How quick does your oil turn dark?

It is pretty funny how this changed from a Q & A session to a "my junk is bigger than yours" kind of thread. To this I will add the following:

1. OP, if your oil is turning black in a short time but there is no smoke or residue, you are probably ok. Change it at 25 hours like many and I'm sure that you will be ok unless your oil temp is high and you are cooking it. This is from years of working on cars and boats, but not airplanes so take it with a grain of salt.

2. Everyone else in the argument.... I always had fun listening to my dad talk about the engineer that refused to listen to the simple Icelandic immigrant with a North Dakota farm education (graduated in '53) when he was warned about the location of the injection ports on the rocket motor that my dad was welding up for their test. See, dad worked on everything from the Voyager series to the Viking lander, shuttle and many of the satellites that we use every day. The difference? Dad was a simple welder with 4 decades of experience but no degree. It always struck my funny when an engineer would take us to dinner as payment for the bet that my dad won even though he wasn't smart like the engineer? :) Many a rocket motor went BANG or at least failed inspection because a book smart guy failed to listen.

When I was working as a test engineer at a deep sea instrument company I helped design more than one set of plumbing for a ship when queried by an engineer with a Phd as to why temp readings from the bow inlet port were lower than the readings midstream or at the exhaust port in the stern. You should have seen the look on the guys face when this AS degree holding guy asked the PhD guy if the plumbing was routed through the engine spaces and how close it was to the engine or exhaust.....

Just because a guy has a lot of letters behind his name doesn't mean that his way of looking at things is perfect.
 
If there's a snowball's chance in Miami that we can circle back to something even remotely close to the OP's question... consider an oil analysis - Blackstone, et al, and have them tell you what's in the oil then you can make a better guess as to why it's so dark so quickly?
I assume you're cutting and inspecting your filter media after oil changes?
 
GlennAB1 said:
That's great, however, that didn't/doesn't make you privy to proprietary information that an employee such as "Tom" could have been privy to.
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You're joking, right? Or maybe you believe organic and physical chemistry are proprietary? Particular additives are proprietary but crude oil isn't.

The basics of hydrocarbon synthesis on an industrial scale have been around since the early 1940s. I have been involved in one project to apply it in the field but the current techniques are still too expensive for anything other than niche markets. There is active research in the area but the challenges are formidable.
 
95085_621a9c4e6ec755df1ac6dc466eb2db03.jpg
 
Stewartb said:
Okie, even if your engine isn't in the break-in phase this article is a good resource for anyone who owns an airplane.
http://www.eci.aero/pdf/BreakInInstructions.pdf
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Thanks.

gkainz said:
If there's a snowball's chance in Miami that we can circle back to something even remotely close to the OP's question... consider an oil analysis - Blackstone, et al, and have them tell you what's in the oil then you can make a better guess as to why it's so dark so quickly?
I assume you're cutting and inspecting your filter media after oil changes?
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Yeah, I've already got a Blackstone sample kit headed my way.

Oil filters have looked fine thus far. Some carbon, no metal.

Thanks.

red4golf said:
1. OP, if your oil is turning black in a short time but there is no smoke or residue, you are probably ok. Change it at 25 hours like many and I'm sure that you will be ok unless your oil temp is high and you are cooking it. This is from years of working on cars and boats, but not airplanes so take it with a grain of salt.
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No smoke, no visible burnt oil residue on the exhaust pipe. Oil doesn't smell burnt.
 
I suggest using Phillips 66 20w50 oil with Camguard...if you don't already.

with several oil changes Camguard will clean your ring groves and the oil control ring. If these get gummed up with carbon you will not seal or wipe oil well and combustion gases will blow by the rings into your sump....causing the black oil. Some will recomend a treatment of Marvel Mystery Oil....but, I'll let others go there.

I've seen oil consumption and blow by decrease using Camguard.

Another factor....<don tin foil hat> some experts claim running LOP (lean of peak) also keeps the oil cleaner longer. <remove tin foil hat>
I do run LOP as much as possible....and it seems to help.
 
Checkout_my_Six said:
I suggest using Phillips 66 20w50 oil with Camguard...if you don't already.

with several oil changes Camguard will clean your ring groves and the oil control ring. If these get gummed up with carbon you will not seal or wipe oil well and combustion gases will blow by the rings into your sump....causing the black oil. Some will recomend a treatment of Marvel Mystery Oil....but, I'll let others go there.

I've seen oil consumption and blow by decrease using Camguard.

