Does the rocker arm really rotate the valve stem?

[gammaxy]

The manual tells us to align each swivel pad off center in order to rotate the valves. Looking at the wear on my valve stems, I'm pretty confident than in 120 hours none of them has ever completed a single rotation. Anyone have any evidence otherwise?

[SonexN76ET]

My valve stem ends look similar to your picture Chris. Maybe they will start to rotate after the valves loosen up in the valve guides.

Did you ever find out the cause of the metal flakes or oil analysis anomaly?

Jake

[Klimek]

I replaced all my valves at 37+- hours. All my valves looked like yours on the
end. None appeared to be rotating. Reason for replacing? After adjusting the
Valves 5 times and finding them tight each time, I was concerned about the stems
Stretching or face / seat distortion. Cylinder leak test showe #1 had higher leakage, 80/65.
The others were 5 or less.(80/75~) I found #1 exhaust sear 25% wider than the others and
It appeared none were rotating. Also all exhaust valve faces were deformed . Now I have 43+-hours and adjusted the valves at
1 hour and 5 hours after replacement and did not find any tight after a 3:34
Flight. Do not have info on rotation yet. Plan on checking valve stems
10 hours after the replacement.

Frank
ONE 090
N1970T
43 hours and counting

[gammaxy]

Did you ever find out the cause of the metal flakes or oil analysis anomaly?

I decided to answer your question in my original thread: http://sonexbuilders.net/viewtopic.php?f=7&t=2471&p=18984#p18984

[gammaxy]

After adjusting the Valves 5 times and finding them tight each time, I was concerned about the stems Stretching or face / seat distortion.

I've re-lapped the exhaust valves on cylinders 1 and 3. I could tell cylinder 1 was leaking while turning the propeller by hand. I just did cylinder 3 since I had the head off anyway and detected a slight leak after testing it with alcohol. I did not notice any exhaust valve face distortion. Did you take any pictures?

Mine also seemed to get tight, but I think I only noticed it after retorquing the head nuts. I haven't noticed any valve stretch and think it was just due to slowly crushing the copper gaskets. I ran out of adjustment on cylinder 1's exhaust rocker and couldn't quite achieve .006" before making new pushrods. This might be how I ended up with the first leak.

[mike.smith]

I have never seen any evidence of my valves rotating. When I had a valve job done by an engine shop they said they know about the direction to offset the two, but advised they have never seen valves rotate, and believe it to be an old wives' tale.

[rizzz]

Again, opinions seem to vary on this subject.
My local VW guy tells me to get the rocker arm adjuster dead center on the valve stem, that's contradicting the AeroVee manual.

This guy in this video is also considered a VW guru on the various forums:
https://www.youtube.com/watch?v=PIb32NNrl7s

He also seems of the opinion that the rocker needs to be centered on the stem.
He has many other very educational VW engine related videos BTW, very interesting to watch.

[nwawingman]

Great video! Thanks for sharing. Always find it valuable to hear from others experiences. The valve ball type adjusters breaking he spoke about seemed concerning to me. Seems like I remember someone on the sonex forum having one break.