[Charlie Sisk]

Seems it wouldn't take too much to build something. A suction hose on the oil drain, going to a pump, then through a filter, discharging into the oil filler spout. Anyone done this ? What pump did you use ? And filter ?
I can see pushing a cart over to the plane, hooking up, and let it run while cleaning all the bugs off the leading edge of the wing. Or updating a GPS. If pumping 1 quart every five minutes, you are done in under an hour.
And as nothing is changed on the engine oil system, no safety issues.
Charlie

 

[Jjackh10]

This.... is what I was talking about in post #6. You do it in the hangar, after a flight and risk nothing during flight without adding any weight to the aircraft.

I plan to use two tubes that are passed down the filler neck. One touches the bottom, cut on a 45. The other tube only goes 1/2 way down the neck. Open the oil door, remove the dip stick and slide in the tubes to the filter and flip a switch and use a timer for the amount desired.... Maybe the same as the last flight.

I have a few gallons of used oil to test the system and the filter media choices.

I think this is a solid 90% solution. You could get virtually all of the oil and address some of Toobuilder's concerns by simply adding a tee and cap at the oil pressure sensor. Connect the cart and pump "clean" oil through all the oil passages so everything is fresh at the next start.

 

[rv8ch]

There are companies that sell oil cleaning carts. The only ones I found were about $1000 which seemed a bit high. If I were building one myself, I'd set up the cart to suck out the oil from the filler/dipstick onto the cart into a reservoir, and then turn on the filter cycle. Let it run as long as you want. Could even heat it so that in the winter you put the oil back in just before flight. Use a glass reservoir and you can see when it's clean. If you want to get fancy, install an inspection port after the filter and use a sensor to determine cleanliness. Another interesting business opportunity - could be sold to aircraft, boat, truck, forklift, tractor, and even car owners.

 

[Jjackh10]

This idea has been bumping around in my head since first mentioned. Could easily adapt it into a real kidney loop with flow through some type of pH conditioner, dehydrator, etc. before the final filtration to help maintain the oil's properties. The two tube/filler neck idea would work better for the former (conditioning) as it would have the benefit of equilibrium to affect oil that was not processed through the loop. The latter would rely on dilution so the bulk oil u level would never be achieved.

@ Several references. Summarizing = "Why does clean oil need to be filtered?" It doesn't stay clean; hence my previous DOD reference (Domestic Object Debris/Damage) for those never baptized in the church of aerospace. Sorry for the reference. Look at some of the opened filter element pix in this forum. Some of that would cause pretty extensive wear being recirculated even in a short flight


You're a smart guy, Sir. Being in Mojave, I assume you have an aerospace job. If all of a commodity is being treated to the level you desire, there's no reason to treat some of it in a bypass loop. Do as you wish and I'm rooting for the outcome you're seeking. A couple of things for you're consideration and I'm done here:

- I'd do a lot of inquiry into the required oil flow for your particular powerplant. As mentioned, the flow is basically constant for a given engine RPM. I'm assuming that oil system flow is similar to the other design parameters related to our machines versus ground dwelling types; the design margins will be much smaller/less conservation. Also, the losses are related to the square of the flow rate so the portioned that gets bypassed will increase at lower RPM. Don't know if that's good or bad but I'll assume that idle speed is the most critical resign point. Before I extracted any primary flow for a proposed bypass, I'd try to get very comfortable knowing that I hadn't swapped one lifeing parameter for another.

- Don't limit yourself to ICE oil filters in your search. Hydraulic systems require much finer filtration; servovalves being the limiting component. Their range of flow design points will also go much lower.

Drift = I got to spend a little time in Moog in NY state for both my aerospace and power industry careers. Dealt with some flat-out stud engineers up there. Anyway, the servovalve motors have very tight clearances, in the tens of thou clearances for their more specialized apps. The related spool which actually controls the actuator flow was even tighter, numbers not shared with me. If you extracted one from the servovalve housing and let it warm up in your hand, it wouldn't go back the bore. Not too much impresses me anymore. Hadn't thought about it in a long time but that memory still makes an impression on me.

