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Maybe I need a top overhaul?

tom paul

tom paul

Well Known Member
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Hi All,
I am having some concerning issues with my engine. Titan IO-360-A4H1N.
It goes through about a quart every 2-3 hours of flight, and the oil turns black within an hour of operation after an oil change. I spoke with Steve Fowler today, at America's Aircraft Engines, where the engine was built in 2010, and he says it sounds like a serious issue that needs attention right away, like maybe a top overhaul. It has been like this for a while, and it runs like a top. Occasionally oil pressure dips to 59-60, but it is usually in the 70's. The engine runs great, starts hot or cold every time on two revolutions max, and never misses a beat. I also spoke with Amanda, a senior analyst at Blackstone today about my recent sample. She says while the numbers look good, relative to a 24 hour average time between changes, but since this oil has only 7 hours on it, and during that time, 3 or 4 quarts have been added, she said the sample is quite diluted and therefor, the numbers may be actually a bit on the high side.

I am writing to get thoughts on how to proceed. The engine has about 1280 hours on it and it runs great. The compressions are in the low to mid 70's. Last June annual borescope: The cylinders all but one have decent crosshatching still, but one doesn't. Valves look pretty good.

I know an overhaul is $35k with new cylinders. I don't know what a top overhaul costs or if that makes sense. With the amount that I fly, it would take me at least ten years to get to 2,000 hours.
Thanks for any thoughts.
Tom
 
Do you have an oil separator?
How many quarts of oil do you fill to?

Are you sure it’s burning oil and not losing it outboard?
 
If you can deal with the oil consumption it is still well within lycoming limits.

You don’t really need to do a “top overhaul” whatever that means. (It means different things to different people). What you can do is rering and hone the original cylinders if within tolerances and do a new break in and it could solve your problem for pretty cheap assuming you do the work.
 
Thanks all!
This is encouraging. I would much prefer not to be grounded and to spend a ton of money. I don't believe I have an oil separator.
JonJay said:
Do you have an oil separator?
How many quarts of oil do you fill to?

Are you sure it’s burning oil and not losing it outboard?
Click to expand...
I don't believe I have an oil separator. I did not build the plane, but I have worked on it a fair amount in the three years that I have owned it, and it has not come up in any conversations about the engine and oil system with my mechanic. From what I have read, an oil separator can cause increased risk of corrosion, which is a concern of mine, since I don't fly as much as I should.
I usually fill to only 6 quarts, as it seems to get to six right away if I put in seven. I can't be sure it isn't going outboard, but there is no sign of that. the belly of the plane stays pretty clean and there are no obvious signs of major oil inside the cowling. That said, there is a little oil seepage at the crankcase halves joint, I think, but nothing substantial, I think.
 
tom paul said:
Thanks all!
This is encouraging. I would much prefer not to be grounded and to spend a ton of money. I don't believe I have an oil separator.

I don't believe I have an oil separator. I did not build the plane, but I have worked on it a fair amount in the three years that I have owned it, and it has not come up in any conversations about the engine and oil system with my mechanic. From what I have read, an oil separator can cause increased risk of corrosion, which is a concern of mine, since I don't fly as much as I should.
I usually fill to only 6 quarts, as it seems to get to six right away if I put in seven. I can't be sure it isn't going outboard, but there is no sign of that. the belly of the plane stays pretty clean and there are no obvious signs of major oil inside the cowling. That said, there is a little oil seepage at the crankcase halves joint, I think, but nothing substantial, I think.
Click to expand...
I read about the Savvy oil control ring flush. That sounds good. I will try that.
Majorpayne317641 said:
If you can deal with the oil consumption it is still well within lycoming limits.

