AndreiC Posted March 15 Report Posted March 15 I fly my M20E about 100 hours between annuals. In the past I would do myself one oil and filter change at around 50 hours, and have the mechanic do a second one at annual time. However, I heard from several sources that letting the oil run for 50 hours is a bit much, and that most people do it at around 25-30. So I decided to change just the oil after 25 hours (what my previous mechanic called "dump and pump") without touching the oil filter. Now my question is: I am sure it is fine to do this, and replace the oil at 25 hour intervals, while replacing the filter at 50 hour intervals. But how bad would it be if I replaced the oil at 25 hour intervals, and the filter at 100 hour intervals? Is this a big no-no? I'm asking because while changing just the oil is an almost painless operation, I have never succeeded in not making a big mess when changing the filter, with quite a bit of oil in the engine compartment, on the front wheel, on the floor... I know it should get better with practice, but over 25 years of "practice" it is still a mess. On a different note, where can I buy a camlock screw for one of the "cheeks" of the cowling? The pin that was going through it is gone, and the hole is mangled, took me quite a bit of time to get the screw out. Attached picture, plane is a 1970 M20E. Not sure how to measure the correct size for it.
PT20J Posted March 15 Report Posted March 15 The answer to the first question is: Who knows? The filter media eventually gets full of trapped contaminants and the internal bypass valve will bypass oil around it when it gets too clogged ceasing filtering action. Who knows when this happens? But it's pretty easy and inexpensive to change the filter with every oil change. As my favorite A&P likes to say, "Filter cheap; engine expensive." The answer to your second question is: Many places. Aircraft Spruce is a good source. There is a little hard to read single digit number on the head that defines the length. You also have a choice of Phillips or slot head, and cad plated steel or stainless.
MikeOH Posted March 15 Report Posted March 15 42 minutes ago, AndreiC said: I know it should get better with practice, but over 25 years of "practice" it is still a mess. I’ve only owned for less than 9 years but I only made a mess on my first oil change. My technique doesn’t seem popular but works for me: 1) remove the safety wire and break the filter loose but don’t unscrew it too much. 2) place a large zip lock bag over the filter and pull the reinforced ziplock edge up behind the flange the filter screws onto. 3) finish unscrewing the filter. It’s in the bag and oil from the mount will also drain into the bag. 4) After a minute or so you can slip the bag edge off the mounting flange and place a shop rag under the flange to catch any drips. (I usually have the new filter prepped and just wipe the flange and spin on the new filter) 3
MikeOH Posted March 15 Report Posted March 15 44 minutes ago, PT20J said: You also have a choice of Phillips or slot head, and cad plated steel or stainless. @PT20J Do you know if hardware is actually cadmium plated any longer? IIRC, cadmium is now considered evil and banned for nearly everything.
Fritz1 Posted March 15 Report Posted March 15 as stated before, it depends, cutting the filter is a good indication of engine health, no metal found makes you feel good and increases safety of flight ops, filter is about $30 if memory serves, I also use a plastic zip lock bag to catch the filter, after some practice zero spill, bottom line changing the filter twice a year is not that excessive, I change oil and filter every 25h, thus 4x a year, drop in the bucket looking at the other expenses of owning an aircraft... 2
hammdo Posted March 15 Report Posted March 15 I use this under the filter: https://www.amazon.com/dp/B016KTC3FO?ref=ppx_pop_dt_b_asin_title&th=1 I can fish it under the filter and have it drain into the bucket… -Don
toto Posted March 15 Report Posted March 15 1 hour ago, AndreiC said: On a different note, where can I buy a camlock screw for one of the "cheeks" of the cowling? The pin that was going through it is gone, and the hole is mangled, took me quite a bit of time to get the screw out. Attached picture, plane is a 1970 M20E. Not sure how to measure the correct size for it. I get bags of these on eBay, and they’re super cheap compared to retailers. Ex: https://ebay.us/m/aWAohp 1
AndreiC Posted March 15 Author Report Posted March 15 Can you guys tell if this is a "3" size or a "6"? I can't tell if the "6" is actually something that looks more like a rounded "E".
