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IO-390-A1B6 for RV-15 build

8

818 AV8R

Active Member
The wait is killing me, but I think I found something to keep me busy in the meantime.
I started looking around for an engine core to build. At first, I figured an IO-360 would be sufficient. I quickly reconciled that idea and decided that anything less than the 390 wouldn’t do it justice.

So I happened to stumble across a 300 hour IO-390-A1B6 off a 2015 Denali Scout, it was involved in a blade separation event.
At first I thought, well, it didn’t hit anything, so it’s not a prop strike, maybe it’s fine as is. Crank dialed out at .001 but when I checked the end play, also .001. Should be closer to .009-.016.
I did some digging and found Lycoming SB533 which describes prop strike or suddenly stoppage inspection criteria.
Apparently, it also mentions blade separation and says to complete the same inspections.

So I’m planning to tear it down, send everything out, and IRAN.
I suspect it will mostly be fine. The bummer is that it calls for replacing the roller tappets. They’re a fortune. Oh well.

This will be an awesome engine I suspect.
Planning to make plenty of videos along the way and share on my channel.
https://youtube.com/@112_adventures?si=9KQtNHkFdEdd-of1

Look forward to hearing from anyone who wants to discuss!
 
Awesome, thanks. Engine should be here Friday, assembling my tools and preparing my shop for surgery!
 
Jason, I subscribed to this thread and will be watching the progress. Of course, since you're in the next hangar row north of me, I will just walk over to see it myself! :)
 
Awesome. Except you might be surprised that it won’t be in my hangar! This project will be taking place in the comfort of my air conditioned garage! Of course you’re always welcome at the house too.
 
818 AV8R said:
Awesome. Except you might be surprised that it won’t be in my hangar! This project will be taking place in the comfort of my air conditioned garage! Of course you’re always welcome at the house too.
Click to expand...

lol perfect!
 
Cyl 1 exhaust leak
Cyl 2 intake leak
Cyl 3 76/80
Cyl 4 exhaust leak
Click to expand...

Don't know when the engine was run last time, but looking forward to the reason(s).
Surprisingly for such a new design :)confused:), we already had some IO-390 equipped -14s valve sticking problems around here... last one with 180TT...

Thanks for sharing your engine adventures, always eager to learn :)
 
Last ran in May (2023).
I suspect the cause was from excessive carbon sticking under the valves, broken free from the vibration of the blade loss. I noticed a lot of loose carbon build up inside the cylinders during tear down. Videos to come.
 
Thanks Jim.
I have a bunch of videos to catch up on, I have all the cylinders off and am about to split the case.
Stay tuned!
 
Thoughts ?

818 AV8R said:
Last ran in May (2023).
I suspect the cause was from excessive carbon sticking under the valves, broken free from the vibration of the blade loss. I noticed a lot of loose carbon build up inside the cylinders during tear down. Videos to come.
Click to expand...

Watched your videos, excellently done!! This may be one of the first 390's to be torn down. You obviously know your way around a Lycoming. Any ideas on why the carbon build up in the cylinders? There seems to be a myriad of possible sources from CHT's being too cold even though # 2 seems to be the culprit in the majority of cases and # 2 is typically the hottest. Any feedback would be great, Thanks.
 
For what it’s worth, when having my last IO-360 rebuilt, two VERY reputable shops suggested that for an experimental, they would HIGHLY recommend inspection and replace only as necessary, the roller tappets. There is almost no way for these things to be damaged in a separation or light prop strike event and they are able to be inspected. This does NOT meet the Lycoming IRAN requirements.
 
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