Looks like the crank seal. Check to see if there's oil pooling inside the ring gear hub.
I replaced my split crank seal on my superior io360 at about year 2. I'm now in year 10.5 without it leaking. I replaced it with a non-split variety.
It's fairly easy to replace as I was surprised how it stretched over the ring gear hub.I sealed it with pliobond as recommened by the lycoming manual.
Houch! I hope the surgery will be minor to stop the bleeding Steve. Please report back. Is your hangar heated?
I couldn't remember if you had a CS prop or not. I'm betting prop seal, based on how it was able to pool on the edge of the air intake of the cowl. Crank front seal is too far back, but was the only idea if the prop was FP.
Steve,
I have a split front seal you can have - but I don't understand how those don't leak...... I had a leaker on my RV6 years ago and I had Jeff at Elite put a new solid one in for me. Took him about 15 minutes. I think he boiled it first to soften it up and then slid it over the crank flange. Then used the Lycoming approved sealant and let it set. Never leaked again. You'll have to take your prop and ring gear off first. Will you be out there tomorrow? (Saturday)
There seems to be more oil on the floor than could drool down from the cowl. Meaning maybe like something that contains oil is leaking. If that much oil was simply splattered around on the cowl, the belly would have been covered, I'd think.
Good luck! Two types of engines - those that have and those that will leak oil...
I am with Alex here. A front seal will only leak when the engine is running. There is no standing oil in that area after shut down. The amount of oil on the floor is indicative of oil leaking from an area with some volume of oil in it. The prop hub holds a decent amount of oil and I would be looking for a leak there first.
Larry
. Or if you have the vent connected to the exhaust... it is probably time to inspect and see if it has plugged.
Wow. I would imagine things could have been much worse - seems like that could lose a lot of oil very quickly in flight. Glad you found it.
Chris
some kind of grey sludge in there
The seal may have been pushed out by crankcase pressure due to vent blockage. Cold temps can cause ice to form in vent,so you must have a V notch cut in vent line as alternate outlet if this happens. I saw your vent line is rubber, if it's all rubber, you might consider puttting a section of aluminum tube in for a place to notch it.
Its lead, you are running a centrifuge there. The lead collects in anything that spins including accessory case gears.
To me it seems like that seal may not have been put in properly as there isn't much sealant and/or the sealant has not stayed on the seal.
The local engine guy we work with recommends 5 minute Araldite for experimental prop seals. He says it works a lot better than the Loaming approved stuff.
I, and several others that run the Superior engines, have had front seal failures. We have all found that the front seal was installed with white silicone sealant. I am not sure what you mean by "the same color as lead" but white flakes is what we all had. New seals and plio bond adhesive were the answer.
My front crankshaft seal that was installed during the rebuild (prior to hanging the engine) leaked a lot. At the first annual, I decided to replace it. It came out way too easy. The seal was put in with some sort of contact cement (like pilobond). I bought the recommended Dow Corning 737 Neutral Cure silicon sealant and used this successfully on the second seal. That seal leaked still (but not as bad as the first one), so I replaced it again at the second annual. This time it was much harder to pull out the seal, so I can highly recommend using the silicon sealant! I guess the third time is the charm, since this last seal seams to be keeping the cowling on the inside from getting an oily spray around the starter ring. It still isn't completely clean in there, but MUCH better than the previous seals.
I, and several others that run the Superior engines, have had front seal failures. We have all found that the front seal was installed with white silicone sealant. I am not sure what you mean by "the same color as lead" but white flakes is what we all had. New seals and plio bond adhesive were the answer.
I have to agree with the gasman this time of year, make sure there's a relief hole in your vent line well above were it can freeze !
what's the vertical temperature gradient at the firewall during cruise flight?
and what about insulating the alum tube?
Hi Steve: Our MDRA inspectors won't pass a airplane up here unless it has a vent tube attached.
This drawing was sent to me by another builder, I've installed mine per drawing.
Hope this helps, Terry.
The seal was put in with some sort of contact cement (like pilobond). I bought the recommended Dow Corning 737 Neutral Cure silicon sealant and used this successfully on the second seal. That seal leaked still (but not as bad as the first one), so I replaced it again at the second annual. This time it was much harder to pull out the seal, so I can highly recommend using the silicon sealant! I guess the third time is the charm, since this last seal seams to be keeping the cowling on the inside from getting an oily spray around the starter ring. It still isn't completely clean in there, but MUCH better than the previous seals.
DanH has posted some temperature deltas for ambient-lowercowl-exit, so you can search. In the shrinking exit, maybe. I seem to remember in excess 100F temp rise from ambient to lower cowl. Anything over 52F rise will leave above freezing.
The blow-by exits just above oil temperature (again DanH number). It is very doubtful that you have iced that blow-by tube, especially since the last 8" is hose.
I would (do some research and ) just properly install that seal. No other change.
Edit: DanH's exit link above is with the cowl door closed. Here is some of his early data - it has 90F temp rise from ambient. Conclusion still the same.