Jeff R

Well Known Member
I am converting a YIO-320 from CS to FP. Per the Lycoming service bulliten, I removed the front expansion plug (part number STD-1211) and, in doing so, noticed that it had been installed with some sort of gasket sealer. Nothing in the Lycoming service bulliten mentions using any sort of gasket or sealing material when installing this plug.

What, if anything, should I use on the expansion plug during re-installation?

Thanks.
 
If you want to, you can use some kind of sealer such as Permatex #2. However, you shouldn't have to use anything.
I personally don't use anything.
 
Prop conversion

hi Jeff,

I'm about to undergo the same conversion process and I'm a bit nervous! How did it go?. Can you do this with the engine in position? I'm in the UK and could not find much assistance and the Lycoming instructions are a bit vague. Any advice gratefully received.
 
I know it is not needed but I just made the first flight yesterday on my new RV-9A and the only real issue was oil leaking from the expansion plug. I would probably put a little sealer on it just for the warm and fuzzy feeling.
 
hi Jeff,

I'm about to undergo the same conversion process and I'm a bit nervous! How did it go?. Can you do this with the engine in position? I'm in the UK and could not find much assistance and the Lycoming instructions are a bit vague. Any advice gratefully received.


It ended up being pretty easy. I drilled a hole in the outer plug and pried it off. A little bit of oil came out, so be ready with a rag for that. The interior plug - the one to pierce - was rather far back, and I wasn't sure what to use to poke it with. I found a round file with a rather narrow tip that was long enough to reach, then it took just a couple of wacks from a hammer to pierce the hole. I understand the hole doesn't have to be very big, and I didn't want to make it so large that pieces of metal might come loose on the other side. I took Mel's suggestion of using some Permatex #2, coating some on the inside rim of the new plug (as it appeared Lycoming had originally done). To place the dimple in the plug (which expands the plug out, providing the seal), I used a hammer and a small block of wood to cushion the blow.
 
Question for Mel, or Mahlon

If you want to, you can use some kind of sealer such as Permatex #2. However, you shouldn't have to use anything.
I personally don't use anything.

Mel, (or Mahlon) would you be concerned that some of the sealer could break free and end up plugging a small hole somewhere in the oil sysem?

Not an engine guy myself, just asking a question. :confused:
 
prop conversion.

Jeff,

Thanks for that. I took the plunge and have removed the front plug without difficulty. Just waiting for a new front plug to arrive before making the hole. As you said, it doesn't look too dificult once the plug is out and you can see whats inside.
My engine also had sealant on the plug and I will put the new one in with something similar because I have read several accounts of rv emergency landings occuring after fitment of plugs where oil leaks subsequently happened and covered the windscreen! Ready to fire up the engine after that , which will be a milestone in a five year build!
 
Mel, (or Mahlon) would you be concerned that some of the sealer could break free and end up plugging a small hole somewhere in the oil sysem?

Not an engine guy myself, just asking a question. :confused:

Not if used sparingly
Good Luck,
Mahlon
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