Another factor....<don tin foil hat> some experts claim running LOP (lean of peak) also keeps the oil cleaner longer. <remove tin foil hat>
I do run LOP as much as possible....and it seems to help.
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I asked about Marvel Mystery Oil earlier. I think nobody wants to go there.

I have used Camguard on the last two oil changes, and will continue to do so.

I have a carburetor and single point EGT and CHT. I don't think LOP operation is wise without knowing what all the cylinders are doing. I actually had a thread a while back about this called "Carbed LOP" or something like that. We came to the conclusion that it probably wasn't safe to try in my case. Thanks though.
 
OkieFlyer said:
I asked about Marvel Mystery Oil earlier. I think nobody wants to go there.

I have used Camguard on the last two oil changes, and will continue to do so.

I have a carburetor and single point EGT and CHT. I don't think LOP operation is wise without knowing what all the cylinders are doing. I actually had a thread a while back about this called "Carbed LOP" or something like that. We came to the conclusion that it probably wasn't safe to try in my case. Thanks though.
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In my Piper, leaning is achieved by leaning till rough, then enrich till roughness goes away. It appeals to the caveman side of me. Screw LOP, ROP, etc. Lean it till it dies, then bring it back. =D
 
keep in mind...so long as your power is 70-65% HP....leaning will not hurt a thing. So in cruise or at altitudes higher than 7,000 feet leaning for best power (peak airspeed) then continue leaning till you lose 2-3kts is good.
 
ircphoenix said:
In my Piper, leaning is achieved by leaning till rough, then enrich till roughness goes away. It appeals to the caveman side of me. Screw LOP, ROP, etc. Lean it till it dies, then bring it back. =D
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My POH has the same procedure for the 182. That's how I've always done it.

Checkout_my_Six said:
keep in mind...so long as your power is 70-65% HP....leaning will not hurt a thing. So in cruise or at altitudes higher than 7,000 feet leaning for best power (peak airspeed) then continue leaning till you lose 2-3kts is good.
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I wonder how rich the mixture is when using the POH procedure? If those of us using the POH procedure are leaning until the engine essentially starts dying, then richen back up until it runs smooth again, are we not LOP? Seems like we on the edge of fuel starvation. In order to run any leaner, we'd have to let the engine run rough. Do you guys that are intentionally running LOP run the engine rough?
 
no rough running engines allowed....that's way too lean.

like I said go for max speed....and keep leaning till she slows a few knots. That'll be well enough on the lean side to see speed and fuel savings. Try cracking the carb heat a tad....that provides a lil heat for better fuel atomization. Also, pull the throttle back a tad from wide open. That puts the butterfly at an angle for more turbulent flow and better fuel atomization.
 
Checkout_my_Six said:
no rough running engines allowed....that's way too lean.

like I said go for max speed....and keep leaning till she slows a few knots. That'll be well enough on the lean side to see speed and fuel savings. Try cracking the carb heat a tad....that provides a lil heat for better fuel atomization. Also, pull the throttle back a tad from wide open. That puts the butterfly at an angle for more turbulent flow and better fuel atomization.
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Yeah, I didn't figure anyone would allow rough running, outside of taxi anyway. Thanks.

I honestly haven't thought about it much until now, but we that use the "lean until rough, richen until smooth," must be LOP, and possibly leaner than other methods. Reckon?

I usually run about 65% BHP, and rarely ever at WOT unless I'm really high. I typically run the 182 at 2300/21" or 2200/22" in cruise at altitudes between 4500' and 7500', which is 64-66% BHP.
 
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Stewartb said:
My 0-520 is an 0-470 with bigger cylinders. It was an 0-470 before I did the mod. Same case, same oil system. The Phillips advantage isn't limited to the 470/520 family. It's been true for other engines I've had as well. These days I use XC for break-in, too.

Okie, I don't presume to know why Phillips XC works better than Aeroshell for the conditions I mentioned. I'm just giving you a pirep and I'm pretty confident that you'll see similar results. I remember when I asked the same questions you're asking so I offered my experience.
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Understand, I'm just trying to figure out how I can get "better" than "doesn't leak". LOL.

OkieFlyer said:
I wonder how rich the mixture is when using the POH procedure? If those of us using the POH procedure are leaning until the engine essentially starts dying, then richen back up until it runs smooth again, are we not LOP? Seems like we on the edge of fuel starvation. In order to run any leaner, we'd have to let the engine run rough. Do you guys that are intentionally running LOP run the engine rough?
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If you get an O-470 to run LOP smoothly, you'll join a group of about ten people worldwide who got lucky. Haha.