You don’t really need to do a “top overhaul” whatever that means. (It means different things to different people). What you can do is rering and hone the original cylinders if within tolerances and do a new break in and it could solve your problem for pretty cheap assuming you do the work.
Click to expand...
I will also look into doing a re-ring and hone job. I haven't had this engine apart aside from cleaning the injector nozzles, but I am not afraid of it. I used to rebuild Porsche 356 engines, which is an air-cooled boxer like the 360, so it feels pretty familiar. I can deal with the oil consumption. That is not a problem. My main concern is safety. My home base (KLDJ) offers nothing but the occasional golf course as a place to put her down in an emergency, and I have to stay very low to sneak out under the KEWR Class Bravo over very inhospitable terrain, so an engine failure is something to reduce the chances of as much as possible.
 
I was in a similar state a few years ago with my O-360; with 1800 hrs SMOH, my oil consumption was at around 3-4 hrs/qt on Cerminil nickel cylinders. I tried the ring wash, didn't work. It ran well and compression was decent, except...1 cyl was in the mid 60s at my last check. So, I decided to pull all 4 jugs and send 'em for overhaul; one of my cyls was scrapped so I got 3 original cyls plus one used OH replacement. This was post-Covid so the shop was sloooow... took 4 months and $4000. But, it's back to running fine with good compressions and consumption is back to 8-ish hrs/qt. On these nickel cylinders even when new I'd only get 10 or so hrs/qt. If I can do another 800-ish hrs on this thing and then full overhaul or replace, I'll be happy.
 
jbDC9 said:
I was in a similar state a few years ago with my O-360; with 1800 hrs SMOH, my oil consumption was at around 3-4 hrs/qt on Cerminil nickel cylinders. I tried the ring wash, didn't work. It ran well and compression was decent, except...1 cyl was in the mid 60s at my last check. So, I decided to pull all 4 jugs and send 'em for overhaul; one of my cyls was scrapped so I got 3 original cyls plus one used OH replacement. This was post-Covid so the shop was sloooow... took 4 months and $4000. But, it's back to running fine with good compressions and consumption is back to 8-ish hrs/qt. On these nickel cylinders even when new I'd only get 10 or so hrs/qt. If I can do another 800-ish hrs on this thing and then full overhaul or replace, I'll be happy.
Click to expand...
That is encouraging. I've spent the last few hours watching Mike Bush videos and I have decided to do the oil control ring flush myself. If it works, great. If not, I will consider the cylinder hone and ring job. I would love to get back to 8 ish hours/quart, and more importantly more peace of mind that my engine is OK.
Thanks!
 
I had similar situation, 10 hrs per add quart down to 5 hrs. Was blow by per my oil separator catch can. I put in 1oz Seafoam per quart, as well as an ounce per added quart. I ran for 10 hours, oil change due, and ran for 25 on next oil change with Seafoam (6oz/6qrts) My issue resolved back to my 9-10 hrs per quart norm. Others have had same results, others will say they wouldn’t do this. No one has shared proof of any negative effects, put many naysayers.
 
I think you have a good plan of attack. Just out of curiosity; What compression ratio are these cylinders?
 
From my neighbor -

Sorry to hear about your issues. I posted several years ago about this issue with my Titan engine with Cermanil cylinders. If you can find the post here on VAF, you will see the pictures of the pistons and stuck rings due to the cylinders going out of round when hot. There were post-AD cylinders and we ended up replacing all of them with first run Lycomings. Engine has been flawless ever since.
 
You didn’t say (or I missed it) what cylinders you have - nitrided, cerminil, etc. My RV-8 originally had Cerminil, and at about 1400 hours, the coating on the rings started flaking off and the oil consumption went from about 7-8 hours per quart to burning a quart an hour in one flight! Unfortunately, I found out that it was a common problem and that the Cerminil cylinders were very difficult to hone - I bought four new Lycoming nitrided cylinders and never looked back - that’s all I run now, and generally get 25 hours to the quart in our four Lyclones.

Something to think about while you’re doing the flush. Look for tiny little rectangular black flakes (the ring coating) if you check your filters.

EDIT: Looks like 280FX and I were posting at the same time!!
 