Design safe, build safe, fly safe, Sir.

This is a concern with a kidney loop I thought about over the weekend. Pulling a bleed from the engine driven pump might negatively impact oil flow through the rest of the engine. It certainly wouldn't be good in those critical moments at startup. Delaying oil flow to the top end even an additional a second or two when everything is cold can not be good. You'd likely end up replacing rocker arms sooner, and possibly cams.

 

[Toobuilder]

Pulling a bleed from the engine driven pump might negatively impact oil flow through the rest of the engine.

I believe people are making too much of this particular issue. First off, the oil flow for this “bleed off” is minuscule… It’s a .050 orifice! keep in mind that this is much smaller than the other accessory bleed offs that Lycoming designed into the system and that most of us don’t use any longer - namely, the lube supply for the vacuum pump and rotary fuel pump that are now firmly capped. The tiny amount of oil going to the bypass filter won’t even be missed by the oil pump if the engine is otherwise healthy - especially if you are not feeding a vacuum pump or rotary fuel pump.

 

[hgerhardt]

That cleaning cart looks like an experiment worth doing. To make it easier, I designed an adapter to screw into the dipstick hole with -4AN flare fittings (or hose barbs if desired). Make it from PA-12 nylon and a 1/4" dia stainless tube pressed in, maybe an inch longer than the dipstick rod. The tube sucks oil out of the sump and the other fitting returns it. If you want an STL of the adapter, PM me with email. Jawstec wants $14 to make one via MJF printing. You'll have to tap the holes for the AN adapters with a 1/8" NPT tap.

 

[Freemasm]

If you had room to add a tube/extension/fitting to the return port, you'd have better mixing options; thus, more effectiveness and lower cycle time. As previously mentioned, this will rely on dilution vs equilibrium so only the oil that physically passes through the polishing filter will see benefit. Mixing would be pretty key to effectiveness. A return tube where the end was plugged and some periphery holes to "spray" the polished oil away from the suction would be beneficial. Plenty of other options if you can work room for the aforementioned into your proposed adapter, I think it would be wise.

Nice proposed approach, BTW. I'd be in to purchase a few with you if possible. Let me know.

 

[hgerhardt]

a tube/extension/fitting to the return port, you'd have better mixing options;

My thought was to have the clean oil dribbling back onto the surface under zero pressure and drawing the "dirty" oil from 3" below the oil surface in the sump. The return hole is angled onto the supply tube, which would break up the stream and remove the energy to splash into the sump.

However, if you think it would be better to have a 2nd dip tube with a 90deg hook at the end to try to create a vortex in the oil pool, that would be easy to do too. If you just had a few spray holes in the end of a return dip tube near the supply tube, I'd think that you'd keep sucking in the same oil over and over.

 

[Freemasm]

My thought was to have the clean oil dribbling back onto the surface under zero pressure and drawing the "dirty" oil from 3" below the oil surface in the sump. The return hole is angled onto the supply tube, which would break up the stream and remove the energy to splash into the sump.

However, if you think it would be better to have a 2nd dip tube with a 90deg hook at the end to try to create a vortex in the oil pool, that would be easy to do too. If you just had a few spray holes in the end of a return dip tube near the supply tube, I'd think that you'd keep sucking in the same oil over and over.

I said there were several ways to do it. Mixing via a single jet or several or whatever will be a key driver for effectiveness. Ejection velocity will be your friend.

Probably more room in your proposed adapter than at first glance. Offset each tube to the front/rear i.e. if the view were rotated 90deg the return would be "hidden" with the supply non-concentric.

Once again, nice approach and I'd be in for a few if that's an option.