I've messed with it. Tried "cocking the throttle plate", "adding a touch of carb heat", different power settings. Anything below peak runs rough in ours and isn't acceptable.

The intake manifold airflow just isn't consistent enough to all cylinders in the O-470 after the carb to run them lean. One always ends up too lean. And there's no buying GAMI injectors to fix it by changing fuel flow per cylinder.

It's just a big fat dumb 1930's design air cooled tractor engine.

Pull the red knob slowly until it's rough and then enrichen until smooth. If you don't have either a factory EGT or engine monitor, I can confirm that when it smooths out, the EGT is about 30 degrees rich of peak, very consistently.

Like most big dumb carb'd big bore engines, it'll tell you more via vibration and power problems and in the worst case, funny noises, if you're flying the red knob wrong. It just wants fuel, and lots of it. It's not efficient.

We've tracked our fuel burn over half a decade now, and it's incredibly consistent on ours. 11.5 GPH average, and home base is at 6885' MSL. At sea level, it's 15 during takeoff and high power ops and about 13 unless you climb above 3000 MSL.

We can get it back to 10 or so by flying really slow with the prop in a high pitch setting. Great if you want to waste time, or build hours, or just go slow in turbulence, all but the last I'm rarely interested in. Ha.

As long as temps are reasonable, it's full rental power and flog it! It'll run better and last just as long as if you baby it. Especially if you climb up to where it's not producing full power anyway.

It's a big draggy truck with a big dumb engine that wants gas built when gas was less than $1.00/gallon.
 
denverpilot said:
Understand, I'm just trying to figure out how I can get "better" than "doesn't leak". LOL.



If you get an O-470 to run LOP smoothly, you'll join a group of about ten people worldwide who got lucky. Haha.

I've messed with it. Tried "cocking the throttle plate", "adding a touch of carb heat", different power settings. Anything below peak runs rough in ours and isn't acceptable.

The intake manifold airflow just isn't consistent enough to all cylinders in the O-470 after the carb to run them lean. One always ends up too lean. And there's no buying GAMI injectors to fix it by changing fuel flow per cylinder.

It's just a big fat dumb 1930's design air cooled tractor engine.

Pull the red knob slowly until it's rough and then enrichen until smooth. If you don't have either a factory EGT or engine monitor, I can confirm that when it smooths out, the EGT is about 30 degrees rich of peak, very consistently.

Like most big dumb carb'd big bore engines, it'll tell you more via vibration and power problems and in the worst case, funny noises, if you're flying the red knob wrong. It just wants fuel, and lots of it. It's not efficient.

We've tracked our fuel burn over half a decade now, and it's incredibly consistent on ours. 11.5 GPH average, and home base is at 6885' MSL. At sea level, it's 15 during takeoff and high power ops and about 13 unless you climb above 3000 MSL.

We can get it back to 10 or so by flying really slow with the prop in a high pitch setting. Great if you want to waste time, or build hours, or just go slow in turbulence, all but the last I'm rarely interested in. Ha.

As long as temps are reasonable, it's full rental power and flog it! It'll run better and last just as long as if you baby it. Especially if you climb up to where it's not producing full power anyway.

It's a big draggy truck with a big dumb engine that wants gas built when gas was less than $1.00/gallon.
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Haha! Nice write up, Denver.

I've been getting about 11.8 gph most of the time, which is pretty close to book at my usual power settings. I understand the LOP thing better now. Got my wires crossed I guess. I'll just continue doing what I've been doing in that regard. I will say that I don't flog it like you indicate. I pull it back because it's quieter and I burn a little less. Probably not enough savings on fuel to justify anything, but I do it anyway.

I agree on the truck-like characteristics and the big dumb long in the tooth engine. In my case, I would only add UGLY to the list of descriptors. Yeah, I drive an, old, dumb, draggy, ugly truck, and I love it!

P.S. What's a GAMIjector?

Joking.
 
OkieFlyer said:
Haha! Nice write up, Denver.

I've been getting about 11.8 gph most of the time, which is pretty close to book at my usual power settings. I understand the LOP thing better now. Got my wires crossed I guess. I'll just continue doing what I've been doing in that regard. I will say that I don't flog it like you indicate. I pull it back because it's quieter and I burn a little less. Probably not enough savings on fuel to justify anything, but I do it anyway.

I agree on the truck-like characteristics and the big dumb long in the tooth engine. In my case, I would only add UGLY to the list of descriptors. Yeah, I drive an, old, dumb, draggy, ugly truck, and I love it!

P.S. What's a GAMIjector?

