It's a "normal" O360, non aerobatic, but with inverted oil and fuel system etc. If that matters.
Flew more negative g's today (time wise, around -1g), similar to when it first happened, and almost no oil leakage.
What sequence/figures would drain the slobber pot or cause it to overflow? From looking at the schematics a low g should have more chance to have it overflow, as the valves might not be positioned properly. But that doesn't match with the flight I did when it overflew.
The file you linked to talks about oil losses in vertical rolls with inverted entry and recovery. I was nowhere close to doing anything like that.
Crankcase breather tube in pitts
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Colonel
- Posts: 3450
- Joined: Wed Apr 29, 2015 10:31 am
Simple sustained zero G will overflow the slobber pot -
it drains via Gz (vertical gravity component), and it drains
via positive G much better than negative G in my experience
due to it's raised mounting location in the engine compartment.
Looking at the S-2B firewall, the slobber pot is mounted
high and on the left, facing aft.
[img width=500 height=375][/img]
This means that the slobber pot drains back into the crankcase
well under positive G, might drain a bit in knife edge right wing
high, and won't drain at all under zero or knife edge left wing
high. I only do knife edge with the right wing high for
this reason, and I watch the oil pressure.
[img width=500 height=387]http://www.pittspecials.com/images/gat_k1.jpg[/img]
Food for thought: this picture was taken by a photographer
standing on the ground.
Frankly, I think a wet sump on an aerobatic engine is
a really bizarre engineering design, but no one asked
me. Kirby and Sean and Skip go through engines like
condoms.
Running LW-16072 (anti-scuff) for those times when you
have no oil pressure would seem to be a wise choice.
As I said, I always run the oil full (indicating 12 qts,
actually contains 13) on the AEIO-540 (costs horsepower
but that's cheaper than an engine) and I try to fly sequences
that drain the slobber pot. I use it like an accumulator.
I do like oil pressure, too.
it drains via Gz (vertical gravity component), and it drains
via positive G much better than negative G in my experience
due to it's raised mounting location in the engine compartment.
Looking at the S-2B firewall, the slobber pot is mounted
high and on the left, facing aft.
[img width=500 height=375][/img]
This means that the slobber pot drains back into the crankcase
well under positive G, might drain a bit in knife edge right wing
high, and won't drain at all under zero or knife edge left wing
high. I only do knife edge with the right wing high for
this reason, and I watch the oil pressure.
[img width=500 height=387]http://www.pittspecials.com/images/gat_k1.jpg[/img]
Food for thought: this picture was taken by a photographer
standing on the ground.
Frankly, I think a wet sump on an aerobatic engine is
a really bizarre engineering design, but no one asked
me. Kirby and Sean and Skip go through engines like
condoms.
Running LW-16072 (anti-scuff) for those times when you
have no oil pressure would seem to be a wise choice.
As I said, I always run the oil full (indicating 12 qts,
actually contains 13) on the AEIO-540 (costs horsepower
but that's cheaper than an engine) and I try to fly sequences
that drain the slobber pot. I use it like an accumulator.
I do like oil pressure, too.
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