would be very bad in dusty conditions. Here in the Midwest with lots of exposed ground, dust is unavoidable. If you lived in costal areas or in forested areas, then the air will not leave that dust layer on your car as much as midwest. Much of the midwest dust is silica and the particles are very hard. Hard particles in the oil just wear things, all things. Again, it is relative.

Factually, but from memory, oil contamination (particles) will gradually increase with operating time. It may take 25 hours to reach stabilization. With a clean system it may take 100. If we set aside the protection for random particles that could score bearings, then theoretically, one would be no better off with filter if oil was changed as the particle count passed that stabilization threshold. Quantifying that threshold would take some/many oil analyses. If you do that get Deere or CAT oil analysis as they are much lower cost. (and they don't come with a nice analysis commentary like Blackstone)

So - a good air filter (whole other topic) and regular (25hr) oil changes would only leave the random risk of errant hard stuff in a bearing. However, a good air filter will be paper, with perfect sealing. Fact. So, living in the desert, around counties full of corn fields, an oil filter would be strongly recommended.

For decades I wondered about exactly wear and engine life issues were vs oil particles level. Engine companies test components with dirty oil (good ones do). Oil at the end of its life, laden with particles. They even have spec particles to add to clean oil now to provide a known repeatable test. Seeing parts from clean and "dirty" oil, convinced me that filters are good. By pass filters with 2-5 micron filtration will definitely extend the life of wear related (not temperature) failure modes.

Round in circles: All that said, it is hard to quantify the difference, you might half the life of your crank, and if you have a slipper cam, lifters and camshaft too. You might know it through scoring, or just wear. So, the engine will likely still go to TBO, but more parts will be closer to replacement specs in the end. The same old "pay me now or pay me later" scenario. Frequent oil changes are a good thing w/o oil filters, and analysis will greatly help tune that in.

Now to decide. Personally, I would use an oil filter, but I would not talk bad about a guy who chose differently knowing the tradeoffs.

Lycoming SB480E 50-hour paper filter interval

Lycoming SB480E lists the factory recommended oil change for our direct drive engines. Lycoming recommends oil change at 25 hours after first placing new, remanufactured or newly overhauled engines and for engines with any newly installed cylinders
in service that replacement/screen cleaning ? oil change, filter replacement or pressure screen cleaning and oil sump suction screen check be preformed.

After the first change, all engines with paper filters regardless of filter length is 50-hours or 4-month intervals. Short spin on paper filters or long paper spin on filters all have the same 50-hour oil change interval.

Okay, I can't find the old 25 hour short filter SB. It was a talked about thing years ago. I remember a Champion rep at an IA meeting going over it, but now I can't find it in lyc or champion docs. All I could find is this in TCM SIL99-2c
" NOTE: When using the small oil filter (4.80 inch high) do not
exceed 50 hours and/or 6 months between oil and filter changes.
When using the larger oil filter (5.80 inch high) do not exceed 100
hours and/or 6 months between oil and filter changes. Oil screens
and oil filter elements must be inspected for contaminates at each
oil change. Oil analysis may be used in addition to the oil screen or
filter element inspection, but not as a replacement for it."
Could be the short filter change was aircraft specific, but I swore it was a Champion thing at one time.
BTW Bill's comment was good. More better ellokwence than me.

The good thing about a filter is that you can take it off and cut it open and see what is going on. Look at the issue Kevin Horton is having. He discovered it from looking at his filter. Chances are it is a broken right. He will get it fixed and not end up in a field because of the oil filter showing him. Would all that stuff get caught in the screen? I am not sure.

I recall reading the Sermons of Bob Hoover (no, not THAT Bob Hoover) who wrote extensively about VW engines, that the increase in life brought about by the introductions of oil filters was something phenomenal (I don't recall the number) according to a paper authored by the Ford Motor Co.

But this is experimental aviation and we all do what we are comfortable with.

Type of oil, and depth of oil sump below the oil pickup are also factors here.

The old time engines designed before filters commonly used the bottom of the sump as a holding place for the crud settling out of the oil after running. Oil pickup was high enough that it was clear of the settled out crud.

Non detergent oils that were used back then did not keep little bits of crud suspended, nor clean off the interior surfaces of the engine like modern oils.

My 1948 Stinson, with the Franklin engine was a prime example of this. When I added an oil filter, I removed the pan and cleaned out a quarter inch of sediment.