Joking.
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GAMIs are something you don't have and won't have. GAMI tries to balance the fuel flow/mixture in fuel injected engines and they do a pretty good job.
 
OkieFlyer said:
I will say that I don't flog it like you indicate. I pull it back because it's quieter and I burn a little less. Probably not enough savings on fuel to justify anything, but I do it anyway.

I agree on the truck-like characteristics and the big dumb long in the tooth engine. In my case, I would only add UGLY to the list of descriptors. Yeah, I drive an, old, dumb, draggy, ugly truck, and I love it!
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I pull mine to the top of the green on the tach after or during the climb out depending on how much noise I want to make, leave it WOT, and at level off, lean until rough, enrichen two half turns of the vernier mixture control, trim slightly left because it was trimmed right so my leg wouldn't fall asleep in the climb, and trim two wheel turns down as it speeds up.

Then take a nap for the next three hours because we ain't going anywhere fast. Haha. 130 knots is about what we get consistently with our extra drag of cuffs and stall fences from the Robby kit.

I usually piddle with tuning VORs and what not to keep track of things, mess with calculating things against the iPad to see if anything changed, look outside at the weather, and sometimes on really long XCs I'll slide my seat back knowing a further rear CG is slightly more efficient, and then stretch way up there to roll a little more nose down trim.

If it's calm enough you can hold altitude by nodding your head fore and aft if you get the trim right. Hahaha. Or lean forward and sit back if it gets mildly bumpy.

Beauty is in the eye of the beholder. I love Cessnas and pickup trucks. :)

* Note: The above only applies VMC, of course. IMC I stay seated forward and play the scan game... Which is a different kind of fun. Not enough of that out here, and I need an IPC, but upcoming check rides will take care of that. Did get to actually log about 0.5 in a Redbird recently. That was fun. ILS to minimums and a SID that's supposedly the most busted SID in the whole country.
 
Clark1961 said:
GAMIs are something you don't have and won't have. GAMI tries to balance the fuel flow/mixture in fuel injected engines and they do a pretty good job.
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Yeah, they make 'em 50 miles from here. I said "joking", Clark.
 
denverpilot said:
I pull mine to the top of the green on the tach after or during the climb out depending on how much noise I want to make, leave it WOT, and at level off, lean until rough, enrichen two half turns of the vernier mixture control, trim slightly left because it was trimmed right so my leg wouldn't fall asleep in the climb, and trim two wheel turns down as it speeds up.

Then take a nap for the next three hours because we ain't going anywhere fast. Haha. 130 knots is about what we get consistently with our extra drag of cuffs and stall fences from the Robby kit.

I usually piddle with tuning VORs and what not to keep track of things, mess with calculating things against the iPad to see if anything changed, look outside at the weather, and sometimes on really long XCs I'll slide my seat back knowing a further rear CG is slightly more efficient, and then stretch way up there to roll a little more nose down trim.

If it's calm enough you can hold altitude by nodding your head fore and aft if you get the trim right. Hahaha. Or lean forward and sit back if it gets mildly bumpy.

Beauty is in the eye of the beholder. I love Cessnas and pickup trucks. :)

* Note: The above only applies VMC, of course. IMC I stay seated forward and play the scan game... Which is a different kind of fun. Not enough of that out here, and I need an IPC, but upcoming check rides will take care of that. Did get to actually log about 0.5 in a Redbird recently. That was fun. ILS to minimums and a SID that's supposedly the most busted SID in the whole country.
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It's funny you mention leaning your body for trim. My passenger to OSH was my brother who is not a pilot, and hasn't spent much time in light aircraft. After we had been cruising for a couple hours, he was starting to get a little uncomfortable in his seat and started leaning forward or backward every few minutes, trying to get comfy. He caught me chuckling after a few times, and ask me what I was laughing at. I told him I was laughing because every time he changed position, I had to re-trim. He weighs about 280 lb, so leaning made a big difference.

I love a truck. Don't even own a car ;)
 
Joshuajayg said:
You will never get all the oil out and really, it isn't THAT important to do so. Get as much out a will drain when you're on a flat surface. And ircphoenix has it right, heat it up first. Warm oil drains faster and makes its way down the engine into the sump easier.

Black oil isn't a big deal. Most of it is carbon coming past your rings as part of the combustion process. Worn rings and running rich are both likely ways to get dark oil sooner.

The airplane I fly gets black oil at about 15-20 hours and I run it hard. I keep it leaned correctly even while climbing. It is 3100 smoh.
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When you posted this you said you had 3100 smoh, how long at it been since your overhaul?
 
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