 

[Bill Boyd]

That cleaning cart looks like an experiment worth doing. To make it easier, I designed an adapter to screw into the dipstick hole with -4AN flare fittings (or hose barbs if desired). Make it from PA-12 nylon and a 1/4" dia stainless tube pressed in, maybe an inch longer than the dipstick rod. The tube sucks oil out of the sump and the other fitting returns it. If you want an STL of the adapter, PM me with email. Jawstec wants $14 to make one via MJF printing. You'll have to tap the holes for the AN adapters with a 1/8" NPT tap.

View attachment 63662View attachment 63663

You, my friend, are well on your way to manufacturing replacement dip sticks, which in another thread here are currently fetching between 3 hundred and 3 thousand dollars a pop. Good job!

 

[Toobuilder]

Appreciate the "post operation" filtration ideas. Here's my quick try at the "in situ" filtration solution.



It's nothing more than a filter mount hung on a magneto block off plate. It will be fed by a local galley plug through a short length of #2 AN hardline and discharge directly through a hole in the block off plate. Admittedly chunky, this prototype weighs 14 ounces. Adding the filter can brings the total to 2 pounds, 9 oz.

 

[Mark Curley]

I've been using a By-pass filter on my pickup for about eight years now. Ford 7.3 diesel with Amsoil 2 micron filter. Oil supply tapped into oil gallery and returned to o fill tube. Having seen this flow, I would estimate it to be about 1 GPM Change the filter every two years, about 20k miles, not every oil change. No problems, good Blackstone reports. I don't have reports before the by-pass was installed. I believe it's a good thing, we do get silicon in our oil from air filter leaks and the by-pass filter should help pull that out. Plus wear metal particles that are larger than 2 microns will be trapped.

Antedotally, I was on a cruise ship last year and attended a Q&A with ships officers. I asked the Chief Engineer how often they changed the main engine oil? For those that don't know cruise ships usually have five large engines set up as generators and propel the ship with electric motors similar to a locomotive. His answer to the oil change question - "Never". They use sophisticated filter systems including centrifugal filtering and this eliminates the need to replace what must be a very large quantity of oil. I asked another engineer on another ship the same question and he confirmed that this is the case.

How does this relate to our aircraft? Cleaner oil can result in less engine wear and longer engine life. The easy example is changing from a pressure screen to full flow filter results in the oil change interval going from 25 hours to 50 hours. With a by-pass could we extend that further? Maybe that's not a thing we are ready to do, but surely the cleaner oil will reduce engine wear. More parts usuable at overhaul, maybe lifetime for some parts?

 

[Freemasm]

I've been using a By-pass filter on my pickup for about eight years now. Ford 7.3 diesel with Amsoil 2 micron filter. Oil supply tapped into oil gallery and returned to o fill tube. Having seen this flow, I would estimate it to be about 1 GPM Change the filter every two years, about 20k miles, not every oil change. No problems, good Blackstone reports. I don't have reports before the by-pass was installed. I believe it's a good thing, we do get silicon in our oil from air filter leaks and the by-pass filter should help pull that out. Plus wear metal particles that are larger than 2 microns will be trapped.

Antedotally, I was on a cruise ship last year and attended a Q&A with ships officers. I asked the Chief Engineer how often they changed the main engine oil? For those that don't know cruise ships usually have five large engines set up as generators and propel the ship with electric motors similar to a locomotive. His answer to the oil change question - "Never". They use sophisticated filter systems including centrifugal filtering and this eliminates the need to replace what must be a very large quantity of oil. I asked another engineer on another ship the same question and he confirmed that this is the case.

How does this relate to our aircraft? Cleaner oil can result in less engine wear and longer engine life. The easy example is changing from a pressure screen to full flow filter results in the oil change interval going from 25 hours to 50 hours. With a by-pass could we extend that further? Maybe that's not a thing we are ready to do, but surely the cleaner oil will reduce engine wear. More parts usuable at overhaul, maybe lifetime for some parts?

Sorry for the drift, Mr, Robinson.

Probably gonna step in it here but....

