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Is this a Landol Ring?

Steve51B

Steve51B

Member
I recently removed this from the RV-4 that I purchased last Autumn. I rarely have a passenger and I'm trying to lighten up my plane.
I think it's a Landol ring, however, I've never seen a picture of one and a google image search netted me noting useful. I'm sure there are a few of you that can identify this thing.



The back side:



Detail of the only marking on it:



This is where it was on the plane:



Thanks
 
It looks like one to me. I had one on my RV-4.

It was hollow and filled with a weight ring and gel that was supposed to dampen the engine pulses in my wood prop.
 
OK, long version, Yes, technically it is called a visconic damper. An engine crankshaft rotation is a series of decelerations due to compression, and accelerations due to the power stroke. Additionally, there are torsional rotations of the crankshaft between the ends. The damper helps "average" the accelerations and decelerations, and is especially helpful at reduction of torsional peaks.

I don't know what specific problem it solves on this application, did you notice more/less vibration or other effects?
 
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I didn't notice any differences in vibrations. I have a Sensenich wood prop and I called them to make certain it wasn't required. They said it is not required.

I get a slightly better pitch response now due to the CG being moved aft by a little bit.

I think that the builder installed it to move the CG forward since he was always hauling a passenger and some baggage. I very rarely fly with a passenger or baggage.

I guess that Landol is a brand name for what you described BillL. I'm wondering if it's a Landol or some other brand?
 
Mark Landoll made what he called a harmonic damper or balancer with the weight in silicone, but also sold a simple steel ring that looked like that; intended to help with CG issues on some of the early RV's with wood props. Basically turned the starter ring gear assembly into a true flywheel. He was also one of the pioneers selling 'light weight' (automotive) starters and alternators. I had his steel ring, starter and alternator on the 1st -4 I owned (installed by the builder before I bought it).

Pretty sharp guy. Was flying a -4 when I first met him; later built a 'super 8' with a big 6cyl on it. I've known him for around 25 years, but haven't heard from him in at least a half dozen. Last time I talked to him he said he was retiring from selling a/c stuff. His company & phone number still come up if you use the google....

Charlie
 
That looks like a Landol harmonic balancer, not a "Landol Ring". The ring is just a plain steel ring. Both are valuable to the right buyer.
 
BillL said:
I don't know what specific problem it solves on this application, did you notice more/less vibration or other effects?
Click to expand...

Adds a little mass moment of inertia, but being located at the node, it's useless as a torsional damper.
 
How much did removing this effect your W&B? you can feel it in pitch, so it must have been quite heavy.
 
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Landol

Put it up for sale, RV-7's with a Catto prop (such as me) use them to help move the CG forward to help with the baggage compartment limits with low fuel.

If you check the archives you will see WTB posts fairly frequently.
 
Mark is still flying

Just wanted to post to say Mark Landol is still around and flying. He is a member of our EAA UL98 chapter. He has been "retired" from supplying parts such as the Landoll ring, starters, alternators, etc. but he is still very much active in our chapter. I do not know exactly how old Mark is but I do believe he is around 85 now. He is a great guy and is a wealth of knowledge about airplanes.
 
Here in a simple "inertia ring" ...

image13-575x288.jpg


The back and front a flat parallel surfaces. It weighs aprox 12 lbs.
 
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