PT20J Posted March 15 Report Posted March 15 1 hour ago, MikeOH said: @PT20J Do you know if hardware is actually cadmium plated any longer? IIRC, cadmium is now considered evil and banned for nearly everything. The catalog still says cad plated. 1
PT20J Posted March 15 Report Posted March 15 2 minutes ago, AndreiC said: Can you guys tell if this is a "3" size or a "6"? I can't tell if the "6" is actually something that looks more like a rounded "E". That's a 3. The other mark identifies the manufacturer. 1
Utah20Gflyer Posted March 15 Report Posted March 15 Send your oil out for analysis. If the report comes back with the oil being in good condition and with adequate lubricity then continue with 50 hour oil/filter changes. If it comes back in poor condition then shorten the oil change interval. There is no reason to speculate without data when the cost to get it is 30 or 35 dollars. Generally speaking a 25-30 hour interval is for guys who have turbocharged engines. The process of cooling the turbocharger is rough on the oil. Another reason might be an engine with a lot of blow by. Last reason is some people LIKE the idea of changing the oil sooner. To answer your question regarding changing the oil but not the filter. Yes, that is acceptable because you are still replacing and inspecting the filter at 50 hours as recommended by Lycoming. You are giving up a potential data point by not replacing and inspecting the filter at 25 hours but that’s a personal choice. I’ve never seen data that following Lycomings 50 hour oil change interval is inferior to a self imposed 25 hour interval. My oil analysis keeps coming back good so I’m going to continue with 50 hours. 3
toto Posted March 15 Report Posted March 15 2 hours ago, Utah20Gflyer said: To answer your question regarding changing the oil but not the filter. Yes, that is acceptable because you are still replacing and inspecting the filter at 50 hours as recommended by Lycoming. You are giving up a potential data point by not replacing and inspecting the filter at 25 hours but that’s a personal choice. I thought the OP question was about changing the filter every 100 hours?
Hank Posted March 15 Report Posted March 15 I change oil and filter every 50 hours. Turbo owners change both every 25-35 hours. Don't know anyone who waits 100 hours to change the filter.
Marc_B Posted March 15 Report Posted March 15 Camlocs quick way to figure out size is measure the grip...rough rule of thumb is the -# is the length of grip in mm. Not perfect but pretty close. Skybolts are cheaper than Camloc...but the pin is less tolerant to improper sizing. If you put in one that's too short and you have to apply any force it will likely damage the pin. Skybolt 2800 series have the wide flange; the one you show above is a 2700 series. The Cad plated are golden colored vs stainless Best thing you can do for engine health is have (and know how to use) a high quality engine monitor, fly regularly and change oil frequently. For NA: most would agree that 50 hours, OR every 4 months (whichever comes first) is good rule of thumb. If you're going through the hassle of changing your oil, why would you not change the filter as well...at least to cut it open and make sure not making metal.
Utah20Gflyer Posted March 15 Report Posted March 15 1 hour ago, toto said: I thought the OP question was about changing the filter every 100 hours? It looks like you are right. I didn’t catch that. Thanks I would not recommend waiting 100 hours before changing the filter. From a filtration standpoint I doubt it will be degraded at 100 hours unless something catastrophic is happening, but that is kinda the point. Do you want to be 100 hours into your engine disassembling itself before you find out? Or would you prefer to find out in half that amount of time? Between visual inspections, oil analysis, filter inspection and bore scoping we can hopefully head off really bad stuff happening while we are on the ground rather than finding out a exhaust valve is burnt or a bearing is coming apart when we are in the air. yeah, part 91 you can do oil and filter changes when ever you want, but personally I will keep doing oil/filter changes at 50 hours.
N201MKTurbo Posted March 15 Report Posted March 15 When I was commuting and flying a couple of hundred hours a year, 30 minute flights at a time. I would sometimes do “express” oil changes and not do the filter. As long as you change the filter a few times a year, you will be fine. The more you fly, and the more you are in touch with your plane, the more you can get away with. Or not, you will know.
AndreiC Posted March 15 Author Report Posted March 15 Interesting points of view above. My main source of the idea that 25-30 hours between oil change intervals was better came precisely from an oil analysis. I had one done at the last annual, and that oil had 55 hours on it. The company (Aviation Laboratories) said it all looked good, but that their reference numbers for metal quantities in oil were based on 30 hour change intervals. (Thus explaining why mine were higher than reference.) So I came to suspect most people were doing the oil changes more frequently. On the other hand, the oil analysis had the oil having good lubricity even after 55 hours, so I guess I'll get back to my 50 hour oil and filter change interval. 1
AndreiC Posted March 15 Author Report Posted March 15 55 minutes ago, Marc_B said: If you're going through the hassle of changing your oil, why would you not change the filter as well... Well, doing the quick dump and pump is very fast: I don't need to remove the top part of the cowling, only the left side cheek, attach a tube to the quick drain and off we go. When you do the oil filter there it is a more involved operation -- drain the oil from the old filter, get the new one on torqued properly, safety wire it, etc.