The above is an example of economies of scale. Your engine oil could be cleaned and the additives and chemistry rebalanced. It doesn't make economic sense. That said, what is probably many hundreds of gallons, maybe thousands would. Our (where I'm employed) gas turbine's lubricating oil never requires changing and the design life is over 100K hours. Periodic analysis reveals if any additives are deficient but this is not too common. Regarding analysis, the guys at Texas Oil Tech are top notch BTW.

The centrifugal filtration is most certainly for water removal which would be a big concern for that application. Another parameter that I can guarantee affects the aforementioned maintenance costs; the ships burning Natural Gas versus any type of fuel oil will have much lower related lube oil operating costs.

 

[[email protected]]

Sorry for the drift, Mr, Robinson.

Probably gonna step in it here but....

The above is an example of economies of scale. Your engine oil could be cleaned and the additives and chemistry rebalanced. It doesn't make economic sense. That said, what is probably many hundreds of gallons, maybe thousands would. Our (where I'm employed) gas turbine's lubricating oil never requires changing and the design life is over 100K hours. Periodic analysis reveals if any additives are deficient but this is not too common. Regarding analysis, the guys at Texas Oil Tech are top notch BTW.

The centrifugal filtration is most certainly for water removal which would be a big concern for that application. Another parameter that I can guarantee affects the aforementioned maintenance costs; the ships burning Natural Gas versus any type of fuel oil will have much lower related lube oil operating costs.

I actually can't believe I read all this thread. Think I got a head ache.
Somebody has to much time on their hands, Our little motors carry all of 6-8 quarts. If It was a D-8 dozer semi engine you're talking dozens of gallons. I have a friend that has an excavating company and they have an oil cleaning machine. It only cost $110,000.00 back in 2001
I'm going to go pop some corn.
Thanks for the stories.
My luck varies FIXIT

 

[Freemasm]

I actually can't believe I read all this thread. Think I got a head ache.
Somebody has to much time on their hands, Our little motors carry all of 6-8 quarts. If It was a D-8 dozer semi engine you're talking dozens of gallons. I have a friend that has an excavating company and they have an oil cleaning machine. It only cost $110,000.00 back in 2001
I'm going to go pop some corn.
Thanks for the stories.
My luck varies FIXIT

Your point is, Sir? No one made you read it.

Drift ensued but some interesting related ideas were discussed. Nice to have people share knowledge, ideas, and approaches to problem solving.

 

[Jjackh10]

Your point is, Sir? No one made you read it.

Drift ensued but some interesting related ideas were discussed. Nice to have people share knowledge, ideas, and approaches to problem solving.

I think the point is around the value of pursuing this idea. As mentioned before, these systems have been effective in some applications but there is an economy of scale issue.

Back of the napkin arithmetic looks something like this. A 7 quart oil change costs around $90 in oil. Whatever system you use; cart, or in situ, filters need to be changed. So no savings there. A filter cart will cost $1000 to build (the pumps are pricey). So once you bypass 11 oil changes the cart could be saving some $$$. An in situ install has a much better ROI if; 1. you own a mill like Toobuilder and can build the system for a few bucks. And 2. it effectively cleans the oil quickly enough.

I don't believe oil filtered at 15 microns and changed every 50hrs. VS oil filtered at 2 microns and changed at greater intervals will have any measurable difference in engine life. The metallurgy and internal tolerances in a Lycoming are just not that fragile.

An argument can be made to pursue either path. But the real world value of either vs running what you got? That might be a kin to the real world value of me owning a diesel truck because it gets better fuel economy and climbs the hills faster than a gas burner when I'm pulling a trailer.

 

[ERJDriver]

I think the point is around the value of pursuing this idea. As mentioned before, these systems have been effective in some applications but there is an economy of scale issue.

Back of the napkin arithmetic looks something like this. A 7 quart oil change costs around $90 in oil. Whatever system you use; cart, or in situ, filters need to be changed. So no savings there. A filter cart will cost $1000 to build (the pumps are pricey). So once you bypass 11 oil changes the cart could be saving some $$$. An in situ install has a much better ROI if; 1. you own a mill like Toobuilder and can build the system for a few bucks. And 2. it effectively cleans the oil quickly enough.

