RV-10 with engine vibration

Hello,
Issue
RV10 with engine vibration
Background
I feel my 10 has an usual engine vibration that follows RPM in frequency.
I purchase a used mid time O-540A1D5 that at one time was overhauled to a A4B5 = the heaver 5 and 6 crankshaft counter weights.
From what I can find this mod supports the compact constant speed hub configuration.
?Can you help me confirm if this engine configuration A4B5 supports the blended Hartzell propeller that is available from Vans for the -10 aircraft?
(it was purchase new from Vans 2011).

The engine vibration is all the time, low RPMs and increases as the RPMs increase. Like a one per rev.
I had the prop engine current configuration balanced and the readings were very low = .07-.1 ips.
I would think that if there was an true vibration issue that the tester would have read larger values.
Yes I continue to question the tester readings and will try as second source.

The engine runs great, good even compressions and strong cylinder compressions pulling the prop through by hand.
It start perfect and shows no other sighs of mag timing concerns, both bendix at 25 deg BTDC, one impulse.
200 hours of operation in the -10 as of today and all oil filter inspections are perfect, no metal of any quantity.

Does this Lycoming just vibrate because how large it is, 540 CI? Like a power stroke vibration?
Any similar report from other RV10 owners or Vans RV 10?

Any ideas what to check?
Any help with understanding if this is a approve/usable engine ? propeller combination?

Thanks

You might have a 1/2 order vibration.
Let me see if I cant find an expert from Hartzell to chime in.

The best way to analyze something like this is by doing a spectrum analysis to deterimine the frequency of the vibration. I would suggest you try to find someone with the equipment to double check your dynamic balance and do the spectrum at the same time.

Just FYI, 0.1 IPS is considered "good" and the upper limit for after balance. At this level you likely won't feel any vibration from the prop. Generally speaking I am able to balance to .04 IPS or less.

A bent or out of track prop can also cause an aerodynamic imbalance which can be difficult to track down and doesn't alway reveal itself during testing.

On a much less technical note, see if you can find another -10 nearby that you can fly in to see if the vibration feels the same as yours.

If the vibration is something you have had and it did not just evolve, you might consider getting a propeller balance done.

The prop might need to be reclocked as well. Buddy had a real paint shaker on the front of his Rocket and it went a whole lot smoother with just this simple mod.

I have gone through the same scenario. I have an IO-540-N1A5 with a heavier crank and 5th and 6th dampers. I thought mine vibrated more than others and I flew other D4A5 engines that ran smoother on RV-10's. I first dynamically balanced the propeller and that helped a little. I later called Lord mounts and spoke to an engineer who talked me into ordering different mounts. They really didn't feel much different but mentally it helped the vibration Mine is worse at lower RPM's and low speed. Better at high rpm's and high speed so I know it's not a control surface.
I always fly LOP during long cruise trips and the engine is super smooth during LOP. My engine vibrates the most during climbs and low speed. I live with it and think it's only me who feels the vibration.

Good luck.

rv10 with engine vibration

Thanks for the great feedback,
Yes the vibe is more noticeable at lower rpms and follows up with RPM which seems to smooth out but it?s just at a higher frequency now.
I have checked the propeller track and it?s as good as I can measure, say within a 1/16 inch at blade tip.
During annual I will have the propeller itself check balance at the local shop, and look into the spectrum analysis to determine the frequency of the vibration.
I think that may help with some answers,
I still wonder if I?m running a acceptable prop engine combination, sounds like it is,
But i would feel better knowing from an expert, my local FBO AI can probably help.

Any more Ideas are appreciated
Thanks

Prop Model?

Yes, the engine and prop are an approved combination assuming you are running stock pistons and magnetos.

What is your propeller model, HC-C2YR-1BFP/F8068D-2?

The advice on getting a spectrum is the best place to start, especially in flight at the condition you the highest level of vibration. Orient the sensor in the horizontal plane for the clearest results.

If you've had the propeller balanced, I suspect you are feeling 1/2-order vibration. There are many causes but the basic source is the engine. The Lord mounts that Vans supplies for the RV-10 have had a good history based on very few, if any complaints from builders that I'm aware of here at Hartzell.

Once you get a spectrum, send me an email with the results and I'll be happy to provide my 2 cents.

Les Doud
[email protected]

One more item to check:
Make sure nothing on the engine is touching the cowl other than baffling and mounts. If you have really tight baffling or possibly something like a prop governor touching the cowl it will transfer a lot of vibration through the plane.

thanks, ill get right on the checks and report soon.