Intake valve stem

Ant CB

Member

• Dec 2, 2011

• #1

Hi all,

Do Lycoming engines have intake valve stem seals?

If oil is getting into the intake manifold at idle would that indicate oil getting around the intake valve (getting sucked into the intake at low power).

Worn intake valve stem seal?

 

C

chaskuss

Well Known Member

• Dec 2, 2011

• #2

No, Lycoming engines do not have valve seals on either the intake or exhaust valves.
Charlie

 

LifeofReiley

Well Known Member

• Dec 2, 2011

• #3

Oh but they can be installed...

 

C

chaskuss

Well Known Member

• Dec 2, 2011

• #4

LifeofReiley said:

Oh but they can be installed...

Click to expand...

Reilly,
Is there an automotive valve seal which will fit the Lycoming valve stems? I ask, because I know of another list member who was considering doing just that.
Charlie

 

LifeofReiley

Well Known Member

• Dec 2, 2011

• #5

chaskuss said:

Reilly,
Is there an automotive valve seal which will fit the Lycoming valve stems? I ask, because I know of another list member who was considering doing just that.
Charlie

Click to expand...

There is... let me see if I can find the info in my files. Might take a day or two if I can locate.

 

LifeofReiley

Well Known Member

• Dec 2, 2011

• #6

I Cryo'ed everything and we're using Roller Rockers so we have not had any wear issues.

 

Ant CB

Member

• Dec 2, 2011

• #7

Interesting, my mechanic told me to order a set of valve stem oil seals for my next annual because the intake valves have a little oil leaking past them at low power. Perhaps I got my wires crossed somewhere.

 

LifeofReiley

Well Known Member

• Dec 2, 2011

• #8

Ant CB said:

Interesting, my mechanic told me to order a set of valve stem oil seals for my next annual because the intake valves have a little oil leaking past them at low power. Perhaps I got my wires crossed somewhere.

Click to expand...

Stock... Valve Guides Only, you could sure order them but it might be a little more detailed than just that.
We also ream precision fit these.

 

rocketbob

Well Known Member

• Dec 2, 2011

• #9

There is a Mack diesel positive seal that will work on the exhaust (.500). Intake valves are a different story, I have not yet been able to locate a positive seal for a .400 valve. Umbrella seals will work on both.

 

Ant CB

Member

• Dec 3, 2011

• #10

So ultimately how does one correct a leaky intake valve stem?

 

airtractor8

Well Known Member

Friend

• Dec 3, 2011

• #11

I fitted stem seals to my 0320H2AD. Here is a link to the thread discussion at the time and some pictures and info on how to fit them with the cylinders still installed. The "standard" Lycoming's will require a different procedure but you get the idea...http://www.vansairforce.com/community/showthread.php?t=69483

Cheers
Graham

 

Last edited: Dec 3, 2011

Ant CB

Member

• Dec 3, 2011

• #12

Are stem seals a standard thing to fit to these engines or is it an experimental only application?

Can I just go out and buy them from a Lycoming engine overhaul shop?

 

airtractor8

Well Known Member

Friend

• Dec 3, 2011

• #13

Ant CB said:

Are stem seals a standard thing to fit to these engines or is it an experimental only application?

Can I just go out and buy them from a Lycoming engine overhaul shop?

Click to expand...

No, they are not a standard Lycoming part on engines fitted to RV's at least. Someone told me that some larger Lycomings use them but I have not seen them and can't confirm this. Your engine will just have reamed valve guides with no seals.

 

T

TangoT

I'm New Here

• Mar 18, 2014

• #14

intake valve stem seal?

I know this thread is old but I'm wondering if this has worked out for anyone on the board?