I don't believe oil filtered at 15 microns and changed every 50hrs. VS oil filtered at 2 microns and changed at greater intervals will have any measurable difference in engine life. The metallurgy and internal tolerances in a Lycoming are just not that fragile.

An argument can be made to pursue either path. But the real world value of either vs running what you got? That might be a kin to the real world value of me owning a diesel truck because it gets better fuel economy and climbs the hills faster than a gas burner when I'm pulling a trailer.

3.5G a min oil pump is 85 bucks on Amazon

 

[Jjackh10]

3.5G a min oil pump is 85 bucks on Amazon

Good find! Admittedly I didn't search too hard lol.

 

[ChiefPilot]

easy example is changing from a pressure screen to full flow filter results in the oil change interval going from 25 hours to 50 hours. With a by-pass could we extend that further? Maybe that's not a thing we are ready to do, but surely the cleaner oil will reduce engine wear. More parts usuable at overhaul, maybe lifetime for some parts?

If extending the oil change interval is the goal, just switch to unleaded fuels. Lycoming allows 100hr intervals when unleaded fuel is used exclusively. See Sl270 for details.

SL270

 

[Toobuilder]

The “goal” is to have cleaner oil than afforded by the typical spin on full flow filter. Increased oil change interval may be a side benefit, but that remains to be proven.

Im confused by the amount of pushback on this thread…. Many of you will gush over the efforts of a member who makes printed headset holders, or wheel chocks, or tailwheel steering links, or funny little tools to open gas caps, or tailwheel lifts, or elaborate, multi thousand dollar custom paint jobs…. I came up with a very simple integration solution to try out a bypass filter. My example was made with scrap material and a few hours of my labor. It cost nothing and weighs very little. I’m not selling it, nor the concept. I have a theory and I want to run the course and see what’s what. If someone gets an “ahhaa” moment and sparks more creativity, that’s all I really care about. Sharing ideas was what home building used to be about. If this is not for you, so be it.

 

[rv8ch]

My example was made with scrap material and a few hours of my labor. It cost nothing and weighs very little. I’m not selling it, nor the concept. I have a theory and I want to run the course and see what’s what. If someone gets an “ahhaa” moment and sparks more creativity, that’s all I really care about.

Michael, I think it's a great idea. I'm waiting to hear your experience with it, plus I'd need to attach it to the vacuum pump, since I need the mag ports. In parallel, I love the idea of an oil cleaning cart, and again, waiting for the pireps for a decent product that won't break the bank.

 

[DanH]

I came up with a very simple integration solution to try out a bypass filter. My example was made with scrap material and a few hours of my labor. It cost nothing and weighs very little. I’m not selling it, nor the concept. I have a theory and I want to run the course and see what’s what.

I like it. Simplicity is a hallmark of good design. Be sure to post an installed photo.

 

[Toobuilder]

plus I'd need to attach it to the vacuum pump,

If you have the vacuum pump pad available, then you have a ready made oil supply and return path. I had a sketch of an adapter that bolts directly to the vacuum pad and picks up the existing ports. No external lines, no modification to the oiling system at all. I ended up using that pad for a generator so I never went any further. It would be a bit more complex to machine than the thing that I came up with, but still not too bad.

 

[Jjackh10]

The “goal” is to have cleaner oil than afforded by the typical spin on full flow filter. Increased oil change interval may be a side benefit, but that remains to be proven.

Im confused by the amount of pushback on this thread…. Many of you will gush over the efforts of a member who makes printed headset holders, or wheel chocks, or tailwheel steering links, or funny little tools to open gas caps, or tailwheel lifts, or elaborate, multi thousand dollar custom paint jobs…. I came up with a very simple integration solution to try out a bypass filter. My example was made with scrap material and a few hours of my labor. It cost nothing and weighs very little. I’m not selling it, nor the concept. I have a theory and I want to run the course and see what’s what. If someone gets an “ahhaa” moment and sparks more creativity, that’s all I really care about. Sharing ideas was what home building used to be about. If this is not for you, so be it.