I think Steve from America Aircraft Engines provided sound advice when suggesting a top overhaul. I had a similar experience with a Citabria I owned (O-235). Ran fine but used excessive amount of oil but still within Lycoming limits. I chose the top overhaul route. Had all 4 cylinders overhauled by Gibson. As I recall, turnaround was about 8 weeks (cylinders were chromed). Turnaround would have been much less if I had exchanged my cylinders (or bought new), but mine were relatively low time and I wanted to keep them. After the top overhaul the engine ran and performed much better than before, particularly during takeoff and climb. Oil consumption returned to normal.
 
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Again from my neighbor -

If your cylinders are exhibiting the same out of round behavior that mine did, no amount of top overhaul will fix them. We did a top overhaul, reassembled the engine and ran it hard on the dyno for five hours. Oil was black and compressions were low. They only discovered the out of round defect after pulling the cylinders off again, heating them up to 250 degrees and measuring the bore diameter of the warm cylinders. They were out of round near the choke. The cylinders are now sitting in a box in my hangar awaiting being turned into table lamps.
 
Some Cerminil cylinders had/have excessive intake valve guide ware. Since there is always a vacuum in the intake port a loose intake guide will suck oil from the rocker box and increase consumption. This increase is most noticeable at low power settings where the differential between ambient pressure, and intake manifold pressure, is greatest and least at wide open throttle. For this reason modern car engines usually have intake valve guide seals.
 
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tom paul said:
My main concern is safety. My home base (KLDJ) offers nothing but the occasional golf course as a place to put her down in an emergency, and I have to stay very low to sneak out under the KEWR Class Bravo over very inhospitable terrain, so an engine failure is something to reduce the chances of as much as possible.
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Assuming the problem is oil ring oil consumption I'm unsure how this could cause an engine failure, so long as you add oil as needed. I'm sure someone will educate us though.
 
I hate to be a downer, but I had a similar situation recently with excessive oil consumption. Tried solvent flush, MMO, Seafoam.....all of it. Nothing made a difference. Pulled cylinders, and it was pretty obvious they needed honing, rings, and pistons. Now.....it's running great. Hardly any oil burn, and significantly more power.
Short answer......the above-mentioned remedies may work for you, and nothing lost by trying them. But, bottom line, expect to be doing a top overhaul. Honestly, it's a bit of a pain, and your plane will be down for awhile, but I don't think you'll regret it. I certainly haven't.
 
tom paul said:
Hi All,
I am having some concerning issues with my engine. Titan IO-360-A4H1N.
It goes through about a quart every 2-3 hours of flight, and the oil turns black within an hour of operation after an oil change. I spoke with Steve Fowler today, at America's Aircraft Engines, where the engine was built in 2010, and he says it sounds like a serious issue that needs attention right away, like maybe a top overhaul. It has been like this for a while, and it runs like a top. Occasionally oil pressure dips to 59-60, but it is usually in the 70's. The engine runs great, starts hot or cold every time on two revolutions max, and never misses a beat. I also spoke with Amanda, a senior analyst at Blackstone today about my recent sample. She says while the numbers look good, relative to a 24 hour average time between changes, but since this oil has only 7 hours on it, and during that time, 3 or 4 quarts have been added, she said the sample is quite diluted and therefor, the numbers may be actually a bit on the high side.

I am writing to get thoughts on how to proceed. The engine has about 1280 hours on it and it runs great. The compressions are in the low to mid 70's. Last June annual borescope: The cylinders all but one have decent crosshatching still, but one doesn't. Valves look pretty good.

I know an overhaul is $35k with new cylinders. I don't know what a top overhaul costs or if that makes sense. With the amount that I fly, it would take me at least ten years to get to 2,000 hours.
Thanks for any thoughts.
Tom
Click to expand...
If it's making the windmill spin, normal power, oil is cheaper than an overhaul
 
Ironflight said:
You didn’t say (or I missed it) what cylinders you have - nitrided, cerminil, etc. My RV-8 originally had Cerminil, and at about 1400 hours, the coating on the rings started flaking off and the oil consumption went from about 7-8 hours per quart to burning a quart an hour in one flight! Unfortunately, I found out that it was a common problem and that the Cerminil cylinders were very difficult to hone - I bought four new Lycoming nitrided cylinders and never looked back - that’s all I run now, and generally get 25 hours to the quart in our four Lyclones.

