Hi,

Bringing a ‘74 185F out of a 6 year nap has been quite something.

The issue is when leveling off at cruise and dialing the prop back around 2350 rpm she really starts to shake. Not vibrate. Shakes. You can quell the issue by increasing RPM back to higher settings or continuing to dial it lower down to 2200.

Doesn’t always happen though..

I notice the shaking as well when pulling the power back entering the pattern. I’m assuming that is occurring due to the prop adjusting to maintain the selected RPM.

Anyways.. going to call some shops tomorrow. I am assuming they will blame the 900 hour prop that sat for 6 years. (I suppose it could be counterweights or even engine mount or crank shaft but who knows)

I just overhauled my old 180’s prop and I’m not so sure I want to deal with that again.

Has anyone ran a Voyager on their IO520D? I feel it would be a better investment of my hard earned cash than overhauling an old C58 for 3 months and $6,000+.

I could use the Voyager on my eventual 550 upgrade…

Just thinking out loud. Thanks.

Voyager--

Don't look back period.

MW

I've heard that the crankshaft counterweights can kind of "take a set",
and that putting a 3 blade prop onto an engine that's always had a 2 blade can result in vibration.
Old wives tale? Maybe, maybe not.

Sounds like your prop overhaul was an ordeal...who did the work?
I've gotten exceptional service in the past from AC Prop in Seattle,
but no experience with them since the owner Mike Worden passed away a few years ago.

I have heard that as well. Seems like Hartzell says “might need a new engine mount if vibration occurs after installing new prop” as their out for that.

AC did my 180 prob. They were fantastic just very much not fast. Months and months. I should have clarified that the down time was what I didn’t want to deal with again.

hotrod180 wrote:I've heard that the crankshaft counterweights can kind of "take a set",
and that putting a 3 blade prop onto an engine that's always had a 2 blade can result in vibration.
Old wives tale? Maybe, maybe not

Hmmm, referencing TCM only or in general? Data to prove/refute? I have removed 2 blade hubs (2D30) and replaced with 3 blade on high time 985's... generally smoother.

TR

TR wrote:

hotrod180 wrote:I've heard that the crankshaft counterweights can kind of "take a set",
and that putting a 3 blade prop onto an engine that's always had a 2 blade can result in vibration.
Old wives tale? Maybe, maybe not

Hmmm, referencing TCM only or in general? Data to prove/refute? I have removed 2 blade hubs (2D30) and replaced with 3 blade on high time 985's... generally smoother.

TR

TR, you are correct about the 985 going from two to three blades.

Run the three blade for a thousand hours or so then have a need to put a 2D30 with the fat ag paddles on there and she will stop your heart at idle RPM as the counterweights clack back and forth.

There is good reason for that 1600 hour AD to inspect the counterweights and the usual ops spec TBO on the P&W R985.

Sorry for the thread drift OP


Rocket

No problem at all. My old 180’s previous owner tried to swap the 88Mac to a 3 blade. Shook too hard so he put the two blade back on. Blamed the old 470. I find this all interesting even in beaver engines.

Lettucelord wrote:Bringing a ‘74 185F out of a 6 year nap has been quite something.
The issue is when leveling off at cruise and dialing the prop back around 2350 rpm she really starts to shake. Not vibrate. Shakes. You can quell the issue by increasing RPM back to higher settings or continuing to dial it lower down to 2200. Doesn’t always happen though..
I notice the shaking as well when pulling the power back entering the pattern. I’m assuming that is occurring due to the prop adjusting to maintain the selected RPM. ........

Curious if the prop was removed at any point.
I bought a timed out C201 prop several years ago,
and had it OH'd before installing on my 180.
It shook like you described when pulling back in the pattern.
I called Mike at AC & described the problem,
he suggested removing the prop & turning it 180 degrees when reinstalling.
That did the trick.
Since the prop was balanced as part of the overhaul,
I wouldn't have thought that would make any difference,
but it just goes to show that some of this stuff is as much black magic as it is science.

Awesome I’ll maybe have them try that.