Prop Clocking Matters

I have always clocked the prop on my RV-6 so it stops at 10:00 and 4:00 when
viewed from the front. The idea being that this is the best orientation for
hand propping if I ever needed to do that.

During my recent condition inspection, I mistakenly reinstalled the prop
with either a 120 degree lead or a 60 degree lag from normal, depending on
how you look at things. On my trip to SnF, I noticed that there was
considerably more vibration than normal, particularly at higher power
settings and rpm, but otherwise things were fine. I noticed the same thing
when I flew earlier this week.

Due to an in-process installation of a 12V outlet in the cockpit, there is
an unclipped zip tie visible during flight which has not been clipped. With
the prop normally clocked, the tip of the zip tie hardly moves. When the
prop was indexed differently, the end of the zip tie shook like a double
jointed hooker on dollar day. OK, maybe not that bad, but I felt a real
need to work that line into my narrative...

So, today I reindexed the prop. And we're back to a very smooth engine/prop
combination, which makes me a happy camper.

It made up for the fact that the videographer (me) completely screwed up the
recording of a prop stopped glide test I conducted earlier this week when I
went to altitude and shut down the engine for about 5 minutes of glider
time.. I had great intentions of filming all of the instrument readings
(ASI, VSI, etc) during the test and having the prop visibly stopped in the
background of the video. Unfortunately, I must have missed when I went to
push the record button, because I had zero, zip, nada, nothing, when I went
to review the recording.

I can tell you that 80 knots indicated is the minimum sink speed on my RV-6
with the prop stopped, and the sink rate is 700-750 fpm at that speed. Also,
it requires 140 knots indicated to get the prop windmilling again to restart
the engine.

And, with the prop stopped, the engine/prop combination is extremely
smooth.... ;-)

KB