O-320 Propeller indexing

[Pacer42Z]

Oh boy, what have I started here? I really thought everything about certified airplanes is science based and (over) regulated and documented. All of the bushings on my prop flange are the same length (short) and the prop can be installed in any direction I like. I guess I will fly my Pacer a couple of more hours and then move it to the 11 and 5 o'clock position and see if there is any difference in vibration.

Juergen
Pacer N3342Z

[Steve Pierce]

One bushing is smaller in diameter to index the flywheel. On a constant speed prop engine there are two longer bushings. There is a Lycoming document on bushing orientation but doesn't matter I don't think to the discussion at hand.

[Gilbert Pierce]

The only odd busing in my flange is the big one to index the flywheel. It has a larger diameter then the others to match the one large hole in the flywheel.

[Steve Pierce]

That's it, larger.

[Brian]

Yet another theory on how best to clock a prop:

http://www.google.com/patents/US5588619

[Pacer 24C]

Yet another theory on how best to clock a prop:

http://www.google.com/patents/US5588619

Interesting - I had positioned my Rocket conversion 0320 Yankee taildragger 1 position forward for this theory since it has a sealed induction tunnel- didn't detect any improvement in power- so I moved it back to the normal position (which is also specified by Grumman) 11-5 from pilot's view

[Jim]

Hi

....Propeller syncro-pulsing....

I wonder if he also has magnets attached to his fuel lines.

[andya]

Mine is same

[SVA402]

This is diverging slightly from topic but I screwed this up a few years ago and we had to fix it. I figured this out quickly because the first flight had pretty high vibration. So on that note after fixing I wondered what else could cause or reduce vibration. I ended up doing a dynamic prop balancing with my local shop (I think quite a few places have the ability to do that now) and it DRAMATICALLY reduced the vibration I thought was normal for the last few years. Cost me almost nothing and took about 2 hours. Just something to consider.

[Pacer42Z]

Just to give everyone an update. I have flown the Pacer for about 12 hours since the prop was put back on by my mechanic. As you can see from previous posts I had questioned my mechanic if he was sure that the prop is in the correct position. I must say, my Pacer has never run this smooth. I took all the weights off the spinner back plate and the fly wheel from previous dynamic balancing and currently have no weights on the airplane. Just the prop mounted to the engine. In my case I must admit my mechanic knew what he was doing. And looking from the front of the airplane my prop always stops in the 10 O'clock/4 O'clock position. I am a happy camper.

Juergen
Pacer N3342Z