Something to think about while you’re doing the flush. Look for tiny little rectangular black flakes (the ring coating) if you check your filters.
Click to expand...
I had the same issue as Paul with my Titan cylinders. Pulled a cylinder and could clearly see the top compression ring delaminating.
Service bulletin : https://continental.aero/service-bulletins/ECi/06-6.pdf
 
280FX said:
From my neighbor -

Sorry to hear about your issues. I posted several years ago about this issue with my Titan engine with Cermanil cylinders. If you can find the post here on VAF, you will see the pictures of the pistons and stuck rings due to the cylinders going out of round when hot. There were post-AD cylinders and we ended up replacing all of them with first run Lycomings. Engine has been flawless ever since.
Click to expand...
I will look for that post. That makes me want to do the same thing! It isn't fun not trusting my engine.
 
Ironflight said:
You didn’t say (or I missed it) what cylinders you have - nitrided, cerminil, etc. My RV-8 originally had Cerminil, and at about 1400 hours, the coating on the rings started flaking off and the oil consumption went from about 7-8 hours per quart to burning a quart an hour in one flight! Unfortunately, I found out that it was a common problem and that the Cerminil cylinders were very difficult to hone - I bought four new Lycoming nitrided cylinders and never looked back - that’s all I run now, and generally get 25 hours to the quart in our four Lyclones.

Something to think about while you’re doing the flush. Look for tiny little rectangular black flakes (the ring coating) if you check your filters.

EDIT: Looks like 280FX and I were posting at the same time!!
Click to expand...
Thanks All! Paul, how can I determine what kind of cylinders I have?

I searched the logbook and it doesn't say. I can call Steve at America's Aricraft Engines tomorrow and ask him, but perhaps one of you might read between the lines from this, in the logbook: "June 9th, 2009: This Experimental Engine, Model IOX-360-A4H1N, serial number 409032 was assembled with 100% NEW parts supplied by Engine Components, Inc. Engine was test ran with Phillips XC20W-50"

Does the timing of the build give any clues?

I did confirm that these cylinders were not part of the recalled Titan cylinders from many years ago.
 
tom paul said:
Thanks All! Paul, how can I determine what kind of cylinders I have?

I searched the logbook and it doesn't say. I can call Steve at America's Aricraft Engines tomorrow and ask him, but perhaps one of you might read between the lines from this, in the logbook: "June 9th, 2009: This Experimental Engine, Model IOX-360-A4H1N, serial number 409032 was assembled with 100% NEW parts supplied by Engine Components, Inc. Engine was test ran with Phillips XC20W-50"

Does the timing of the build give any clues?

I did confirm that these cylinders were not part of the recalled Titan cylinders from many years ago.
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The defective top ring ECI Service Bulletin linked in my earlier post is dated near the end of 2006 so your engine assembled in June 2009 should not have the defective top ring??? The part numbers are listed in the SB but the only way to be sure is to pull the cylinder with the lowest compression and inspect.
 
In the event you have no issues as the ones mentioned in this thread, here is my experience... I had always run Aeroshell 100W. Year ago in a cross country flight my oil consumption went way up. After returning home I spoke with my go to expert at our local engine overhaul shop in Summerdale, AL and he recommended that before pulling the cylinder causing the problem for a hone job, in my case it was #2, I should switch to Phillips XC 20W 50 with one can of avblend added. He said no guarantees but he had seen it work in the past. I did it and after about 25 more hours of flying the oil consumption is back to baseline. After a recent 5.7 hour cross country I haven't had to add any yet so don't know exactly how much but it was down only 1/8 inch on the stick. My consumption has always been about 1/3 of a quart in about 4 hours. When it shot up it went to 3/4 of a quart in 3 hours. Anyway, might be worth a try. I would agree the cylinder flush per Mike Busch is a good idea first.
 
