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AEIO-540 vs IO-540

D

Dorfie

Well Known Member
Some questions regarding aerobatic engine compared to regular IO-540.
This is not for aerobatic use in RV 10!! I've seen them advertised and wondered if they can be installed easily if they have the same suffix. I am not sure how the AEIO-540 differs from the IO-540.
Do they have a dry sump/inverted oil system?
Different air intake?
Standard compression ratio?
Same crankshaft? Same main bearings?
And any other differences?
Thanks.
Johan
 
As far as I'm aware, the biggest difference is an inverted oil system. You could probably even remove it to save the weight and complexity.

I've also heard the crank flange is stronger (heavier) to help deal with gyroscopic effects of the prop. I could be wrong though.
 
If you are buying it with a governor, the governor might be "backwards" (e.g., no oil pressure = feather, like on a twin, vs fine pitch as on most singles).
 
rear facing sump?

I bought one for my RV10 and it had a rear facing sump. I removed the sump because it interfeared with the nose gear. I put on one of Barretts forward facing cold air induction sumps.

The engines are the same but the sump is quiet a bit shallower than the std one. Let me know if you need more info.

Gary Specketer
Tech counselor/flight advisor
 
The AEIO-540 has 100% more vowels than the IO-540, which makes it highly sought-after in Eastern European countries.
 
Gary 40274 said:
I bought one for my RV10 and it had a rear facing sump. I removed the sump because it interfeared with the nose gear. I put on one of Barretts forward facing cold air induction sumps.

The engines are the same but the sump is quiet a bit shallower than the std one. Let me know if you need more info.

Gary Specketer
Tech counselor/flight advisor
Click to expand...

I would appreciate all you have to share before I commit to buying. Will PM you.
Johan
 
What I found out about AEIO vs IO

Thanks for the replies. I've been digging real hard and found out:
They have the same crankshaft, but AEIO prop flange is solid (without lightning holes) As David mentioned.
Same crank cases and camshafts.
Same cylinders and compression ratios.
AEIO is a wet sump and air induction system goes through sump on both.
The one I am looking at is a narrow deck engine. I believe the ND crank cases have less "dowels" that stabilizes the two halves and as such more prone to "fretting" if not bolted and torqued well compared with the WD. The WD is more prone to cracking at the base of #2 cyl than ND. I think these are not major issues or cause for concern. I was hoping Bob meant more "dowels" that hold the case halves together....but I think not!!
Gary, is the sump not useable in the RV10? Does it need replacement?
There is an engine designated AIO-, which is aerobatic and has inverted oil system, but not sure how that works.
I believe the engine mounts are the same as well. Can anyone tell me the angle of the dynafocal mount from VAN'S? I know there is a type 1 @ 31 degree, and type 2 @ 20 degrees.
Thanks for your input
Johan
 
The mount ears on a 540 actually bolt on. You need the model 70456 mount ears which are the "small hole" version. If the engine has the wrong ears you can swap them for what you need. The Rocket guys need the large hole ears so trading is also possible.

Bob
 
Cold air induction

What is the setup for AEIO 540 C4B5 with cold air induction? Is it difficult make fit in RV10? From pictures it seems to bolt on to the sump where the normal updraft induction bolts on. I assume it involves a different sump.
What is the effect of higher compression ratio (9.1 vs 8.5 to 1) on the engine?
So many questions and more seems to creep out of the woodwork! I'm seriously looking at engines, want to stay close to Van's recommendations and have good engine life expectancy and installation that is not too far off the norm.
Thanks.
Johan
 
bcondrey said:
The mount ears on a 540 actually bolt on. You need the model 70456 mount ears which are the "small hole" version. If the engine has the wrong ears you can swap them for what you need. The Rocket guys need the large hole ears so trading is also possible.

Bob
Click to expand...

Bob,
Do you know the diameters of the two types?
Johan
 
The hole diameter is about 1-7/16" on the small hole mounts. I don't have any of the large ones around to measure but they're much larger.

Bob
 
Last edited:
I did a little searching and it appears that the large mounts have holes that are about 2" diameter.

Bob
 
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