Bad vibrations ???

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I have an RV-6A 0-360 c/s prop 650 hours Channel chrome cylinders burns 1 quart in 6 hours. SDS EM5F fuel and ignition systems run LOP. Dynon Hdx panel. I've owned it for 4 years flown 200 hours in that time.
Always thought about balancing the prop. Have normal vibrations,
Compressions just checked cold 80/75,76,79,79 borescoped exhaust valves look very good. cylinder walls no real scratches. Oil changes every 25-30 hours Blackstone labs are clean as is filter. Phillips X/C 20/50

Here's the kicker. I decided to put on an Active Balancer ring from Balance Masters to see if it would work. I like the concept.
We Dyna-Vibed the engine before install 0.41 At 71 degrees. After install 0.31 at 61 degrees. Not real good HUH?
Flew aircraft on autopilot: 4500 feet 2300 RPM WOT (26.0 Inches) First hour and half smoother than before. Liking it!!!
Then out of the blue, the engine/prop started going WA WA WA no up and down of RPM just a vibrating/pulsing like the prop was going to come off. Checked all parameters of engine all good.
Pulled throttle back to 20" and 2200 RPM and it smoothed out enough for me to not land and check it out. Anything over 2220 and the vibration came back.
Headed home at that rate. Still at 4500 feet and 100 miles from home. When descending through 4100 feet 20" 2200 RPM I could make the vibration come back 21.5" through 15.0"
Getting close to home I started to play with it:: The higher the RPM (2400) the greater the vibration. Wa Wa Wa
AS long as I keep the RPM below 2300 in cruise and 20" it's fine. Oh ya when taking off RPM is 2740 WOT no problem.
I checked the valve travel and all are in spec, Ranging from .392-.410
Oh ya I even got a second Balance Master ring and it was no different. Worse yet, is I now have a vibration/pulsing noise without the Balance ring. Something is going BAD and I think it just popped it's ugly head up. And the RPM is steady.
But what????? I could say a ton more, But, this is the jest of it. Something is happening and it ain't good for sure.
Any ideas would be helpful.
My luck usually varies FIXIT

 

[rich]

My nose wheel went out of balance and started spinning on decent from altitude. When I was above 180mph it felt like the prop was severely out of balance. Slowed down and it went away. Marked the nose wheel with a stripe and my wing man confirmed it was spinning on next flight. Might apply brakes on main wheels to rule them out.

 

[vic syracuse]

Something is going on with that prop. I‘ve only seen a few which were initially that far out of balance. Most start around .2-.3. Carefully check it and measure the blade angles with a smart level. Also, make sure there aren’t any dings in the blades

Vic

 

[Scott Hersha]

I also didn’t have much luck with the balance master ring. I had a .31 vibe at full static on the ground, which is in the rough range. That level of vibration was the same at any RPM above about 1200. RV6, O-36-A1A, Sensenich carbon GA prop. I flew it with the ring still on and it was definitely rougher at all power settings. I removed the ring and reset the blades using the pitch pin system Sensenich has,, and that gets it close but not always perfect. I then set pitch of each blade using the Vans tool and my digital smart level as Vic recommends to get them within .1 degree. It Is very smooth now, although I haven’t checked again with the DynaVibe yet.
I think you should try the digital level as suggested, and also check blade runout to make sure they are tracking the same. I don’t know how to check low pitch stops on a CS prop, but I’ve read that it’s something else you could check.

 

[[email protected]]

Something is going on with that prop. I‘ve only seen a few which were initially that far out of balance. Most start around .2-.3. Carefully check it and measure the blade angles with a smart level. Also, make sure there aren’t any dings in the blades

Vic

Thanks for the note Vic. NO nicks in blades. Was overhauled a year ago. I also was aghast as to the 0.41 on the Dyna-Vibe. And then the only 0.31 reading after the Balance wheel was on. I will be checking again when my buddy gets back to the airport to help me. It's his tool.
The thing that got me was the fact I flew for an hour and half and was fine with no flight parameters changed just direction. Then HEY I'm going to wake you up in there!!!!
All my looking at the engine has found nothing. Probably heading to the prop shop next week. Thankfully it only an hour away.
Before I do I'll check the blade pitch.

My luck still varies Thanks FIXIT

 

[D-Dubya]

Have you tried balancing the prop with the Dyna-Vibe but without the auto-balancing gizmo? It's really pretty easy and you should be able to get pretty close to "sewing machine" smooth in just a few ground runs. Of course, that's assuming there's no other problem with wheels, prop or engine, as others have said.

 

[[email protected]]

Have you tried balancing the prop with the Dyna-Vibe but without the auto-balancing gizmo? It's really pretty easy and you should be able to get pretty close to "sewing machine" smooth in just a few ground runs. Of course, that's assuming there's no other problem with wheels, prop or engine, as others have said.

The direct answer is no.
I believe in the Balance Masters concept of balancing something. I use 5 ounces of BB's in my 16" work van tires and have for 20 years with great success.
I'm concerned about the Wa Wa Wa along with vibration that started an hour and half after with no changes in anything. And was repeatable on the second flight closer to home. Then after the balance wheel was removed it still did it. Especially showing up on decent.
Me the thinks something might be or is amiss in the prop.
More research Monday after the Easter doings.
I'm smoking a 19 pound brisket for the gathering we have here.
Yum!!!!
My luck will surely vary with the amount of money I spend fixing the problem FIXIT

 

[D-Dubya]

Methinks you may be right about something being amiss with the prop and taking it to a prop shop. While that's an inexpensive procedure, it may prevent that smoked brisket from being a last supper.

 

[[email protected]]

Methinks you may be right about something being amiss with the prop and taking it to a prop shop. While that's an inexpensive procedure, it may prevent that smoked brisket from being a last supper.

I don't know about inexpensive. The last overhaul was about $3,200.00. Most won't tear one down and just put it back together again.
But like you mentioned. The brisket is done just and will hit the table in a couple hours or so. Then it's "" Over the lips and past the gums Look out tummy here it comes""
My luck varies and I'm gonna be a bit cautious on this one. FIXIT

 

[D-Dubya]

DOH! My bad. My brain said "expensive" but my fingers (or maybe autocorrect) said inexpensive. And yes, I would absolutely be cautious with this one.

 

[[email protected]]

DOH! My bad. My brain said "expensive" but my fingers (or maybe autocorrect) said inexpensive. And yes, I would absolutely be cautious with this one.

NO bad.
I took it to the prop shop Monday morning and they had serious doubts the prop is causing the problem. But it had been three years since overhaul.
BUT I needed to have a go at the governor.
Haven't bought a governor for a while and WOW have the prices gone through the roof.
It's the MT Czech Republic P-420-003 Model and the OH shop won't/can't over haul it. OUCH!!! In case anybody has one laying around they want to part with. He HE HE
Probably into the new market again. And this one is only 650 hours old.
Oh Well that's what money is for SPENDING Woo Hoo.
I'll update after I get to spend money on a new governor and see how it works.
My luck varies FIXIT