Home > VansAirForceForums

- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

Old 07-15-2019, 11:21 AM
Lizard Lips Lizard Lips is offline
Join Date: May 2012
Location: Longview, Texas
Posts: 49
Default IO-390 Expansion Plug Removal

I have just received and mounted a Lycoming IO-390 on my RV-14. Maybe I am not understanding all that I am reading, but one source says the Expansion Plug must be removed for constant speed props. That's all they say. Another source also says the expansion plug must be removed AND another expansion plug installed behind the "oil valve". If this is true where can I purchase this phantom expansion plug and how can it be inserted behind the oil valve?

I'm still trying to remove the outer expansion plug with no luck at all. Per VAF thread I have drilled a 1/4" hole in the plug, but where do I go from there? Tried inserting a Phillips screwdriver in the hole and prying it out but it won't budge. Any suggestions? I'm stuck!

Longview, Texas

RV-14A Fuse and Wings ~80% Complete
Arion Lightning LS-1 Flying regularly
2019 Dues Paid
Reply With Quote
Old 07-15-2019, 11:27 AM
jrs14855 jrs14855 is offline
Join Date: Apr 2008
Location: Lake Havasu City AZ
Posts: 2,318
Default Plug

The front plug is similar to the expansion plugs on automotive engines. You need to partially collapse the plug, then it will pop right out. Take a piece of steel bar 3/4 or so in diameter. Round the edges slightly. Hold the bar on the center of the plug and strike it with a hammer until the plug is "dished" in the opposite direction.
There is lots of info on the rear plug, you just have to search for it.
Reply With Quote
Old 07-15-2019, 11:42 AM
Nova RV Nova RV is offline
Join Date: Aug 2015
Location: Leesburg, VA
Posts: 408

Drill hole

Auto body slide hammer

No need to do anything about a rear plug, it's ready to go when you remove front plug
Chris Moon
Leesburg, VA

CFI-I ASMEL, ATP, B-1900, A319/320, B-757/767, B-737, Flight Engineer-Turbojet

RV-14A kit # 140243 (flying as of 11/18)
VAF 2018 and 2019 paid
Reply With Quote
Old 07-15-2019, 12:28 PM
Lizard Lips Lizard Lips is offline
Join Date: May 2012
Location: Longview, Texas
Posts: 49

FANTASTIC !!!!!!! A few licks with a 2-lb sledge hammer and it popped right out. You just gotta get its attention first! I really appreciate all the help I get from you guys. Thanks a bunch. :


Longview, Texas

RV-14A Fuse and Wings 80%

Arion Lightning LS-1 flying regularly

2019 Dues paid
Reply With Quote
Old 11-15-2019, 07:25 AM
Stockmanreef Stockmanreef is offline
Join Date: Nov 2012
Location: Midland, mi
Posts: 805

I take it that I don't need to drill any holes first. Just get the plug to invert.

Ken Stockman
Midland, MI
EAA Chapter 1093 member

RV-14a (serial number 140073)
N73XP (at least that # reserved now)
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 10:36 PM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.