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oil question

Paul 5r4

Well Known Member
Hi all.
I had changed the oil in the process of starting the annual condition inspection. Not really started the inspection yet but wanted to get it done anyway. I flew with the new oil for an hour and half. I started the condition inspection and my number two cylinder which has always had lower compression than the other three was reading only 30/80! I obtained another cylinder which had been overhauled and swapped them out. In the process of doing everything by the book, I replaced the barley used oil with mineral oil for the break in. All is well again in the compression department. The mineral oil needs to be run about 25 hours before going back to my usual aeroshell w100.

Here's the question. I drained the oil in a clean bucket. It's currently sitting inside my house covered. Can I put this oil back in when I drain the mineral oil? With a case costing $59 plus shipping... well you see why I'm asking?
Thanks for your thoughts.
 
Yes you can run any oil you want in your EAB aircraft engine. Personally I would just put new oil in, but that's just me.

-Marc
 
There’s nothing wrong with putting the oil back in. There’s a recent discussion about this, at length, if you search the forum.
 
As long as you made sure the “almost new” oil went into a clean bucket, and you can transfer it back in cleanly,. I’d say you’d be good. I did something similar recently when, after changing all the pool in all four Lycomings in the same month, I bought sump heaters for all of them. So I drained the sumps, keeping the “almost new oil”, installed the sump heaters, and poured the oil back in…..
 
I'm the cautious type.

IF I were planning to drain and reuse oil, I would only use a squeaky clean new bucket that couldn't possiblly have had anything but rinse water in it. I'd also probably find a way to filter it into a second squeaky clean bucket before going back in.

Reality? My engine and my life are worth at least $100/ea on the average day.

Fresh Oil for me, please.
 
What do you think they do in Alaska when it's -40*F and the plane is outside all night? After flying, they drain the oil, keep it inside in a warm environment, then put it back in the next time they're ready to fly.......
 
What do you think they do in Alaska when it's -40*F and the plane is outside all night? After flying, they drain the oil, keep it inside in a warm environment, then put it back in the next time they're ready to fly.......

What Fred said. Providing the oil was kept clean it would be foolish and environmentally unsound to discard perfectly good oil just because.
 
Thanks everyone. Yes, the bucket was squeaky clean. Feels good to know I don't have to spend money on "new" oil when I already it!
 
Hi all.
I had changed the oil in the process of starting the annual condition inspection. Not really started the inspection yet but wanted to get it done anyway. I flew with the new oil for an hour and half. I started the condition inspection and my number two cylinder which has always had lower compression than the other three was reading only 30/80! I obtained another cylinder which had been overhauled and swapped them out. In the process of doing everything by the book, I replaced the barley used oil with mineral oil for the break in. All is well again in the compression department. The mineral oil needs to be run about 25 hours before going back to my usual aeroshell w100.

Here's the question. I drained the oil in a clean bucket. It's currently sitting inside my house covered. Can I put this oil back in when I drain the mineral oil? With a case costing $59 plus shipping... well you see why I'm asking?
Thanks for your thoughts.

What was the cause of the low compression? Could anything from the bad cylinder have contaminated the freshly changed oil? This would be my only concern. I would have no concern with the draining and storage of the oil.
 
The compression in this cylinder has been an the bottom end of acceptable for awhile. I had hoped it would come up... it didn't. The cylinder is good just will need to be overhauled. I do plan to check the oil closely before putting in back into the engine. Like run it through a coffee filter to see if anything shows up. I think it will be good though.
 
I would think that the oil filter would contain any sort of debris in the recycled oil before it could get into the cylinders/crank/cam.
 
As long as you made sure the “almost new” oil went into a clean bucket, and you can transfer it back in cleanly,. I’d say you’d be good. I did something similar recently when, after changing all the pool in all four Lycomings in the same month, I bought sump heaters for all of them. So I drained the sumps, keeping the “almost new oil”, installed the sump heaters, and poured the oil back in…..

I recently added the heater to my Buddy’s plane.. I used a shop vac on the engine breather, pulled the drain plug, and inserted the heater.. not a drop of oil spilled! Also I used the same trick when I filled the oil but forgot to do the suction screen.
 
I would have no problem putting the oil back in and have done like operations in the past. Clean oil is clean oil.
It ain't rocket science here.
But that's my opinion Art
 
This isn’t suppose to be a surgically sterile environment. It’s engine oil and it has a filter. As long as the container you put it in is sealed to keep moisture and other things out it is perfectly fine. I think sometimes we can overthink things way too much
 
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FireMedic... keeping the oil clean and moisture free is why I brought it home as opposed to leaving in sitting in the hanger. Especially to keep moisture/condensation out.
 
"New" old oil....

This isn’t suppose to be a surgically sterile environment. It’s engine oil and it has a filter. As long as the container you put it in is sealed to keep moisture and other things out it is perfectly fine. I think sometimes we can overthink things way too much

Agreed. We are not transfusing blood here. Even the moisture that 'might' accumulate in the bucket would burn off, just like it would if it were still in the engine. Your bucket is likely way cleaner than the interior of your engine which is where it would be if not in the bucket. ;) Engine oil is in a very hostile, dirty environment and its job is to keep things in suspension and clean. This "nearly new" oil has not had a chance to do its job.

Of course you will be changing your filter when you drop the nondetergent oil after your break-in. :p

As far as break-in time, I've seen everything from 5-25 hours. I recently put a new cylinder on the Cub and, as I remember, Superior recommends at least 5 hours doing variable RPM changes and, after that, when the oil consumption stabilizes. I had 15 hours on my new cylinder and the oil consumption had stabilized at about that 5 hours. It's been 79/80 since. Do whatever your cylinder manufacturer recommends.
 
Break-in time to seat rings

Break-in time to seat rings on a steel cylinder is within a few hrs, for chrome cylinders supposedly it can take 25-40 hrs if I remember correctly and for the other type of cylinder between steel and chrome (can’t remember the type) it can 10-20 hrs or so if I remember correctly.
 
Yes you can reuse the oil, it's your airplane but in the Part 121 world anything that has been drained from a airplane cannot ever be reused.
The only exemption I have ever witnessed is a airplane being defueled by a fuel truck, but honestly I have no idea what happened to that fuel. It didn't go back into the underground fuel system, it was a tanker truck not a pumper.
 
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