I sincerely apologize for pushing back. I do really like the solution you came up with to get cleaner oil. It will no doubt achieve that goal. I'm all about trying things and experimenting. Your initial posts mentioned cost benefit analysis, that is what I was attempting to help with based on my experience with oil filtration in heavy industry. To my knowledge, any application where this type of "oil maintenance" has been performed and studied, the only real benefit is extended oil change intervals. In all of the equipment its been tested on maintenance PM's were in place to change the oil before it got dirty enough to increase wear. Manufacturers and maintainers of pumps, compressors, turbines, and mobile equipment (including lycoming) have established recommendations with long histories.

 

[Toobuilder]

The “pushback” comment was not aimed entirely at you…. There is plenty of that to go around. But the bottom line remains that nobody has any “hard data” to make an informed CBA to this scheme. PLENTY of opinion, but even the most vocal have been unable to articulate why ”…it’s not worth it…”.

In the absence of actual data, I’m going to put my nearly new LyCon 540 on the line once again and try it out. In the process of this thread we have established that:

The integration is not expensive
the integration is low risk
the integration is low weight
the oil WILL be significantly cleaner

Thats more than enough motivation for me to move forward.
Stay tuned

 

[Jjackh10]

The “pushback” comment was not aimed entirely at you…. There is plenty of that to go around. But the bottom line remains that nobody has any “hard data” to make an informed CBA to this scheme. PLENTY of opinion, but even the most vocal have been unable to articulate why ”…it’s not worth it…”.

In the absence of actual data, I’m going to put my nearly new LyCon 540 on the line once again and try it out. In the process of this thread we have established that:

The integration is not expensive
the integration is low risk
the integration is low weight
the oil WILL be significantly cleaner

Thats more than enough motivation for me to move forward.
Stay tuned

Agree 100% Your system will result in cleaner oil. I don't know of any hard data supporting cleaner oil improving component life so I can't help you there. But given the low cost of your system extending oil changes even by a little bit will result in a solid cost benefit. I'd think you could get there relatively quickly and comfortably. Just check the labs on a sample from your first oil change and go from there. Get err bolted up and get flying.

 

[Jjackh10]

All that said I wonder if there is a way to verify and quantify if there is any improvement in component life? So many things impact that outside of oil quality. Two engines mounted on the same plane still have different failures and times before overhaul. Maybe some specific component with a steady, known, wear rate?

 

[Toobuilder]

All that said I wonder if there is a way to verify and quantify if there is any improvement in component life?

I’m not a lubrication engineer, but it seems to me that the oil in a typical oil change lifecycle starts out good and immediately begins to degrade until it’s so loaded with junk that it’s unusable. I don’t think it’s like milk, where it’s “good” for a period of time and then suddenly goes “bad”. Put another way, 25 hour oil is “half dead”, and 49 hour oil is 98% dead…. Point being, even if you keep the same oil change interval with the extra filtering, it stands to reason that you simply push the “almost bad” part of the oil life out further, then you are running in “better” oil for longer.

I mean, if this scheme somehow doubles the time it takes to plug up the oil, then you are running the oil for the full 50 hours at no worse than the “half dead” stage. That HAS to be better for the engine somehow, right, otherwise why does Lycoming require an oil change at all?

 

[Jjackh10]

I’m not a lubrication engineer, but it seems to me that the oil in a typical oil change lifecycle starts out good and immediately begins to degrade until it’s so loaded with junk that it’s unusable. I don’t think it’s like milk, where it’s “good” for a period of time and then suddenly goes “bad”. Put another way, 25 hour oil is “half dead”, and 49 hour oil is 98% dead…. Point being, even if you keep the same oil change interval with the extra filtering, it stands to reason that you simply push the “almost bad” part of the oil life out further, then you are running in “better” oil for longer.