Hey Tom,
The cylinders are nickel.
Silver paint on top of the cylinders.

Steve can help you out.

Boomer
 
Bruce said:
Hey Tom,
The cylinders are nickel.
Silver paint on top of the cylinders.

Steve can help you out.

Boomer
Click to expand...
Amazing to hear from you Boomer! thanks for the info!
(Boomer was the builder of my beautiful plane, for anyone that doesn't know, which is why his plane pic is the same bird as mine!)
 
280FX said:
The thread is here - https://vansairforce.net/threads/titan-eci-cylinder-issues.206080/#post-1605935
Click to expand...
Reading this thread, and getting the confirmation of nickel cylinders on my engine, and having the symptoms that are what people had with the "bad" cylinders makes me wonder if the batch of cylinders named in the recall, that didn't include mine by serial number, was not broad enough. I could try Mike Bush's oil control ring flush, and I may, but after reading all of this, I am leaning toward a new set of jugs. I don't want to spend that kind of money, and I hear the calls for a measured, non-hasty/pricey response to this, but given all that I learned, and the behavior of my engine, I do want to have a look at the pistons and rings, at the very least hone them and put in new rings, but quite likely a new set of cylinders. I appreciate all the thoughtful replies. Please keep them coming.
 
tom paul said:
Reading this thread, and getting the confirmation of nickel cylinders on my engine, and having the symptoms that are what people had with the "bad" cylinders makes me wonder if the batch of cylinders named in the recall, that didn't include mine by serial number, was not broad enough. I could try Mike Bush's oil control ring flush, and I may, but after reading all of this, I am leaning toward a new set of jugs. I don't want to spend that kind of money, and I hear the calls for a measured, non-hasty/pricey response to this, but given all that I learned, and the behavior of my engine, I do want to have a look at the pistons and rings, at the very least hone them and put in new rings, but quite likely a new set of cylinders. I appreciate all the thoughtful replies. Please keep them coming.
Click to expand...
That was pretty much the approach I took when I had my issue - we didn;t know about the ring delaminating issue (ECI did, but wasn’t talking….), so I figured remove, hone, re-ring….and then when we did that, we found the delaminated rings and went with new jugs after some communications with various experts. See what you’ve got, then proceed as required!
 
Ironflight said:
That was pretty much the approach I took when I had my issue - we didn;t know about the ring delaminating issue (ECI did, but wasn’t talking….), so I figured remove, hone, re-ring….and then when we did that, we found the delaminated rings and went with new jugs after some communications with various experts. See what you’ve got, then proceed as required!
Click to expand...
Thanks Paul! and thanks all!
 
Hi All,
Update here. I did the oil control ring flush the other day. I destroyed one lead of my lower ignition harness along the way, so I replaced that as well. Got her back together yesterday with fresh oil and filter. She runs like a top. I only took a short hop of .6 so I don't know anything yet really, but I am encouraged that the oil was not dark afterwords. I will report back after a few more hours to comment on the oil use and the color.
 
That’s encouraging.
Make sure you aggressively ground leaning and in general operating on the leaner side of things. My flying pattern changed a couple years ago and most of my flights were short, local, and at a low elevation. I was noticing dark oil and during my CI wet bottom plugs, oil on cylinder walls, and piston top and valves quite “cruddy” looking.
This past year I started leaning more aggressively. What a difference. The “crud” is completely gone from the valve tops and the piston top is much cleaner. I still have oily cylinder walls, so the oil ring flush will be done this week. I have 950 hours on the engine.
I believe running too rich as a practice will eventually cause the oil rings to clog up and quit doing there job. I didn't think I was running too rich but the evidence proves otherwise.
 
I did the flush yesterday per the Savvy instructions. While it is an easy process, here is what I learned.

The oil in the solvent mixture will drop to the bottom of the bucket so, I used a stir stick to mix it up.

