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Identifying AEIO-360 vs IO-360

Pneuma

I'm New Here
Hi all
I'm going to look at an a/c soon that is registered in the UK as having an AEIO-360-A1B6, but the seller lists it as an IO-360 with no inverted oil. I realise they could have modified the engine to remove the inverted systems - but being a novice how can I check whether this is still an AEIO or not?
Many thanks in advance!
 
From Tech Data Sheet:
- AEIO has an inverted oil system
- AEIO has the governor drive on the left front of the crankcase
- AEIO is equipped with Bendix mags
- AEIO weighs 5 pounds more (oil system)

Check engine data plate.
 
Thanks for that - engine data plate is a top tip.
Any tips on how I can identify the inverted oil system (this is what I'm particularly interested to know if it is still present)? I did warn you I was a novice...
 
Big sump with a ball check setup... probably says Christian on it. Oh... and a snakes nest of stainless an tubes. Screenshot_20250520_054116_Gallery.jpgScreenshot_20250520_054105_Gallery.jpg
 
From Tech Data Sheet:
- AEIO has an inverted oil system
- AEIO has the governor drive on the left front of the crankcase
- AEIO is equipped with Bendix mags
- AEIO weighs 5 pounds more (oil system)

Check engine data plate.
Some AEIO's have rear governors and some have Slick mags!
 
The actual system is external to the engine as shown above. It does indeed take up a lot of space. If it has been removed, don’t mistake a large air/oil separator for the canister in the inverted system. The inverted system will have a continuous loop from the top of the engine, through the large canister, to the bottom of the engine.
The smaller flop valve unit allows the engine breather to switch from the top of the engine to the bottom when pulling negative G.
 
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Some AEIO's have rear governors and some have Slick mags!
Another novice here: so it seems Everything identifying the engine as “AEIO-…” is external to the engine case? If that is so, I’m wondering why the data tag has the “AEIO-…” designation at all? As such, in the event someone removing all the inverted items would make the data tag incorrect…! Is the data tag supposed to be changed?
 
Another novice here: so it seems Everything identifying the engine as “AEIO-…” is external to the engine case? If that is so, I’m wondering why the data tag has the “AEIO-…” designation at all? As such, in the event someone removing all the inverted items would make the data tag incorrect…! Is the data tag supposed to be changed?
The Lycoming AEIO is a standard IO with the addition of a Christen inverted oil system (Lycoming relabeled those parts as being Lycoming). The only thing that is not external is a plug that blocks off the oil pick up passage at the back of the oil screen cavity and a shortened oil screen. The oil, on an AEIO is picked up from a port on the bottom of the case, while right side up, and from the top of the case while inverted; either from the vacuum pump pad or a "T" in the breather line.

It is a grey area on changing the data tag, most likely a log book entry saying the system was removed and the engine is now similar to/ or reverted back to a Io-XXX-a1a or what ever the designation would have been.
 
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First of all take someone with you who knows what they are at.
You will miss many things that someone experienced will spot quickly.
Many AEIO motors have been converted to IO. Look at the sump, is the a large diameter pipe connected to the scavenge filter plug on the back? If yes it is likely the front of the filter remains plugged (part of the AE modification) and the oil flow is in at that point.
But it doesn't really matter, as long as the engine runs properly. The AE oil system needs more maintenance. It can be added to just any (I)O-360, at a cost. Check that any changes have LAA approval from the records.
 
The AE oil system needs more maintenance
Yep. On top of that I'd extra cautious before buying one of those.
Those balls inside whatever system (Christen, Raven, others?), tend to remain stuck in the wrong position, the more so in cold weather, so sometimes interrupting or disturbing a normal oil pressure rise... most of those engines don't reach their published TBOs.
 
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