I mean, if this scheme somehow doubles the time it takes to plug up the oil, then you are running the oil for the full 50 hours at no worse than the “half dead” stage. That HAS to be better for the engine somehow, right, otherwise why does Lycoming require an oil change at all?

Yes your assessment of how oil "degrades" is correct. It doesn't go bad, other than a bit of additive loss it just gets dirty. An aircraft engine see's a fairly consistent duty cycle. I would expect the rate of getting dirty to be fairly linear. So a constant cleaning from the start should bend that curve way up. Far more than double the time till the contamination is excessive. And yes cleaner sounds better. But I'm not sure going from 15 micron to 2 micron contaminant particles will have any impact. I just googled "oil film thickness in journal bearings" and saw two figures, 2- 100 microns and 5-75 microns. So theoretically It would take quite a volume of <15 micron (normal filter) contamination before any wear took place. I'm pretty sure that data is how oil change intervals are determined. Lycoming figured out that it takes around 50hrs for the <15 micron filter to become plugged and allow contamination to head toward an unacceptable level.

I'd love to be able to determine what the reality is here. I am just not sure how to go about measuring a tangible real world result. Because there are so many other things that Impact engine life. Moisture, thermal cycling, metallurgy, casting or forging flaws, machining variances, and many more.
The only idea I can think of would be to somehow put a fixed load on an air cooled small engine. Put oil from your last oil change in it, run for a prescribed period, and precisely measure fuel consumption. Then repeat the test, same engine, same conditions, with fresh oil. Poor, wear causing lubrication is drag. More drag is more energy. So a reduction in fuel consumption would prove the theory.

 

[moosepileit]

The external electric pump made of chineseium may need its own FEA or filter or oil analysis, primed or not.

Is there a really reuseable and easy access quick drain attach for the sump/supply side by Fumoto?

 

[lr172]

Yes your assessment of how oil "degrades" is correct. It doesn't go bad, other than a bit of additive loss it just gets dirty. An aircraft engine see's a fairly consistent duty cycle. I would expect the rate of getting dirty to be fairly linear. So a constant cleaning from the start should bend that curve way up. Far more than double the time till the contamination is excessive. And yes cleaner sounds better. But I'm not sure going from 15 micron to 2 micron contaminant particles will have any impact. I just googled "oil film thickness in journal bearings" and saw two figures, 2- 100 microns and 5-75 microns. So theoretically It would take quite a volume of <15 micron (normal filter) contamination before any wear took place. I'm pretty sure that data is how oil change intervals are determined. Lycoming figured out that it takes around 50hrs for the <15 micron filter to become plugged and allow contamination to head toward an unacceptable level.

I'd love to be able to determine what the reality is here. I am just not sure how to go about measuring a tangible real world result. Because there are so many other things that Impact engine life. Moisture, thermal cycling, metallurgy, casting or forging flaws, machining variances, and many more.
The only idea I can think of would be to somehow put a fixed load on an air cooled small engine. Put oil from your last oil change in it, run for a prescribed period, and precisely measure fuel consumption. Then repeat the test, same engine, same conditions, with fresh oil. Poor, wear causing lubrication is drag. More drag is more energy. So a reduction in fuel consumption would prove the theory.

In dirty engines like our Lyc's, the drain interval is based upon a least common denominator approach to guessing WHEN the debris load that the oil is holding in suspension has reached it's max capacity. Once this capacity has been reached, the debris begins to form sludge in the engine and this greatly reduces engine longevity. The oil base stocks don't really wear out, though shearing can destroy it over time, but don't believe there is a lot of shearing in Lycs. THe additive packages wear out, but aviation oil uses very few additives and they last WAYYY longer than 50 hours.

IFFFF these bypass filters can pull the contaminants out of the oil, it should exponentially lengthen the drain intervals. Not a scientist and still wonder about the particle size of the debris that is being held in suspension. Will probably need some lab work to figure that out. 2 microns sounds great, but no real help if most of the crud floating in our oil is 1 micron.