Will.iam Posted March 16 Report Posted March 16 48 minutes ago, AndreiC said: Well, doing the quick dump and pump is very fast: I don't need to remove the top part of the cowling, only the left side cheek, attach a tube to the quick drain and off we go. When you do the oil filter there it is a more involved operation -- drain the oil from the old filter, get the new one on torqued properly, safety wire it, etc. Mike from savvy has a video on oil change and he claims the oil is never changed due to oil wearing iout as our engines are very low demand compared to high reving car engines. The bigger problem is the dirty blowby with lead deposits hince the bigger need to change the filter more so than the oil. They claim running the engine more often with higher hours helps boils out water from the case you can go linger between intervals than when an engine sits subject to temperature swings and moisture collecting in the crankcase. I try to mitigate. The later by using a dehumidifier on the crankcase to pull what moisture is in the oil out and keep any new moisture from getting in.
M20F Posted March 16 Report Posted March 16 I change my oil and filter every 25ish hours because it is the cheapest thing I do. Plastic bag from Krogers around the filter.
LANCECASPER Posted March 16 Report Posted March 16 This subject has come up many times on here. On engines that have a filter, neither Lycoming nor Continental have ever recommended or sanctioned changing the oil without the filter. In fact the Lycoming 480F Mandatory Service Bulletin says: "7. During every oil change, either replace the oil filter or clean the oil pressure screen (whichever is on your engine) and clean the oil suction screen. Refer to respective procedures in this Service Bulletin." No ambiguity there, sounds pretty clear - you change the filter every time you change the oil. We now all have $40,000 to $140,000 engines. If you cheap out on a $30 oil filter once or twice a year you're in the wrong hobby. That is tripping over hundred dollar bills to pick up pennies. 2
TheAv8r Posted March 16 Report Posted March 16 Fellow M20E owner. Keep in mind the guidance to change the oil is not JUST hours in service, but also 4 calendar months. Oil’s job aside from lubrication is cleaning. It picks up the nasty byproducts of combustion, acids and water holds suspended in it if it didn’t exit the engine another way. The more time on the oil, the more it picks up. The more those contaminants sit on metal parts, the more damage they can cause. That’s the basis for why the recommendation is 4 months and many say to do it 25-30 hours. As to changing the filter - think about what it’s telling you. Cutting it open and inspecting the element is an important diagnostic tool about the condition of the engine. Reusing the filter means it’s hard to understand when and what. If it has metal in it, was that from the last oil change or the current? Did you fly more frequently recently or before? It’s now an unknown. In terms of doing it without making a mess, see below. 1
DC_Brasil Posted March 16 Report Posted March 16 8 hours ago, TheAv8r said: Fellow M20E owner. Keep in mind the guidance to change the oil is not JUST hours in service, but also 4 calendar months. Oil’s job aside from lubrication is cleaning. It picks up the nasty byproducts of combustion, acids and water holds suspended in it if it didn’t exit the engine another way. Exactly! Oil is a complex chain of polymers. When it gets used there's a phenomenon called polymer shearing in which these chains get broken and the oil's ability to do it's job well greatly reduces. Additionally, the level of acidity increases, reversing one of the oil's main job within our engines: prevent corrosion. If old enough and broken enough, the oil can actually start to promote corrosion. Consequently, you should be using a combination of two metrics: X number of hours or 4 calendar months, whichever comes first. I have read here the ziplock technique and it solved my problem of making a mess with the filter removal. I personally think it's a waste of opportunity to follow on the engine's health not changing the filter at every oil change. But that's my philosophy.
varlajo Posted March 16 Report Posted March 16 I mostly fly long(ish) cross-country missions. Based on a lot of UOA and other forms of soul searching, I settled on changing the oil every 25 h, which turns out to be every 6 weeks or so, and the filter every 50 h. Air filter element replacement, suction screen and gascolator screen cleaning, lubrication of flights controls, every 100 h.
TangoTango Posted March 16 Report Posted March 16 13 hours ago, TheAv8r said: Fellow M20E owner. Keep in mind the guidance to change the oil is not JUST hours in service, but also 4 calendar months. Oil’s job aside from lubrication is cleaning. It picks up the nasty byproducts of combustion, acids and water holds suspended in it if it didn’t exit the engine another way. The more time on the oil, the more it picks up. The more those contaminants sit on metal parts, the more damage they can cause. That’s the basis for why the recommendation is 4 months and many say to do it 25-30 hours. As to changing the filter - think about what it’s telling you. Cutting it open and inspecting the element is an important diagnostic tool about the condition of the engine. Reusing the filter means it’s hard to understand when and what. If it has metal in it, was that from the last oil change or the current? Did you fly more frequently recently or before? It’s now an unknown. In terms of doing it without making a mess, see below. I have a very similar custom part made with a PVC pipe and a sawzall, but I drain mine into a bucket. I'm pretty successful at keeping the oil from spilling down into the cowling: 75% of the time it works every time
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