It’s messy, especially if you are an idiot. My recommendation is to follow the instructions. Read them and follow for each cylinder. Don’t assume you have committed them to memory or, you might forget to put the top plug back in before turning the prop.

The instructions tell you to put a rag under the bottom plug to catch the solvent that is still in the cylinder and remove the plug. Use a beach towel as a rag won’t cut it. After the first huge mess, I grabbed the vacuum evacuator and sucked the remaining fluids out.

They state that it might take three or four times before the oil ring clears. My first cylinder took 6 or 8. My second took just a few, the fourth one was clear. That cylinder was topped due to a stuck valve at 400 hours, so it only had 550 hours while the others have 950.
Oh the third, cylinder #4, it took oh, perhaps 15 or more before it finally started to pass fluid. It was really plugged up, but it did finally clear. I ran out of mix and had to run to the hardware store and mixed up a half batch which got me through.

Cylinder #3 was an an anomaly. Immediately upon compression, a small stream of fluid came out of the exhaust. I double checked to insure I was on the correct stroke and even verified with my boroscope. Obviously something was allowing the fluid to pass that valve. Even though the oil ring was clear, I repeated the procedure a few more times and the fluid leak through the valve stopped. All my cylinders have always check out, the valves look great, good compressions, so I assumed a small piece of carbon had been trapped and then cleared.

All in all this is an easy process. We shall see if it has the desired results. My cylinders look great. Cross hatching still very evident and no signs of any other issue. I am hopeful.

Hope this helps someone.
 
Sometimes a small chunk of carbon can get stuck to the seat or sealing face of the valve and cause a very small leak that is usually temporary.
That is why it is best to not panic if a compression test indicates a valve leak. Particularly if a bore scope inspection doesn't show any indication of a heat problem with a valve. After running the engine for a few hrs it will usually retest good.
Might have been the cause of your leak as well.
 
Compression Test?
How many hours on engine?
What kind of disuse (engine sitting for years)?

Air breather can be installed to create too much negative pressure and suck oil out. Whistle Slots are made in the tube to keep this from happening,, or sometimes just a hole so drilled in tube to not create a vacuum by slip stream going by end of breather tube.

Oil getting black is normal, in an air cooled engine like this.
 
tom paul said:
Hi All,
Update here. I did the oil control ring flush the other day. I destroyed one lead of my lower ignition harness along the way, so I replaced that as well. Got her back together yesterday with fresh oil and filter. She runs like a top. I only took a short hop of .6 so I don't know anything yet really, but I am encouraged that the oil was not dark afterwords. I will report back after a few more hours to comment on the oil use and the color.
Click to expand...
OK I'll jump in here and say on my 600 hour 0-360 full SDS ignition and fuel oil burn at 1 in 6 hours. "" It does/did have Channel Chrome cylinders""---Bad---
ran good, high compressions on all cylinders. dry belly etc etc
Oil turned quite dark (black) 6 hours after changes happening at 25 hours between every oil change. I've owned the plane for 250 hours. And fly 60-70 hours per year
I did the flush 4-6 times and no difference after all that effort. #1-3 pulled through fine, But, #4 wouldn't budge at all first couple times. In the end it took quite a bit to pull it through.
All the things I did didn't reduce oil consumption.
Pulled the engine for a nonrelated reason and tore it down.
WOOOOOOW top ring on Number 4 was broken into 14 pieces and had been for quite awhile by how worn the pieces were. By the way there was no "crud" in any of the oil rings either.
Can I say I was happy to have torn the engine down. YES YES YES
I replaced that engine with another fresh overhauled Channel Chrome Cylinder engine I had on hand. Well the oil consumption is now 1-6.5 BUT BUT BUT the oil doesn't turn black at all. Third oil change and at 25 hours it is still quite clear.
I'm happy to have the reworked engine in and no black oil, But, disappointed with the oil burn. But, oil is cheap and I know I do not have a broken ring anymore. So good luck with yours
AS for an air cooled engine oil turning black, Because, it is an air cooled engine, I have to disagree. But, I've only been a mechanic for 55 years so have a lot to learn yet. My air cooled engines do not make black oil that fast.
My luck varies FIXIT
 
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OK, so what causes the oil to go dark in a few hours ???
Blow-by combustion gases from a defective/broken ring ??
I use 1 qt/~12 hours
Compressions are all above 77
Borescope is all good
115 hours, engine is smooth and pulls like there's no tomorrow...
My oil darkens/blackens very quickly, within a few hours.
I'm not preoccupied, should I be ?
 