Larry

 

[Toobuilder]

I guess we are all struggling with the definition of “dirty” oil in the context of a lead burning Lycoming. High particle count leading to a plugged filter is easy to envision, but I’m not sure a properly functioning engine is creating that much debris. If that were the case, then just change filters and start the collection of < 15 micron particles all over. The oil must be dirty in some other context, and it’s probably lead accumulation. It would be nice if these 2 micron filters pulled the lead out too.

 

[Jjackh10]

The external electric pump made of chineseium may need its own FEA or filter or oil analysis, primed or not.

Is there a really reuseable and easy access quick drain attach for the sump/supply side by Fumoto?

I'm not well versed in the myriad of hose connections in the world. In industrial applications we use a lot of hydraulic hose quick connects. They're similar to air hose fittings but seal closed when disconnected. They make small ones for things like Port-A-Powers.

 

[lr172]

I guess we are all struggling with the definition of “dirty” oil in the context of a lead burning Lycoming. High particle count leading to a plugged filter is easy to envision, but I’m not sure a properly functioning engine is creating that much debris. If that were the case, then just change filters and start the collection of < 15 micron particles all over. The oil must be dirty in some other context, and it’s probably lead accumulation. It would be nice if these 2 micron filters pulled the lead out too.

Well at 50 hours lycoming believes that the oil has reached the max limit of what the oil can hold in suspension. Clearly this debris is too small to be filtered out by the filter, else we would have limits on the filters age and not the oil's age.

The fact that the oil turns black and not grey leads me to speculate that it is not just lead being held in suspension. THere must be carbon too.

 

[Jjackh10]

In dirty engines like our Lyc's, the drain interval is based upon a least common denominator approach to guessing WHEN the debris load that the oil is holding in suspension has reached it's max capacity. Once this capacity has been reached, the debris begins to form sludge in the engine and this greatly reduces engine longevity. The oil base stocks don't really wear out, though shearing can destroy it over time, but don't believe there is a lot of shearing in Lycs. THe additive packages wear out, but aviation oil uses very few additives and they last WAYYY longer than 50 hours.

IFFFF these bypass filters can pull the contaminants out of the oil, it should exponentially lengthen the drain intervals. Not a scientist and still wonder about the particle size of the debris that is being held in suspension. Will probably need some lab work to figure that out. 2 microns sounds great, but no real help if most of the crud floating in our oil is 1 micron.

Larry

Thanks Larry, that was a more detailed way of explaining what I was trying to say.

I guess we are all struggling with the definition of “dirty” oil in the context of a lead burning Lycoming. High particle count leading to a plugged filter is easy to envision, but I’m not sure a properly functioning engine is creating that much debris. If that were the case, then just change filters and start the collection of < 15 micron particles all over. The oil must be dirty in some other context, and it’s probably lead accumulation. It would be nice if these 2 micron filters pulled the lead out too.

Relating to wear how big of a concern is lead? Lead is way softer than the metals in the engine. Lead has been used as bearing material for steel.

 

[lr172]

Thanks Larry, that was a more detailed way of explaining what I was trying to say.

Relating to wear how big of a concern is lead? Lead is way softer than the metals in the engine. Lead has been used as bearing material for steel.

again wear is not the concern. It is the accumulation of sludge that will eventually plug up the oil system and then the wear comes from oil starvation. Ever pull a constant speed prop off and look inside the crank. The centrifuge process leaves A LOTTTT of grey sludge.

 

[Toobuilder]

Clearly this debris is too small to be filtered out by the filter, else we would have limits on the filters age and not the oil's age.

The SL270 in post 69 requires a filter inspection at 50 hours, but the oil is extended to 100 hrs. Seems to indicate the lead is a big poison for the oil, yet they are also worried about the wear material particle count as well, so the filter goes at 50 regardless.