Oil on the belly -- does it bother you?

I always prided myself on my amateur luck of having zero oil leaks in all of Smokey's tubing, even with the Raven inverted oil system. None. Well, except for mounting the oil separator too low initially and dumping most of the oil out the breather ... but that's another story.

However, after that issue was resolved, I had months of an oil-free belly.

One day, I went into the hangar to see a small puddle of oil about the size of a quarter under the right exhaust pipe. Hmmm ...

Long story short, I tracked the leak to a swivel fitting on the back of the sump for the inverted oil system. I removed the exhaust system to get a wrench on the fitting (to remove it would literally involve removing the engine from the plane because of its proximity to the engine mount!) and cranked it down as tightly as I could without cracking the sump. That worked.

However, after a year or two of more flying, I've noticed that the fitting still weeps a drop of oil or two, which naturally get swept away along the belly of the plane. No more drops on the hangar floor, but it's annoying to have to clean the belly of the plane a couple times a year.

Other airplane owners laugh at my concern. They enjoy oily bellies all the time. Their hangar floors have oil stains all over. "It's UNNATURAL for an airplane engine to NOT leak some oil," they all say.

I still don't like it. I want a tight engine again.

Am I being too anal?

I would also be looking to solve that oil drop "issue". Not important at all but knowing that my airplane can not stay "clean" without me would annoy me. I am too perfectionist on that point.
I am the kind a person who didn't put a wingwalk on the plane to keep my paint scheme nice.. Instead I put a carpet on the wing each time I jump in it (and forgot to remove it at start up half the time...). I am using my 4th carpet in 50hrs.

Your oil drop issue made me laugh because the first time I did some acro with the plane was after the 25 hours inspection of the plane and I had almost 8qt of oil.
I took off and after 10 minutes, on the top off a hammerhead turn I saw a smoke trail when I turned my head. I stopped the acro and asked if my plane was smoking for a long during maneuvers. The controller answered me "Oh Yeah your smoke system works very well!!!!".... I don't have a smoke system. I landed, stop the engine at the apron, go out of the RV and saw that I had an oil tricker at the rudder... I checked the oil level and was at 6qt. 2 qt oil loss in 15 minutes. I let you imagine the time I took the clean the belly, wings, empennage...

Now you may understand my phobia of oil on the belly

N8RV said:

No more drops on the hangar floor, but it's annoying to have to clean the belly of the plane a couple times a year.

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Yeah, having to clean the belly a couple times a year is really a terrible ordeal

Other airplane owners laugh at my concern.

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My ribcage is starting to hurt

They enjoy oily bellies all the time. Their hangar floors have oil stains all over. "It's UNNATURAL for an airplane engine to NOT leak some oil," they all say.
I still don't like it. I want a tight engine again.
Am I being too anal?

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Seriously, all air-cooled airplane engines are going to develop some amount of oil leaks. The rapid changes between temperature extremes and vibrations are going to eventually make every metal-to-metal sealing surface with oil behind it start to seep over time. My 300-hour TTSN factory Lyc O-320 in the RV-6 has already started to seep a little between the case halves right under the big front bearing area, and also the right mag seal has started oozing a little oil too. But none of that compares to the mess that the smoke system makes! (but that sure is fun... expensive, but fun) ...and yeah, my hangar floor even has oil spots under the tailcone too

If your sump fitting is like a banjo fitting with thin copper or aluminum washers on each side of the banjo, then the next time you drain the oil you might try cleaning all the oil off of the fitting and surrounding area with some spraycan carburetor cleaner (B-12 Chemtool, etc) to ensure all the oil is gone, then brush on some Permatex #3 Form-a-Gasket (in the plastic jar that has the paint brush in the lid) around the fitting where the oil is seeping and let it dry real good before refilling the engine with oil. That might take care of the seep... for a while anyway.

N8RV said:

Am I being too anal?

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Maybe, but it's your plane, so you get to be as anal as you want.

Me? I clean the belly once every couple of years, whether it needs it or not.

Bastien said:

I am the kind a person who didn't put a wingwalk on the plane to keep my paint scheme nice.. Instead I put a carpet on the wing each time I jump in it (and forgot to remove it at start up half the time...). I am using my 4th carpet in 50hrs.

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Bastien,
Take a length of thin rope long enough to reach from a corner of your carpet into the cockpit. Tie one end to the carpet, and put one of those red "Remove Before Flight" flags on the other end. Put the carpet on the wing and loop the other end around your throttle quadrant.

Assuming you don't trip over the rope when you get in , you should be reminded of the carpet before engine start-up by the rope and flag around the throttle.

Michael White said:

Bastien,
Take a length of thin rope long enough to reach from a corner of your carpet into the cockpit. Tie one end to the carpet, and put one of those red "Remove Before Flight" flags on the other end. Put the carpet on the wing and loop the other end around your throttle quadrant.

Assuming you don't trip over the rope when you get in , you should be reminded of the carpet before engine start-up by the rope and flag around the throttle.

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That is a good idea. I thought of the rope but adding it to the throttle with a remove before flight flag is a great plus!
No need to have a stock of carpet anymore.
Thanks you

Bastien said:

That is a good idea. I thought of the rope but adding it to the throttle with a remove before flight flag is a great plus!
No need to have a stock of carpet anymore.
Thanks you

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Avec plaisir!

N8RV said:

Am I being too anal?

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No where near anal. I clean my belly after every flight and I am not anal.

plehrke said:

No where near anal. I clean my belly after every flight and I am not anal.

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...I very meticulously clean my belly after every meal! Need it or not! I guess I should install one of our oil separators and a vacuum evacuater system, but can't find the proper hose and fittings. We only have the ones for aircraft at present. Allan...

A little OT?

I've had really good training for this subject, having owned British motorcycles from the 50's & 60's, Triumph, BSA, yes even AJS. They were all vigorously "externally lubricated"! Gawd, but I wish I still had 'em, brings a tear to the eye...

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