My experience is the engines that have oil squirts spraying oil on the under side of the piston* turn the oil dark quicker than those that have no oil squirts.

* all Lycoming 200 HP engines, some field modified 180 HP engines and my Mattituck Lyclone engine, have oil squirts that spray oil on the underside of the piston.
 
BoydBirchler said:
My experience is the engines that have oil squirts spraying oil on the under side of the piston* turn the oil dark quicker than those that have no oil squirts.

* all Lycoming 200 HP engines, some field modified 180 HP engines and my Mattituck Lyclone engine, have oil squirts that spray oil on the underside of the piston.
Click to expand...

tom paul said:
Hi All,
Update here. I did the oil control ring flush the other day. I destroyed one lead of my lower ignition harness along the way, so I replaced that as well. Got her back together yesterday with fresh oil and filter. She runs like a top. I only took a short hop of .6 so I don't know anything yet really, but I am encouraged that the oil was not dark afterwords. I will report back after a few more hours to comment on the oil use and the color.
Click to expand...
Just for giggles and because its a topic of discussion on another thread, did you pull the sump screen and look for sludge?
 
TS Flightlines said:
Just for giggles and because its a topic of discussion on another thread, did you pull the sump screen and look for sludge?
Click to expand...
I did pull the sump screen. It was clean as a whistle.
This is an interesting discussion. When I first got the plane, four years and probably 75 hours ago (I don't get to fly very much) the oil consumption was noticeably less, and the oil color a few hours after a change was still clear. The black oil after an hour or two started happening in the last year. I haven't been able to fly since the .6 hop I did right after the flush, so I don't have any more data yet, but I hope to this week.
 
Flew for about an hour over three flights this week, and the oil is still pretty clear. I know that is not a lot of time, but I think it would have been black by now, prior to the oil control ring flush. I don't know yet about oil usage. One interesting thing about the oil color is this: When I land and park, the oil looks pretty clear. When I preflight next, the oil on the stick looks black. When I land and park next, it looks clear again. Why would the oil on the stick turn black while sitting for a few days, but then clear up after a short flight? By the way, I am in the habit of loosening and pulling out my dipstick just an inch when I park (in a hangar) to let the vapor moisture escape to reduce corrosion. Does anyone else do that?
 
tom paul said:
Flew for about an hour over three flights this week, and the oil is still pretty clear. I know that is not a lot of time, but I think it would have been black by now, prior to the oil control ring flush. I don't know yet about oil usage. One interesting thing about the oil color is this: When I land and park, the oil looks pretty clear. When I preflight next, the oil on the stick looks black. When I land and park next, it looks clear again. Why would the oil on the stick turn black while sitting for a few days, but then clear up after a short flight?
Click to expand...
Probably because of the viscosity difference at different temperatures.
When the oil is cool it will leave a thicker coat of oil on the dipstick than when hot.
The thicker coating of oil will look darker.

I unscrew the dipstick after a flight… don’t know if it helps or hurts.
 
rvbuilder2002 said:
Probably because of the viscosity difference at different temperatures.
When the oil is cool it will leave a thicker coat of oil on the dipstick than when hot.
The thicker coating of oil will look darker.

I unscrew the dipstick after a flight… don’t know if it helps or hurts.
Click to expand...
Makes good sense, Thanks!
 
What power settings do you run the engine at in cruise?
What oil level do you try to keep it at?
 
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